Preparation and morphology of pyramidal MFI single-crystal segments.
Single-crystal segments of tetra-n-propylammonium-templated Silicalite-1 and ZSM-5 were prepared by postsynthetic treatment of twinned MFI prisms. Microwave irradiation of the parent crystallites in alkaline solution containing hydrogen peroxide, followed by ultrasound treatment, led to disintegration of the zeolite prisms. The resulting wedge-shaped crystal segments proved to be single crystals of excellent crystallinity as shown by optical and X-ray investigations. The hydroxyl ions, compensating the positive charges of the tetrapropylammonium cations, were located by single-crystal structure refinement in template-containing Silicalite-1 and ZSM-5 but absent from the calcined samples.
Schmidt
Wolfgang
W
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim a.d. Ruhr, Germany. wolfgang.schmidt@kofo.mpg.de
Wilczok
Ursula
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Weidenthaler
Claudia
C
Medenbach
Olaf
O
Goddard
Richard
R
Buth
Gernot
G
Cepak
Alexander
A