Reference : Synthesis of SiO2 xerogels and Pd/SiO2 cogelled xerogel catalysts from silylated acet...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Chemistry
Engineering, computing & technology : Chemical engineering
http://hdl.handle.net/2268/20079
Synthesis of SiO2 xerogels and Pd/SiO2 cogelled xerogel catalysts from silylated acetylacetonate ligand
English
Lambert, Stéphanie mailto [Université de Liège - ULg > Département de chimie appliquée > Génie chimique - Chimie physique appliquée > >]
Sacco, Luigi [> > > >]
Ferauche, Fabrice [Université de Liège - ULG > Département de Chimie appliquée > Génie chimique - Chimie physique appliquée > >]
Heinrichs, Benoît mailto [Université de Liège - ULg > Département de chimie appliquée > Génie chimique - Chimie physique appliquée > >]
Noels, Alfred mailto [Université de Liège - ULg > Services généraux (Faculté des sciences) > Relations académiques et scientifiques (Sciences) >]
Pirard, Jean-Paul mailto [Université de Liège - ULg > Département de chimie appliquée > Génie chimique - Chimie physique appliquée > >]
1-Sep-2004
Journal of Non-Crystalline Solids
Elsevier Science Bv
343
1-3
109-120
Yes (verified by ORBi)
International
0022-3093
Amsterdam
[en] METAL DISPERSION ; 1,2-DICHLOROETHANE ; HYDRODECHLORINATION ; PALLADIUM ; DECHLORINATION ; COMPLEXES ; AEROGELS ; AG/SIO2
[en] SiO2 xerogels and Pd/SiO2 cogelled xerogel catalysts have been prepared in a mixture of tetrahydrofurane (THF) and ethanol containing tetraethoxysilane (TEOS), and an aqueous ammonia solution of 0.18 mol/l, from synthesized new silylated acetylacetonate ligands, respectively, 3-[3-(trimethoxysilyl)propyl]-2,4-pentanedione (MS-acac-H), 2,2,6,6-tetramethyl-4-[3-(trimethoxysilyl)propyl]-3,5-heptanedione (MS-dPvM), and 1,3-diphenyl-2-[3-(trimethoxysilyl)propyl]-1,3-propanedione (MS-dBzM), able to form a chelate with a metal ion such as Pd2+. All samples form homogeneous colored gels. The resulting catalysts are composed of palladium crystallites with a diameter of about 3.5 nm, located inside primary silica particles exhibiting a monodisperse microporous distribution as well as large palladium particles from 20 to 50 nm, situated outside the silica aggregates. The silylated organic ligand has a strong influence on the textural properties of xerogels and catalysts, both before and after calcination and reduction steps. Changing the nature of the silylated ligand permits tailoring textural properties such as pore volume, pore size and surface area. Although small palladium crystallites are located inside the silica particles, their complete accessibility, via the micropore network, has been shown. 1,2-Dichloroethane hydrodechlorination over Pd/SiO2 catalysts mainly produces ethane and the reaction rate increases linearly with palladium dispersion. Hydrodechlorination over Pd/SiO2 cogelled xerogel catalysts is a structure insensitive reaction compared to the ensemble size concept. (C) 2004 Elsevier B.V. All rights reserved.
Fonds de la Recherche Scientifique (Communauté française de Belgique) - F.R.S.-FNRS
http://hdl.handle.net/2268/20079
also: http://hdl.handle.net/2268/17765

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