Ab initio structure determination and quantitative disorder analysis on nanoparticles by electron diffraction tomography.

Acta Crystallogr A Found Adv

Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg University, Jakob-Welder-Weg 11, Mainz, D-55128, Germany.

Published: March 2018

Nanoscaled porous materials such as zeolites have attracted substantial attention in industry due to their catalytic activity, and their performance in sorption and separation processes. In order to understand the properties of such materials, current research focuses increasingly on the determination of structural features beyond the averaged crystal structure. Small particle sizes, various types of disorder and intergrown structures render the description of structures at atomic level by standard crystallographic methods difficult. This paper reports the characterization of a strongly disordered zeolite structure, using a combination of electron exit-wave reconstruction, automated diffraction tomography (ADT), crystal disorder modelling and electron diffraction simulations. Zeolite beta was chosen for a proof-of-principle study of the techniques, because it consists of two different intergrown polymorphs that are built from identical layer types but with different stacking sequences. Imaging of the projected inner Coulomb potential of zeolite beta crystals shows the intergrowth of the polymorphs BEA and BEB. The structures of BEA as well as BEB could be extracted from one single ADT data set using direct methods. A ratio for BEA/BEB = 48:52 was determined by comparison of the reconstructed reciprocal space based on ADT data with simulated electron diffraction data for virtual nanocrystals, built with different ratios of BEA/BEB. In this way, it is demonstrated that this smart interplay of the above-mentioned techniques allows the elaboration of the real structures of functional materials in detail - even if they possess a severely disordered structure.

Download full-text PDF

Source
http://dx.doi.org/10.1107/S2053273317018277DOI Listing

Publication Analysis

Top Keywords

electron diffraction
12
diffraction tomography
8
zeolite beta
8
adt data
8
initio structure
4
structure determination
4
determination quantitative
4
quantitative disorder
4
disorder analysis
4
analysis nanoparticles
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!