Catalytic oxidation of ethylbenzene: kinetic modeling, mechanism, and implications

A detailed reaction mechanism and kinetic model have been developed to study the catalyzed oxidation of ethylbenzene. The model is used to compute the time profiles of ethylbenzene and three products: acetophenone, benzaldehyde, and benzoic acid. The kinetic model is evaluated on three different reported studies for ethylbenzene oxidation with iron- and cobalt-based catalysts using tert-butyl hydrogen peroxide as an oxygen source, in solventless condition and at various experimental conditions. The model shows good fit for the concentration profiles with time and with the change in parameters like ethylbenzene-to-tBHP ratio and temperature. Activation energy and pre-exponential factors are calculated from Arrhenius plots using the values of rate constants derived using the proposed model. It was established that the excess amount of oxidant in the reaction mixture leads to over-oxidation products, which was not captured experimentally. The hypothesis is supported with the simulation results from modified model.