Density functional theory study of CO₂ reduction on Cu₁₃, Cu₁₂Zr and Cu₁₂Zn clusters

In this study, we used density functional theory to study the adsorption and activation capacity of Cu₁₃, Cu₁₂Zn, and Cu₁₂Zr clusters for CO₂ reduction. The calculated results showed that Cu₁₂Zr enhanced the adsorption capacity of reactants and intermediates compared with Cu₁₃ clusters, while Cu₁₂Zn clusters decreased the adsorption capacity of reactants and intermediates. We calculated that the energy barriers for CO₂ reduction to CO on Cu₁₃, Cu₁₂Zr, and Cu₁₂Zn clusters were 0.65, 0.35 and 0.58 eV, respectively, and the energy barriers for CO₂ plus H to generate HCOO were 0.87, 0.77 and 0.49 eV, while the energy barriers of CO₂ hydrogenation to COOH were 1.67, 1.89 and 0.99 eV. The doping of Zn and Zr elements improved the CO₂ catalytic reduction ability of the Cu clusters, which showed that the Cu₁₂Zr clusters were favorable for the dissociation of CO₂ to form CO, and the Cu₁₂Zn clusters were favorable for the hydrogenation of CO₂ to HCOO.