Regulated CO adsorption by the electrode with OH- repulsive property for enhancing C-C coupling

Electrochemical CO2 reduction driven by renewable electricity is one of the promising strategies to store sus-tainable energy as fuels. However, the selectivity of value-added multi-carbon products remains poor for further application of this process. Here, we regulate CO adsorption by forming a Nafion layer on the copper (Cu) electrode that is repulsive to OH-, contributing to enhanced selectivity of CO2 reduction to C2+ products with the suppression of C1 products. The operando Raman spectroscopy indicates that the local OH- would adsorb on part of active sites and decrease the adsorption of CO. Therefore, the electrode with repulsive to OH- can adjust the concentration of OH-, leading to the increased adsorption of CO and enhanced C-C coupling. This work shows that electrode design could be an effective strategy for improving the selectivity of CO2 reduction to multi-carbon products.