Journal of Physical Chemistry A, Vol.101, No.18, 3305-3316, 1997
Pyrolysis and Oxidation of Anisole Near 1000 K
Experiments near 1000 K have revealed the thermal decomposition of anisole to proceed exclusively via homolysis of the O-CH3 bond. The anisole decay was observed to be first order even in the presence of oxygen. The distribution of reaction intermediates was virtually independent of equivalence ratio, phi = ([anisole]/[O-2])/([anisole]/[O-2])(stoichiometric). Phenol, cresols, methylcyclopentadiene, and CO were major products. Minor species included benzene, cyclopentadiene, ethane, and methane. Trace yields of ethene, toluene, and naphthalenes were observed under all conditions; trace C-2-C-4 species including acetylene, allene, and 1,3-butadiene were observed only in the oxidation experiments. Oxidation occurs preferentially through methylcyclopentadiene. A multichannel reaction scheme is proposed involving the formation of a chemically activated adduct from phenoxy and methyl. The complex reacts to form primarily cresols and methylcyclopentadiene + CO either directly or subsequent to stabilization. A kinetic model for anisole pyrolysis has been developed to predict the disappearance of anisole and the production of reaction intermediates. Excellent agreement is obtained between experimental data and model predictions of anisole, CO, methylcyclopentadiene, and total phenolics.
Keywords:THERMAL-DECOMPOSITION;SHOCK-WAVES;BENZENE;HYDROGEN;PHENOL;MECHANISMS;KINETICS;RADICALS;FLAMES