P‐Mediated Cu–N4 Sites in Carbon Nitride Realizing CO2 Photoreduction to C2H4 with Selectivity Modulation

Abstract Photocatalytic CO 2 reduction to high value‐added C 2 products (e.g., C 2 H 4 ) is of considerable interest but challenging. The C 2 H 4 product selectivity strongly hinges on the intermediate energy levels in the CO 2 reduction pathway. Herein, Cu–N 4 sites anchored phosphorus‐modulated carbon nitride (CuACs/PCN) is designed as a photocatalyst to tailor the intermediate energy levels in the the C 2 H 4 formation reaction pathway for realizing its high production with tunable selectivity. Theoretical calculations combined with experimental data demonstrate that the formation of the C−C coupling intermediates can be realized on Cu–N 4 sites and the surrounding doped P facilitates the production of C 2 H 4 . Thus, CuACs/PCN exhibits a high C 2 H 4 selectivity of 53.2% with a yielding rate of 30.51 µmol g −1 . The findings reveal the significant role of the coordination environment and surrounding microenvironment of Cu single atoms in C 2 H 4 formation and offer an effective approach for highly selective CO 2 photoreduction to produce C 2 H 4 .