The electrochemical reduction of nitrate over micro-architectured metal electrodes with stainless steel scaffold

[Display omitted] •Applied potential determines the reaction products of nitrate reduction.•Cu/SS and Pd–Cu/SS electrode exhibited different surface morphologies.•Mechanism of nitrate reduction over Cu/SS electrode was different from that of Pd–Cu/SS electrode.•Pd–Cu/SS electrode enhanced the selectivity of nitrogen generation. Cu and Pd–Cu (Pd=40wt%) electrodes supported on stainless steel (Cu/SS and Pd–Cu/SS) were prepared using electrodeposition methods and characterized by X-ray diffraction, scanning electron microscope, and X-ray photoelectron spectroscopy. The electrocatalytic reduction of nitrate on Cu/SS and Pd–Cu/SS electrodes was studied in sodium perchlorate electrolyte. By tuning the applied potential, nitrate was found to be selectively reduced to different products, indicating a strong dependence of nitrate reduction reaction on the applied potential. Moreover, the effect of electrode material on nitrate reduction was studied also. Results showed that the nitrate reduction over the two electrodes was different due in part to distinct surface morphology. Results demonstrated a novel avenue to improve the selectivity of nitrate reduction products through controlling the applied potential and selection of electrode material. Results also showed strategy warrant further studies on nitrate conversion to harmless nitrogen gas.