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How is ammonia used to make nitric acid in the Ostwald process?

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Difference in molecular structure between ammonia/amines and quaternary ammonium ions — ammonia Ammonia and amines have a slightly flattened trigonal pyramidal shape with a lone pair of electrons above the nitrogen. In quaternary ammonium ions, this area is occupied by a fourth substituent.

The Ostwald process, developed by the German chemist Wilhelm Ostwald in 1901, is the primary industrial method for manufacturing nitric acid from ammonia.1

The process involves the following steps:

Catalytic Oxidation: Ammonia gas is oxidized by air or oxygen in the presence of a platinum gauze catalyst. This reaction converts the ammonia into nitric oxide and subsequently into nitrogen dioxide.1
Absorption: The resulting nitrogen dioxide is absorbed in water to form nitric acid.1
Concentration: The process yields an acid-in-water solution typically containing 50–70 percent acid by weight, which can be further dehydrated through distillation with sulfuric acid.1

This method is essential for the chemical industry, as nitric acid is a critical component in the production of fertilizers and various explosives.21