Organic-Molecular Modification Strategy on the Local Microenvironment and Catalysts for CO ₂ Electroreduction to C ₂₊

The electrocatalytic CO 2 reduction reaction, which converts excess CO 2 into high-value multi-carbon (C 2+ ) products using renewable energy, is critical for carbon cycling and mitigating energy-environmental issues. Cu-based catalysts, to date, are still the sole monometallic systems capable of generating C 2+ products at appreciable rates, yet their activity and selectivity toward ethylene still demand enhancement. Organic molecular modification strategies, via a “molecular regulation layer”, enable precise regulation of reaction interfaces’ microenvironment, active sites’ electronic structure, and intermediate adsorption, though underlying mechanisms are unclear. To further guide catalyst design, this review synthesizes recent advances in organic molecular modification strategy in electrocatalytic (ECO 2 RR)-to-ethylene (C 2 H 4 ), covering reaction pathways and five key strategies: hydrophilicity and hydrophobicity regulation, structural adjustment, local microenvironment modulation, intermediate adsorption enhancement, and driving tandem reaction via constructing reaction microdomains. Furthermore, current research challenges and prospects are analysed, with the aim of providing critical insights to guide future catalyst development.