Synthesis methods and recent advances in hierarchical zeolites: a brief review

• Published in: Journal of the Iranian Chemical Society 2021-09, Vol.18 (9), p.2215-2229
• Main Authors: Mumtaz, Faisal, Irfan, Muhammad F., Usman, Muhammad R.
• Format: Article
• Language: English
• Subjects: Aluminosilicates; Aluminum silicates; Analytical Chemistry; Biochemistry; Chemical synthesis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organic Chemistry; Physical Chemistry; Recrystallization; Review; Selectivity; Surface stability; Zeolites
• ISSN: 1735-207X; 1735-2428
• DOI: 10.1007/s13738-021-02183-2

Zeolites are crystalline microporous aluminosilicates that are extensively used as adsorbents and catalysts in the chemical and petrochemical industry. This is due to the reason they exhibit distinct properties such as hydrothermal stability, large surface area, strong acidity, shape selectivity, and ability to accommodate various metal ions. However, due to their microporous nature, they pose a difficulty in transporting large feed and product molecules. Such limitations can be avoided by creating hierarchical zeolites which then have shorter diffusion paths and larger pore diameters for the movement of bulky molecules. There are numerous approaches by which hierarchical zeolites can be prepared. Generally, these can be categorized as bottom-up approaches (hard templating, soft templating, and zeolitization) and top-down approaches (demetallation, recrystallization, and irradiation). In the present contribution, the aim is to review the important strategies used in synthesizing hierarchical zeolites and to survey the recent advances in the field.