Gas diffusion electrodes and membranes for CO2 reduction electrolysers

The CO2 reduction reaction (CO2RR) is a potential means of using renewable electricity to synthesize commodity chemicals and fuels. The CO2RR can be performed at industrially relevant product formation rates in an electrolyser, which must simultaneously manage the transport of electrons, water, CO2 and protons at a cathode. Gas diffusion electrodes (GDEs) and polymer electrolyte membranes are used to mediate these critical processes. Consequently, the design and development of GDEs and membranes tailored for the CO2RR is critical. In this Review, we discuss how the properties of GDEs and polymer electrolyte membranes affect CO2RR electrolysis.