FC-PAD: Components and Characterization · Characterization Presenter: Karren L. More Tuesday, June...
Transcript of FC-PAD: Components and Characterization · Characterization Presenter: Karren L. More Tuesday, June...
2016 DOE Fuel Cell Technologies Office Annual Merit Review
2016 DOE Hydrogen and Fuel Cells Program Review
XYZ Thrust Area Co-ordinatorRod amp Adam FC PAD Directors
Wednesday June 8th 2016
FC136 ndash FC-PAD Components and Characterization
Presenter Karren L More Tuesday June 6th 2017
This presentation does not contain any proprietary confidential or otherwise restricted information
12017 DOE Fuel Cell Technologies Office Annual Merit Review
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Part of
FC-PAD Consortium to Advance Fuel Cell Performance and Durability
Approach Objectives
bull Improve component stability and durability Couple national lab capabilities with funding bull Improve cell performance with optimized opportunity announcements (FOAs) for an influx of
transport innovative ideas and research bull Develop new diagnostics characterization tools
and models
Consortium fosters sustained capabilities and collaborations
Structured across six component and cross-cutting thrusts
Core Consortium Team
Prime partners added in 2016 by DOE solicitation (DE-FOA-0001412)
2wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Consortium - Overview
Fuel Cell Technologies Office (FCTO) bull FC-PAD coordinates activities related to fuel cell performance and durability bull The FC-PAD team consists of five national labs and leverages a multishy
disciplinary team and capabilities to accelerate improvements in PEMFC performance and durability
bull The core-lab team consortium was awarded beginning in FY2016 builds upon previous national lab (NL) projects
bull Provide technical expertise and harmonize activities with industrial developers bull FC-PAD serves as a resource that amplifies FCTOrsquos impact by leveraging the
core capabilities of constituent members
3wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
4
FC-PAD Consortium Relevance and Objectives Overall Objectives bull Advance performance and durability of polymer electrolyte membrane
fuel cells (PEMFCs) at a pre-competitive level bull Develop the knowledge base and optimize structures for more durable
and high-performance PEMFC components bull Improve high current density performance at low Pt loadings bull Loading 0125 mgPt cm2 total bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2
bull Improve component durability (eg membrane stabilization self-healing electrode-layer optimization)
bull Provide support to industrial and academic developers from FOA-1412 bull Each thrust area has a sub-set of objectives which support the overall
performance and durability objectives
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
5
FC-PAD Overview and Relevance
Timeline Barriers Project start date 10012015 Project end date 09302020
Budget bull FY17 project funding $5150000 bull As proposed 5-year consortium with
quarterly yearly milestones amp GoNo-Go bull Total Expected Funding $25M (NLs only)
PartnersCollaborations (To Date Collaborations Only)
bull IRD Fuel Cells Umicore NECC GM TKK USC 3M JMFC WL Gore Ion Power Tufts KIER PSI UDelaware CSM SGL NPL NIST CEAULorraine
bull Partners added by DOE DE-FOA-0001412
bull Cost $40kW system $14kWnet MEA
bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2 (150 kPa abs)
bull Durability with cycling 5000 (2020) ndash 8000 (ultimate) hours plus 5000 SUSD Cycles
bull Mitigation of Transport Losses bull Durability targets have not been met
bull The catalyst layer is not fully undershystood and is key in lowering costs by meeting rated power
bull Rated power low Pt loadings reveals unexpected losses
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
6
FC-PAD Objectives How We Get There bull Develop the knowledge base and optimize structures for more durable and
