Hydrogenation of CO2 to Methanol on a Auδ+–In2O3–x Catalyst

CO₂ hydrogenation to methanol has attracted increasing attention with the development of renewable hydrogen. A big challenge is to identify catalysts able to achieve high conversion and selectivity. In this work, we report an In₂O₃-supported Au catalyst that exhibits excellent performance for hydrogenation of CO₂ selectively to methanol. In situ characterizations using time-resolved X-ray diffraction, ambient-pressure X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy confirm that a strong metal–support interaction leads to a reactive Au^δ+–In₂O_3–x interface for activation and hydrogenation of CO₂ to methanol. An effective gold-indium oxide bonding favors the dispersion of the noble metal and prevents its sintering under reaction conditions. The methanol selectivity reaches 100% at temperatures below 225 °C and is more than 70% at 275 °C over the Au^δ+–In₂O_3–x catalyst. It is even 67.8% with a space time yield of methanol of 0.47 g_MeOH/(h·g_cat) at 300 °C, 5 MPa, and 21,000 cm³ h^–1 g_cat^–1. The results obtained here represent the highest selectivity and activity ever reported for CO₂ hydrogenation over supported gold catalysts. Our study shows that the strong Au/In₂O₃ interaction and the intrinsic chemical activity of In₂O₃ can be used to significantly improve the catalytic performance of Au catalysts, providing promising routes for the rational design and application of Au catalysts beyond CO₂ hydrogenation.