From existing knowledge about CO2 reduction, we can infer that the thermodynamics and kinetics of reactions on a catalytic surface will be impacted by testing under these elevated reaction conditions. Further modelling and direct-measurement experimental studies of the local electrolyte environment are of course warranted, however, to even better understand how various factors may influence the reaction (e.g. 2D/3D effects, morphology, partial pressure of CO2 in the gas-diffusion layer, etc.). A more detailed representation of CO2 diffusion through a porous electrode structure, for instance, may provide further insight but requires consideration of pore sizes, structures and additives, which are catalyst-specific and beyond the scope of this article. These studies are particularly needed for zero-gap membrane electrode assemblies where the extremely-low catholyte volume is expected to make the local reaction conditions more sensitive to the specific device configuration and the properties of the ion-exchange membrane.