Bimetallic Site Regulation for CO ₂ Photoreduction to C ₂₊ Products

ABSTRACT Photocatalytic CO 2 reduction, driven by solar energy, can convert CO 2 into high‐value carbon‐based products. However, the production of C 2+ products faces key challenges such as the stability of CO 2 molecules, high energy barriers for C–C coupling, and low product selectivity. Inspired by natural bimetallic enzymes, bimetallic sites, with their synergistic electron transfer, site specialization, and spatial regulation effects, can effectively reduce the energy barriers for C─C coupling, promote charge separation, and stabilize key intermediates, becoming a core strategy to enhance the selectivity and yield of C 2+ products. This article systematically reviews the mechanism of bimetallic sites in the photoreduction of CO 2 to C 2+ products. It summarizes the design principles of catalysts from five aspects: support selection, component matching, coordination environment, spatial configuration, and multidimensional synergy. It elucidates the regulation mechanisms of bimetallic sites on light absorption, charge transfer, and product selectivity. Additionally, several typical bimetallic photocatalysts are introduced, such as oxide‐based, sulfide‐based, and MOF/COF‐based. Finally, it points out the current challenges in precise construction, mechanistic characterization, performance enhancement, and industrial application.