Details

Autor(en) / Beteiligte

• Nyathi, Thulani M.
• Fadlalla, Mohamed I.
• Fischer, Nico
• York, Andrew P.E.
• Olivier, Ezra J.
• Gibson, Emma K.
• Wells, Peter P.
• Claeys, Michael

Titel

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

Ist Teil von

• Applied catalysis. B, Environmental, 2021-11, Vol.297, p.120450, Article 120450

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2021

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• [Display omitted] •Supported Co3O4 catalysts studied under different CO-PrOx environments using in situ PXRD and magnetometry.•Weak nanoparticle-support interactions (NPSI) allow for high CO-PrOx performance over Co3O4.•Strong NPSI minimise Co0 and associated CH4 formation.•Co-fed H2O suppresses CO-PrOx and Co3O4 reduction, while co-fed CO2 causes methanation and the reverse water-gas shift over Co0.•Bi-functionality of support materials is required – enhancing CO-PrOx performance and stabilising the Co3O4 phase. 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.