CO2 electroreduction towards ethylene on copper phosphate-derived catalysts in alkaline flow cell†

Abstract

CO₂ electroreduction into valuable hydrocarbons with high selectivity is of high market interest yet challenging. Cu-based catalysts have a unique catalytic activity toward hydrocarbon products in the CO₂ electroreduction reaction. They are widely studied to promote the corresponding selectivity and activity. The control of the oxidation state of the catalyst is essential in driving the reaction toward the desired hydrocarbon. Herein, we steer CO₂ electroreduction toward ethylene production with high selectivity in an alkaline flow cell configuration from a copper phosphate catalyst. An optimum faradaic efficiency of 55% for ethylene was obtained in a 7 M KOH electrolyte at a total current density of 150 mA cm⁻². The investigation of the mechanism shows that Cu nanoparticles are derived during electrolysis, which may favour the dimerisation of *CO to ethylene formation. This work provides new insights into designing catalysts for high-selectivity hydrocarbon formation.