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 N2 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 N2 oxidation (N2OR) at the molecular level and its competition with the parasitic oxygen evolution reaction (OER).

We suggest the design strategies for N2 oxidation electro-catalysts by first comparing the performance of two catalysts - TiO2(110) (poor OER catalyst) and IrO2(110) (good OER catalyst), towards dinitrogen oxidation and then establish trends/scaling relations to correlate OER and N2OR activities. The challenges associated with electrochemical N2OR are highlighted.