Reducing the onset potential of CO2 electroreduction on CuRu bimetallic particles

Lower onset potentials for hydrocarbon products were observed during the electrochemical reduction of carbon dioxide (CO2RR) on copper particles (40-60 nm) coated with a thin layer of ruthenium via galvanic displacement, referred to as Ru@Cu. Hydrocarbons detected include ethane, ethylene, acetate, ethanol, propanol and CO. In the case of ethane (C2H6), the onset potential is 200 mV lower on Ru@Cu than on bare Cu particles. Increasing Ru coverage decreases the CO2RR activity while hydrogen evolution (HER) activity increased substantially. An optimum Ru coverage was found when the displacement was performed for 10 s. The results presented here highlight the importance of surface chemistry in determining reaction selectivity.