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/Cu 2 In interfaces as efficient catalysts for electrochemical carbon dioxide reduction reaction (CO 2 RR). As a result, Cu–In MAs with the highest Cu/Cu 2 In interfaces abundance (Cu 2 In MAs) achieve the high Faradaic efficiency of CO up to 94.5% at −0.6 V vs reversible hydrogen electrode (RHE), outperforming Cu 1 In MAs, Cu 3 In MAs, Cu 4 In MAs, and Cu MAs. Furthermore, Cu 2 In MAs with the highest Cu/Cu 2 In interface abundance also exhibit excellent stability after continuous electrolysis for 10 h. Mechanism research indicates that the rich Cu/Cu 2 In interfaces in Cu 2 In MAs allow for moderate adsorption of CO 2 and accelerate electronic transmission, which greatly reduce the energy barrier of the potential-limiting step, thus improving the CO 2 RR performance. This study indicates that interface engineering plays an important role in improving the CO 2 RR performance, providing a new strategy for preparing efficient CO 2 RR catalysts.