Enhancement Mechanism of CO ₂ RR toward Ethanol on Cu-CoPc/CNT Electrocatalysts: Dual-Site Synergetic C–C Coupling

The electrochemical reduction of CO 2 to high-value C 2 products, especially ethanol, presents a feasible approach for alleviating greenhouse gas emissions and tackling climate-related challenges. Nevertheless, the rational design of efficient electrocatalysts is still restricted by insufficient activity, suboptimal selectivity, and a limited understanding of the underlying mechanisms. In this study, a hierarchically structured Cu-CoPc/CNT catalyst was fabricated by electrochemical deposition and drop-casting techniques. Comprehensive characterization (BET/SEM/XRD/EDS/XPS) confirmed its electronic configuration and surface properties. Electrochemical evaluations (CV/LSV/EIS/GC/ 1 H NMR) demonstrated an ethanol Faradaic efficiency of 42.3% at a partial current density of 10.65 mA·cm –2, with exceptional ethanol selectivity of 98.6% among C 2 products at −1.15 V vs RHE. In conjunction with density functional theory (DFT) calculations, mechanistic investigations have demonstrated that an adequate supply of those intermediates such *COOH and the facilitation of the C–C coupling are the primary factors contributing to the performance improvement of the CO 2 RR toward ethanol through the synergistic effect between CoPc/CNT and Cu. This research proposes a novel strategy for designing efficient and stable CO 2 -to-ethanol catalysts, thereby deepening the fundamental understanding of the ethanol formation mechanisms.