To further understand the interaction of NH2OH with the electrocatalyst surface, the electroreduction of NH2OH to NH3 was investigated on pure Zn, Zn93Cu7, and pure Cu (Figure ). Experiments with pure Cu led to a significantly higher FE for NH3 and a lower potential compared to pure Zn and Zn93Cu7, demonstrating that the electroreduction of NH2OH to NH3 is much more favorable on the Cu surface compared to Zn. The central role of NH2OH in the production of oxime was further confirmed by mixing cyclohexanone and NH2OH in solution without electrolysis, which readily produced cyclohexanone oxime with 98% yield after only 5 min (Figure ). The fast kinetics and favorable thermodynamics of this non-catalytic additionelimination reaction ensures effective C-N bond formation. Given that NH2OH is the most nucleophilic species among all the proposed NO3R intermediates, and the widely known nucleophilic addition of NH2OH to ketones, we concluded that NH2OH is the NO3R intermediate that reacts with cyclohexanone to generate oxime. These results collectively support hypothesis 2 that, on Zn-rich electrocatalysts, the electrochemically generated NH2OH tends to undergo a subsequent chemical reaction with cyclohexanone to produce oxime rather than being further reduced to NH3. Further insights were obtained by analyzing the surface-adsorbed species during electrochemical NO3R at different potentials by in-situ Raman spectroscopy (Figure ). Experiments with pure Zn showed a single Raman peak at 1045 cm -1 , which was attributed to the NO3 -in solution (control experiment with an aqueous KNO3 solution in absence of electrocatalyst also showed the peak at 1045 cm -1 ). On the other hand, for Zn93Cu7, a small peak at 865 cm -1 was observed at -0.5 VRHE, which gradually grew as the potential increased to -0.8 VRHE before disappearing at -1.1 VRHE. This peak can be attributed to the N-O stretch mode of surface-adsorbed *NH2OH intermediate, providing direct experimental evidence for this species on the Zn93Cu7 surface. This observation also confirms hypothesis 2 that Zn93Cu7 can generate *NH2OH intermediate which plays a central role in the reaction. In contrast, the pure Cu electrocatalyst exhibited two peaks at 1005 cm -1 and 1385 cm -1 corresponding to adsorbed *NO3 -species, which grew with the potential increasing to -0.3 VRHE and then disappeared at more negative potentials. The absence of the *NH2OH peak on pure Cu can be explained by the favoured further reduction of *NH2OH into NH3 on Cu. Overall, these observations on pure Cu and the absence of any adsorbed species on pure Zn collectively support hypothesis 1 that Cu provides a stronger binding for NO3 -compared to Zn, which is beneficial for electrochemical NO3R.