Highly Active Au/In2O3 Catalyst for the Reverse Water Gas Shift Reaction

Abstract

Supported gold catalysts are fundamentally and practically important for hydrogenation reactions due to their unique electronic properties and catalytic activity. In this work, Au nanoparticles were successfully deposited onto an In2O3 support via a deposition-precipitation method to form Au/In2O3 catalyst, which was subsequently evaluated for CO2 hydrogenation under atmospheric pressure. The catalyst exhibits outstanding low-temperature activity for the reverse water gas shift (RWGS) reaction, achieving a CO2 conversion of 21.3%, 100% CO selectivity, and a CO formation rate of 0.30 mmolCO•gcat - 1 •min -1 at 350 °C. Characterization results reveal that Au nanoparticles are uniformly dispersed on the In2O3 surface, accompanied by charge transfer from Au to the In2O3 support. This strong electronic metal-support interaction (EMSI) results in the formation of positively charged Au δ+ species, which facilitates H2 dissociation. Meanwhile, the generation of surface oxygen vacancies on In2O3 is promoted, enhancing CO2 adsorption and activation. These synergistic effects between Au nanoparticles and In2O3 account for the superior RWGS activities of Au/In2O3 catalyst.