On many catalysts and in many experimental conditions, NO3RR proceeds at appreciable rates below 0 V vs the reversible hydrogen electrode (RHE), where HER can also thermodynamically occur. At these electrochemical potentials adsorbed NO 3 -is first reduced to nitrite, NO 2 -. This NO 2 intermediate can desorb from some catalyst surfaces, and depending on electrochemical potential, also reduce . Subsequent reduction to NO is generally understood to proceed via two primary pathways : one where NO desorbs or one where NO stays bound and/or dissociates. We focus on the latter, which yields hydroxylamine, NH2OH, or NH3/NH4 + depending on pH. Against this backdrop, important metrics frequently discussed are the NO3RR Faradaic efficiency (FE):