After optimizing the reaction conditions as 100 mA/cm 2 and 25 mM cyclohexanone, we next monitored the temporal changes in the concentrations of the reactants and products by analyzing reaction aliquots every 30 mins over 2.5 h of electrolysis. As shown in Figure , oxime was produced with 97±2% yield and the ketone reactant was almost fully converted after 2.5 h (conversion ~ 98%), which is consistent with the recorded 1 H-NMR spectrum. These results also demonstrated a high carbon selectivity which is close to 100%, while the nitrogen selectivity was investigated by monitoring the relative amounts of all nitrogen compounds over the 2.5 h electrolysis (Figure ). The NO3 -reactant was first converted into NO2 -, which achieved a maximum yield of ca. 45% after 1 h, indicating that NO2 -is a reaction intermediate, in line with previous reports. After 2.5 h of electrolysis, ca. 3% NO3 -and 15% NO2 - remained in solution, while cyclohexanone oxime and NH3 were the main species produced in ca. 24% and 40% yields, respectively. Under these conditions, N2 was generated as byproduct (~15%), which is consistent with previous NO3R studies driven by Zn-rich electrocatalysts. Importantly, the morphology of the Zn93Cu7 electrocatalyst remained stable after three tests of 2.5 h electrolysis (Figure ), and the electrocatalyst could be reused to produce cyclohexanone oxime with similar yields compared to the initial test (Figure ).