Inverse Design of Ag-Cu Bimetallic Alloys: Tuning C₁₊ Selectivity during CO₂ Electroreduction

Electrochemical CO₂ reduction (CO₂RR) provides an economically feasible and environmentally sustainable pathway to transform atmospheric carbon dioxide into value-added fuels and chemicals. Copper is one metal that can catalyze this process but suffers from issues related to product diversity, high overpotential requirements, and poor stability. Cu-Ag bimetallic alloys offer an improved stability selectivity performance owing to a synergy between both components. In this study, we elucidate this functionality by mapping the relationship between the composition and coordination of metal sites on a CuAg surface with their preferred product profile. We parametrize a model that predicts the energy of metal atoms within a bimetallic nanoparticle as a function of their local composition and coordination environment. We choose CO and OH binding energies as descriptors for CO₂RR and demonstrate their correlation with the site metal binding energies. We further construct plots forecasting the thermodynamic preference for CO₂RR products as a function of descriptor energies and overlay predicted CO/OH binding energies on those plots. Through these comparisons, we infer the appropriate site compositions and design principles for electrocatalysts optimal for driving the process toward desirable multicarbon products.