high-performance PEMFC components bull Understanding Electrode Layer Structure o Characterization bull New Electrode Layer Design and Fabrication o Stratified (Spray Embossed Array) Pt - Deposition Jet Dispersion bull DefiningMeasuring Degradation Mechanisms o Membrane Catalyst Pt-alloy dissolution
FC-PAD Presentations bull FC135 FC-PAD Fuel Cell Performance and Durability Consortium (Rod Borup LANL)
ndash Overview Framing Approach and HighlightsDurability bull FC136 FC-PAD Components and Characterization (Karren L More ORNL)
ndash Concentration on Catalysts and Characterization bull FC137 FC-PAD Electrode Layers and Optimization (Adam Weber LBNL)
ndash Concentration on Performance - MEA construction and modeling bull FC155 (3M) FC156 (GM) FC157 (UTRC) FC158 (Vanderbilt) FOA-1412 Projects
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Part of
FC-PAD Consortium to Advance Fuel Cell Performance and Durability
Approach Objectives
bull Improve component stability and durability Couple national lab capabilities with funding bull Improve cell performance with optimized opportunity announcements (FOAs) for an influx of
transport innovative ideas and research bull Develop new diagnostics characterization tools
and models
Consortium fosters sustained capabilities and collaborations
Structured across six component and cross-cutting thrusts
Core Consortium Team
Prime partners added in 2016 by DOE solicitation (DE-FOA-0001412)
2wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Consortium - Overview
Fuel Cell Technologies Office (FCTO) bull FC-PAD coordinates activities related to fuel cell performance and durability bull The FC-PAD team consists of five national labs and leverages a multishy
disciplinary team and capabilities to accelerate improvements in PEMFC performance and durability
bull The core-lab team consortium was awarded beginning in FY2016 builds upon previous national lab (NL) projects
bull Provide technical expertise and harmonize activities with industrial developers bull FC-PAD serves as a resource that amplifies FCTOrsquos impact by leveraging the
core capabilities of constituent members
3wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
4
FC-PAD Consortium Relevance and Objectives Overall Objectives bull Advance performance and durability of polymer electrolyte membrane
fuel cells (PEMFCs) at a pre-competitive level bull Develop the knowledge base and optimize structures for more durable
and high-performance PEMFC components bull Improve high current density performance at low Pt loadings bull Loading 0125 mgPt cm2 total bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2
bull Improve component durability (eg membrane stabilization self-healing electrode-layer optimization)
bull Provide support to industrial and academic developers from FOA-1412 bull Each thrust area has a sub-set of objectives which support the overall
performance and durability objectives
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
5
FC-PAD Overview and Relevance
Timeline Barriers Project start date 10012015 Project end date 09302020
Budget bull FY17 project funding $5150000 bull As proposed 5-year consortium with
quarterly yearly milestones amp GoNo-Go bull Total Expected Funding $25M (NLs only)
PartnersCollaborations (To Date Collaborations Only)
bull IRD Fuel Cells Umicore NECC GM TKK USC 3M JMFC WL Gore Ion Power Tufts KIER PSI UDelaware CSM SGL NPL NIST CEAULorraine
bull Partners added by DOE DE-FOA-0001412
bull Cost $40kW system $14kWnet MEA
bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2 (150 kPa abs)
bull Durability with cycling 5000 (2020) ndash 8000 (ultimate) hours plus 5000 SUSD Cycles
bull Mitigation of Transport Losses bull Durability targets have not been met
bull The catalyst layer is not fully undershystood and is key in lowering costs by meeting rated power
bull Rated power low Pt loadings reveals unexpected losses
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
6
FC-PAD Objectives How We Get There bull Develop the knowledge base and optimize structures for more durable and
