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

Solar-driven CO₂ conversion holds great promise in carbon recycling. CO₂ activation and hydrogen spillover are crucial for high-selectivity CO₂ reduction, while with great challenges. Here, heteronuclear metal phthalocyanine aggregates with atomically active sites are synthesized and then assembled on BiVO₄ nanosheets. The CuNiPc/BiVO₄ nanocomposite achieves a 238 mmol g_Cu ^-1 h^-1 CO yield with nearly 100% selectivity (vs 77% for mononuclear CuPc/BiVO₄) without H₂ 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-N₄ moiety enhances CO₂ adsorption and activation relative to CuPc due to the regulated Cu configuration caused by the Ni atom incorporation, while the adjacent Ni-N₄ unit activates H₂O to generate ^*H, which subsequently undergoes intramolecular spillover to ^*Cu-COO site, consequently accessing both CO₂ activation and protonation for ^*COOH generation towards highly selective CO₂ reduction.