Effects of microwave radiation on one-step oxidation of benzene to phenol with nitrous oxide over Fe-ZSM-5 catalyst

摘要

Direct oxidation of benzene to phenol over Fe-ZSM-5 catalyst was chosen as a model reaction to characterize the influence of microwave irradiation on ad-/desorption processes during heterogeneously catalyzed reactions.The direct oxidation of benzene was investigated under different reaction conditions (temperature,residence time,reactant-concentrations) and microwave power in a specially designed reactor.The results obtained by additional microwave radiation were compared to those obtained by conventional heating under similar reaction conditions.In addition,ex situ TG-MS analyses were also conducted to study the sorption behaviour.Extensive investigations were carried out to determine adsorption-desorption effects (benzene,phenol and a mixture of both) and the coking behaviour under microwave conditions.Microwave induces a trend towards increased phenol selectivity and relative deactivation during the reaction.However,there was no conclusive improvement in the performance was obtained by means of microwave heating.