Modeling the Structure and Composition of Nanoparticles by Extended X-Ray Absorption Fine-Structure Spectroscopy
Modeling the Structure and Composition of Nanoparticles by Extended X-Ray Absorption Fine-Structure Spectroscopy
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DOI：
10.1146/annurev-anchem-061010-113906
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发表时间：
2011-01-01
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影响因子：
--
通讯作者：
Vasic, Relja
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文献类型：
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作者：
Frenkel, Anatoly I.;Yevick, Aaron;Vasic, Relja
许多金属团簇在1 nm的尺寸范围内具有催化活性，它们的反应活性的提高通常归因于它们的尺寸、结构、形貌和合金化的细节。同步加速器源为研究催化提供了广泛的机会。其中，扩展X射线吸收精细结构(EXAFS)光谱是研究纳米催化剂结构和组成的首选方法。在这篇综述中，我们总结了EXAFS分析纳米颗粒几何和组成表征的常用方法。我们讨论了实验和分析的几个方面，这些方面对于可靠地模拟EXAFS数据是至关重要的。最重要的是样品的均匀性、大小和成分分布函数的宽度，以及对EXAFS的多次散射贡献。我们着重于结构无序和结构/成分的异质性对三维建模精度的贡献。
Many metal clusters in the 1-nm size range are catalytically active, and their enhanced reactivity is often attributed to their size, structure, morphology, and details of alloying. Synchrotron sources provide a wide range of opportunities for studying catalysis. Among them, extended X-ray absorption fine-structure (EXAFS) spectroscopy is the premier method for investigating structure and composition of nanocatalysts. In this review, we summarize common methods of EXAFS analysis for geometric and compositional characterization of nanoparticles. We discuss several aspects of the experiments and analyses that are critical for reliably modeling EXAFS data. The most important are sample homogeneity, the width of the size and compositional distribution functions, and accounting for multiple-scattering contributions to EXAFS. We focus on the contribution of structural disorder and structural/compositional heterogeneity to the accuracy of three-dimensional modeling.