high-performance PEMFC components bull Understanding Electrode Layer Structure o Characterization bull New Electrode Layer Design and Fabrication o Stratified (Spray Embossed Array) Pt - Deposition Jet Dispersion bull DefiningMeasuring Degradation Mechanisms o Membrane Catalyst Pt-alloy dissolution
FC-PAD Presentations bull FC135 FC-PAD Fuel Cell Performance and Durability Consortium (Rod Borup LANL)
ndash Overview Framing Approach and HighlightsDurability bull FC136 FC-PAD Components and Characterization (Karren L More ORNL)
ndash Concentration on Catalysts and Characterization bull FC137 FC-PAD Electrode Layers and Optimization (Adam Weber LBNL)
ndash Concentration on Performance - MEA construction and modeling bull FC155 (3M) FC156 (GM) FC157 (UTRC) FC158 (Vanderbilt) FOA-1412 Projects
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Consortium - Overview
Fuel Cell Technologies Office (FCTO) bull FC-PAD coordinates activities related to fuel cell performance and durability bull The FC-PAD team consists of five national labs and leverages a multishy
disciplinary team and capabilities to accelerate improvements in PEMFC performance and durability
bull The core-lab team consortium was awarded beginning in FY2016 builds upon previous national lab (NL) projects
bull Provide technical expertise and harmonize activities with industrial developers bull FC-PAD serves as a resource that amplifies FCTOrsquos impact by leveraging the
core capabilities of constituent members
3wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
4
FC-PAD Consortium Relevance and Objectives Overall Objectives bull Advance performance and durability of polymer electrolyte membrane
fuel cells (PEMFCs) at a pre-competitive level bull Develop the knowledge base and optimize structures for more durable
and high-performance PEMFC components bull Improve high current density performance at low Pt loadings bull Loading 0125 mgPt cm2 total bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2
bull Improve component durability (eg membrane stabilization self-healing electrode-layer optimization)
bull Provide support to industrial and academic developers from FOA-1412 bull Each thrust area has a sub-set of objectives which support the overall
performance and durability objectives
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
5
FC-PAD Overview and Relevance
Timeline Barriers Project start date 10012015 Project end date 09302020
Budget bull FY17 project funding $5150000 bull As proposed 5-year consortium with
quarterly yearly milestones amp GoNo-Go bull Total Expected Funding $25M (NLs only)
PartnersCollaborations (To Date Collaborations Only)
bull IRD Fuel Cells Umicore NECC GM TKK USC 3M JMFC WL Gore Ion Power Tufts KIER PSI UDelaware CSM SGL NPL NIST CEAULorraine
bull Partners added by DOE DE-FOA-0001412
bull Cost $40kW system $14kWnet MEA
bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2 (150 kPa abs)
bull Durability with cycling 5000 (2020) ndash 8000 (ultimate) hours plus 5000 SUSD Cycles
bull Mitigation of Transport Losses bull Durability targets have not been met
bull The catalyst layer is not fully undershystood and is key in lowering costs by meeting rated power
bull Rated power low Pt loadings reveals unexpected losses
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
6
FC-PAD Objectives How We Get There bull Develop the knowledge base and optimize structures for more durable and
high-performance PEMFC components bull Understanding Electrode Layer Structure o Characterization bull New Electrode Layer Design and Fabrication o Stratified (Spray Embossed Array) Pt - Deposition Jet Dispersion bull DefiningMeasuring Degradation Mechanisms o Membrane Catalyst Pt-alloy dissolution
FC-PAD Presentations bull FC135 FC-PAD Fuel Cell Performance and Durability Consortium (Rod Borup LANL)
ndash Overview Framing Approach and HighlightsDurability bull FC136 FC-PAD Components and Characterization (Karren L More ORNL)
ndash Concentration on Catalysts and Characterization bull FC137 FC-PAD Electrode Layers and Optimization (Adam Weber LBNL)
ndash Concentration on Performance - MEA construction and modeling bull FC155 (3M) FC156 (GM) FC157 (UTRC) FC158 (Vanderbilt) FOA-1412 Projects
