Oxidation of CO by N2O between 1076 and 1228 K: Determination of the Rate Constant of the Exchange Reaction

Article abstract of DOI:10.1021/j100310a023

New measurements of the rate constant of the direct reaction of CO with N2O are reported with the principal purpose of removing some of the remaining discrepancies on its value.Experiments were performed at lower temperatures (1076-1228 K) and lower pressure (ca. 15 Torr) than those prevailing in most of previous works, by using a static reactor.It is shown that, under these experimental conditions, the reaction proceeds essentially according to the direct reaction CO + N2O -- CO2 + N2 (1).The previously proposed wet mechanism is not significant under our experimental conditions.It has to be taken into account, however, to describe the observed production and consumption of molecular oxygen.The Arrhenius expression derived from these experiments is k₁ = 10^14.4+/-0.3exp<-(46+/-2)kcal mol^-1/RT> cm³ mol^-1 s^-1.A detailed analysis of the results shows that the uncertainties in side reactions do not greatly influence the value of k₁.A critical discussion of the data reported in the literature is presented.In spite of remaining uncertainties in the reaction mechanism, the present results, obtained in a low-temperature range, show that the low activation energy values of reaction 1, reported in several works performed at higher temperatures, are highly unlikely.