Three-dimensional inhomogeneity of zeolite structure and composition revealed by electron ptychography

• 成果类型: Article
• 署名作者: Zhang, Hui; Li, Guanxing; Zhang, Jiaxing; Zhang, Daliang; Chen, Zhen; Liu, Xiaona; Guo, Peng; Zhu, Yihan; Chen, Cailing; Liu, Lingmei; Guo, Xinwen; Han, Yu
• 署名单位: South China University of Technology; South China University of Technology; King Abdullah University of Science & Technology; Dalian University of Technology; State Key Laboratory Surfactant Fine Chemistry; Chongqing University; Chongqing University; Tsinghua University; Chinese Academy of Sciences; Dalian Institute of Chemical Physics, CAS; Zhejiang University of Technology; Zhejiang University of Technology; Zhejiang University of Technology
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8614
• DOI: 10.1126/science.adg3183
• 发表日期: 2023-05-11
• 页码: 633-638
• 关键词: acid sites; comparative nmr; RESOLUTION; aluminum; trimethylphosphine; tomography; microscopy; nanosheets; mordenite

摘要

Structural and compositional inhomogeneity is common in zeolites and considerably affects their properties. Thickness-limited lateral resolution, lack of depth resolution, and electron dose-constrained focusing limit local structural studies of zeolites in conventional transmission electron microscopy (TEM). We demonstrate that a multislice ptychography method based on four-dimensional scanning TEM (4D-STEM) data can overcome these limitations. Images obtained from a similar to 40-nanometer-thick MFI zeolite exhibited a lateral resolution of similar to 0.85 angstrom that enabled the identification of individual framework oxygen (O) atoms and the precise determination of the orientations of adsorbed molecules. Furthermore, a depth resolution of similar to 6.6 nanometers allowed probing of the three-dimensional distribution of O vacancies, as well as the phase boundaries in intergrown MFI and MEL zeolites. The 4D-STEM ptychography can be generally applied to other materials with similar high electron-beam sensitivity.