Shock tube determination of the rate coefficient for the reaction N 2+O→NO+N

Abstract

The rate coefficient for the reaction N 2 + O → k 1 NO + N has been measured in the temperature range 2384–3850 K using a shock tube technique. Test gas mixtures consisting of N2, O2, N2O and Kr were heated by incident shock waves, and the concentration of NO in the post-shock region was monitored using two independent spectroscopic techniques: IR emission at 5.3 μm, and absorption of CO laser radiation at 5.17 μm. The two methods yielded excellent agreement. The importance of interferences from other reactions was minimized by careful tailoring of the test mixture composition, in particular by using N2O rather than O2 as a source of 0 atoms. The rate coefficient k1 was determined by comparing experimental and calculated NO profiles using a computer simulation in which k1 was an adjustable parameter. The results of 20 experiments indicate that k1=1.84×1014 exp (−76,250/RT) cm3/mol×s with an uncertainty of approximately ±35% in the temperature range investigated.