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1775974 
Journal Article 
Incorporation of RuO2 nanoparticles into MFI-type zeolites 
Altwasser, S; Glaser, R; Lo, AS; Liu, PH; Chao, KJ; Weitkamp, J 
2006 
1 
Microporous and Mesoporous Materials
ISSN: 1387-1811 
89 
1-3 
109-122 
WOS:000235441600014 
Ruthenium oxide particles were introduced into the medium pore zeolite ZSM-5 (MFI) by ion exchange in aqueous suspension and by the addition of ruthenium
chloride to the synthesis gel in hydrothermal zeolite syntheses. The latter approach was
systematically studied in the presence and absence of tetrapropyl ammonium ions as organic
structure-directing agents. The materials were characterized by chemical analysis, XRD, SEM,
XANES, EXAFS, HRTEM, hydrogen chemisorption and the competitive hydrogenation of 1-hexene and
2,4,4-trimethyl-1-pentene. This catalytic test reaction was applied to discriminate between
ruthenium species in the zeolite pores and on the outer crystal surface. The addition of
ruthenium chloride during the zeolite synthesis strongly affects the rate of crystallization. In
the case of the template-free synthesis, the presence of ruthenium chloride in the synthesis gel
also changes the size and the morphology of the zeolite crystals. Independent of the preparation
conditions, the ruthenium species are oxidized during the hydrothermal synthesis or during the
post-synthesis modification to ruthenium oxide with ruthenium in the oxidation state +IV.
However, by ion exchange in aqueous suspension or by adding ruthenium chloride to the gel of a
tetrapropyl ammonium-templated hydrothermal synthesis with subsequent calcination, large
anhydrous ruthenium oxide particles are formed. These are predominantly located on the outer
surface of the zeolite crystals. Upon adding ruthenium chloride to a template-free gel of a
hydrothermal ZSM-5 synthesis, hydrous ruthenium oxide nanoparticles can be prepared. The majority
of these particles are between 0.5 nm and 0.9 nm in diameter, located inside the pores of the MFI
structure, and are, thus, available for shape-selective catalytic conversions. (c) 2005 Elsevier
Inc. All rights reserved. 
Ru/Na-ZSM-5 (MFI); addition of ruthenium salts to the gel in a hydrothermal zeolite synthesis; X-ray absorption spectroscopy; shape selectivity; competitive hydrogenation as catalytic test reaction