The Complex Crystal Structure and Abundant Local Defects of Zeolite EMM-17 Unraveled by Combined Electron Crystallography and Microscopy

Xiaona Liu; Lingmei Liu; Tingting Pan; Nana Yan; Xinglong Dong; Yuanhao Li; Lu Chen; Peng Tian; Yu Han; Peng Guo; Zhongmin Liu

doi:10.1002/anie.202109957

The Complex Crystal Structure and Abundant Local Defects of Zeolite EMM-17 Unraveled by Combined Electron Crystallography and Microscopy

Angew Chem Int Ed Engl. 2021 Nov 2;60(45):24227-24233. doi: 10.1002/anie.202109957. Epub 2021 Oct 4.

Authors

Xiaona Liu^{1

2}, Lingmei Liu³, Tingting Pan⁴, Nana Yan¹, Xinglong Dong⁴, Yuanhao Li^{1

2}, Lu Chen⁵, Peng Tian¹, Yu Han⁴, Peng Guo¹, Zhongmin Liu^{1

2}

Affiliations

¹ National Engineering Laboratory for Methanol to Olefins, State Energy Low Carbon Catalysis and Engineering R&D Center, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, P. R. China.
² University of Chinese Academy of Sciences, Beijing, 100049, Beijing, P. R. China.
³ Multi-scale Porous Materials Center, Institute of Advanced Interdisciplinary Studies & School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, P. R. China.
⁴ Advanced Membranes and Porous Materials Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
⁵ Thermo Fisher Scientific (China) Co., Ltd. Shanghai, 201203, Shanghai, P. R. China.

PMID: 34473888
DOI: 10.1002/anie.202109957

Abstract

In this study, we successfully solve polymorphs A and B of zeolite EMM-17, which can only crystallize in sub-micrometer-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)×10(12)×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. We also demonstrate that the unique porous structure of EMM-17 enables efficient kinetic separation of C₆ alkane isomers.

Keywords: C6 isomer separation; EMM-17; electron crystallography; zeolites.

Abstract

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