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 H-2, oxidation with CO2, reaction with ethylbenzene, regeneration with CO2 and coke combustion and reoxidation with O-2. These experiments were carried out at three temperatures (450, 500 and 550 degrees 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. (C) 2012 Elsevier B. V. All rights reserved.