Pressure and temperature dependence kinetics study

The flash photolysis-ultraviolet absorption technique has been utilized to study the reactivity of nitric oxide with BrO radicals over a wide range of pressure (100-700 torr) and temperature (224-398 K). Pseudo-first-order conditions were used in order to minimize complications caused by secondary kinetic processes. The reaction and its corresponding Arrhenius expression in units of cm3 molecule-l s-l can be written (1) NO + BrO- NO2 + Br =-17.0 kcal mol-l kl = (1.28 f 0.23) X exp((l81 f 46)/T) (T = 224-398 K) The results are compared with previous measurements, and atmospheric implications of the reaction are discussed. It is shown that this reaction is important in controlling the ratios [BrO]/[Br] and [BrO]/[HBr] in the stratosphere but that it does not affect the catalytic efficiency of BrO, in ozone destruction