Rate coefficient for the BrO + HO2 reaction at 298 K

The kinetics of the BrO + HO2reaction (1) have been studied using the technique of flash photolysis/time resolved UV absorption spectroscopy. BrO and HO2 radicals were generated via the Br + O3 and Cl + CH3OH/O2 methods respectively. The rate coefficient for the reaction was found to be k1 = (2.35 ± 0.82) × 10−11 molecule−1 cm3 s−1 at 298 K and 760 Torr O2. Uncertainty limits correspond to combined 2 standard deviation statistical variation and systematic factors. This result is briefly compared with previous determinations of k1. A study of the enhancement of the HO2 self-reaction rate in the presence of methanol was also performed, with the observed second-order loss rate coefficient given by kobs = (2.9 × 10−12 + αβ[CH3OH])/(1 + α[CH3OH])2, with α = (6.15 ± 0.90) × 10−19 molecule−1 cm3 and β = (3.2 ± 0.5) × 10−11 molecule−1 cm3 s−1 at 298 K and 760 Torr O2, for [CH3OH] ⩽ 5.5 × 1017 molecule cm−3.