Micro/Nano‐Structured Superhydrophobic Gas Diffusion Electrode for Boosting the Stability of Industrial‐Compatible Electrochemical CO Production in Flow Cells

Abstract

AbstractElectrochemical flow cells based on gas diffusion electrodes (GDEs) provide a potential means to achieve industrial‐compatible massive CO production. However, the application of flow cells is hindered by the stability issue caused by GDE hydrophilizing and electrolyte flooding. The current strategies have certain limitations in maintaining the long‐term hydrophobicity of GDE. Inspired by the superhydrophobic materials in nature, here a constructionally engineered superhydrophobic GDE is presented for boosting the stability of CO2 reduction to CO in flow cells under industrial‐compatible current densities. This superhydrophobic GDE is comprised of micro/nano‐structured CNTs/graphene composites with abundant and robust single‐atomic Ni‐Nx active sites (NiSA‐CNT@G). The unique integrated hierarchical structure with highly exposed surface area and enhanced mass/charge transfer contributes to an industrial‐scale CO partial current density of 406.5 mA cm−2 with a FECO of 96.3% in a flow cell. Notably, the robust superhydrophobic micro/nanostructure efficiently resists electrolyte flooding over the GDE during the CO2RR, thus maintaining a stable three‐phase interface. Over 70 h stability is demonstrated at an industrial‐compatible current density of 300 mA cm−2. These results open up new opportunities for industrial‐level CO production via electrochemical CO2RR.