Efficient electrocatalytic CO2 reduction to ethylene using cuprous oxide derivatives

Copper-based materials play a vital role in the electrochemical transformation of CO 2 into C 2 /C 2+ compounds. In this study, cross-sectional octahedral Cu 2 O microcrystals were prepared in situ on carbon paper electrodes via electrochemical deposition. The morphology and integrity of the exposed crystal surface (111) were meticulously controlled by adjusting the deposition potential, time, and temperature. These cross-sectional octahedral Cu 2 O microcrystals exhibited high electrocatalytic activity for ethylene (C 2 H 4 ) production through CO 2 reduction. In a 0.1 M KHCO 3 electrolyte, the Faradaic efficiency for C 2 H 4 reached 42.0% at a potential of −1.376 V vs. RHE. During continuous electrolysis over 10 h, the FE (C 2 H 4 ) remained stable around 40%. During electrolysis, the fully exposed (111) crystal faces of Cu 2 O microcrystals are reduced to Cu 0 , which enhances C-C coupling and could serve as the main active sites for catalyzing the conversion of CO 2 to C 2 H 4 .