Electrocatalytic Reduction of CO2 to Ethanol at Close to Theoretical Potential via Engineering Abundant Electron‐Donating Cuδ+ Species

Electrochemical CO2 reduction to liquid multi-carbon alcohols provides a promising way for intermittent renewable energy reservation and greenhouse effect mitigation. Cuδ+ (0δ+ is insufficient and easily reduced to Cu0 . Here a Cu2 S1-x catalyst with abundant Cuδ+ (0δ+ , gaining an economic profit based on techno-economic analysis. The calculation and in situ spectroscopic results reveal that the abundant Cuδ+ sites display electron-donating ability, leading to the decrease of the reaction barrier in the potential-determining C-C coupling step and eventually making the applied potential close to the theoretical value.