NTRS - NASA Technical Reports Server

Back to Results
Temperature Dependence of the O + HO2 Rate CoefficientA pulsed laser photolysis technique has been employed to investigate the kinetics of the radical-radical reaction O((sup 3)P) + HO2 OH + O2 over the temperature range 266-391 K in 80 Torr of N2 diluent gas. O((sup 3)P) was produced by 248.5-nm KrF laser photolysis of O3 followed by rapid quenching of O(1D) to O((sup 3)P) while HO2 was produced by simultaneous photolysis of H2O2 to create OH radicals which, in turn, reacted with H2O2 to yield HO2. The O((sup 3)P) temporal profile was monitored by using time-resolved resonance fluorescence spectroscopy. The HO2 concentration was calculated based on experimentally measured parameters. The following Arrhenius expression describes our experimental results: k(sub 1)(T) equals (2.91 +/- 0.70) x 10(exp -11) exp[(228 +/- 75)/T] where the errors are 2 sigma and represent precision only. The absolute uncertainty in k, at any temperature within the range 266-391 K is estimated to be +/- 22 percent. Our results are in excellent agreement with a discharge flow study of the temperature dependence of k(sub 1) in 1 Torr of He diluent reported by Keyser, and significantly reduce the uncertainty in the rate of this important stratospheric reaction at subambient temperatures.
Document ID
Acquisition Source
Document Type
Reprint (Version printed in journal)
Nicovich, J. M.
(Georgia Inst. of Tech. Atlanta, GA United States)
Wine, P. H.
(Georgia Inst. of Tech. Atlanta, GA United States)
Date Acquired
August 17, 2013
Publication Date
April 9, 1997
Publication Information
Publication: Laboratory Investigations of Stratospheric Halogen Chemistry
Publisher: American Chemical Society
ISSN: 0022-3654
Subject Category
Inorganic And Physical Chemistry
Funding Number(s)
Distribution Limits
Work of the US Gov. Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available