Theoretical insights into interface effects on CO2 hydrogenation to methanol over In4O6/ZrO2(1 1 1) catalyst

Abstract

Methanol synthesis from CO2 hydrogenation on the defective In4O6/ZrO2(111) surface with surface oxygen vacancies has been investigated by using periodic density functional theory calculations. The calculated oxygen vacancy formation energies indicate that the D1 surface with Ov1 defective sites on the surface of the In4O6 clusters is thermodynamically the most favorable for the adsorbed CO2 to generate methanol along the HCOO pathway. In contrast, the D4 surface with Ov4 defect sites at the interface is the most unstable, reacting along the RWGS path on clusters near the Ov4 defects, and hydrogenating along the HCOO path at the interfacial position to generate methanol. The differential charge density curves further reveal the close relationship between the electronic structure of the metal oxide interface and the CO2 hydrogenation mechanism to methanol.