Absolute Rate Constants for the Reaction of OH with NO2 in N2 and He from 225 to 389 K

Article abstract of DOI:10.1021/j100454a009

The temperature dependence of the rate of the reaction OH + NO2 + N2 --> HNO3 + N2 was investigated by using a discharge flow system for OH production and resonance fluorescence for its detection.The reaction was investigated at room temperature in He, and between 225 and 389 K in N2.The temperature dependence could be fit by the Arrhenius expression (1.6 +/- 0.4)E-31 exp<(1560 +/- 270)/1.987T> cm⁶ molecule^-2 s^-1 or preferably by (2.3 +/- 0.6)E-30(T/298)^-2.9 cm⁶ molecule^-2 s^-1.Earlier data have been used to determine the temperature dependence of the high-pressure limiting rate constant for this reaction.Troe's simplified expression for calculating rate constants in the falloff region was used to compare the appropriateness of different limiting values for the description of the experimentally observed pressure dependence of the rate constant.This reevaluation of the rate data suggests more appropriate values for k₀ and k for use in atmospheric modeling: k₀ = 2.3E-30(T/298)^-2.9 cm⁶ molecule^-2 s^-1 and k = 1.2E-11(T/298)^-1.6 cm³ molecule^-1 s^-1.