A shock tube study of the NH 2+NO 2 reaction

Abstract

The overall rate coefficient and the branching ratio of the NH 2 +NO 2 reaction were determined inshock tube experiments. Benzylamine (C 6 H 5 CH 2 NH 2 ) was used as a thermal source of the NH 2 radical. To obtain the overall rate coefficient, the NH 2 mole fraction was measured using frequency-modulation absorption spectroscopy. For the branching ratio deterrnination, the IR emission from N 2 O was mornitored. During the N 2 O emission experiments, the NO 2 mole fraction was measured simultaneously using a tunable diode laser. The mesured species profiles were interpreted using a detailed 118-reaction mechanism, which was based on the reaction mechanism from our previous study of the NH 2 +NO reaction with added reactions involving N 2 O and NO 2 . The overall rate coefficient is (5.5±0.8)×10 12 cm 3 mol −1 s −1 in the temperature range, 1330–1527 K, and pressure range 1.31–1.49 bar. This value is 1.6 times the result of Glarborg et al. and 2.5 times that extrapolated from the expression reported by Park and Lin. The measured branching ratio for the N 2 O+H 2 O product channel of the NH 2 +NO 2 reaction was 0.17±0.04 for the temperature range 1319–1493 K, which is consistent with the results of Park and Lin and Quandt and Hershberger at lower temperatures.