DFT studies on the catalytic hydrogenation of carbon dioxide on Ni (111) in a liquid-phase environment

Abstract

CO₂ catalytic hydrogenation attracts interest in converting CO₂ into useful chemicals and mitigating the greenhouse effect. In this study, CO₂ hydrogenation in a liquid-phase environment on the Ni (111) surface was investigated using density functional theory calculations. Based on the analysis of hydrogenation in the gas phase, the water H migration model was introduced to examine the kinetic processes in the liquid phase. The results reveal that water plays a key role in this reaction. During the hydrogenation of CO₂* to COOH* or HCOO*, the adsorbed H atom is first transferred to the water molecule, which subsequently donates another H atom to COOH* or HCOO*. During this process, water directly participates in the reaction as a medium, enabling H* to hydrogenate the adsorbed reactant over a limited distance. According to the proposed mechanism, the HCOO pathway is the optimal route for the reaction, exhibiting an energy barrier of 1.08 eV.