Rate constants of the reactions of O(3P) atoms with Br2 and NO2 over the temperature range 220‐950 K

Authors:
Publisher website
Google Scholar
Abstract
The kinetics of the reactions of Br2 and NO2 with ground state oxygen atoms have been studied over a wide temperature range, T = 220‐950 K, using a low‐pressure flow tube reactor coupled with a quadrupole mass spectrometer: O + NO2 → NO + O2 (1) and O + Br2 → Br + BrO (2). The rate constant of reaction (1) was determined under pseudo–first‐order conditions, either monitoring the kinetics of O‐atom or NO2 consumption in excess of NO2 or of the oxygen atoms, respectively: k1 = (6.1 ± 0.4) × 10−12 exp((155 ± 18)/T) cm3 molecule−1 s−1 (where the uncertainties represent precision at the 2σ level, the estimated total uncertainty on k1 being 15% at all temperatures). The temperature dependence of k1, found to be in excellent agreement with multiple previous low‐temperature data, was extended to 950 K. The rate constant of reaction (2) determined under pseudo–first‐order conditions, monitoring the kinetics of Br2 consumption in excess of O‐atoms, showed upward curvature at low and high temperatures of the study and was fitted with the following three‐parameter expression: k2 = 9.85 × 10−16 T1.41 exp(543/T) cm3 molecule−1 s−1 at T = (220‐950) K, which is recommended from the present study with an independent of temperature conservative uncertainty of 15% on k2.
Funding Information
  • Centre National de la Recherche Scientifique

This publication has 27 references indexed in Scilit: