Abstract
Structure determination of zeolites is of great significance for understanding their fascinating properties. In this study, we successfully solve one of polymorphic structures (polymorph A) of zeolite EMM-17, which can only crystallize in sub-micron-sized crystals while containing complex stacking disorders, from the three-dimensional (3D) electron diffraction (ED) data. This is the first time that the atomic structure of this polymorph has been ab initio solved, and the result reveals a unique 10(12) X 10(12) X 11-ring channel system. Moreover, we acquire the first atomic-resolution images of EMM-17 using integrated differential phase-contrast scanning transmission electron microscopy. The images allow us to directly observe polymorphs B and C and discover a large number of local structural defects. Based on structural features unraveled from the reciprocal-space 3D ED data and real-space images, we propose a series of energetically feasible local structures in EMM-17. In addition, we demonstrate that the unique porous structure of EMM-17 enables efficient kinetic separation of C6 alkane isomers.
Original language | English (US) |
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Journal | Angewandte Chemie International Edition |
DOIs | |
State | Published - Sep 2 2021 |
Bibliographical note
KAUST Repository Item: Exported on 2021-09-07Acknowledgements: This work is supported by the National Natural Science Foundation of China (No. 21972136, 21991090, and 21991091), the Pioneer Hundred Talents Program, Chinese Academy of Sciences (No. Y706071202), the Dalian National Laboratory for Clean Energy Cooperation Fund, Chinese Academy of Sciences (No. DNL201908), the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (No. QYZDB-SSW-JSC040), and the Center Competitive Fund (CCF) to Yu Han from King Abdullah University of Science and Technology. Dr. Nana Yan acknowledges financial support from the CAS Special Research Assistant Program and the scholarship from STOE. We thank Dr. Lei Wang (Nanjing Tech University) for optimizing hypothetical structures. We thank the assistance from Professor Hao Wang at Hoffmann Institute of Advanced Materials about adsorption isotherms of nHEX, 3MP, and 22DMB at different temperatures. We also thank Mr. Yingjiang Lian from Dalian Institute of Chemical Physics for his assistance in the synthesis of OSDA.
ASJC Scopus subject areas
- General Chemistry
- Catalysis