Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media

► Ammonium cation is the main reaction product in the electroreduction of nitrates regardless of the cathode material. ► Graphite is the most efficient and conductive diamond the least. ► Stainless steel and graphite completely reduce nitrates to ammonium, without significant production of gaseous nitrogen. ► Mediated oxidation process clearly affects the product speciation.