上海科技大学知识管理系统

Methanol synthesis is one of the most important industrially-viable approaches for carbon dioxide (CO2) utilization, as the produced methanol can be used as a platform chemical for manufacturing green fuels and chemicals. The In2O3 catalysts are ideal for sustainable methanol synthesis and have received considerable attention. Herein, Co-, Ni- and Cu-modified In2O3 catalysts were fabricated with high dispersion and high stability to improve the hydrogenation performance. The Ni-promoted In2O3 catalyst in the form of high dispersion possessed the largest amount of oxygen vacancies and the strongest ability for H2 activation, leading to the highest CO2 conversion and space time yield of methanol of 0.390 gMeOH gcat−1 h−1 with CH3OH selectivity of 68.7%. In addition, the catalyst exhibits very stable performance over 120 h on stream, which suggests the promising prospect for industrial applications. Further experimental and theoretical studies demonstrate that surface Ni doping promotes the formation of oxygen defects on the In2O3 catalyst, although it also results in lower methanol selectivity. Surprisingly, subsurface Ni dopants are found to be more beneficial for methanol formation than surface Ni dopants, so the Ni-promoted In2O3 catalyst with a lower surface Ni content at the similar Ni loading can reach higher methanol selectivity and productivity. This work thus provides theoretical guidance for significantly improving the CO2 reactivity of In2O3-based catalysts while maintaining high methanol selectivity.