Unveiling Asymmetric Dual-Metal Interfaces for Solar-Driven CO 2 -to-CH 4 Reduction Coupled with C–H Activation

Solar-driven conversion of CO₂ and biomass-derived alcohols offers a promising strategy for mitigating CO₂ emissions and providing value-added chemicals. However, due to complex reaction pathways and sluggish C-H bond activation, it remains challenging to attain efficient photocatalytic CO₂ reduction to CH₄ alongside the valorization of biomass-derived alcohols. Herein, we report a judicious design to construct asymmetric dual-metal catalytic centers via anchoring semiconductor nanoclusters in vacancy-rich MOFs, achieving tandem CO₂-to-CH₄ photoreduction with C-H oxidation. Through loading Fe₂O₃ clusters in O-vacancy-rich Mil-125(Ti)-NH₂, interfacial O-vacancy renders a newly formed Fe-O bond as an atomic-level electron transfer pathway toward Z-scheme construction. Furthermore, the interfacial vacancies trigger intimate interactions and modulate the d-band center to form asymmetric Ti-Fe dual-metal sites. Remarkably, a superior selectivity of 87.0% toward CH₄ production coupled with 100% selectivity for benzyl alcohol-to-benzaldehyde oxidation is realized. Mechanistic investigations reveal that the heteronuclear Ti-Fe units synergistically facilitate the hydrogenation of *CO to *CHO through d-p hybridization, thereby enabling CH₄ synthesis to be thermodynamically favorable, while photogenerated holes from Fe₂O₃ preferentially oxidize the α-C-H bond of benzyl alcohol. Further supported via another MOFs-based catalyst, this work enlightens a general design of building asymmetric dual-metal interfaces to concurrently realize selective CO₂ photomethanation coupled with C-H activation.