Abstract: A process for the fixation of nitrogen comprising, combining a gaseous nitrogen and oxygen at a total temperature of about 100 atmospheres with a solid oxide which can produce a nitrate, in the presence of a catalyst for the acceleration of a reaction between nitrogen and oxygen to produce nitrogen oxides, initially heating the combination of a temperature of between 600.degree. C. to 800.degree. C. and below the dissociation pressure of the nitrate to start an exothermic reaction for producing nitrogen oxides from the nitrogen and oxygen and for producing nitrate from the solid oxide and to establish an equilibrium between the nitrogen, oxygen, nitrogen oxides, solid oxide and nitrate. The reacting combination in equilibrium is then cooled and either the nitrate or the nitrogen oxides are removed from the reaction as products.