Understanding the mechanisms of CO2RR with Cu atom doping low Miller index surfaces in Ni metal as an effective catalyst

The carbon dioxide electrocatalytic reduction reaction (CO₂RR) can be used to convert CO₂ into single carbon products such as methane, which is an effective means of mitigating CO₂ levels in the atmosphere. CO₂RR was simulated using DFT calculations on model catalysts doped with Cu at different cuts of Ni. The catalytic performance of different surfaces of Ni metal doped with Cu atoms, including formation energy, density of states, differential charge density, and energy of adsorption, were investigated comprehensively to evaluate the performance of these catalysts. The results indicate that all the Cu atoms doped in the first layer of the Ni surface enhance the stability of the catalyst and facilitate the conversion of CO₂ to formic acid (HCOOH). During the CO₂ adsorption process, the lower the formation energy of the catalyst, the lower the adsorption energy of CO₂, and the greater the change in bond angle during CO₂ adsorption, the more intense the electron transfer, and the better the catalytic effect, which promotes its reduction reaction. Additionally, a smaller change in bond angle indicates that the CO₂ molecule is more uniformly adsorbed on the catalyst surface, which is beneficial for the formation of stable intermediates, thereby improving catalytic efficiency.