Nucleation and growth mechanism of Pd/Pt bimetallic clusters in sodium bis(2-ethylhexyl)sulfosuceinate (AOT) reverse micelles as studied by in situ X-ray absorption spectroscopy

被引：37

作者：

Chen, CH ^{[1
]}

Hwang, BJ ^{[1
]}

Wang, GR ^{[1
]}

Sarma, LS ^{[1
]}

Tang, MT ^{[1
]}

Liu, DG ^{[1
]}

Lee, JF ^{[1
]}

机构：

[1] Natl Taiwan Univ Sci & Technol, Nanoelectrochem Lab, Dept Chem Engn, Taipei 106, Taiwan

来源：

JOURNAL OF PHYSICAL CHEMISTRY B | 2005年 / 109卷 / 46期

关键词：

D O I：

10.1021/jp054062t

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We report in situ X-ray absorption spectroscopy (XAS) investigations on the formation of palladium -platinum (Pd/Pt) bimetallic clusters at the early stage within the water-in-oil microemulsion system of water/AOT/n-heptane. The reduction of palladium and platinum ions and the formation of corresponding clusters are monitored as a function of dosage of reducing agent, hydrazine (N2H5OH). Upon successive addition of the reducing agent, hydrazine (N2H5OH), five distinguishable steps are observed in the formation process of Pd/Pt clusters at the early stage. Both in situ X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) analysis for both the Pd K-edge and Pt L-III-edge revealed the formation of Pd/Pt bimetallic clusters. A corresponding structural model is proposed for each step to provide a detailed insight into the nucleation and growth mechanism of Pd/Pt bimetallic clusters. We also discussed the atomic distribution of Pd and Pt atoms in Pd/Pt bimetallic clusters based on the calculated XAS structural parameters.

引用

页码：21566 / 21575

页数：10

共 46 条

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