Catalysts for the production of styrene from ethylbenzene: Redox and deactivation study

In this work, a pulse plant has been used to study the redox properties, activity and coke generation of four catalysts in ethylbenzene dehydrogenation to produce styrene. CO2 was used as weak oxidant. A physicochemical and structural characterization was carried out in order to verify possible changes in the catalysts after the tests. The experiments consisted of a reduction test with H2, oxidation with CO2, reaction with ethylbenzene, regeneration with CO2 and coke combustion and reoxidation with O2. These experiments were carried out at three temperatures (450, 500 and 550 °C). With the catalyst that exhibited the best results, MnO2–ZrO2, additional experiments with different oxidation states were carried out in order to determine the influence on its activity and redox properties to assess the feasibility of using CO2 as a regenerating agent during the ethylbenzene dehydrogenation reaction.