Intramolecular Synergy of CO 2 Activation and H Spillover on Heteronuclear Dual‐Metal Phthalocyanine Assemblies for Selective CO 2 Photoreduction

ABSTRACT Solar‐driven CO 2 conversion holds great promise in carbon recycling. CO 2 activation and hydrogen spillover are crucial for high‐selectivity CO 2 reduction, while with great challenges. Here, heteronuclear metal phthalocyanine aggregates with atomically active sites are synthesized and then assembled on BiVO 4 nanosheets. The CuNiPc/BiVO 4 nanocomposite achieves a 238 mmol g Cu −1 h −1 CO yield with nearly 100% selectivity (vs 77% for mononuclear CuPc/BiVO 4 ) without H 2 evolution, ranking among top atomic‐engineered photocatalysts. Femtosecond‐transient absorption spectra, in situ synchrotron radiation measurements, and theoretical simulations, etc., reveal that such a difference is mainly ascribed to the fast interfacial Z‐scheme charge transfer kinetics and the synergy catalysis between dual sites in CuNiPc. The Cu–N 4 moiety enhances CO 2 adsorption and activation relative to CuPc due to the regulated Cu configuration caused by the Ni atom incorporation, while the adjacent Ni–N 4 unit activates H 2 O to generate * H, which subsequently undergoes intramolecular spillover to * Cu–COO site, consequently accessing both CO 2 activation and protonation for * COOH generation towards highly selective CO 2 reduction.