Low-Temperature Kinetics of the Reaction of the OH Radical With Hydrogen Peroxide
A B. Vakhtin, D C. McCabe, A R. Ravishankara, S R. Leone
The kinetics of the reaction of the OH radical with hydrogen peroxide. H2O2 are studied over a temperature range of 96-296 K. The low-temperature environment is provided by a pulsed Laval nozzle supersonic expansion of nitrogen with admixed H2O2. Hydrogen peroxide serves as both the OH radical photolytic precursor (2 = 248 mn) and a reactant. Laser-induced fluorescence of the OH radicals excited in the (l, 0) band of the A2ς+-X2IIi transition is used to monitor the kinetics of OH removal. The rate coefficient of the OH + H2O2 reaction (k1) shows a negative temperature dependence within this temperature range, which can be expressed as k1 = (6.8 1.0) x10-13 exp(285 27)/T]cm3 molecule-1 s-1. The combined low-and high-temperature (literature) kinetic data form a U-shaped Arrhenius plot, which suggests the reaction mechanism changes from direct abstraction (at high temperatures) to a mechanism involving formation of a hydrogen-bonded complex (at low temperatures). Atmospheric implications of the new low-temperature kinetic data are discussed.
, McCabe, D.
, Ravishankara, A.
and Leone, S.
Low-Temperature Kinetics of the Reaction of the OH Radical With Hydrogen Peroxide, Journal of Physical Chemistry A
(Accessed December 2, 2023)