There is significant interest in fuel and chemical production via CO2 hydrogenation to reach a more sustainable chemical and energy industry. Working with our experimental collaborators, we previously investigated the catalytic role of oxygen vacancies over In2O3 surfaces and the promoting mechanism of the Zr dopant. However, there is still much room to improve the catalytic performance of the In2O3-based catalysts, as the catalytic activity and selectivity remain low at the required relatively high reaction temperature of &gt;350 °C. Here, based on the experimental work of our collaborators on the catalytic performance of In2O3 catalysts of different phases and shapes, we systematically studied the low-index surfaces of cubic and hexagonal In2O3 phases to reveal their possibly different catalytic mechanisms and to establish the structure-property-activity relationship for rational catalyst design. Our calculations show that CO2 can only be physisorbed on the (111) surface of the cubic In2O3 phase, which is the most stable one for this phase. For the experimentally observed (104) surface of the hexagonal In2O3 phase, CO2 chemisorption does occur, and the adsorption is surprisingly much stronger than that on the widely studied (110) surface of the cubic In2O3 phase. Different pathways proposed in the literature for the CO2 hydrogenation reaction over these surfaces were systematically studied. Preliminary analysis of our results show that In2O3 catalysts of the hexagonal phase will have higher performance than those of the cubic phase, consistent with the experimental data. In addition, we are also investigating the role of oxide-oxide and metal-oxide interfaces on the activity and selectivity of the In2O3-based catalysts for this reaction.

CO2 hydrogenation over cubic and hexagonal In2O3 phases: Catalytic mechanism and structure-property-activity relationship

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.