Oxidation of ammonia in shock waves

Abstract

The oxidation of ammonia in shock waves has been studied in the temperature range 2000–3000°K by following the appearance of OH and NH and the loss of NH₃ spectrophotometrically. NH is shown to be unimportant in the oxidation and arises from the high-temperature decomposition of ammonia. The induction times for the appearance of OH and loss of NH₃ are approximately identical. The following mechanism appears to explain the main features of the oxidation reaction : a non-branching chain sequence OH + NH₃→ NH₂+ H₂O, NH₂+ O₂→ HNO + OH, with branching caused by the subsequent reaction of HNO, HNO → H + NO, HNO + O₂→[NO + HO₂]→ H + O₂+ NO.