PEM Electrolysis‐Assisted Catalysis Combined with Photocatalytic Oxidation towards Complete Abatement of Nitrogen‐Containing Contaminants in Water

Electrolysis‐assisted nitrate (NO(3) (−)) reduction is a promising approach for its conversion to harmless N(2) from waste, ground, and drinking water due to the possible process simplicity by in‐situ generation of H(2)/H/H(+) by water electrolysis and to the flexibility given by tunable redox potential of electrodes. This work explores the use of a polymer electrolyte membrane (PEM) electrochemical cell for electrolysis‐assisted nitrate reduction using SnO(2)‐supported metals as the active cathode catalysts. Effects of operation modes and catalyst materials on nitrate conversion and product selectivity were studied. The major challenge of product selectivity, namely complete suppression of nitrite (NO(2) (−)) and ammonium (NH(4) (+)) ion formation, was tackled by combining with simultaneous photocatalytic oxidation to drive the overall reaction towards N(2) formation.