Conducting Polymer Transforms Hydrophobic Porous Membranes into Robust Gas Diffusion Layers in Electrochemical Applications

The increasing demand for sustainable chemical production due to strict regulations for carbon emission aligns with growing availability of solar and wind energy, making electrochemical manufacturing a viable route toward decarbonized chemical syntheses. Electrodes with gas diffusion layers (GDLs) critically enhance reaction efficiency for continuous-flow electrochemical reactors with liquid electrolytes fed with gaseous reactants, but they currently suffer from challenges like electrolyte flooding and poor long-term stability. Porous polytetrafluoroethylene (PTFE) membrane-based GDLs overcome some of these issues, but they require additional functionality to enable conductivity. Herein, we demonstrate a novel GDL structure, introducing a porous conductive polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), onto a porous PTFE membrane. Compared to a carbon-based GDL, the PEDOT-coated PTFE GDL exhibited similar electrochemical performance with enhanced stability under industrially relevant conditions for the CO2 reduction reaction. PEDOT-coated PTFE GDL demonstrates remarkable resistance to electrolyte flooding, making it a promising candidate for various gas-fed electrocatalytic reactions.