Support and gas environment effects on the preferential oxidation of carbon monoxide over Co3O4 catalysts studied in situ
Support and gas environment effects on the preferential oxidation of carbon monoxide over Co3O4 catalysts studied in situ
We have studied the effect of different supports (CeO2, ZrO2, SiC, SiO2 and Al2O3) on the catalytic performance and phase stability of Co3O4 nanoparticles during the preferential oxidation of CO (CO-PrOx) under different H2-rich gas environments and temperatures. Our results show that Co3O4/ZrO2 has superior CO oxidation activity, but transforms to Co0 and consequently forms CH4 at relatively low temperatures. The least reduced and least methanation active catalyst (Co3O4/Al2O3) also exhibits the lowest CO oxidation activity. Co-feeding H2O and CO2 suppresses CO oxidation over Co3O4/ZrO2 and Co3O4/SiC, but also suppresses Co0 and CH4 formation. In conclusion, weak nanoparticle-support interactions (as in Co3O4/ZrO2) favour high CO oxidation activity possibly via the Mars-van Krevelen mechanism. However, stronger interactions (as in Co3O4/Al2O3) help minimise Co0 and CH4 formation. Therefore, this work reveals the bi-functional role required of supports used in CO-PrOx, i.e., to enhance catalytic performance and improve the phase stability of Co3O4.
CO-PrOx, CoO, Gas environment effects, In situ characterisation, Support effects
Nyathi, Thulani M.
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Fadlalla, Mohamed I.
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Fischer, Nico
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York, Andrew P.E.
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Olivier, Ezra J.
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Gibson, Emma K.
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Wells, Peter P.
bc4fdc2d-a490-41bf-86cc-400edecf2266
Claeys, Michael
19cb6adb-b243-4dba-b0a8-94fd2c1f9658
15 November 2021
Nyathi, Thulani M.
e5a3f8fb-63de-4b2c-a7d2-3b6be6f8107e
Fadlalla, Mohamed I.
f1188dbb-fe38-480c-ba6c-5395f7721a07
Fischer, Nico
35b81bb7-173c-4a45-a2fd-0a99910b1e5f
York, Andrew P.E.
fbd1bacf-79f8-4e88-842e-af3e4ab7dd3d
Olivier, Ezra J.
7564fc93-b3f1-49d2-bb37-ebb753e50548
Gibson, Emma K.
738c74e4-ab68-42fe-bda8-9d4a43669b31
Wells, Peter P.
bc4fdc2d-a490-41bf-86cc-400edecf2266
Claeys, Michael
19cb6adb-b243-4dba-b0a8-94fd2c1f9658
Nyathi, Thulani M., Fadlalla, Mohamed I., Fischer, Nico, York, Andrew P.E., Olivier, Ezra J., Gibson, Emma K., Wells, Peter P. and Claeys, Michael
(2021)
Support and gas environment effects on the preferential oxidation of carbon monoxide over Co3O4 catalysts studied in situ.
Applied Catalysis B: Environmental, 297, [120450].
(doi:10.1016/j.apcatb.2021.120450).
Abstract
We have studied the effect of different supports (CeO2, ZrO2, SiC, SiO2 and Al2O3) on the catalytic performance and phase stability of Co3O4 nanoparticles during the preferential oxidation of CO (CO-PrOx) under different H2-rich gas environments and temperatures. Our results show that Co3O4/ZrO2 has superior CO oxidation activity, but transforms to Co0 and consequently forms CH4 at relatively low temperatures. The least reduced and least methanation active catalyst (Co3O4/Al2O3) also exhibits the lowest CO oxidation activity. Co-feeding H2O and CO2 suppresses CO oxidation over Co3O4/ZrO2 and Co3O4/SiC, but also suppresses Co0 and CH4 formation. In conclusion, weak nanoparticle-support interactions (as in Co3O4/ZrO2) favour high CO oxidation activity possibly via the Mars-van Krevelen mechanism. However, stronger interactions (as in Co3O4/Al2O3) help minimise Co0 and CH4 formation. Therefore, this work reveals the bi-functional role required of supports used in CO-PrOx, i.e., to enhance catalytic performance and improve the phase stability of Co3O4.
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More information
Accepted/In Press date: 11 June 2021
e-pub ahead of print date: 16 June 2021
Published date: 15 November 2021
Additional Information:
Funding Information:
The financial support from Johnson Matthey, the DSI-NRF Centre of Excellence in Catalysis (c*change), and the Science and Technology Facilities Council (STFC) via GCRF-START (Global Challenges Research Fund ? Synchrotron Techniques for African Research and Technology (ST/R002754/1)) is gratefully acknowledged. The authors would also like to thank Ms. Zulfa le Riche (from the University of Cape Town) for carrying out the ICP-OES analysis. Finally, Dr. Nitya Ramanan (from Diamond Light Source) and Mr. Monik Panchal (from the UK Catalysis Hub) are thanked for assisting with the XAS measurements on beamline B18 at Diamond Light Source (sessions: SP19850-3, SP19850-4, SP19850-5).
Funding Information:
The financial support from Johnson Matthey, the DSI-NRF Centre of Excellence in Catalysis (c*change) , and the Science and Technology Facilities Council (STFC) via GCRF-START (Global Challenges Research Fund – Synchrotron Techniques for African Research and Technology ( ST/R002754/1 )) is gratefully acknowledged. The authors would also like to thank Ms. Zulfa le Riche (from the University of Cape Town) for carrying out the ICP-OES analysis. Finally, Dr. Nitya Ramanan (from Diamond Light Source) and Mr. Monik Panchal (from the UK Catalysis Hub) are thanked for assisting with the XAS measurements on beamline B18 at Diamond Light Source (sessions: SP19850-3, SP19850-4, SP19850-5).
Publisher Copyright:
© 2021 Elsevier B.V.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
Keywords:
CO-PrOx, CoO, Gas environment effects, In situ characterisation, Support effects
Identifiers
Local EPrints ID: 450407
URI: http://eprints.soton.ac.uk/id/eprint/450407
ISSN: 0926-3373
PURE UUID: 4e9fbca1-41d7-4bd4-b440-1e7adc748fec
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Date deposited: 27 Jul 2021 17:24
Last modified: 06 Jun 2024 04:19
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Contributors
Author:
Thulani M. Nyathi
Author:
Mohamed I. Fadlalla
Author:
Nico Fischer
Author:
Andrew P.E. York
Author:
Ezra J. Olivier
Author:
Emma K. Gibson
Author:
Michael Claeys
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