Interface-Engineered Cu/Cu₂In Metallic Aerogels for Efficient Electrochemical CO₂ Reduction

Interface engineering has been widely explored due to its potential for regulating the intermediate adsorption, controlling mass/electron transfer, and preventing severe aggregation of catalysts. Hence, we have synthesized a series of Cu-In metallic aerogels (MAs) with a controlled ratio of Cu/Cu2In interfaces as efficient catalysts for electrochemical carbon dioxide reduction reaction (CO2RR). As a result, Cu-In MAs with the highest Cu/Cu2In interfaces abundance (Cu2In MAs) achieve the high Faradaic efficiency of CO up to 94.5% at -0.6 V vs reversible hydrogen electrode (RHE), outperforming Cu1In MAs, Cu3In MAs, Cu4In MAs, and Cu MAs. Furthermore, Cu2In MAs with the highest Cu/Cu2In interface abundance also exhibit excellent stability after continuous electrolysis for 10 h. Mechanism research indicates that the rich Cu/Cu2In interfaces in Cu2In MAs allow for moderate adsorption of CO2 and accelerate electronic transmission, which greatly reduce the energy barrier of the potential-limiting step, thus improving the CO2RR performance. This study indicates that interface engineering plays an important role in improving the CO2RR performance, providing a new strategy for preparing efficient CO2RR catalysts.