Sensitivity of CO oxidation toward metal oxidation state in ceria-supported catalysts: an operando DRIFTS-MS study. Issue 3 (10th September 2015)

• Record Type: Journal Article
• Authors: Kaftan, Andre; Kollhoff, Fabian; Nguyen, Thanh-Son; Piccolo, Laurent; Laurin, Mathias; Libuda, Jörg
• Is Part Of: Catalysis science & technology. Volume 6:Issue 3(2016)
• Page Start: 818
• Page End: 828
• Publication Date: 2015-09-10
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c5cy00827a
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : CeO2 and Rh/CeO2 show CO to CO2 conversion according to the input gas mixture, independent of the state of the catalyst powder. Pt/CeO2 demonstrates additional dependence on the initial state of the catalyst (oxygen coverage/oxidation state). Abstract : The oxidation of carbon monoxide has been studied on pristine CeO2, Rh–CeO2, and Pt–CeO2 powders prepared in one step by solution combustion synthesis (SCS). The reaction was cycled between an oxygen-rich and a CO-rich feed with regard to the stoichiometric conditions. CO2 production was monitored by mass spectrometry, while the surface species were probed by operando DRIFTS (Diffuse Reflectance Infrared Fourier Transform Spectroscopy). Whereas the reaction starts above 150 °C on CeO2 and Rh–CeO2 and does not depend on the state of the surface (oxidized or reduced), the reaction on Pt–CeO2 shows strong dependency on the initial state and substantial activity is achieved at much lower temperatures with the CO-rich feed. We relate this result to the change in the oxidation state of Pt via strong interaction with ceria.