The effects of metal oxides doping on the surface stability of In2O3 for CO2 hydrogenation

Abstract

The significance of maintaining the surface stability of the In2O3 catalyst in the conversion of CO2 to methanol through hydrogenation cannot be overstated. To improve surface stability, doping with metal oxides is usually employed. To explore high-efficiency In2O3 based catalysts, density functional theory calculations were utilized to explore the effects of doping CuO, Co2O3, NiO, TiO2, HfO2, Nb2O3, Ta2O5, and CeO2 on the stability of the In2O3(110) surface. It was found that in a CO atmosphere, the crucial step in determining the creation of oxygen vacancies on the In2O3 plane occurred during the desorption of CO2 from the vacancy location. The results indicate that doping CuO, Co2O3, NiO, Nb2O3, Ta2O5, and CeO2 on the In2O3(110) surface promotes the reduction process through the reaction of CO with the O atoms on the surface, resulting in reduced surface stability. Conversely, the doping of Ti and Hf can raise the reaction energy barriers for CO reacting with the O atoms on the surface and enhance CO2 molecule adsorption on vacant sites, thereby suggesting the potential of TiO2 and HfO2 as effective modifiers to improve the efficiency and durability of the In2O3 catalyst. Furthermore, it is crucial to enhance its stability by modifying the density of the electron cloud or Fermi level of the In2O3 catalyst.