CuAg nanoparticle/carbon aerogel for electrochemical CO2 reduction

Abstract

The electrochemical carbon dioxide reduction reaction (eCO₂RR) is a promising technology that uses electrical energy to catalytically reduce greenhouse gas-CO₂, converting CO₂ into high value-added products such as hydrocarbons and alcohols. However, due to the complexity of the eCO₂RR, the activity and selectivity of the eCO₂RR is highly dependent on the intrinsic catalytic activity of a catalyst with mass transportation-favorable morphology. Herein, silk fibroin-derived carbon aerogels (CAs) loaded with small amounts of Cu and Ag nanoparticles were synthesized. Based on the molar content of Cu, the catalysts were labeled SF-CuAg/CA-N (N = 20%, 40%, 60%, 80%). Among them, SF-CuAg/CA-40% showed a good FE_CO of 71% at −1.26 V vs. a reversible hydrogen electrode (RHE), and a significant current density of −15.77 mA cm⁻² towards CO at −1.06 V vs. RHE, which is close to 2.6, 2.53 and 2.71 times those of SF-CuAg/CA-20% (−6.02 mA cm⁻²), SF-CuAg/CA-60% (−6.24 mA cm⁻²) and SF-CuAg/CA-80% (−5.82 mA cm⁻²). The SF-CuAg/CA-N composite materials prepared in this study provide new ideas for the design of highly efficient electrocatalysts for the eCO₂RR.