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 CO2 reduction reaction (CO2RR) because it can facilitate CO2 activation and C-C dimerization. However, the selective electrosynthesis of C2+ 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/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 (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.