Isomorphously substituted of Fe and Al in ZSM-5 Zeolites: Preparation and Characterization

FeZSM-5 with high silica to alumina ratio and low content of Iron is known to catalyze the partial oxidation of benzene to phenol with high selectivity. The state of iron in FeZSM-5 is strongly dependent on the method of iron exchange, the level of Fe exchange (i.e., the Fe/Al ratio), and the pretreatment of the as exchanged material. There are three methods for loading Iron into the ZSM-5 structure; Ion Exchange, chemical vapor deposition (CVD) and isomorphously substituted. Experiments show that Isomorphously substituted is the best method for loading the low content of iron into the ZSM-5 to act as a good catalyst for partial oxidation of benzene to phenol. The preparation of isomorphously substituted FeZSM-5 zeolites enriched with Fe under hydrothermal synthesis is described. FeZSM-5 zeolites with varying iron and aluminum Contents were synthesized and characterized by ICP analysis and x-ray diffraction (XRD).Although XRD indicated that zeolite prepared under hydrothermal synthesis were crystalline with ZSM-5 zeolite structure, other characterization study suggest the presence of phase silicon, aluminum, and iron in the synthesized zeolites.ICP Analysis of ZSM-5 zeolite with varying iron and Aluminum content prepared under hydrothermal condition reveal the presence of Fe2O3 incorporated in the zeolite framework for FeZSM-5 zeolite with low iron content (0.1%) and high silica to alumina ratio (Si/Al:50).

کلیدواژه ها:

FeZSM-5 ، Isomorphously Substituted ، Iron incorporation