Multiple Scattering Approach to Pt L3-edge X-Ray Absorption near Edge Structure Spectra of Small Pt Clusters with Hydrogen Adsorption
Multiple Scattering Approach to Pt L3-edge X-Ray Absorption near Edge Structure Spectra of Small Pt Clusters with Hydrogen Adsorption
复制标题
氢吸附小 Pt 团簇近边缘结构光谱的 Pt L3 边缘 X 射线吸收的多重散射方法
DOI：
10.1143/jjap.36.6504
复制
发表时间：
1997
影响因子：
1.5
通讯作者：
Y. Iwasawa
中科院分区：
文献类型：
--
作者：
K. Ohtani;T. Fujikawa;T. Kubota;K. Asakura;Y. Iwasawa
近期对铂团簇的铂L边X射线吸收近边结构（XANES）光谱的实验研究表明，光谱受氢吸附的影响很大。在本文中，我们所开发的完全多重散射方法被用于研究氢吸附前后所测XANES光谱的差异。尽管计算所得的光谱对吸附位点不是很敏感，但氢原子更有可能吸附在团簇外的位点上，而非团簇内的吸附位点。由于电荷从铂原子转移，吸附的氢原子带有较多负电荷。在电荷转移过程中，铂的6s（或6p）电子比5d电子起着更重要的作用。此外，还研究了铂箔和小团簇的XANES光谱的微小差异，我们发现这是由于后者体系中表面铂原子所占比例较大。
Recent experimental studies on the Pt L-edge X-ray absorption near edge structure (XANES) spectra of Pt clusters show that the spectra are greatly influenced by hydrogen adsorption. In this paper the full multiple scattering method, which we developed, is applied to study the difference in measured XANES spectra before and after the hydrogen adsorption. Hydrogen atoms are more plausible on adsorbed sites out of the cluster than on absorbed sites inside the cluster though the calculated spectra are not so sensitive to the adsorption sites. The adsorbed hydrogen atoms have rather negative charge due to the charge transfer from Pt atoms. In the charge transfer process Pt 6s (or 6p) electrons play a more important role than 5d electrons. Furthermore the small difference in the XANES spectra for Pt foil and small cluster is studied, and we find that it is due to the large fraction of surface Pt atoms in the latter system.