Nitric acid is a key starting material for the production of fertilisers, helping to boost arability and yield of farmland.

Nitric acid is mainly produced through the Ostwald process in which a mixture of air and ammonia is passed over a heated platinum or rhodium gauze which can stand the high temperatures necessary. The catalytic properties of these PGMs oxidise the ammonia into nitrogen dioxide which is absorbed into water to produce nitric acid.

Ammonia itself is produced in the Kellogg Advanced Ammonia Process (KAAP) which uses ruthenium as a catalyst to synthesise it from natural gas.