Preparation of Mesoporous Pd/Si3N4 Nanocomposites as Heterogeneous Catalysts via Three Different Chemical Routes

详细信息    查看全文

• 作者：Fei Cheng ; Stephen M. Kelly ; Nigel A. Young ; Chris N. Hope ; Katie Beverley ; M. Grazia Francesconi ; Stephen Clark ; John S. Bradley ; Fré ; dé ; ric Lefebvre
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：December 12, 2006
• 年：2006
• 卷：18
• 期：25
• 页码：5996 - 6005
• 全文大小：437K
• 年卷期：v.18,no.25(December 12, 2006)
• ISSN：1520-5002

文摘

Mesoporous palladium/silicon nitride nanocomposites were prepared via three different chemical routesto generate simultaneous control of the solid-state morphology of the palladium nanoparticles and that ofthe silicon nitride support at the same time as controlling the pore size and size distribution. Pyrolysis ofthe reaction product of silicon diimide gel with PdCl₂ under a NH₃ flow at 1000 mages/entities/deg.gif">C gave a compositewith highly crystalline Pd nanoparticles dispersed in an mages/gifchars/alpha.gif" BORDER=0>-Si₃N₄ matrix. A composite with partiallycrystallized Pd nanoparticles dispersed in an amorphous Si₃N₄ matrix was obtained by the hydrogenreduction of the reaction product of silicon nitride with PdCl₂, whereas hydrogen reduction of animpregnated mixture of Si₃N₄ with bis(dibenzylideneacetone)palladium (DBA) led to the formation of acomposite with amorphous Pd nanoparticles dispersed in an amorphous Si₃N₄ matrix. Most of these newmesoporous nanocomposites exhibit a high surface area >400 m² g^-1 and a narrow pore size distributionof 5-12 nm with a loading of up to 2% Pd nanoparticles 2-20 nm in diameter. Preliminary investigationsshow that these nanocomposites are potentially useful heterogeneous catalysts for a range of liquid-phase chemical reactions.