The restricted oxidation of NH3 can be done with air, when the mixture is passed over heated platinum gauze at 700∘C to 800∘C. 4NH3+5O2→4NO+6H2O+Calories21,600 2NO+O2→2NO2 3NO2+H2O→2HNO3+NO
This is the Ostwald’s process used for manufacture of HNO3