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Support and gas environment effects on the preferential oxidation of carbon monoxide over CO3O4 catalysts studied in situ

DOI: 10.1016/j.apcatb.2021.120450 DOI Help

Authors: Thulani M. Nyathi (University of Cape Town) , Mohamed I. Fadlalla (University of Cape Town) , Nico Fischer (University of Cape Town) , Andrew P. E. York (Johnson Matthey Technology Centre) , Ezra J. Olivier (Nelson Mandela University) , Emma K. Gibson (University of Glasgow; UK Catalysis Hub, Research Complex at Harwell) , Peter P. Wells (UK Catalysis Hub, Research Complex at Harwell; University of Southampton; Diamond Light Source) , Michael Claeys (University of Cape Town)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Applied Catalysis B: Environmental , VOL 5

State: Published (Approved)
Published: June 2021
Diamond Proposal Number(s): 19850

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.

Journal Keywords: CO-PrOx; Co3O4; Support effects; Gas environment effects; In situ characterisation

Diamond Keywords: Fuel Cells

Subject Areas: Chemistry, Materials, Energy

Instruments: B18-Core EXAFS

Added On: 21/06/2021 13:36

Discipline Tags:

Energy Storage Energy Physical Chemistry Catalysis Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS)