Title : The Effect of Na2SO4 Salt on the Crystallization kinetics of Mordenite Framework Inverted (MFI) zeolite
Abstract:
Zeolites are crystalline aluminosilicate pores materials that are widely used in different applications such as catalytic cracking, ion exchange, and membrane separation. Since the beginning of their synthesis in the middle of the 20th century, scientists have made substantial efforts to understand and explicate zeolites' synthesis mechanism. Despite the tremendous ongoing efforts in understating zeolites' crystallization process, little is known about the complexity of this process. This created a considerable challenge encountered by multiple strategies and approaches. One of these approaches is to examine the effect of inorganic salts on the crystallization kinetics of zeolites. These inorganic salts composed of alkali cations and anions. The alkali cations (Na+, K+, Ca+2, etc.) act as charge neutralizers and structure-directing agents. The anions (SO-4, PO-3, Cl-, etc.) of the inorganic salt work as promoters for enhancing the nucleation and crystallization rates of zeolites and sequentially reducing their synthesis time.
The main aim of this study is to investigate the impact of adding Na2SO4 on the crystallization kinetics of MFI zeolite and morphological and physical properties using colloidal silica as raw material. The research activity was divided into multiple tasks. The first task is to establish a kinetic Formation window of MFI Zeolite, SiO2/Al2O3 =50, without organic Template. This can be done by fixing the temperature and synthesis time at 170 ?C for 24h. other factors like mixing rate and impeller type will be adjusted accordingly. The kinetic formation window of amorphous to MFI zeolite will be created based on upper and lower alkalinity limits. The second task involves the adjustment of the molar quantities of the reactive species. the molar quantities will be added and controlled based on the kinetic formation window obtained. The last task will be dedicated to characterize the synthesized zeolite. The crystal phases, types, and structure of the MFI zeolite will be identified via XRD. Meanwhile, the morphological properties of the obtained crystals will be determined via SEM. This research activity could be expanded upon changing experimental factors like silica to alumina ratio.
