Highly Efficient and Selective Photocatalytic CO ₂ Reduction to Ethanol by Cu ₄ Clusters with Adjacent Cu Single Atoms Anchored on Carbon Nitride

Abstract An efficient photocatalyst for CO 2 ‐to‐CH 3 CH 2 OH conversion comprising atomically dispersed Cu clusters (Cu 4 ) and single Cu sites coordinated with 2 N and 1 O anchored on two‐step calcinated C 3 N 4 (Cu 4 /Cu 1 @CN) is reported. It was found to catalyze the reduction of CO 2 to ethanol with production rate of 154 µmol g −1 h −1 and selectivity of 98%, the yield rate and selectivity exceed most of the reported results for ethanol production. Experimental and theoretical calculations indicate that the high efficiency of this catalyst arises from the strong synergy between Cu 4 clusters and adjacent Cu single atoms, which facilitates OC─CO coupling and promotes ethanol production.