Stable CuIn alloy for electrochemical CO2 reduction to CO with high-selectivity

High-selective and stable electrocatalysts are highly desired for CO2 reduction in large scale. To achieve CO2 reduction to CO with high selectivity and longtime running stability, CuIn alloy nanowires (NWs) is prepared by the combining of chemical oxidation and electrodeposition method. More importantly, due to electrochemical pretreatment during synthesis process, the CuIn alloy shows remarkable stability and its structure remains unchanged under harsh negative bias during CO2 reduction. In addition, the alloy NWs achieve the optimal CO2 to CO selectivity with a Faradaic efficiency of 86% at −1.0 V vs. RHE. Through DFT calculation, it is found that the stable CuIn alloy surface is crucial for the modulation of *COOH intermediate bonding to catalyst for easier formation of *CO, and the *CO dimerization is inhibited by CuIn alloy surface due to the weaker *CO adsorption compared to metallic Cu. We believe this work will shed light on the preparation of stable electrocatalysts for CO2 reduction with high selectivity, and deep understanding of metal surface evolution under electrochemical environment.