Kinetics of the reaction ClO+ClO→products and its potential relevance to Antarctic ozone

Abstract

The reaction ClO + ClO → products has been studied by a molecular modulation technique as a function of temperature from 268 to 338 K using pressures from 2 to 700 Torr. The reaction is found to have a strong pressure dependence and to be second order under the conditions used. The data have been interpreted in terms of three pressure‐independent channels and a fourth, pressure‐dependent channel in which the ClO dimer is formed. The termolecular rate constant for the formation of the dimer is The title reaction is then discussed in the light of the large ozone depletions seen in the Antarctic spring. A catalytic cycle involving the ClO dimer is presented which may account for these observations.