Ambient-Pressure NEXAFS and XPS at CSX2 Beamline: Soft X-rays for the In-situ Study of Catalytic Processes

Workshop on First Experiments at NSLS-II, August 2013 djs@bnl.gov

Chemistry Dept Sanjaya Senanayake Dario Stacchiola Jingguang Chen (SCC) Jose Rodriguez (SCC)

CFN Peter Sutter Samuel Tenney Anibal Boscoboinik

Photon Sciences Cecilia Sanchez Hanke Dario Arena

Goals Instrumentation: Build and use end-stations for soft X-ray ambient-pressure AP-XPS and AP-NEXAFS at NSLS-II CSX2 beamline: pressure range up to 1 atm.

Catalysis: Study in-situ the water-gas shift (WGS) on (Au,Cu)/CeOx/TiO2

Surface chemistry: Study in-situ the processes of CO2 capture on solid sorbents.

Polarization control: Identify surface species and reaction intermediates taking advantage of the unique polarization-switching capabilities of the CSX2 beamline.

Sci

ence

cas

e

H2O + CO → CO2 + H2

CSX-2 Full polarization control branch

CSX-1 High coherent flux branch

Endstation 1 (Chemistry) AP-NEXAFS Powder catalysts

Endstation 2 (CFN) AP-XPS & AP-NEXAFS on Planar catalysts

CSX2 beamline real-space layout

AP-XPS & AP-NEXAFS at NSLS-II

AP-XPS AP-NEXAFS

model catalysts AP-NEXAFS

powders

Endstation 1 Endstation 2

AP-STM: CeOx/CuO

beam

E-TEM: CeOx/CuO

ALS, ACS Catal. 2 (2012) 2250

ALS, Phys. Chem. Chem. Phys. 13 (2011) 19988

Model catalysts Powder catalysts

AP-XPS Endstations in the U.S.

ALS, 2 End-stations SSRL NSLS

AP-XPS Endstations Worldwide

ALS Beamline 11.0.2: consistently most oversubscribed beamline for time at the ALS - Berkeley Current cycle: Only 9% of requested beamtime allocated

Location Status Log P (Torr)

-12 -10 -8 -6 -4 -2 0 2 4

AP-XPS at NSLS AP-XPS at NSLS-II

UHV Surface Science Industrial Catalysis

Ambient pressure XPS: chemically sensitive spectroscopy at elevated pressures

AP-XPS – Powerful Method with High User Demand

International growth – Opportunity for leading-edge performance at NSLS II

Chem. Soc. Rev., 2013, 42, 5833--5857

AP-XPS at NSLS II CSX2 Beamline

z

hν

Background Gas Pressure = P

e-

Entrance Nozzle to Differentially Pumped

Electrostatic Lens

Sample

d

Towards Ambient Pressure XPS

dNozzle spacing, z Pmax Performance

300 μm 300 μm 5 Torr Current AP-XPS @ ALS, Berkeley

2 μm 2 μm 750 Torr Atmospheric P

Fundamental pressure limit: Elastic & inelastic e- scattering in gas phase.

P ∝ 1d

z ≈ d

Ip = Ivac ⋅exp −zσ E( )P kT( )

Current config.

Plus two focusing mirrors

Pres

sure

(Tor

r)

Temperature (K)

Current AP-XPS

Future AP-XPS

at NSLS-II

Atmospheric and environmental chemistry

Catalysis

200 400 600 800 1000 10-4 10-3 10-2 10-1 10 0 10 1 10 2 10 3 10 4

clean H2

10 x 106 t $ 134 b

Preferential oxidation Methanation 99.99% H2

WGS

99% H2

CO removal Reforming steam dry autothermal Partial oxidation

Electrolysis of water

Energy

4 %

96 %

NG (48%) Oil (30%) Coal (18%) Biomass

Hydro Solar Wind Geo Ocean

Nuclear

Ammonia

Fuel processing

Hydrogenation

Hydrogen Fuel Cells

~ 50%

~ 50%

PRODUCTION USE

Syngas 80% H2 20% CO

CO + H2O ↔ CO2 + H2

Need for clean hydrogen : Water Gas Shift (WGS) Reaction

WGS

HTS (600-750 K): Cr2O3 + Fe3O4 LTS (450-550 K) : Cu/ZnO

AP-XPS for Catalysis & Surface Chemistry

Example I: Water-gas-shift catalysis Stacchiola, Senanayake, Rodriguez, Chem Dept ALS 9.2

