Support and gas environment effects on the preferential oxidation of carbon monoxide over Co3O4 catalysts studied in situ

Nyathi, T. M., Fadlalla, M. I., Fischer, N., York, A. P.E., Olivier, E. J., Gibson, E. K. , Wells, P. P. and Claeys, M. (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.

• Item Type: Articles
• Additional 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.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gibson, Dr Emma

Creator Roles

Gibson, E. K.: Methodology, Investigation, Formal analysis, Writing – review and editing

• Authors: Nyathi, T. M., Fadlalla, M. I., Fischer, N., York, A. P.E., Olivier, E. J., Gibson, E. K., Wells, P. P., and Claeys, M.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Applied Catalysis B: Environmental
• Publisher: Elsevier
• ISSN: 0926-3373
• ISSN (Online): 1873-3883
• Published Online: 16 June 2021
• Copyright Holders: Copyright © 2021 Elsevier B.V.
• First Published: First published in Applied Catalysis B: Environmental 297:120450
• Publisher Policy: Reproduced in accordance with the publisher copyright policy