Redox replacement of silver on MOF-derived Cu/C nanoparticles on gas diffusion electrodes for electrocatalytic CO2CO_{2} reduction

Bimetallic tandem catalysts have emerged as a promising strategy to locally increase the CO flux during electrochemical $CO_{2}$ reduction, so as to maximize the rate of conversion to C−C-coupled products. Considering this, a novel Cu/C−Ag nanostructured catalyst has been prepared by a redox replacement process, in which the ratio of the two metals can be tuned by the replacement time. An optimum Cu/Ag composition with similarly sized particles showed the highest $CO_{2}$ conversion to $C_{2+}$ products compared to non-Ag-modified gas-diffusion electrodes. Gas chromatography and in-situ Raman measurements in a $CO_{2}$ gas diffusion cell suggest the formation of top-bound linear adsorbed *CO followed by consumption of CO in the successive cascade steps, as evidenced by the increasingνC−H bands. These findings suggest that two mechanisms operate simultaneously towards the production of $HCO_{2}H$ and C−C-coupled products on the Cu/Ag bimetallic surface