Paramelaconite‐Enriched Copper‐Based Material as an Efficient and Robust Catalyst for Electrochemical Carbon Dioxide Reduction

A copper-oxide-based catalyst enriched with paramelaconite (Cu4O3) is presented and investigated as an electrocatalyst for facilitating electroreduction of CO2 to ethylene and other hydrocarbons. Cu4O3 is a member of the copper-oxide family and possesses an intriguing mixed-valance nature, incorporating an equal number of Cu+ and Cu2+ ions in its crystal structure. The material is synthesized using a solvothermal synthesis route and its structure is confirmed via powder X-ray diffraction, transmission electron microscope based selected area electron diffraction, and X-ray photoelectron spectroscopy. A flow reactor equipped with a gas diffusion electrode is utilized to test a copper-based catalyst enriched with the Cu4O3 phase under CO2 reduction conditions. The Cu4O3-rich catalyst (PrC) shows a Faradaic efficiency for ethylene over 40% at 400 mA cm(-2). At -0.64 versus reversible hydrogen electrode, the highest C2+/C-1 product ratio of 4.8 is achieved, with C2+ Faradaic efficiency over 61%. Additionally, the catalyst exhibits a stable performance for 24 h at a constant current density of 200 mA cm(-2).