Mixed-Phase Indium Oxide as a Highly Active and Stable Catalyst for the Hydrogenation of CO2 to CH3OH

Indium oxide has been demonstrated to be a suitable catalytic material for CO2 adsorption and activation, and in this study a phase-mixing strategy is used to improve its catalytic hydrogenation of CO2 to CH3OH. Mixed-phase indium oxide with controllable cubic and hexagonal phases is synthesized by a solvothermal method, and its CO2 conversion and CH3OH space-time yield are about 2 times higher than those of single-phase indium oxide. Experimental investigation shows a significant mixed-crystal effect resulting from the phase mixing, which substantially promotes oxygen vacancy formation and medium-strength CO2 adsorption and thereby enhances the catalytic performance. Furthermore, the mixed-phase catalyst is very stable and too difficult to reduce during reaction. These results give a good technique for the development of highly active and long-lived CO2 hydrogenation catalysts through crystal phase engineering.

Automated summary

The study demonstrates that mixed-phase indium oxide shows significantly improved catalytic hydrogenation of CO2 to CH3OH compared to single-phase indium oxide. The mixed-phase catalyst exhibits better CO2 conversion and CH3OH space-time yield, with a significant enhancement in catalytic performance attributed to the mixed-crystal effect resulting from phase mixing. The stable nature and difficulty of reduction of the mixed-phase catalyst during reaction indicate its potential as a highly active and long-lived CO2 hydrogenation catalyst.