Copper Electrode Fabricated via Pulse Electrodeposition: Toward High Methane Selectivity and Activity for CO2 Electroreduction

Abstract

Electrochemical reduction of CO2 (ERC) to methane has significant economic benefits and represents one promising solution for energy and environmental sustainability. However, traditional metal electrodes suffer from higher overpotentials, low activities, and poor selectivity. In this article, the pulse electrodeposition (P-ED) method is employed to prepare a copper electrode for ERC. The P-ED method can easily create Cu coatings on carbon paper with a much rougher surface and extended surface area, which is highly beneficial for improving their activity and selectivity. As a result, the prepared Cu electrodes exhibit high faradaic efficiency (of 85% at −2.8 V) and enhanced partial current density (jCH4 = 38 mA cm–2) for methane, which is by far the highest value ever reported at room temperature and ambient pressure. The enhanced activity is attributed to the extended reactive areas with rough morphology and loosened coating structure to ensure CO2 access the reaction sites located at the sublayers of th...