Catalytic performance of the Pt/TiO2 catalysts in reverse water gas shift reaction: Controlled product selectivity and a mechanism study

Abstract

In this study, the catalytic performance of CO2 hydrogenation reaction over Pt/TiO2 catalyst has been evaluated. The effect of Pt particle size and reaction conditions (e.g., temperature and space velocity) on the selectivity of CO and CH4 was identified. CH4 formed over the Pt/TiO2 catalysts following a consecutive pathway (likely, CO2→CO→CH4) and the Pt-CO species derived from the reverse water gas shift (RWGS) reaction was supposed to be the key intermediate for the formation of CH4. By introducing an in situ FTIR experiment, the Pt-Ov-Ti3+ species formed at the interface between Pt and reducible TiO2 support was identified as the active sites for the formation of CO, while large Pt particles facilitate the hydrogenation of CO to produce CH4 at higher temperature.