Sonochemical post-synthesis modification of Y zeolite with iron species

Abstract

Faujasite is a zeolite that, when in a Y structure, is widely used as a catalyst to produce fuel by fluid catalytic cracking (FCC) and is recently being investigated for applications in sustainable processes. Hence, there is an increased interest in modifying Y zeolites with metals such as Fe to improve and optimize their catalytic properties. Several post-synthesis methods such as chemical vapor deposition, impregnation and ion exchange have been explored for the introduction of Fe. Nevertheless, these currently developed methods can be time-consuming and unable to selectively tune the Fe species. Therefore, this study explores the use of ultrasonic irradiation in a liquid state modification of a Fe-exchanged Y zeolite (FeY) in a buffer solution with different pH values (5 and 9) and oxidation states of Fe ions (ferrous and ferric) for the introduction of Fe species. At the tested ultrasonic modification conditions, the zeolitic structure was preserved with slight Si/Al ratio and pore structure adjustments in correlation with the introduced Fe species (ions, hydroxides and oxides). Setting the sonochemical method as a potential path for the search of reaction conditions for the design and fabrication of Fe-modified zeolitic materials with tuned properties for a wide range of applications.