Temperature dependence of the O + HO/sub 2/ rate coefficient

Journal Article · Thu Sep 10 04:00:00 EDT 1987 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100303a049· OSTI ID:5952954

Nicovich, J M; Wine, P H

A pulsed laser photolysis technique has been employed to investigate the kinetics of the radical-radical reaction O(/sup 3/P) + HO/sub 2/ ..-->.. /sup k1/ OH + O/sub 2/ over the temperature range 266-391 K in 80 Torr of N/sub 2/ diluent gas. O(/sup 3/P) was produced by 248.5-nm KrFlaser photolysis of O/sub 3/ followed by rapid quenching of O(/sup 1/D) to O(/sup 3/P), while HO/sub 2/ was produced by simultaneous photolysis of H/sub 2/O/sub 2/ to create OH radicals which, in turn, reacted with H/sub 2/O/sub 2/ to yield HO/sub 2/. The O(/sup 3/P) temporal profile was monitored by using time-resolved resonance fluorescence spectroscopy. The HO/sub 2/ concentration was calculated based on experimentally measured parameters. The following Arrhenius expression describes our experimental results: k/sub 1/(T) = (2.91 +/- 0.70) x 10/sup -11/ exp((228 +/- 75)/T) where the errors are 2sigma and represent precision only. The absolute uncertainty in k/sub 1/ at any temperature within the range 266-391 K is estimated to be +/- 22%. The authors 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.

• Research Organization: Georgia Institute of Technology, Atlanta
• OSTI ID: 5952954
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 91:19; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ABSORPTION
ARRHENIUS EQUATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ELEMENTS
EQUATIONS
EXCIMER LASERS
FLUORESCENCE
GAS LASERS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
HYDROPEROXY RADICALS
KINETICS
LASERS
LUMINESCENCE
NONMETALS
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOLYSIS
RADICALS
REACTION KINETICS
RESONANCE ABSORPTION