Copper hollow fiber electrode for efficient CO2 electroreduction

Electrocatalytic reduction of CO2 to useful chemicals is a prospective strategy that can address both carbon emission abatement and sustainable energy development. Due to the low solubility and intrinsic inertness of CO2, efficient CO2 conversion remains a challenge in aqueous CO2 electroreduction. Herein we report that a copper hollow fiber of gas-diffusion electrode constructed by a phase-inversion/sintering process enables CO2 reduction to formate maintains considerable faradaic efficiency (80%) at high current density (210 mA∙cm−2), delivering its formate yield about 16 and 30 times those of copper foam and copper foil, respectively. CO2 molecules are forced to penetrate through the porous wall of Cu hollow fiber electrode, resulting in CO2 effective activation and compulsive interaction with active sites, which synergistically facilitates formate formation. This work indicates a positive potentiality of employ a distinct gas-diffusion electrode of hollow fiber to optimize reaction kinetics for efficient and selective electroreduction of CO2 to formate.