In Situ Study of the Effect of the Exposed Surface of Ceria (100 vs 111) on the Highly Oxidized Species Formation on Ru/Ceria Catalysts

In-depth recognition of chemical processes that occur in Ru/CeO2 catalysts under realistic reaction conditions of C3H8 oxidation was studied using the near-ambient pressure X-ray photoelectron spectroscopy technique. The relevance of the proposed study is based on the wide use of ceria-based catalysts in industrially relevant red–ox reactions for reducing volatile organic compound emissions. Primary attention was paid to the effect of the exposed face of CeO2 support ((100) or (111)) on the formation of highly oxidized Ru species (volatile RuO4), which are decisively responsible for the Ru loss and thus deactivation of Ru-based catalysts.