The electroreduction of CO₂ into value-added products (e.g. CO) constitutes an excellent means of decreasing this greenhouse gas emissions, but limited efforts have been devoted to the implementation of this reaction within the socalled co-electrolysis cells operating at process-relevant currents >> 100 mA·cm^-2_geom. Reaching such performances shall require a combination of gas-fed reactants and the corresponding diffusion electrodes, along with ion-exchange membranes and ionomers that set the operative pH at the cells' cathode and anode. The latter constitutes a key design parameter that must be combined with the need to minimize the crossover of reaction products and/or (bi)carbonate anions from the cathode to the anode, whereby their reoxidation to carbon dioxide leads to a decrease in the device’s net CO₂ consumption.