Achieving High Single‐Pass Carbon Conversion Efficiencies in Durable CO<sub>2</sub> Electroreduction in Strong Acids via Electrode Structure Engineering
Le Li, Zhaoyang Liu, Xiaohan Yu, Miao Zhong
Abstract
Abstract Acidic CO 2 reduction (CO 2 R) holds promise for the synthesis of low‐carbon‐footprint chemicals using renewable electricity. However, the corrosion of catalysts in strong acids causes severe hydrogen evolution and rapid deterioration of CO 2 R performance. Here, by coating catalysts with an electrically nonconductive nanoporous SiC‐Nafion TM layer, a near‐neutral pH was stabilized on catalyst surfaces, thereby protecting the catalysts against corrosion for durable CO 2 R in strong acids. Electrode microstructures played a critical role in regulating ion diffusion and stabilizing electrohydrodynamic flows near catalyst surfaces. This surface‐coating strategy was applied to three catalysts, SnBi, Ag, and Cu, and they exhibited high activity over extended CO 2 R operation in strong acids. Using a stratified SiC‐Nafion TM /SnBi/polytetrafluoroethylene (PTFE) electrode, constant production of formic acid was achieved with a single‐pass carbon efficiency of >75 % and Faradaic efficiency of >90 % at 100 mA cm −2 over 125 h at pH 1.