In this study, a series of catalysts with the composition 1 wt% Pt/X% CeO2-Y% TiO2 (where X and Y range from 0 to 20%) was prepared via impregnation. The effects of different ratios of CeO2/TiO2 on the catalytic activity were examined during the reverse water gas shift reaction (RWGS). The catalytic activities of the Pt-impregnated catalysts were enhanced by increasing CeO2 loading. The activity tests, temperature-programmed reduction via H2, and step test of an elementary RWGS reaction over the catalysts confirmed that the catalytic activity depends on the number of TiO2 or CeO2 sites, which participate in the RWGS reaction, on the surface of the support.
Keywords: CeO2/TiO2; catalytic activity; redox mechanism; reverse water gas shift; temperature-programmed reduction.