Dual electronic regulation by carbon interfaces and oxygen vacancies in Cu2O for selective CO2 electroreduction to ethylene

Electrochemical CO 2 reduction to valuable multi‑carbon fuels offers a compelling route toward carbon neutrality, yet the selective conversion remains challenging because it requires the coordinated regulation of CO 2 activation, key intermediate hydrogenation, C C coupling, and the competing hydrogen evolution reaction. Herein, we propose a dual electronic regulation strategy by coupling graphene-derived carbon interfaces and oxygen vacancies into Cu 2 O to construct a G/Vo-Cu 2 O catalyst for selective CO 2 reduction reaction (CO 2 RR) toward ethylene. Experimental characterizations and theoretical calculations reveal that the carbon interface promotes interfacial charge transfer, enhances CO 2 adsorption/activation, improves reaction kinetics, and suppresses excessive hydrogen evolution, while oxygen vacancies create localized electron-rich centers that facilitate *CO hydrogenation toward the key *CHO intermediate. Benefiting from this complementary regulation, G/Vo-Cu 2 O balances the formation and stabilization of *CO and *CHO intermediates, thereby favoring the thermodynamically downhill *CO *CHO coupling pathway over conventional *CO *CO or *CHO *CHO dimerization. In situ Fourier-transform infrared spectroscopy further confirms the enhanced generation of *CHO and *COCHO intermediates during CO 2 RR. As a result, the optimized G/Vo-Cu 2 O catalyst achieves a C 2 H 4 Faradaic efficiency of 62.4 ± 4.4% at −1.2 V versus reversible hydrogen electrode, accompanied by suppressed H 2 and CO formation. This work highlights the importance of interface-defect dual electronic regulation in steering CO 2 RR selectivity and provides mechanistic insights for designing Cu-based catalysts toward efficient C 2+ production. Download: Download high-res image (125KB) Download: Download full-size image