Sulfurization-derived Cu0–Cu+ sites for electrochemical CO2 reduction to ethanol

The transformation of CO 2 into value-added products is a hot research topic. Metal copper as an electrochemical catalyst shows activity for generating multi-carbon products in CO 2 electroreduction. Herein, Cu 2 S nanorods/copper mesh (Cu 2 S/CM) is successfully fabricated, and exhibits high performance of CO 2 electroreduction to ethanol. At −0.8 V vs RHE , it achieved the Faraday efficiency (FE) of 13.5%, the partial current density of 13.3 mA cm −2 and the yield of 986.4 μmol L −1  h −1 for ethanol. Experiments and theoretical calculations indicated that the high performance is benefits from the high density of Cu 0 and Cu  +  pairs derived from Cu 2 S/CM during CO 2 electroreduction and an appropriate surface Cu 0 /Cu  +  ratio of 0.17. The Cu 0 –Cu + sites facilitate the adsorption of key intermediate *CH 2 CHO and decrease the energy barrier of the ethanol pathway. This work provides not only a new comprehension of CO 2 electroreduction with Cu 2 S catalyst but also a design idea based on Cu 0 –Cu + sites in Cu/Cu 2 S catalyst.