On the Mesoporogen-Free Synthesis of Single-Crystalline Hierarchically Structured ZSM-5 Zeolites in a Quasi-Solid-State System

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• 作者：Dr. Tongguang Ge ; Prof. Dr. Zile Hua ; Dr. Xiaoyun He ; Dr. Jian Lv ; Prof. Dr. Hangrong Chen ; Prof. Dr. Lingxia Zhang ; Dr. Heliang Yao ; Dr. Ziwei Liu ; Dr. Chucheng Lin and Prof. Dr. Jianlin Shi
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：June 1, 2016
• 年：2016
• 卷：22
• 期：23
• 页码：7895-7905
• 全文大小：2555K
• ISSN：1521-3765

文摘

Hierarchically structured zeolites (HSZs) have gained much academic and industrial interest owing to their multiscale pore structures and consequent excellent performances in varied chemical processes. Although a number of synthetic strategies have been developed in recent years, the scalable production of HSZs single crystals with penetrating and three-dimensionally (3-D) interconnected mesopore systems but without using a mesoscale template is still a great challenge. Herein, based on a steam-assisted crystallization (SAC) method, we report a facile and scalable strategy for the synthesis of single-crystalline ZSM-5 HSZs by using only a small amount of micropore-structure-directing agents (i.e., tetrapropylammonium hydroxide). The synthesized materials exhibited high crystallinity, a large specific surface area of 468 m² g⁻¹, and a pore volume of 0.43 cm³ g⁻¹ without sacrificing the microporosity (≈0.11 cm³ g⁻¹) in a product batch up to 11.7 g. Further, a kinetically controlled nucleation–growth mechanism is proposed for the successful synthesis of single-crystalline ZSM-5 HSZs with this novel process. As expected, compared with the conventional microporous ZSM-5 and amorphous mesoporous Al-MCM-41 counterparts, the synthesized HSZs exhibited significantly enhanced activity and stability and prolonged lifetime in model reactions, especially when bulky molecules were involved.