Transformation of alkylbenzenes in an oxidizing medium on H-ZSM-5 catalyst under supercritical conditions

Abstract

Reactions of the substituted benzenes toluene, p-xylene, fluorobenzene, phenol, cumene and styrene with nitrous oxide as an oxidant on H-ZSM-5 catalyst under supercritical conditions at 345–420°C and 70–150 atm were studied. It is shown that the products of disproportionation, isomerization and condensation that do not contain oxygen form predominantly. Only in the oxidation of toluene does the selectivity to the oxidation product (cresols) reach 35%. The yield of corresponding phenols in the oxidation of alkyl-, hydroxy- and fluorobenzenes is negligible. The double bond conjugated with the π-system of benzene rings (styrene), as well as the presence of branched alkyl substituents (in cumene) and hydroxyl-group (in phenol) hinder the formation of benzene ring oxidation products.