Iron-based catalyst supported on sulfated alumina was proved to be highly active and selective in catalytic dehydrogenation of propane to propylene. At 560 degrees C, 20% propylene yield along with more than 80% selectivity was obtained on 20Fe/5S-Al. It was demonstrated that sulfate species mainly existed in the form of SO42- and interacted with Fe atoms via Fe-O-S bond, leading to enhanced acidity especially the generation of Bronsted acids. Meanwhile, propane is more likely to adsorb on Fe species at the electron-deficient state, resulting in higher activity. XPS and on-line MS results indicated the loss of sulfur species in the form of SO2 was the main reason for the irreversible deactivation of catalysts. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.