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Creation of Al-Enriched Mesoporous ZSM-5 Nanoboxes with High Catalytic Activity: Converting Tetrahedral Extra-Framework Al into Framework Sites by Post Treatment |
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| Authors: | Yilai Jiao Luke Forster Shaojun Xu Huanhao Chen Jingfeng Han Xuqing Liu Yangtao Zhou Jinmin Liu Jinsong Zhang Jihong Yu Carmine D'Agostino Xiaolei Fan |
| Institution: | 1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 China;2. Department of Chemical Engineering and Analytical Science, School of Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL UK;3. National Engineering Laboratory for Methanol to Olefins, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023 China;4. Department of Materials, School of Natural Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL UK;5. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012 China
International Center of Future Science, Jilin University, 2699 Qianjin Street, Changchun, 130012 China |
| Abstract: | ZSM-5 zeolite nanoboxes with accessible meso-micro-pore architecture and strong acid sites are important in relevant heterogeneous catalysis suffering from mass transfer limitations and weak acidities. Rational design of parent zeolites with concentrated and non-protective coordination of Al species can facilitate post-synthetic treatment to produce mesoporous ZSM-5 nanoboxes. In this work, a simple and effective method was developed to convert parent MFI zeolites with tetrahedral extra-framework Al into Al-enriched mesoporous ZSM-5 nanoboxes with low silicon-to-aluminium ratios of ≈16. The parent MFI zeolite was prepared by rapid ageing of the zeolite sol gel synthesis mixture. The accessibility to the meso-micro-porous intra-crystalline network was probed systematically by comparative pulsed field gradient nuclear magnetic resonance diffusion measurements, which, together with the strong acidity of nanoboxes, provided superb catalytic activity and longevity in hydrocarbon cracking for propylene production. |
| Keywords: | ZSM-5 post-synthetic treatment mesoporous nanoboxes diffusion PFG-NMR |