IR Microimaging of Direction‐Dependent Uptake in MFI‐Type Crystals

• Published in: Chemie ingenieur technik Vol. 89; no. 12; pp. 1686 - 1693
• Main Authors: Hwang, Seungtaik, Parditka, Bence, Cserháti, Csaba, Erdélyi, Zoltán, Gläser, Roger, Haase, Jürgen, Kärger, Jörg, Schmidt, Wolfgang, Chmelik, Christian
• Format: Journal Article
• Language: English
• Published: 01.12.2017
• Subjects: Catalysis; Diffusion; Microimaging; Nanoporous materials; Zeolite
• ISSN: 0009-286X; 1522-2640
• DOI: 10.1002/cite.201700128

Covering MFI‐type zeolite crystals with Al2O3 by atomic layer deposition is shown to make the external zeolite crystal impermeable for guest molecules. By corresponding manipulations of the crystal certain faces can be opened for guest molecules. In this way, IR microimaging can be applied to record the evolution of transient intracrystalline concentration profiles along the crystals longitudinal extension. The introduced method of covering may provide the possibility of observing fluxes of reactant and product molecules within single zeolite crystals during catalytic reactions. Covering MFI‐type zeolite crystals with Al2O3 by atomic layer deposition is shown to make the external surface impermeable for guest molecules. After breaking the crystals, molecular fluxes in longitudinal extension can be observed using IR microimaging. The interplay of diffusion anisotropy and the MFI crystal intergrowth structure can be studied directly.