Synthesis of Fe Catalysts Doped in SBA-15 by EISA Method: Characterization and Catalytic Studies in 2-Propanol Decomposition

Abstract: A series of Fe catalysts doped in SBA-15 was synthesized in one step by the EISA method at room temperature and without inorganic acids. Every catalyst was characterized by XRD, N₂ adsorption, SEM–EDS, FTIR and UV–Vis Diffuse Reflectance, and their catalytic activity was evaluated by performing a 2-propanol decomposition reaction. The ordered mesoporous structure was confirmed for SBA-15 silica by XRD and N₂ adsorption studies. Even though the pore order was reduced through the incorporation of Fe into the silica framework, the mesostructured characteristics were maintained. In addition, the morphology of these catalysts prepared by this method was revealed, and the amount of Fe added to the catalysts was maintained at the end of the synthesis with only small losses. Isolated Fe³⁺ species in a tetrahedral location were identified by UV–Vis DR into the framework and extra-framework, respectively. This Fe³⁺ species generated strong acidic sites, whose acidity increased due to the addition of Fe, producing a high conversion and selectivity of propene greater than 99% for all the catalysts. The relation between the amount of Fe, the coordination of Fe species, the creation of acidic sites in the catalysts, and their effect on 2-propanol decomposition was analyzed based on the information obtained in this work.