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

Use of Cu and Cu+ is one of the most promising approaches for the production of C2 products by the electrocatalytic CO2 reduction reaction (CO2RR) because it can facilitate CO2 activation and CC dimerization. However, the selective electrosynthesis of C2+ products on Cu0Cu+ interfaces is critically limited due to the low electrocatalytic production of ethanol relative to ethylene. In this study, a novel porous Cu/Cu2O aerogel network is introduced to afford high ethanol productivity by the electrocatalytic CO2RR. The aerogel is synthesized by a simple chemical redox reaction of a precursor and a reducing agent. CO2RR results reveal that the Cu/Cu2O aerogel produces ethanol as the major product, exhibiting a Faradaic efficiency (FEEtOH) of 41.2% and a partial current density (JEtOH) 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 Cu0Cu+ interfaces and an increase of the local pH in the confined porous aerogel network structure with a high‐surface‐area. A Cu/Cu2O interconnected porous aerogel network exhibits remarkably high selectivity and productivity in ethanol electrosynthesis from CO2 (41.2% and 32.55mA cm−2 in an H‐cell). This high performance arises from a large population of Cu0Cu+ interfaces in the confined porous structure with a high surface area. This aerogel electrocatalyst is thought to be an appealing model for the commercial electrosynthesis of ethanol from CO2.