A highly active Au/In₂O₃ catalyst for the reverse water gas shift reaction

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 a Au/In₂O₃ catalyst, which was subsequently evaluated for CO₂ hydrogenation under atmospheric pressure. This catalyst exhibits outstanding low-temperature activity for the reverse water gas shift (RWGS) reaction, achieving a CO₂ conversion of 21.3%, a CO selectivity of 100%, and a CO formation rate of 0.30 mmol_CO g_cat^-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 the Au/In₂O₃ catalyst.