Reaction-Induced Formation of CoO<i><sub>x</sub></i>–InO<i><sub>x</sub></i> Interfaces for the Hydrogenation of CO<sub>2</sub> to Methanol
Mingchao Zhang, Hui Chen, Kang Cheng, Liangqun Zhao, Hengliang Huang, Jincan Kang, Qinghong Zhang, Ye Wang
Abstract
In 2 O 3 -based composite oxide catalysts have been widely employed for the hydrogenation of CO 2 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 In 2 O 3 -based catalysts fabricated with nonprecious metals was prepared for CO 2 hydrogenation, among which the Co–In 2 O 3 exhibited superior performance with a methanol selectivity of 85% at a CO 2 conversion of 14% under the reaction conditions of H 2 /CO 2 = 3/1, 50 bar, and 280 °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 H 2 . 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 In 2 O 3 nanoparticles is proposed, providing insights into the chemical structure of the active sites for In 2 O 3 -based catalysts.