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

Abstract

Gas diffusion electrodes (GDEs) show great potential to improve the current densities of the industrial electrochemical carbon dioxide reduction reaction (eCO₂RR). 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 eCO₂RR with improved stability for potential industrial applications.