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 sustainable 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.