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
4
FC-PAD Consortium Relevance and Objectives Overall Objectives bull Advance performance and durability of polymer electrolyte membrane
fuel cells (PEMFCs) at a pre-competitive level bull Develop the knowledge base and optimize structures for more durable
and high-performance PEMFC components bull Improve high current density performance at low Pt loadings bull Loading 0125 mgPt cm2 total bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2
bull Improve component durability (eg membrane stabilization self-healing electrode-layer optimization)
bull Provide support to industrial and academic developers from FOA-1412 bull Each thrust area has a sub-set of objectives which support the overall
performance and durability objectives
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
5
FC-PAD Overview and Relevance
Timeline Barriers Project start date 10012015 Project end date 09302020
Budget bull FY17 project funding $5150000 bull As proposed 5-year consortium with
quarterly yearly milestones amp GoNo-Go bull Total Expected Funding $25M (NLs only)
PartnersCollaborations (To Date Collaborations Only)
bull IRD Fuel Cells Umicore NECC GM TKK USC 3M JMFC WL Gore Ion Power Tufts KIER PSI UDelaware CSM SGL NPL NIST CEAULorraine
bull Partners added by DOE DE-FOA-0001412
bull Cost $40kW system $14kWnet MEA
bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2 (150 kPa abs)
bull Durability with cycling 5000 (2020) ndash 8000 (ultimate) hours plus 5000 SUSD Cycles
bull Mitigation of Transport Losses bull Durability targets have not been met
bull The catalyst layer is not fully undershystood and is key in lowering costs by meeting rated power
bull Rated power low Pt loadings reveals unexpected losses
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
6
FC-PAD Objectives How We Get There bull Develop the knowledge base and optimize structures for more durable and
high-performance PEMFC components bull Understanding Electrode Layer Structure o Characterization bull New Electrode Layer Design and Fabrication o Stratified (Spray Embossed Array) Pt - Deposition Jet Dispersion bull DefiningMeasuring Degradation Mechanisms o Membrane Catalyst Pt-alloy dissolution
FC-PAD Presentations bull FC135 FC-PAD Fuel Cell Performance and Durability Consortium (Rod Borup LANL)
ndash Overview Framing Approach and HighlightsDurability bull FC136 FC-PAD Components and Characterization (Karren L More ORNL)
ndash Concentration on Catalysts and Characterization bull FC137 FC-PAD Electrode Layers and Optimization (Adam Weber LBNL)
ndash Concentration on Performance - MEA construction and modeling bull FC155 (3M) FC156 (GM) FC157 (UTRC) FC158 (Vanderbilt) FOA-1412 Projects
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
5
FC-PAD Overview and Relevance
Timeline Barriers Project start date 10012015 Project end date 09302020
Budget bull FY17 project funding $5150000 bull As proposed 5-year consortium with
quarterly yearly milestones amp GoNo-Go bull Total Expected Funding $25M (NLs only)
PartnersCollaborations (To Date Collaborations Only)
bull IRD Fuel Cells Umicore NECC GM TKK USC 3M JMFC WL Gore Ion Power Tufts KIER PSI UDelaware CSM SGL NPL NIST CEAULorraine
bull Partners added by DOE DE-FOA-0001412
bull Cost $40kW system $14kWnet MEA
bull Performance 08 V 300 mA cm2
bull Performance rated power 1000 mW cm2 (150 kPa abs)
bull Durability with cycling 5000 (2020) ndash 8000 (ultimate) hours plus 5000 SUSD Cycles
bull Mitigation of Transport Losses bull Durability targets have not been met
bull The catalyst layer is not fully undershystood and is key in lowering costs by meeting rated power
bull Rated power low Pt loadings reveals unexpected losses
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
6
FC-PAD Objectives How We Get There bull Develop the knowledge base and optimize structures for more durable and
