A Bottom‐Up Strategy for the Synthesis of Highly Siliceous Faujasite‐Type Zeolite

• Published in: Advanced materials (Weinheim) Vol. 32; no. 26; pp. e2000272 - n/a
• Main Authors: Zhu, Dali, Wang, Linying, Fan, Dong, Yan, Nana, Huang, Shengjun, Xu, Shutao, Guo, Peng, Yang, Miao, Zhang, Jianming, Tian, Peng, Liu, Zhongmin
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.07.2020
• Subjects: Alkalinity; Aluminum oxide; Catalytic cracking; Chemical synthesis; Crystallization; Faujasite‐type zeolites; Materials science; organic structure‐directing agents; Petroleum refining; Silicon dioxide; Strategy; Thermal stability; zeolite synthesis; zeolite Y; Zeolites; zeolite synthesis; organic structure-directing agents; catalytic cracking; zeolite Y; Faujasite-type zeolites
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202000272

High‐silica zeolite Y is a desired catalytic material for oil refining and the petrochemical industry. However, its direct synthesis remains a symbolic challenge in the field of zeolite synthesis, with a limited improvement of the framework SiO2/Al2O3 ratio (SAR) from ≈5 to 9 over the past 60 years. Here, the synthesis of highly siliceous zeolite Y with tunable SAR up to 15.6 through a cooperative strategy is reported, which involves the use of FAU nuclei, a bulky organic structure‐directing agent (OSDA), and a gel system with low alkalinity (named NOA‐co strategy). A series of quaternary alkylammonium ions is discovered as effective OSDAs based on the NOA‐co strategy, and the relevant crystallization mechanism is elucidated. Moreover, the high‐silica products are demonstrated to have greatly improved (hydro)thermal stability, high concentration of strong acid sites, and uniform acid distribution, which lead to superior catalytic performance in the cracking of bulky hydrocarbons. It is anticipated that this synthetic strategy will benefit the synthesis and development of zeolitic catalysts in a wide range of reaction processes. High‐silica zeolite Y with tunable SiO2/Al2O3 ratio up to 15.6 is synthesized through a cooperative strategy that involves the use of FAU nuclei, a bulky organic structure‐directing agent (OSDA), and a gel system with low alkalinity. The obtained materials show greatly improved (hydro)thermal stability, high concentration of strong acid sites, and superior catalytic cracking performance.