4N{{H}_{3}}+5{{O}_{2}}\underset{1100K}{\mathop{\xrightarrow{PT\,\,GUAGE}}}\,4NO\xrightarrow{{{O}_{2}}}4N{{O}_{2}}\] \[\xrightarrow{2{{H}_{2}}O+{{O}_{2}}}4HN{{O}_{3}}\]