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 Auδ+–In2O3–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 Auδ+–In2O3–x catalyst. It is even 67.8% with a space time yield of methanol of 0.47 gMeOH/(h·gcat) at 300 °C, 5 MPa, and 21,000 cm3 h–1 gcat–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.