Efficient electroreduction of CO2 to CO on silver single-atom catalysts: Activity enhancement through coordinated modulation of polyaniline

The electrochemical reduction of CO 2 to CO is considered to be one of the most mature routes that could be commercialized for efficient utilization of large amount of CO 2 . Silver (Ag) has shown high selectivity towards CO but usually requires high reduction potential. Herein, a novel Ag single atom-polyaniline (PANI) is constructed directly on gas diffusion electrode (GDE). The amino group with strong electron-donating ability in PANI can effectively promote the adsorption and activation of CO 2 . In addition, the adsorption of *COOH is significantly enhanced on N-coordinated Ag. The proposed catalyst electrode shows an outstanding performance with the Faraday efficiency of CO close to 100% at −0.75 V (vs. RHE), the energy efficiency is 12.8% and the output of CO is 108.7 mL cm −2 h −1 , which exceeds most state-in-art Ag-based catalysts, highlighting the importance for the rational design and controllable fabrication of active sites and their favorable chemical environments.