AP-XPS for Catalysis & Surface Chemistry

Example I: Water-gas-shift catalysis Stacchiola, Senanayake, Rodriguez, Chem Dept ALS 9.2

CO + H2O CO2 + H2

1.50 1.55 1.60 1.65 1.70 1.75-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

1000 K/T

Ln{r

ate/

(1015

mol

ecul

es c

m-2

s-1

)}

292 287 282BE / eV

CO(g)

C 1s

CO C0

CeOx / Cu(111)

Cu(111)

Angew. Chemie Int. Ed 2013 DOI 10.1002/anie.201210077

Activity of ceria/metal catalysts, andAmbient Pressure XPS under in-situ conditions

CO + H2O ↔ CO2 + H2

WGS

Inverse

Oxi Metal

CeOx / Cu(111)

Binding energy (eV)104106108110112114116118120122124126128

Inte

nsity

(arb

itrar

y un

its)

Ce4d

300K

550K

CeO1.90

CeO1.65

State of catalyst under reaction conditions

Beamline 9.3.2 Zhi Liu

0.5 Torr

Oxide-supported amines

Questions:- Capture mechanism- Influence of support- Effect of ‘poisons’, NOx,SOx

- Capture & release kinetics

Inte

nsity

(a.u

.)

Binding energy (eV)

3AP

Issues:- Energy intensive CO2 removal.- MEA solution corrosive.- NOx/SOx poison solution.

Conventional liquid-phase CO2 capture

CO2(aq) → H2CO3 → HCO3- + AH+H2O MEA

CO2(aq) + MEA → -OOCHNC2H4OH + AH+

AP-XPS on model systems: Amines on TiO2(110)

011

101

AP-XPSC1s

1.90 Å1.93 Å2.27 Å

2.44 Å 1.84 Å

3AP/TiO2(110)

MEA/TiO2(110)

Ti O

N

✓

✗

A = monoetanolamine [MEA] = H2NC2H4OH

Example II: Solid-state CO2 capture S. Tenney, P. Sutter, CFN, NSLS X1A

Issues:- Energy intensive CO2 removal.- MEA solution corrosive.- NOx/SOx poison solution.

Conventional liquid-phase CO2 capture

CO2(aq) → H2CO3 → HCO3- + AH+H2O MEA

CO2(aq) + MEA → -OOCHNC2H4OH + AH+

A = monoetanolamine [MEA] = H2NC2H4OH

AP-NEXAFS at NSLS-II

AP-XPS AP-NEXAFS

model catalysts AP-NEXAFS

powders

Endstation 1 Endstation 2

AP-STM: CeOx/CuO

beam

E-TEM: CeOx/CuO

ALS, ACS Catal. 2 (2012) 2250

ALS, Phys. Chem. Chem. Phys. 13 (2011) 19988

Model catalysts Powder catalysts

Experiments of AP-NEXAFS on model catalysts

Unique tool:

Cross-section and features in the

AP-NEXAFS will change with

polarization of light

AP-NEXAFS at NSLS-II

S. Kaya et al. / Catalysis Today 205 (2013) 101–105 JCP 138, 024704 (2013)

SSRL ALS

AP-NEXAFS at NSLS-II

1 Torr, 700 K

Ambient-Pressure NEXAFS and XPS at CSX Beamline: Soft X-rays for the In-situ Study of Catalytic Processes

Objectives: First light experiments: - In-situ Study of the WGS on (Au,Cu)/CeOx/TiO2 Planar and Powder catalysts - Study the mechanism for capture of CO2 on solids

- We will be testing the linear polarization devices of the beamline Development of instrumentation: -Unique facilities for studying reaction mechanisms at the surface of planar and powder catalysts. These will benefit users at CFN and Synchrotron Catalysis Consortium (SCC)

-The combination of the linearly polarized light with AP-NEXAFS is unique. Will be the first to achieve Atmospheric pressures in AP-XPS

CeOx / TiO2(110)

TiO2

CeOx