While several studies have operated at elevated current densities using membrane electrode assemblies or neutral-pH catholytes such as KCl and bicarbonate-based salts, a larger number of gas-diffusion layer experiments have used KOH directly as a bulk catholyte, with much of the original CO2 reduction research pioneered by the Kenis Group. By using an alkaline catholyte directly, the impact of a higher pH environment on catalyst performance can be probed across both low and high current densities. In a 1 M KOH environment, CO2 reduction products have been observed on Cu, Au and Ag catalysts at earlier overall onset potentials than in neutral conditions, with current densities of >100 mA/cm 2 having been reached for CO, C2H4 and ethanol at more anodic potentials than -0.6 V vs. RHE and with <10% H2 selectivities. These experiments, however, do not pay the same overpotential price associated with the large local pH swing from neutral to alkaline conditions, which are not taken into account when cathode potential are reported versus a reversible hydrogen electrode (RHE). Additionally, the interaction between unreacted CO2 and hydroxide is problematic for overall stability, as described in the following section. Using an alkaline electrolyte for testing and characterizing catalyst performance is however a promising means of mimicking the local environment of high current densities while being able to measure catalytic activity even at lower current densities.