Changing the Product Selectivity for Electrocatalysis of CO2 Reduction Reaction on Plated Cu Electrodes

Abstract Electrochemical reduction of carbon dioxide (CO 2 RR) on various types of Cu electrodes to useful chemicals and fuels has attracted much attention. Herein, we comparatively investigate the distributions of CO 2 RR products over electroplated Cu, chemically plated boron‐doped Cu (Cu−B) and electroplated phosphorus‐doped Cu (Cu−P) electrodes. A global Faradaic efficiency of more than 50 % can be reached for the C2+ (ethylene, ethanol and n‐propanol) products on both plated Cu−B and Cu−P electrodes at ∼−1.15 V vs. RHE in 0.1 M KHCO 3 electrolyte. Moreover, in situ surface enhanced infrared spectroscopy results together with quantitative analysis of the CO 2 RR products reveal a more facile conversion/depletion of the *CO intermediate after B‐ and P‐doping, for which Cu−B promotes the C2+ products while Cu−P enhances both C2+ generation and CH 4 evolution at faster *CO consumption. The present work suggests the vital role of *CO in the step of C−C bonding formation and highlights that the metalloid doping may alter the reactivity and selectivity of the intermediate.