Phase analysis and structure characterization are essential in the developments of new zeolite materials. The conventional methods have been X-ray diffraction. I will present several new 3D electron diffraction (ED) techniques for such purposes and show their advantages over X.-ray diffraction; rotation electron diffraction (RED), continuous rotation electron diffraction (cRED), and serial crystallography using electron diffraction (SX-ED).<br/>RED is a software-based method for automated collection of complete 3D ED data. More than 1000 ED frames can be collected from an arbitrarily oriented crystal in less than an hour and used for solving unknown zeolite structures. In combination with a fast hybrid pixel quantum area detector, cRED data is collected by continuous goniometer tilt. Today complete cRED data can be collected in 15-150 seconds, and a structure determination can be achieved within a few hours, from the data collection to structure solution. RED/cRED methods have shown to be powerful for structure determination of zeolite crystals too small or too complex for X-ray diffraction.<br/>To further automate the data collection, we have developed SX-ED by taking ED patterns (snapshots) of individual randomly oriented particles. ED patterns from 3000 particles can be collected automatically in less than one hour! The large number of particles makes it possible for quantitative phase analysis, and for detection of minor phases that may not be detectable even by X-ray diffraction.<br/>I will demonstrate the 3D ED method for accurate structure determination of novel zeolites and phase analysis. I will show how RED data initiated the development of a novel approach that combines structure solution with structure prediction, and inspires subsequent targeted synthesis of new super-complex zeolites. Finally I demonstrate the combination of RED and high resolution transmission electron microscopy (HRTEM) /electron tomography (ET) for studying complex and mesostructured zeolite structures.  <br/>

Automated electron diffraction techniques for phase analysis and structure characterization of zeolite materials

255th National Meeting (2018)

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