Antiflooding Gas Diffusion Electrodes Enabled by Liquid-Solid-Liquid Interfaces for Durable CO2 Electrolysis

Gas diffusion electrodes (GDEs) show great potential to improve the current densities of the industrial electrochemical carbon dioxide reduction reaction (eCO(2)RR). The triple-phase boundary (TPB) in GDEs is the key for promoted reaction kinetics, yet such a reaction interface typically suffers from rapid degradation due to electrolyte flooding and salt precipitation. Herein, we demonstrate that a GDE modified with liquid perfluorocarbon (PFC) would notably prolong the lifespan of the GDE with a Bi catalyst in flow-cell electrolyzers. PFC with superhydrophobicity and high CO2 solubility would construct a liquid-solid-liquid reaction interface that prevents the intrusion of electrolytes into the microporous layer (MPL) without hampering the mass transport of CO2. Our work demonstrates an effective strategy to construct a robust and efficient electrochemical reaction interface for the eCO(2)RR with improved stability for potential industrial applications.