Liquid-Phase Ethyl Benzene Oxidation Catalysed by Manganese Salts

The liquid-phase oxidation of ethyl benzene by O2 catalysed by manganese stearate (MnSt2) in a stirred batch reactor has been studied. The main reaction products are ethyl benzene hydroperoxide, methyl phenyl carbinole, and acetophenone. It was established that the reaction includes four basic macro-stages: an induction period, a period of accelerated ethyl benzene consumption, a period of slowing-down, and an inhibition step. It was shown that the initial rate of the second step is described by the equation r0 = k[EB]0 . The observed experimental data allowed the supposition that the reaction proceeds by the radical-chain mechanism with participation of hydroperoxide radicals. The overall process is possibly initiated by Mn3+ ions.