Highly Efficient and Selective Photocatalytic CO2 Reduction to Ethanol by Cu4 Clusters with Adjacent Cu Single Atoms Anchored on Carbon Nitride

An efficient photocatalyst for CO2‐to‐CH3CH2OH conversion comprising atomically dispersed Cu clusters (Cu4) and single Cu sites coordinated with 2N and O anchored on two‐step calcinated C3N4 (Cu4/Cu1@CN) is reported. It was found to catalyze the reduction of CO2 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 beween Cu4 clusters and adjacent Cu single atoms, which facilitates OC−CO coupling and promotes ethanol production.