Temperature-dependent rate constant for the reaction NNH + O → NH + NO

The rate constant of NNH + O → NH + NO has been derived by comparing experiments in low-pressure (0.05 and 0.103 bar) hydrogen-air flames at ~ 1200 K [1] with modeling that uses an updated detailed H/N/O kinetic scheme. To match calculations with experimental [NO] profiles along these flames, the currently adopted rate constant of this reaction has to be reduced significantly (by 50%). Combination of the adjusted rate constant with measurements in the range 1800 to 2500 K strongly suggests a non-zero activation energy for the reaction. The rate constant derived from 1200 to 2500 K is k1 = (2 ± 1)× 1014 exp (−16.8 ± 4.2 kJ/mol/RT) cm3/mol/s. The sum of the rate constants of every channel of the reaction NH + NO → Products, including that of the reverse Reaction −1 proposed in the present work, is in good agreement with available experimental data.