Heterogeneity of nano-sized zeolite crystals

• Published in: Microporous and mesoporous materials 2020-03, Vol.294, p.109897, Article 109897
• Main Authors: Wennmacher, Julian T.C., Li, Teng, Zaubitzer, Christian, Gemmi, Mauro, Mugnaioli, Enrico, Gruene, Tim, van Bokhoven, Jeroen A.
• Format: Article
• Language: English
• Subjects: Electron crystallography; Energy dispersive X-ray spectroscopy; H-ZSM-5; Heterogeneity between particles; Nanocrystals; TEM
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2019.109897

Analytical characterization and evaluation of performance of zeolite catalysts are normally done under the assumption of a homogeneous batch. However, it is known that in the same batch particles of the zeolite ZSM-5 can be very different one from another, regarding their aluminum content and catalytic performance. Here, we quantify the extent of this heterogeneity within a singular synthesis batch of nanocrystalline ZSM-5, through the analysis of single crystalline individua. We found that the overall aluminum content was distributed unequally between two kinds of crystal populations. Cornered crystals contained three times more aluminum than round-shaped crystals. This observation connects morphological differences to the chemical composition of each zeolite crystal for the first time. This finding could provide a means for performance optimization in zeolite synthesis. [Display omitted] •A singular synthesis batch of nano-ZSM-5 crystals can yield very different crystals.•The aluminium content of some crystalline individua was up to threefold higher than the overall determined aluminium content.•Morphology was linked to chemical composition: Cornered crystals contained more aluminium than round-shaped crystals.