Kinetics of the O + ClO Reaction

The rate coefficient for the reaction O + ClO → Cl + O<INF>2</INF> (1) was measured over the range 227 to 362 K using a discharge flow tube coupled to a pulsed laser photolysis-atomic resonance fluorescence apparatus. The title reaction was studied under pseudo-first-order conditions in O atoms in an excess of ClO. ClO radicals were produced in the discharge flow tube by the reaction of Cl with either O<INF>3</INF> or Cl<INF>2</INF>O and its concentration was measured in situ by UV absorption. O atoms were produced by pulsed laser photolysis of ClO at 308 nm and detected by atomic resonance fluorescence. The measurements yield k<INF>1</INF>(T) = (3.0 ± 0.8) × 10^-11 exp((75 ± 40)/T) cm³ molecule^-1 s^-1, where the uncertainties are at the 95% confidence level and include estimated systematic errors. These results are compared with previous data and an expression that can be used for atmospheric purposes is suggested.