Ionomer tuning in catalyst layers boosts current density while maintaining high selectivity in CO-to-methanol electroreduction using gas-diffusion electrodes.

Tuning the ionomer content in the catalyst layers of gas-diffusion electrodes (GDEs) for CO electroreduction controls wettability and enhances CO accessibility. This approach boosts methanol partial current densities exceeding 30 mA cm-2 while maintaining faradaic efficiencies close to 90%, providing a mechanistic basis for improving electrolysis performance using GDEs.