Implications of Surface Strain for Enhanced Carbon Dioxide Reduction on Copper-Silver Alloys

Abstract

The electrochemical reduction of atmospheric carbon dioxide to value added chemicals and fuels using renewable energy is a promising route to a sustainable economy. In this work we present results from the electrochemical reduction of carbon dioxide on copper/silver alloy electrodes alongside pure copper and pure silver in acetonitrile-water electrolyte mixtures. EIS measurements show that the copper/silver alloys exhibit lower charge-transfer resistance when compared to the pure metal electrodes. Reduced product analysis identifies carbon monoxide (CO) as the major product on pure Ag, Ag with alloyed with 10% Cu, and Cu alloyed with 10% Ag with Faradaic efficiencies over 60%. Formate is the major reduced product close to the 50:50 (Cu:Ag) ratio with Faradaic efficiencies exceeding 30%. Our results suggest that changes in the metallic lattice and structural strain of the bimetallic electrodes influences reduced product selectivity.