A CuOx/Cu/C electrocatalyst-based gas diffusion electrode for the electroreduction of CO2 with high selectivity to C2H4

Abstract

Electrochemical conversion of CO2 (CO2RR) has received significant attention since it could provide pathways for renewable energy storage to energy-dense chemicals and synthetic fuels. We developed a novel CuOx/Cu/C type electrocatalyst via pyrolysis, which we used to convert CO2 at industrially relevantly current densities using gas diffusion electrodes. The influence of the pyrolysis conditions on the electrocatalytic CO2RR activity and selectivity was evaluated. Optimization of the electrode structure to mitigate electrowetting was done by mixing the catalyst with polytetrafluoroethylene (PTFE). We found that mixing the most active catalyst with PTFE in a mass ratio of 1 to 0.25 substantially increased the formation of C2H4 displaying 41% Faradaic efficiency (FE) at –240 mA cm–2. Prolonged CO2RR at different current densities shows that the electrode containing 25 wt.% PTFE in the catalyst layer display FEC2H4> 40% at –280 mA cm–2 for 2 h.