Rigid nanoscopic containers for highly dispersed, stable metal and bimetal nanoparticles with both size and site control Article

cited authors

  • Wang, C; Zhu, G; Li, J; Cai, X; Wei, Y; Zhang, D; Qiu, S

fiu authors

abstract

  • We demonstrate a novel strategy for the preparation of mesoporous silica-supported, highly dispersed, stable metal and bimetal nanoparticles with both size and site control. The supporting mesoporous silica, function-alined by polyaminoamine (PAMAM) dendrimers, is prepared by repeated Michael addition with methyl acrylates (MA) and amidation reaction with ethylenediamine (EDA), by using amino-propyl-functionalized mesoporous silica as the starting material. The encapsulation of metal nanoparticles within the dendrimer-propagated mesoporous silica is achieved by the chemical reduction of metal-salt- impregnated dendrimer-mesoporous silica by using aqueous hydrazine. The site control of the metal or bimetal nanoparticles is accomplished by the localization of inter- or intradendrimeric nanoparticles within the mesoporous silica tunnels. The size of the encapsulated nanoparticles is controlled by their confinement to the nanocavity of the dendrimer and the mesopore. For Cu and Pd, particles locate at the lining of mesoporous tunnels, and have diameters of less than 2.0 nm. For Pd/Pt, particles locate at the middle of mesoporous tunnels and have diameters in the range of 2.0-4.2 nm. The Pd and Pd/Pt nanoparticles are very stable in air, whereas the Cu nanoparticles are stable only in an inert atmosphere. © 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

publication date

  • August 19, 2005

Digital Object Identifier (DOI)

start page

  • 4975

end page

  • 4982

volume

  • 11

issue

  • 17