Reaction-Induced Formation of CoO x -InO x Interfaces for the Hydrogenation of CO2 to Methanol

In2O3-based composite oxide catalysts have been widely employed for the hydrogenation of CO2 to methanol, but it is still challenging to identify their active structure and the synergy between indium and the second metal. Here, a class of In2O3-based catalysts fabricated with nonprecious metals was prepared for CO2 hydrogenation, among which the Co-In2O3 exhibited superior performance with a methanol selectivity of 85% at a CO2 conversion of 14% under the reaction conditions of H2/CO2 = 3/1, 50 bar, and 280 degrees C, outperforming most reported catalysts. We have evidence that the combination with cobalt not only increased the density of oxygen vacancies but also modulated the dissociative adsorption of H2. Regardless of the mixing methods for indium and cobalt, the catalyst composition plays a crucial role in determining the catalytic performance, suggesting that the reaction may lead different precursors to converge into a similar steady-state structure. By high-resolution electron microscopy, an active structure of CoO x -InO x interfaces formed on In2O3 nanoparticles is proposed, providing insights into the chemical structure of the active sites for In2O3-based catalysts.