State of Pt in Dried and Reduced PtIn and PtSn Catalysts Supported on Carbon
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- 作者：M. Carmen Romá ; n-Martí ; nez ; Juan A. Maciá ; -Agulló ; I. Ma. Julieta Vilella ; Diego Cazorla-Amoró ; s ; Hiromi Yamashita
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：March 29, 2007
- 年：2007
- 卷：111
- 期：12
- 页码：4710 - 4716
- 全文大小：210K
- 年卷期：v.111,no.12(March 29, 2007)
- ISSN：1932-7455
文摘
The state of platinum in carbon-supported bimetallic PtSn and PtIn catalysts, prepared by two different methods,coimpregnation and successive impregnation, has been investigated by X-ray photoelectron spectroscopy,X-ray absorption fine structure (XAFS), transmission electron microscopy (TEM), and a catalytic test. Animportant effect of the nature of the second metal in the state of platinum, related to the preparation conditions,has been found. Different states of platinum are found, mainly platinum metal and binary intermetalliccompounds with the second metal. The preparation method has a clear effect on the state of platinum inreduced PtSn samples, while it is much lower in the reduced PtIn catalysts. As deduced from TEM, in generalin the bimetallic catalysts the mean particle size is smaller and the particle size distribution is narrower thanin the monometallic Pt/C catalyst, and there is an effect of the preparation method. In general, PtIn catalystsare more homogeneous than PtSn. Because of the mentioned differences, catalytic activity for cyclohexanedehydrogenation, a structure insensitive test reaction, depends on the second metal and preparation method.