high-performance PEMFC components bull Understanding Electrode Layer Structure o Characterization bull New Electrode Layer Design and Fabrication o Stratified (Spray Embossed Array) Pt - Deposition Jet Dispersion bull DefiningMeasuring Degradation Mechanisms o Membrane Catalyst Pt-alloy dissolution
FC-PAD Presentations bull FC135 FC-PAD Fuel Cell Performance and Durability Consortium (Rod Borup LANL)
ndash Overview Framing Approach and HighlightsDurability bull FC136 FC-PAD Components and Characterization (Karren L More ORNL)
ndash Concentration on Catalysts and Characterization bull FC137 FC-PAD Electrode Layers and Optimization (Adam Weber LBNL)
ndash Concentration on Performance - MEA construction and modeling bull FC155 (3M) FC156 (GM) FC157 (UTRC) FC158 (Vanderbilt) FOA-1412 Projects
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
6
FC-PAD Objectives How We Get There bull Develop the knowledge base and optimize structures for more durable and
high-performance PEMFC components bull Understanding Electrode Layer Structure o Characterization bull New Electrode Layer Design and Fabrication o Stratified (Spray Embossed Array) Pt - Deposition Jet Dispersion bull DefiningMeasuring Degradation Mechanisms o Membrane Catalyst Pt-alloy dissolution
FC-PAD Presentations bull FC135 FC-PAD Fuel Cell Performance and Durability Consortium (Rod Borup LANL)
ndash Overview Framing Approach and HighlightsDurability bull FC136 FC-PAD Components and Characterization (Karren L More ORNL)
ndash Concentration on Catalysts and Characterization bull FC137 FC-PAD Electrode Layers and Optimization (Adam Weber LBNL)
ndash Concentration on Performance - MEA construction and modeling bull FC155 (3M) FC156 (GM) FC157 (UTRC) FC158 (Vanderbilt) FOA-1412 Projects
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
FC-PAD Component Characterization - Capabilities
Thin film characterization
Advanced microscopy amp spectroscopy
AST DevelopmentRefinement
Synchrotron X-ray techniques Time-resolved on-line ICP-MS
7wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress AST Development amp Refinement New catalyst durability AST is 5X faster than old AST and 70
20X faster than FCTT durability protocol 60
50
40
30
20
10
0
06 -10V cycles 30000 cycles 06 -095V cycles 30000 cycles Target ndash 133 hr Target ndash 50 hr
bull Square wave lowers test duration from 133 to 50 hours (does not include characterization time)
bull Square wave still representative of drive cycle 80
70degradation 60
bull AST reflective of Pt dissolution and independent 50
E
CSA
Loss
ECS
A Lo
ss
FCTT Drive cycle TEC10E20E
Old AST (5X) TEC10E20E
New AST (25X) TEC10E20E
New AST Low flow 4-serp (25X) TEC10E20E
0 500 1000 1500 2000 2500
New AST E-carbon
New AST V-carbon
New AST EA-carbon
0 10000 20000 30000 40000
of carbon type
Other durability protocols under development and refinement
40
30
bull Membrane durability 20
bull Carbon durability 10
0
bull SUSD protocols bull Freeze protocols bull Drive cycle protocols
PtC 015mgPtcm2
Time (hrs)
of Potential Cycles
8wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Aqueous Stability of PtCo Alloys Time-Resolved On-Line ICP-MS Measurements
Objectives bull Real time measurements of Pt and Co dissolution
under cyclic potentials bull Resolve anodic vs cathodic dissolution of Pt and Co Catalysts bull TEC36E52 Pt3CoHSC 465 wt Pt
47 wt Co 57 nm TEM bull Umicore Elyst P30 0670 275 wt Pt
3 wt Co 44 nm TEM bull Catalyst-ionomer ink deposited on GC at
2 microg-Ptcmsup2
ICP-MS Agilent 7500ce Octopole Cell BASi
bull Co dissolution observed at all potentials bull Distinct peaks in anodic and cathodic dissolution of Pt
above 09 V bull Potential dependent dissolution rates of Pt and Co
9wwwfcpadorg
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
10
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Pt from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Cathodic dissolution not significant for UPL lt09 V in square wave potentials
bull Distinct anodic and cathodic peaksbull Anodic peaks higher at higher potentialsbull Highest cathodic peak on potential step from 08 to 075 V
