Electrochemical oxidation of molecular nitrogen to nitric acid - towards a molecular level understanding of the challenges.

Nitric acid is manufactured by oxidizing ammonia where the ammonia comes from an energy demanding and non-eco-friendly, Haber-Bosch process. Electrochemical oxidation of N to nitric acid using renewable electricity could be a promising alternative to bypass the ammonia route. In this work, we discuss the plausible reaction mechanisms of electrochemical N oxidation (NOR) at the molecular level and its competition with the parasitic oxygen evolution reaction (OER). We suggest the design strategies for N oxidation electro-catalysts by first comparing the performance of two catalysts - TiO(110) (poor OER catalyst) and IrO(110) (good OER catalyst), towards dinitrogen oxidation and then establish trends/scaling relations to correlate OER and NOR activities. The challenges associated with electrochemical NOR are highlighted.