Recombination reaction between O atoms and CO

The reaction between oxygen atoms and carbon monoxide produces visible evidence of its occurrence in that it is accompanied by the emission of a blue chemiluminescence in the visible and near UV. The emission is particularly noticeable from CO/O2 flames, and has been discussed in Sect. 10.2.1. 

Clyne and Thrush [404] have examined the intensity / of the chemiluminescent emission between 200 and 300 K in a fast flow system. Oxygen atoms were generated either by dissociation of pure oxygen or 

At 273 K it is about 2000 times less (for M = O2) than the proportionality constant for O + NO. The latter has a small negative temperature coefficient, and plots of log /q.co and log 7o,no versus T show that the two pre-exponential factors are similar. The rate coefficient ks-j has also been found to be very much smaller than the corresponding coefficient for O + NO at 300 K, and the evaluation to be given below indicates that fe 7 also has an activation energy of about 4 kcal. mole. The mechanism of light emission is therefore closely related to the mechanism of combination. 

The fact that Iq depends on the nature of the carrier gas indicates that the chemiluminescent reactions take place in three body processes. The whole range of phenomena may then be explained by postulating an initial termolecular combination to an excited state of CO2, followed at a later stage by the emission of radiation or by collisional quenching to form CO2 in the ground electronic state, viz. 

Using a stationary state treatment for CO then gives 

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