Mechanistic Insights for Selective CO2 Electrolysis to Multicarbon Products

ABSTRACT Electrocatalytic CO ₂ reduction reaction utilizes renewable energy to convert CO ₂ into fuels and chemicals with low carbon footprint, standing as a promising technology for addressing climate change, energy decarbonization, and industrial revolution. However, the multielectron reduction steps typically involve complicated reaction pathways and competing key intermediates, resulting in the electrosynthesis of highly valuable multicarbon products inferior to the single carbon counterparts. In this contribution, state‐of‐the‐art progress regarding multicarbon production from a micro‐mechanism viewpoint is comprehensively overviewed, starting from fundamental reaction pathways to underline C─C coupling and route branching in regulating product distribution. Subsequently, the promotional approaches for the dimerization of carbonaceous monomers are thoroughly discussed from the thermodynamic and kinetic perspectives, and strategies for regulating the bond evolution of dimer intermediates are elucidated. Finally, challenges and innovative opportunities in theoretical exploration, dynamic service, and industrial scaling‐up are identified, delineating a viable roadmap for refining the artificial carbon cycle.