DFT study of In2O3-catalyzed methanol synthesis from CO2 and CO hydrogenation on the defective site

Research on the mechanism of methanol synthesis from CO2 hydrogenation on the defective surface of In2O3 catalyst plays a pivotal role in the promotion of its catalytic performance and the catalytic conversion of CO2. Methanol synthesis from the hydrogenation of CO2 and CO on the vacancy site, consisting of O-v1 and O-v2, of the defective In2O3(110) surface (D surface) has been studied using the density functional theory method in the present work. The calculated results indicate that the HCOO route and RWGS route both are possible reaction pathways for methanol synthesis on the D surface. In the HCOO route, the reaction of p-HCOO with the surface H atom to form H2COO species is the rate-determining step, with an activation barrier of 1.25 eV. In the RWGS route, the dissociation of CO2 to CO on the D surface with a barrier of 0.99 eV is the rate-determining step for methanol synthesis. The hydrogenation of CO and HCO species on the D surface both are kinetically and energetically favorable.