The NiNC-IMI catalysts were cast into cathode layers of varying catalyst loadings, which were deployed into zero-gap AEM electrolyzer cells. Operated under neutral-pH anolyte conditions, the NiNC-IMI CO2-to-CO electrolyzer design outperformed state-of-art Ag and previously reported NiNC cathodes. Under optimized catalyst loading and layer thickness, the experimental faradaic CO efficiency, FEco, reached 100% up to a current density of -200 mA cm -2 (Ecell ~ 3 V) and remained at 85% at -300 mA cm -2 (Ecell = 3.5 V). Beyond these popular performance metrics, we rigorously defined and experimentally considered a number of additional kinetic cell performance indicators, such as single pass conversion, SP, stoichiometric CO2 excess,  stoich , and total energy efficiency, EE.