Structural analysis of sonochemically prepared Au/Pd nanoparticles dispersed in porous silica matrix

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• 作者：Nakagawa ; Takashi ; Nitani ; Hiroaki ; Tanabe ; Shuji ; Okitsu ; Kenji ; Seino ; Satoshi ; Mizukoshi ; Yoshiteru ; et. al.
• 关键词：81.07.Bc ; Nanoparticles ; Bimetallic particles ; XAFS ; Structural analysis ; Gold ; Palladium
• 刊名：Ultrasonics Sonochemistry
• 出版年：2005
• 出版时间：March, 2005
• 年：2005
• 卷：12
• 期：4
• 页码：249-254
• 全文大小：719 K

文摘

Bimetallic Au/Pd nanoparticles supported on a silica matrix were prepared by an ultrasonic technique. The samples heat-treated at 100, 200, 300 and 400 °C were examined with techniques of XRD (X-ray diffraction), TEM and XAS (X-ray absorption spectrometry) for studying correlation between their structure and the catalytic activity of hydrogenation of cyclohexene. Even after the heat treatment at 400 °C, the particles were smaller than 20 nm and well dispersed in the matrix without agglomeration nor sintering. Results of the XRD, TEM and XAS indicated that the as-prepared particles have a core/shell structure of Au/Pd and transform into a random alloy at 300 °C. The catalysis seemed to be deactivated by alloying.