A computational study of CO2hydrogenation on single atoms of Pt, Pd, Ni and Rh on In2O3(111)Electronic supplementary information (ESI) available: Description of the structure of SA-In2O3models and oxygen vacancy formation (section S1–S3), geometries of elementary reaction steps (section S4–S7) full DFT dataset (section S8), and further microkinetic and DFT results (section S9 and S10). See DOI: https://doi.org/10.1039/d3cy00222e

Metal promoted indium oxide (In2O3) catalysts are promising materials for CO2hydrogenation to products such as methanol and carbon monoxide. The influence of the dispersion of the promoting metal on the methanol selectivity of In2O3catalysts is a matter of debate, which centers around the role of atomically dispersed single metal atoms vs.metal clusters as catalysts for methanol formation. In this study, we used density functional theory calculations to compare the role of single atoms (SAs) of Ni, Pd, Pt and Rh placed on the In2O3(111) surface to study CO2hydrogenation to CO and methanol. Direct and hydrogen-assisted CO2dissociation pathways leading to CO as well as methanol formation viaeither formate or CO intermediates are explicitly considered. Microkinetic simulations show that all SA models mainly catalyze CO formation viaa redox pathway involving oxygen vacancies where adsorbed CO2dissociates followed by CO desorption and water formation. The higher barriers for hydrogenation of formate intermediates compared to the overall barrier for the rWGS reaction explain the negligible CH3OH selectivity.