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.