Susana Tostón Serrano (Susana.Toston@uclm.es)

Department of Chemical Engineering – Faculty of Environmental Sciences and

Biochemistry. UCLM. Toledo (Spain)

INDEX

1. Introduction Approaching the problem Alternative proposal CO2 photocatalytic conversion

2. Experimental High pressure synthesis of photocatalysts Catalyst characterization Photocatalytic activity assessment Analysis of conversion products 3. Results Photocatalyst physicochemical properties (DRX, DR- UV-Vis) Compound production in CO2 reduction 4. Conclusions

Introduction

APPROACHING THE PROBLEM

IPCC, 5th Assessment Report , Working Group I, 2013 (Figure subject to final copy edit)

Reduce CO2 emission rate in order to

minimize impacts

Introduction

APPROACHING THE PROBLEM

International Energy Outlook 2013

Liquid fuels

Coal

Natural gas

projections history

Introduction

ALTERNATIVE PROPOSAL

CO2 PHOTOCATALYTIC CONVERSION

CO2

capture and recycling

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

Decreasing deforestation

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

Improved energy

efficiency

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

CO2

capture and storage (CCS)

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

REDUCCIREDUCCIÓÓN N DE GASES DE DE GASES DE

EFECTO EFECTO

INVERNADEROINVERNADERO

REDUCCIREDUCCIÓÓN DE LA N DE LA DEFORESTACIDEFORESTACIÓÓNN

CAPTURA Y CAPTURA Y

ALMACENAMIENTO COALMACENAMIENTO CO22

FUENTES FUENTES ALTERNATIVAS ALTERNATIVAS

DE ENERGDE ENERGÍÍAA

MEJORA MEJORA EFICIENCIA EFICIENCIA

ENERGENERGÉÉTICATICA

CAPTURA Y CAPTURA Y

CONVERSICONVERSIÓÓN CON CO22

Alternative energy sources

Reduction of greenhouse

gases

Introduction

CO2 RECYCLING CO2 PHOTOCATALYTIC CONVERSION

Conduction band

Valence band

h+

e-

Gap Band hv

Incre

asing E

CO2 + H2O

CH4 CH2O CH3COOH

TiO2 nanoparticle

hv

Doping metal

Photocatalyst TiO2

Ideal candidate photocatalysis

Experimental

HIGH PRESSURE SYNTHESIS OF PHOTOCATALYSTS

EXPERIMENTAL SETUP SYNTHESIS PROCESS

Ti{OCH(CH3)2}4 / DIPBAT

2-propanol/ Ethanol

Acetylacetonate Cu/Pd

Drying at 105 ° C

Calcination at 400 ° C, 6h

Thermohydrolysis 2 h

200 bar 300 °C

Cu/Pd/TiO2

Ad hoc design based on Alonso et al., 2009

Experimental

CATALYST CHARACTERIZATION

X RAY DIFFRACTION UV-Vis SPECTROSCOPY DIFFUSE REFLECTANCE

CRYSTALLINITY ABSORPTION THRESHOLD

CRYSTALLINE PHASES: ANATASE/RUTILE

BAND GAP ENERGY

Experimental

PHOTOCATALYTIC ACTIVITY ASSESSMENT

EXPERIMENTAL SETUP SOLAR REACTOR

Quartz window

Photocatalytic reactor

Adapted from Varghese y col., 2009

Ad hoc design based on Zhang et al., 2011

Dew point Gauge

Xe Arc Lamp

GC-TCD/FID

Stainless Steel Wall

Experimental

ANALYSIS OF CONVERSION PRODUCTS

Agilent MSD 5975C: - Unknown compounds

Agilent GC 7890A: - 2 TCD detectors - FID detector with

methanizer

- Gases: H2, O2, CO, CO2

- Low-molecular-weight HCs: C1 – C7

- LMW alcohols, esters and ketones

Results

PHOTOCATALYST CHARACTERIZATION (I)

X RAY DIFFRACTION

Lower peak height and resolution

0

200

400

600

800

1000

1200

1400

20 30 40 50 60 70 80

Ángulo (2 Theta)

Cu

en

tas

-600

-400

-200

0

200

400

600

800

TiO2 sintet. TTIP-ISOP. TiO2 Comercial

TTIP-Isopropanol

A

A A

A A A R

Commercial TiO2

A: Anatase phase R: Rutile phase

Co

un

ts

Angle (2 Theta)

0

200

400

600

800

1000

1200

1400

20 30 40 50 60 70 80

Ángulo (2 Theta)

Cu

en

tas

-600

-400

-200

0

200

400

600

800

TiO2 sintet. TTIP-Etanol TiO2 Comercial

TTIP-Ethanol

Commercial TiO2

0

200

400

600

800

1000

1200

1400

20 30 40 50 60 70 80

Ángulo (2 Theta)

Cu

en

tas

-600

-400

-200

0

200

400

600

800

TiO2 sintet. DIPBAT-ISOP. TiO2 Comercial

DIPBAT-Isop.

