Abstract: The Rh/CeOx catalysts prepared by co-precipitation method were studied by a complex of physical-chemical methods. The formation of RhxCe1-xO2-δ solid solution was shown. Catalysts demonstrated activity in CO oxidation reaction at temperatures below 500C. Heating of the samples up to 10000C resulted in substantial decrease of activity. By TPR-CO experiments several types of active centers were detected. For identification of the nature of active species the XPS experiments with step-by-step reduction and re-oxidation of the samples were performed in ex situ regime. CO interaction with Rh/CeOx-4500C samples at temperatures below 100-1500C resulted in reduction of CeO2 surface whereas Rh remained in oxidized state. At higher temperatures formation of Rhnδ+ species were detected with 80% reduction of rhodium at T>3000C. Catalysts could be reoxidized by O2 already at RT. For Rh/CeOx-10000C samples redox processes required higher temperatures.

Cite: Kibis L.S. , Kardash T.Y. , Derevyannikova E.A. , Slavinskaya E.M. , Stonkus O.A. , Boronin A.I.
The Redox Properties of RhxCe1-xO2-δ Solid Solution in CO Oxidation Reaction
EuropaCat-XIII: 13th European Congress on Catalysis 27-31 Aug 2017