THE OXIDATION OF TOLUENE PERTURBED BY NO2

The use of N02for chemical kinetic analysis has been extended to the simplest of the alkylbenzenes—toluene. The results of a series of toluene oxidation experiments performed with and without NO2 and over a range of initial oxygen concentrations have not only confirmed the conclusions of a prior series of benzene oxidation experiments but also added to the understanding of the toluene oxidation mechanism. Specifically, comparison of carbon monoxide, C4 and CH4/C2 profiles as a function of extent of reaction for conditions with and without NO2 addition as well as the large decrease in phenol and cresols concentrations indicate that oxygen atom addition to the aromatic ring is not a significant consumption route and that the dominant fuel consumption route involves phenyl radical reaction with oxygen molecule: (f) + O2—â Φ O + O When NO2 was added to toluene oxidation experiments, not only was the consumption of the toluene accelerated but also the concentration of benzaldehyde increased. However, the rate of change of the benzaldehyde concentration as a function of the extent of reaction decreased signifying that though the benzaldehyde is an essential intermediate in the oxidation of toluene to small hydrocarbons, its reactions are not rate determining. © 1990, Taylor & Francis Group, LLC. All rights reserved.