Abstract
The product branching ratio of NH2 + NO → NNH + OH and NH2 + NO → N2 + H2O has been determined in the temperature range 1826-2159 K in a shock tube study. The pressure range behind reflected shock waves was 1.10 to 1.21 bar. The time history of the NH2 radical was measured using a frequency modulation absorption technique. The initial gas mixture compositions were 8-28 ppm monomethylamine (CH3NH2), 0.4-1.2% ammonia (NH3), and 0.4% NO, and the balance Ar. According to sensitivity analysis using a detailed 125-reaction mechanism, the NH2 profiles are mainly sensitive to the branching ratio α = k1a/(k1a + k1b) under the experimental conditions of this study, and they exhibit only a small sensitivity to secondary reactions and the overall rate coefficient, k1 = k1a + k1b. The branching ratio increases from 0.59 ± 0.02 at 1826 K to 0.66 ± 0.04 at 2159 K. These results are consistent with our earlier measurements of the branching ratio at lower temperature and agree with the theoretical result of Miller and Klippenstein.
Original language | English |
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Pages (from-to) | 9233-9235 |
Number of pages | 3 |
Journal | Journal of Physical Chemistry A |
Volume | 106 |
Issue number | 40 |
DOIs | |
Publication status | Published - 2002 Oct 10 |
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry