CO2 electroreduction to ethylene via hydroxide-mediated copper catalysis at an abrupt interface

Carbon dioxide (CO2) electroreduction could provide a useful source of ethylene, but low conversion efficiency, low production rates, and low catalyst stability limit current systems. Here we report that a copper electrocatalyst at an abrupt reaction interface in an alkaline electrolyte reduces CO2 to ethylene with 70% faradaic efficiency at a potential of –0.55 volts versus a reversible hydrogen electrode (RHE). Hydroxide ions on or near the copper surface lower the CO2 reduction and carbon monoxide (CO)–CO coupling activation energy barriers; as a result, onset of ethylene evolution at –0.165 volts versus an RHE in 10 molar potassium hydroxide occurs almost simultaneously with CO production. Operational stability was enhanced via the introduction of a polymer-based gas diffusion layer that sandwiches the reaction interface between separate hydrophobic and conductive supports, providing constant ethylene selectivity for an initial 150 operating hours.

Source: ScienceNOW - May 17, 2018 Category: Science Authors: Dinh, C.-T., Burdyny, T., Kibria, M. G., Seifitokaldani, A., Gabardo, C. M., Garcia de Arquer, F. P., Kiani, A., Edwards, J. P., De Luna, P., Bushuyev, O. S., Zou, C., Quintero-Bermudez, R., Pang, Y., Sinton, D., Sargent, E. H. Tags: Chemistry reports Source Type: news