Abstract: The deactivation of the prepared industrial Fe-K catalyst for ethylbenzene dehydrogenation to styrene was characterized by X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed reduction, and Mossbauer spectroscopy. The activity of fresh and spent catalyst samples was evaluated in a fixed-bed reactor. The results showed that regeneration of the spent catalyst by coke burning could improve activity, but the activity was reduced to the level of the spent catalyst after a short time of reaction. The characterization results indicated that coke deposition, catalyst sintering, and potassium loss were not responsible for the catalyst deactivation. However, the migration and uneven redistribution of potassium and reduction of Fe3+were the major reasons for the deactivation.

Key words: catalyst deactivation, ethylbenzene dehydrogenation, styrene, iron, potassium