Redox Behavior of In−O−Ti Interface for Selective Hydrogenation of CO2 to CO in Doped In−TiO2 Catalyst

Abstract

AbstractIn the CO2 hydrogenation reaction, selective synthesis of CO at low temperature and high pressure is needed to integrate the reverse water gas shift reaction with Fischer‐Tropsch synthesis. Here, we show that a mixed oxide catalyst prepared by doping indium (In) into TiO2 produces CO with the formation rate of 22 μmol g−1 s−1. The CO selectivity was more than 99 % at 350 °C and 3 MPa pressure. Moreover, the catalyst was durable for over 100 h on stream. During reaction the interfacial In3+−O−Ti4+ sites were first reduced in presence of H2 and then oxidized back with CO2 producing CO. Because of the redox mechanism, the formation of methanol and methane was limited. This study shows the development of a promoter‐free oxide catalyst for CO2 hydrogenation and the importance of the redox property at the oxide interface for selective hydrogenation of CO2 to CO under unfavorable conditions.