Roles of potassium in potassium-promoted iron oxide catalyst for dehydrogenation of ethylbenzene

Abstract

Experimental kinetic data on the dehydrogenation of ethylbenzene over potassium-promoted iron oxide catalysts containing various amounts of potassium were obtained in the temperature range 550–620 °C. Unimolecular reactions for the formations of styrene, benzene and toluene on the different sites, where potassium reduced the activation energies, were considered on the basis of Langmuir-Hinshelwood type mechanism. Using a method of in situ catalyst deactivation with CO 2, potassium ferrite formed in the surface of the catalyst under reaction was suspected to take part in the formation of the active sites.