Kinetics of the C2H5O2 + NOx reactions: Temperature dependence of the overall rate constant and the C2H5ONO2 branching channel of C2H5O2 + NO

Abstract

The temperature dependence of the overall rate constant for the C2H5O2 + NO reaction and the rate constant for the minor branching channel resulting in the production of C2H5ONO2 have been measured using the turbulent flow technique with high-pressure chemical ionization mass spectrometry for the detection of reactants and products. The temperature dependence of the overall rate constant for the C2H5O2 + NO reaction was investigated between 299 and 213 K at 100 Torr pressure, and the data was fit to the following Arrhenius expression (with 2 standard deviation error limits indicated):  × 10-12exp[(290 ± 110)/T] cm3 molecule-1 s-1. The temperature dependence of the overall rate constant agrees well with the current recommendation for atmospheric modeling. The minor reaction channel C2H5O2 + NO → C2H5ONO2 was directly observed for the first time, and the temperature dependence of the rate constant for this channel was investigated between 298 and 213 K at 100 Torr pressure. The following Arrhenius expression was determined for the minor channel:  × 10-15exp[(1160 ± 310)/T] cm3 molecule-1 s-1. The Arrhenius expressions for the overall rate and the C2H5ONO2 producing channel indicate a branching ratio of about 0.006 at 298 K and 0.02 at 213 K at 100 Torr pressure. The temperature dependence of the overall rate constant for the C2H5O2 + NO2 reaction was also investigated between 299 and 213 K at 100 Torr pressure, and the data was fit to the following Arrhenius expression:  × 10-13exp[(620 ± 89)/T] cm3 molecule-1 s-1.

Publisher

American Chemical Society

Publication Date

6-22-2000

Publication Title

Journal of Physical Chemistry A

Department

Chemistry and Biochemistry

Document Type

Article

DOI

https://dx.doi.org/10.1021/jp000353k

Language

English

Format

text

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