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Synthesis and Characterization of Epitaxial FAU‐on‐EMT Zeolite Overgrowth Materials
Author(s) -
Goossens Ann M.,
Wouters Bart H.,
Grobet Piet J.,
Buschmann Veronique,
Fiermans Lucien,
Martens Johan A.
Publication year - 2001
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200105)2001:5<1167::aid-ejic1167>3.0.co;2-z
Subject(s) - crystallite , x ray photoelectron spectroscopy , nucleation , crystallization , chemistry , physisorption , epitaxy , crystallography , mesoporous material , chemical engineering , zeolite , scanning electron microscope , magic angle spinning , materials science , layer (electronics) , nuclear magnetic resonance spectroscopy , adsorption , stereochemistry , composite material , organic chemistry , engineering , catalysis
Epitaxial FAU zeolite films were achieved on micrometer‐sized EMT support crystals using a two‐step synthetic procedure, in which EMT support crystals with hexagonal‐platelet morphology, were added to a synthesis gel for the crystallization of an FAU phase. Identification of the appropriate synthesis parameters made it possible to suppress homogeneous nucleation and initial breeding, and to promote the secondary nucleation of the FAU crystallites on the surface of the EMT support crystals. The presence of both an FAU and an EMT phase was verified with powder X‐ray diffraction (XRD). Scanning electron microscopy (SEM) was used to confirm the formation of a layer of FAU crystallites on the EMT support crystals. The growth of the FAU phase was found to start at the corners and edges of the EMT support. An FAU crystallization front progressed from the edges towards the center of the hexagon until the EMT support crystals became completely covered by an FAU zeolite film with a thickness of ca. 300 nm. The compositional difference between the EMT support and the FAU film was investigated with 29 Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy, X‐ray photoelectron spectroscopy (XPS) and energy‐dispersive analysis of X‐rays (nano‐EDAX). The continuous nature of the film was confirmed by the absence of intracrystalline mesopores, which was evidenced by nitrogen physisorption.