Optimal Icosahedral Copper-Based Bimetallic Clusters for the Selective Electrocatalytic CO2 Conversion to One Carbon Products

Electrochemical CO₂ reduction reactions can lead to high value-added chemical and materials production while helping decrease anthropogenic CO₂ emissions. Copper metal clusters can reduce CO₂ to more than thirty different hydrocarbons and oxygenates yet they lack the required selectivity. We present a computational characterization of the role of nano-structuring and alloying in Cu-based catalysts on the activity and selectivity of CO₂ reduction to generate the following one-carbon products: carbon monoxide (CO), formic acid (HCOOH), formaldehyde (H₂C=O), methanol (CH₃OH) and methane (CH₄). The structures and energetics were determined for the adsorption, activation, and conversion of CO₂ on monometallic and bimetallic (decorated and core@shell) 55-atom Cu-based clusters. The dopant metals considered were Ag, Cd, Pd, Pt, and Zn, located at different coordination sites. The relative binding strength of the intermediates were used to identify the optimal catalyst for the selective CO₂ conversion to one-carbon products. It was discovered that single atom Cd or Zn doping is optimal for the conversion of CO₂ to CO. The core@shell models with Ag, Pd and Pt provided higher selectivity for formic acid and formaldehyde. The Cu-Pt and Cu-Pd showed lowest overpotential for methane formation.