Programmable Molecular Hubs Orchestrate Orthogonal CO₂-to-CH₄ Photocatalysis and Biomass Valorization

Semi-artificial photosynthesis that merges biocatalytic specificity with engineered materials enables sustainable solar fuel production, yet it remains constrained by low solar-to-chemical efficiency and limited scalability. Here, we present a supramolecular strategy by programmatically integrating photocatalysts, biocatalysts, and cofactors on a single protein scaffold, and realize the coupling of photocatalytic CO₂-to-CH₄ conversion with enzymatic biomass upgrading. A rationally designed molecular hub-comprising switchable μ-oxo-bridged bis(Fe^III-porphyrin) units and NADH mimics-drives deep CO₂ reduction to CH₄ at rates up to 32 000 µmol g^-1 h^-1 with >99% selectivity and a total apparent quantum efficiency of 1.82%. Modular tethering of diverse dehydrogenases activates inert C(sp³)─H bonds, delivering C_2─C₆ chemicals, including enantioenriched compounds (ee >96%). This programmable platform establishes a redox-balanced strategy for solar-driven synthesis of fuels and fine chemicals from CO₂ and low-value feedstocks, unifying abiotic and biotic catalysis within a single framework.