Cu/Cu2O Interconnected Porous Aerogel Catalyst for Highly Productive Electrosynthesis of Ethanol from CO2

Abstract Use of Cu and Cu + is one of the most promising approaches for the production of C 2 products by the electrocatalytic CO 2 reduction reaction (CO 2 RR) because it can facilitate CO 2 activation and CC dimerization. However, the selective electrosynthesis of C 2+ products on Cu 0 Cu + interfaces is critically limited due to the low electrocatalytic production of ethanol relative to ethylene. In this study, a novel porous Cu/Cu 2 O aerogel network is introduced to afford high ethanol productivity by the electrocatalytic CO 2 RR. The aerogel is synthesized by a simple chemical redox reaction of a precursor and a reducing agent. CO 2 RR results reveal that the Cu/Cu 2 O aerogel produces ethanol as the major product, exhibiting a Faradaic efficiency (FE EtOH ) of 41.2% and a partial current density ( J EtOH ) of 32.55 mA cm −2 in an H‐cell reactor. This is the best electrosynthesis performance for ethanol production reported thus far. Electron microscopy and electrochemical analysis results reveal that this dramatic increase in the electrosynthesis performance for ethanol can be attributed to a large number of Cu 0 Cu + interfaces and an increase of the local pH in the confined porous aerogel network structure with a high‐surface‐area.