As the synthetic substrate of polymer products such as plastics and rubber, styrene has a great demand in current production. For global energy saving and emission reduction, it is necessary to adopt a more efficient and energy-saving way to produce styrene. In this study, a manganese-based composite catalyst was prepared for the efficient catalytic chemical looping oxidative dehydrogenation of ethylbenzene. High conversion and selectivity of styrene are achieved at 450 ℃ (600 ℃ in industrial production with high-temperature steam). Manganese-based composite catalyst had an effective conversion and styrene selectivity because of (i) ethylbenzene efficient catalytic active phase, (ii) stable redox oxygen storage and release species, and (iii) Al-based structural stable phase in the oxidative dehydrogenation of ethylbenzene. The synergy of composite metals, the supporting role of inert carrier, and the characteristics of the surface active species optimization and modification maintain high activity of species in the catalyst, contributing to the high stability of the catalyst. The hydrogen loss in the oxidative dehydrogenation of ethylbenzene to styrene results in a positive reaction, which improves the reaction rate and reduces the energy loss, providing a new idea for the efficient and energy-saving preparation of styrene.
 

Chemical looping, Oxidative dehydrogenation, Ethylbenzene, Mn-based composite catalyst