bull ~3-time higher Pt dissolution during cathodic than anodic steps stair-case potential 1 V UPL
bull Both anodic and cathodic Pt dissolution rates (amount dissolved divided by cycle time) increase at higher potential steps
Peak cathodic dissolution rate depends on the initial potential and the potential step
0
1
2
3
4
5
6
7
8
9
10
04 05 06 07 08 09 1
PeakCatho
dicP
tDissolutio
nRa
tengh-
1
Step-downPotentialV
50mVstep100mVstep150mVstep200mVstep300mVstep600mVstep
Peak cathodic rate reaches a
maximum at 065-075 V step down
potential
50 mV stair-case180 s hold
SquareWaveUPLvaries120shold
wwwfcpadorg
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
11
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Dissolution of Co from UmicorePt7Co3C Cathode Catalyst on Stair-Case Potentials
Break-in protocol requires gt1-h conditioning on 04-10 V square wave potentials
bull Anodic Co dissolution rate nearly constant for potentials up to 08 V
bull Anodic peaks observed at potentials gt08 Vbull Highest cathodic peak on potential step from 08 to 06 V
bull Comparable Co dissolution during anodic and cathodic steps
bull Anodic and cathodic Co dissolution rates (amount dissolved divided by cycle time) lowest for 200 mV potential step
Peak cathodic dissolution rate depends on the initial potential and the potential step
00
05
10
15
20
25
30
35
40
45
04 05 06 07 08 09 1
PeakCatho
dicC
oDissolutionRa
tengh-
1
Step-downPotentialV
100mVstep
150mVstep
200mVstep
300mVstep
600mVstep
Break-in (04-1 V 180s hold)
200 mV stair-case 180 s hold
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
Catalyst Supplier
CatalystHSAC Catalyst Loading (mgPtcm2) amp ECSA (m2
PtgPt)
Membrane
Umicore PtCo (Elyst Pt30 0670) spray-coated CCL NREL
01 amp 37 Nafion 211
IRD (EWII) Pt3Co (IRD SOA catalyst) IRD-prepared MEA
02 amp 41 Reinforced
GM - SOA GM SOA PtCo catalyst GM-prepared MEA
01 amp 43 DuPont XL-100
MEAs characterized bull Conditioned BOL bull NEW Catalyst AST bull OLD Catalyst AST bull 1200 hr Wet Drive Cycle
06 -10V cycles 30000 cycles
Target ndash 133 hrs
06 -095V cycles 30000 cycles
Target ndash 50 hrs
12
Old triangle-wave catalyst AST New square-wave catalyst AST
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Extensive Study of PtCo Catalysts
segmented PtC 3D surfaces
SOA Pt-CoHSAC Fresh MEA
bull Avg PtCo particle sizebull 44nm diameter
bull Avg PtCo compositionbull 85 Pt ndash 15 Co
bull majority of PtCoparticles are insideHSAC support
bull 77 within corebull 23 on surface
rotation animation
STEM-BF image
volume clipping animation
single z-slice
single z-slice
PtCo NPs located at surface
internal PtCo NPs
13 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Extensive Study of PtCo Catalysts
at
Co
BOL 1200hr wet drive cycle
50nm 50nm
BOL 45nm
Square-wave AST 51nm
Triangle-wave AST 50nm
Wet Drive Cycle 74nm
36
30
24
18
12
6
0
equivalent diameter (nm)
bull Significant increase in PtCo particle size from 45nm to ~74nm during 1200 hr wet drive cycle Significant drop in Co content within CCL shyaverage particle composition changes from 85Pt15Co to ~95Pt5Co
bull Significant Pt-enrichment of most particles (except for very large particles)
BOL triangle square wet drive
0 5 10 15 20 25 30
14wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
single z-slice
internal PtCo NPs
Technical Progress Extensive Study of PtCo Catalysts
SOA Pt-CoHSAC Wet Drive cycle 1200 hrs
bull Avg PtCo particle size bull 75nm diameter
bull Avg PtCo composition bull 95 Pt ndash 5 Co
bull Some change of PtCo particles from inside to surface of HSAC support bull 65 remain in core bull 35 on surface
single STEMBF image
single z-slice
PtCo NPs located at surface
segmented PtC 3D surfaces
15
rotation animation volume clipping animation
Increased PtCo particles on surface of HSAC after testing due to Pt and Co dissolution
wwwfcpadorg
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
16
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Pt and Co mol fractions in particles and d-spacing calculated from fit to position of WAXS (111) peak ndash PtCo catalysts become more ldquoPt-likerdquo during ASTs
