The rate coefficient of the reaction NH2 + NO → products (R1) was determined in shock tube experiments using frequency modulation absorption spectroscopy for detection of NH2. Due to the sensitivity of the diagnostic system, very low reactant concentrations could be employed to reduce the influence of secondary reactions on the NH2 profiles. The source of the NH2 radicals in the experiments was the thermal decomposition of CH3NH2. To determine κ1, a perturbation strategy was employed that is based on changes in the NH2 profiles when NO is added to the CH3NH2/Ar mixtures. Analysis showed that NH2 profiles in the CH3NH2/NO/Ar mixtures were sensitive primarily to reaction R1, with significantly lower sensitivity to the branching ratio and other NH2 reactions. The measured NH2 profiles were interpreted by detailed kinetic modeling to obtain κ1 values in the temperature range 1716-2507 K. The present κ1 values are consistent with recent theoretical results of Miller and coworkers. There is no evidence for a positive activation energy for this reaction at elevated temperatures as reported in several other high-temperature experimental studies. Combining the present high-temperature data with lower temperature determinations yields the following simple expression for the overall reaction rate, κ 1= 2.08 × 1016 T-1.34 cm3/mol s for the temperature range 300-2500 K.
|Number of pages||7|
|Journal||Proceedings of the Combustion Institute|
|Publication status||Published - 2000|
|Event||30th International Symposium on Combustion - Chicago, IL, United States|
Duration: 2004 Jul 25 → 2004 Jul 30
Bibliographical noteFunding Information:
This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Mechanical Engineering
- Physical and Theoretical Chemistry