0

200

400

600

800

1000

1200

1400

20 30 40 50 60 70 80

Ángulo (2 Theta)

Cu

en

tas

-600

-400

-200

0

200

400

600

800

TiO2 sintet. DIPBAT-Etanol TiO2 Comercial

DIPBAT-Ethanol

Co

un

ts

Angle (2 Theta) C

ou

nts

Angle (2 Theta)

Angle (2 Theta)

Co

un

ts

Commercial TiO2

Commercial TiO2

Higher crystallinity

Results

Visible

PHOTOCATALYST CHARACTERIZATION (II)

UV-Vis SPECTROSCOPY DIFFUSE REFLECTANCE

0

0,5

1

1,5

2

2,5

3

200 250 300 350 400 450 500 550 600 650 700

Longitud de onda (nm)

Ab

so

rba

nc

ia (

u.a

.)

PRECURSOR:

DIPBAT

PRECURSOR:

TTIP

TiO2 comercialCommercial TiO2

Precursor TTIP

Precursor DIPBAT

Ab

sorb

ance

(a.

u.)

Wavelength (nm)

Results

Visible

PHOTOCATALYST CHARACTERIZATION (II)

UV-Vis SPECTROSCOPY DIFFUSE REFLECTANCE

Ab

sorb

ance

(a.

u.)

COMMERCIAL TiO2

Wavelength (nm)

Cu CONTENT

Results

Reaction products identified in preliminary tests

CONTROL SAMPLES

SAMPLE AFTER PHOTOCATALYTIC REACTION

tR: 6,79 min

Ethane

tR: 11,95 min

Methane

tR: 12,68 min

CO

tR: 14,09 min

Propylene

tR: 15,73 min

Propane

PHOTOCATALYTIC ACTIVITY ASSESSMENT

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

UV-Vis Spectroscopy DR → DIPBAT catalysts, higher absorbance at visible wavelenghts, without decreasing in UV region → more effective use of energy from Xe arc lamp (solar spectrum)

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

UV-Vis Spectroscopy DR → DIPBAT catalysts, higher absorbance at visible wavelenghts without decreasing in UV region → more effective use of energy from Xe arc lamp (solar spectrum)

Cu-doped photocatalysts UV-Vis DR → progressive increase in absorbance in visible region up to 2% wt. of metal

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

UV-Vis Spectroscopy DR → DIPBAT catalysts, higher absorbance at visible wavelenghts without decreasing in UV region → more effective use of energy from Xe arc lamp (solar spectrum)

Cu-doped photocatalysts UV-Vis DR → progressive increase in absorbance in visible region up to 2% wt. of metal

Preliminary PC tests → main reaction products → methane and CO; ethane, propylene and propane in lower concentrations

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

UV-Vis Spectroscopy DR → DIPBAT catalysts, higher absorbance at visible wavelenghts without decreasing in UV region → more effective use of energy from Xe arc lamp (solar spectrum)

Cu-doped photocatalysts UV-Vis DR → progressive increase in absorbance in visible region up to 2% wt. of metal

Preliminary PC tests → main reaction products → methane and CO; ethane, propylene and propane in lower concentrations

Further experiments of CO2 reduction → selection of the best precursor-alcohol combination and optimum metal load. In addition, further tests with other metals (Pd)

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

UV-Vis Spectroscopy DR → DIPBAT catalysts, higher absorbance at visible wavelenghts without decreasing in UV region → more effective use of energy from Xe arc lamp (solar spectrum)

Cu-doped photocatalysts UV-Vis DR → progressive increase in absorbance in visible region up to 2% wt. of metal

Preliminary PC tests → main reaction products → methane and CO; ethane, propylene and propane in lower concentrations

Further experiments of CO2 reduction → selection of the best precursor-alcohol combination and optimum metal load. In addition, further tests with other metals (Pd)

Future stage of the project, energy source → Solar radiation

Conclusions

XRD → among undoped synthesis combinations, TTIP-isopropanol shows the highest crystallinity, very similar to commercial TiO2. All combinations, crystalline phase anatase → enhance photocatalytic process

UV-Vis Spectroscopy DR → DIPBAT catalysts, higher absorbance at visible wavelenghts without decreasing in UV region → more effective use of energy from Xe arc lamp (solar spectrum)

Cu-doped photocatalysts UV-Vis DR → progressive increase in absorbance in visible region up to 2% wt. of metal

Preliminary PC tests → main reaction products → methane and CO; ethane, propylene and propane in lower concentrations

Further experiments of CO2 reduction → selection of the best precursor-alcohol combination and optimum metal load. In addition, further tests with other metals (Pd)

Future stage of the project, energy source → Solar radiation

This process can constitute an interesting alternative technology to CO2 storage: valorization of the gas, possibility to obtain fuels (recycling), environmentally friendly.

Project CTM 2011-26564 (2012-2014)

Project PEII10-0310-5840 (2010-2013)

Research Grant in Energy and the Environment (2010-2012)