2210
2215
2220
2225
2230
2235
2240
2245
2250
00
01
02
03
04
05
06
07
08
09
10
d-sp
acin
g(Aring
)
Mol
eFr
actio
nPtmolfraction Comolfraction d-spacing(ang)
Technical Progress Extensive Study of PtCo Catalysts
wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress Co Loss During ASTs
SOA PtCo exhibits improved initial performance (ECSA) compared to other PtCoHSAC catalysts but after 30000
cycles ECSA values are the same
Performance (ECSA) loss can be directly attributed to extensive Co loss from
catalystCCL into membrane during AST
0
10
20
30
40
50
60
70
80
0 5000 10000 15000 20000 25000 30000 35000
ECSA(m
2 gm)
ofPotenalCycles (squarewaveAST)
PtHSAC
GMSOAPtCoHSAC
UmicoreElystPtCoHSAC
IRDldquospongyrdquoPtCoHSAC
0
5
10
15
20
PtC
o R
atio
in C
CL
Umicore 7030
Umicore 8020
Umicore 9010
IRD 6040
IRD 6634
IRD 8218
GM SOA 9515
GM SOA 8911GM SOA
8515
PtCo Powder
BOL MEA
Square-wave AST
Wet Drive Cycle
17 wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Au
Technical Progress Quantifying Co Loss to Membrane
Method
bull Au-coat MEAs for internal standard (should not use Cu Pt C)
bull Acquire EDS maps of cathode catalyst layer(CCL) and membrane
bull Assume most Pt lost redeposits in ldquoPt-bandrdquo in membrane near the CCL calculate Pt migration from cathode into membrane usingAu referencestandard
bull Use average PtCo ratio in untested CCL and amount of Co in tested CCL to calculate ~Co in membrane
sputtered
~1-2 nm Au
W Bi GE Gray and TF Fuller Electrochemical and Solid-State Letters 10 (5) B101 (2007)
DA Cullen R Koestner RS Kukreja ZY Liu S Minko O Trotsenko A Tokarev L Guetaz HM Meyer III CM Parish and KL More Journal of the Electrochemical Society 161 (10) F1111 (2014)
18wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss to Membrane Umicore GM XL square 1600
1400
1200CCL 1000
800
600
400
200
0 60 membrane
near cathode 1600
1400
1200
1000
800 membrane 600
near 400 co
unts
coun
tsanode
200
0 60
Umicore
Co-Kα1
Pt-Lα1
cathode mem near cat mem near an anode
65 70 75 80 85 90 95 100 keV GM XL square
cathode mem near cat mem near an anode
Co-Kα1
Pt-Lα1
19
65 70 75 80 85 90 95 100 keV
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Quantifying Co Loss
Co migration from cathode to membrane nominal loading
-BOL conditionedshy(mgcm2)
GM XL (square wave)
01
0018
Umicore (triangle wave)
01
0025
AST STEMEDS
quantification
32 Pt loss
50 Co loss
28 Pt loss
52 Co loss
Loss to membrane (mgcm2)
0032
0009
0028
0013
remaining cathode
content(mgcm2)
0068 Pt
0009 Co
0072 Pt
0012 Co
Next step - how much Co remains within the ionomer in CCL
20wwwfcpadorg
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress RDE Testing - Film Deposition Impurities
bull RDE technique used by basicapplied science community for PEMFC electrocatalyst screening bull Standard test protocol and best practices can enable procedural consistency and less variability bull Test protocol and best practices validated at NREL and ANL using poly-Pt PtC-TKK JM Umicore
3 film depositiondrying methods Cell and Electrolyte Impurity Levelsmdash evaluated NREL poly-Pt specific activity as a diagnostic
SAD (stationary air-dry)
RAD (rotational air-dry)
SIPAD (stationary IPA dry)
Statistical reproducibility Poly-Pt specific activity Poly-Pt specific activity NREL inter-lab comparison
RDE cell configurations used at NREL and ANL
Nafion-based Rotational Air Drying (N-RAD) most reliable method for routine screening
SS Kocha K Shinozaki JW Zack D Myers N Kariuki T Nowicki V Stamenkovic Y Kang D Li and D Papageorgopoulos ldquoBest Practices and Testing Protocols for Benchmarking ORR
RHE No Salt Bridge SCE Salt Bridge HgHg2SO4 Salt BridgeActivities of Fuel Cell Electrocatalysts using RDErdquo Electrocatalysis (2017) DOI ECCL NREL ESC ANL HFCM ANL
CE
RE (RHE) WE
(RDE)
21 wwwfcpadorg
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
22
2016DOEFuelCellTechnologiesOfficeAnnualMeritReview
Technical Progress TF-RDE Protocols and BaselinesRDE Protocols
Statistical Reproducibility PtC Specific Activity (micromicroAcm2Pt)
