Abstract
The rate of oxidation of pyridine and the nitrogen containing products formed during the oxidation were studied in the temperature range of 675–775° C using a Vycor, stirred-flow reactor. The rate was found to be half-order in pyridine, first-order in oxygen and half-order in oxygen consumed for both rich and lean mixtures. The activation energy and log frequency factor were 54·0 kcal/mole and 14·9 (using M-1 sec-1), respectively. Coating the reactor wails with KG had no significant effect on reaction order or activation energy, although the rate was increased by about a factor of two. An alternative to the apparent autocatalysis factor, ( δO2)1/2, could be that the rate of radical escape was competitive with that of chemical termination. The treatment using this assumption was applied to the data, however, the scatter prevented drawing a definite conclusion concerning these two alternatives. Product determinations indicated that nitrogen was accounted for by the HCN and N2 formed for lean mixtures when oxygen concentration was 7·0 mole percent or below; significant nitrogen appeared in the smoke for rich mixtures. However, at higher oxygen concentrations, N2O and NO became more significant as products. The mechanistic implications of these observations are discussed.