TEMPERATURE-DEPENDENCE OF THE REACTION OF CLO AND HO2 RADICALS

The rate constant for the reaction of ClO with HO2, k 1, was measured over the temperature range 235≤T≤393 K using laser magnetic resonance detection to monitor directly the concentrations of both reactants. Measurements were made at low pressures, 0.8≤P≤3.4 Torr, in three different discharge-flow tubes, 14.0, 25.4, and 36.7 mm i.d., and with two different sources for ClO radicals, Cl+O3 and Cl+Cl2O. The observed temperature dependence is fitted by the expression, k 1=3.3×10-11 exp(-850/T)+4.5×10-12 (T/300)-3.7 cm3 molecule-1s-1 The products of the reaction were not detected but the possible channels HOCl+O 2 and HCl+O3 have important implications for stratospheric chemistry.