at NREL (Rotational Air Dry or N-RAD technique)
PtC mass activity (mAmgPt) Inter-lab comparison(N-RAD technique)
464 wt Pt d~25nm 376 wt Pt dlt2nm 472 wt Pt d~49nm
Gas N2 or O2
Temperature rtRotation Rate [rpm] 1600
Potential Range [V vs RHE] minus001 to 10 (anodic)Scan Rate [Vs] 002
Rsol measurement method i-interrupter or EIS (HFR)iR compensation applied during measurement
Background Subtraction LSV (O2)minusLSV (N2)
ORRCVBreak-inORR Protocol Details
wwwfcpadorg
0
300
600
900
1200
1500
1800
TKKPtHSC Umi5PtHSC Umi5PtCoHSC
MassA
cltvity(m
AmgPt)
NafionFree5SIPADRDE
NafionBased5RADRDE
NafionBasedMEA
Test protocol and best practices validated at NREL and ANL
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Technical Progress Ionomer-TM Effect on ORR Kinetics RDE 60
50
ORR Kinetics on bare and
Film Pt Ni2+
OR
R k
inet
ic1
i at0
9 V
40
30
20 Film Pt
10 Pt
00 0 001 002 003
W-frac12
004 005
Pt Ni2+
006
Cur
rent
0
9 V
(Ac
m2 )
ik gt 20 mAcm2 indicative of ldquocleanrdquo system 25 2
PFSA thin film-coated Poly-Pt with 10 mM Ni2+ in
23
15 electrolyte 1
05 Studies on Co2+ underway 0
Bare Pt Pt-Ionomer Bare Pt in 10 Pt-Ionomer Film mM Ni2+ Film in 10 mM
Ni2+
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
24
Proposed Future Work bull Catalysts and Catalyst Layers o Characterize new catalysts incorporated into MEAs and new CCL architectures before and after ASTs
(ANL BNL Umicore etc) o Work with FOA partners and implement FC-PAD capabilities to characterize novel catalystsMEAs o Coordinate characterization results with refined models bull Testing and AST Refinement o Quantify the effect of Co and Ce in the ionomer and how it affects performance (both sheet resistance and
local oxygen resistance) o Complete 5000 hr benchmarking test o Initiate durability testing using a differential cell (currently using GMs 5cm2 cell) and validate using new
10cm2 differential cell hardware o Understand the effect of Co alloying on carbon corrosion at 30C bull Dissolution Studies o Correlate Pt and Co dissolution with extent of oxidation and oxide structure for PtCo alloy catalysts o Measure Pt re-deposition rates as a function of potential using on-line ICP-MS for input to catalyst
degradation models
o On-line ICP-MS measurements of Pt and TM dissolution as a function of catalyst particle size and support o EXAFS analysis of changes in Pt and Co coordination and bonding after AST
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
25
Summary bull RelevanceObjective o Optimize performance and durability of fuel-cell components and assemblies bull Approach o Use synergistic combination of modeling and experiments to explore and optimize component
properties behavior and phenomena bull Technical Accomplishments o Understanding of the aqueous stability of PtCo alloys using time-resolved on-line ICP-MS
measurements o Refinement of catalyst durability AST to better simulate FCTT drive cycle protocol o Extensive characterization of multiple PtCo catalysts showed performance loss correlation with
accelerated Co leachingdissolution o Quantification of Co loss from CCL to membrane during AST o Initiated work with FOA partners bull Future Work o Further our understanding of Pt-alloy durability by incorporating new catalystMEAs in FC-PAD o Elucidate critical bottlenecks for performance and durability from ink to CCL formation to
conditioning to testing o Use critical characterization data as input for multiscale modeling of cell and components o Expand dissolution studies to better understand the behavior of Pt-based TM catalysts
wwwfcpadorg
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26
2016 DOE Fuel Cell Technologies Office Annual Merit Review
Acknowledgements
DOE EERE Energy Efficiency and Renewable Energy Fuel Cell Technologies Office (FCTO)
bull Fuel Cells Program Manager amp Technology Manager o Dimitrios Papageorgopoulos o Greg Kleen
bull Organizations we have collaborated with to date
bull User Facilities o DOE Office of Science SLAC ALS-LBNL APS-ANL LBNL-Molecular Foundry CNMSshy
ORNL CNM-ANL o NIST BT-2
26