We first introduce potential-dependent NO3RR FE and ammonium selectivity data for Cu and Ni foils (Figure ), expanding to include the role of alloying in this system (Figure ) and additional monometallic TMs (Figures and). Cu demonstrates appreciable (>70%) NO3RR FE at potentials prior to the onset of water-dissociative HER (>-0.6 V vs RHE; Figure ).