Electrocatalytic CO2 Reduction to C2 Products via Enhanced C─C Coupling Over Cu‐based Catalysts: Dynamic Reaction and Regulation Mechanism

Benefiting from the optimal interaction strength between Cu and reactants, Cu-based catalysts exhibit a unique capability of facilitating the formation of various multi-carbon products in electricity-driven CO₂ reduction reactions (CO₂ERR). Nonetheless, the CO₂ERR process on these catalysts is characterized by intricate polyproton-electron transfer mechanisms that are frequently hindered by high energy barriers, sluggish reaction kinetics, and low C─C coupling efficiency. This review employs advanced characterization techniques, such as sum frequency generation technology, to provide a comprehensive analysis of the CO₂ERR mechanism on the Cu surface, examining it from both spatial and temporal dimensions and proposing a spatial-temporal coupling reaction mechanism. To improve C─C coupling efficiency, a series of regulatory strategies are focused on surface microenvironment, catalyst surface structure, and internal electronic structure, thereby offering novel insights for the upcoming design and enhancement of Cu-based electrocatalysts.