Dendritic Ag/Pd Alloy Nanostructure Arrays for Electrochemical CO2 Reduction

Electrochemical reduction of CO2 to value‐added chemicals is a promising strategy for the utilization of excess CO2. But, such reaction suffers from poor efficiency due to insufficient selectivity of electrocatalysts. Aimed at developing highly efficient electrocatalysts, dendritic Ag/Pd alloys with different compositions were synthesized through a simple galvanic replacement reaction. We found that the Ag/Pd alloy with an atomic ratio of 70 % Ag and 30 % Pd can selectively convert CO2 to CO with a maximum faradaic efficiency of 98.6 % and a current density of 9.3 mA/cm2 at −0.8 V, showing the best catalytic properties. Such improved performance can be ascribed to the factors that the introduction of Pd boosts the key intermediate formation and the dendrite morphology with a hydrophobic surface provides multiple active sites and increases CO2 concentration. This study may benefit the design of bimetallic alloy catalysts with improved activity and selectivity for CO2 reduction. See the wood for the trees: Dendritic Ag/Pd alloys prepared through a simple galvanic replacement reaction show improved selectivity of CO2 to CO formation in comparison to single Ag wire, owing to the optimized coupling of the intermediate in CO2 reduction reaction and increased concentration of CO2 gas on the alloy surface.