Stability and Electronic Structures of Pt-Rh Icosahedral Nanoparticles
Stability and Electronic Structures of Pt-Rh Icosahedral Nanoparticles
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DOI：
10.2320/matertrans.m2011055
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发表时间：
2011-07
影响因子：
1.2
通讯作者：
Koretaka Yuge
中科院分区：
文献类型：
--
作者：
Koretaka Yuge
基于第一性原理计算研究了Pt-Rh二十面体纳米粒子的能量稳定性和电子结构。我们发现Pt原子在能量上更倾向于在表面的顶点和边缘位置，而不是亚表面和核心位置，这是一种类似于PtRh立方八面体纳米颗粒的趋势。这可以归因于与Rh相比Pt的较低表面能。配位数次低的纳米颗粒边缘是Pt原子最有利的位置。这可能是由于增强的原子间的距离在边缘网站。Pt原子d态电子贡献的一阶矩与Pt配位数几乎呈负相关。这可以定性地解释为Pt原子的态密度的二阶矩对配位数的正相关性。Pt表面偏析预计主要是由于贡献Pt的现场偏析能量相比，弱有序化倾向的Pt-Rh不喜欢的原子对。[doi：10.2320/matertrans.M2011055]
We investigate the energetic stability and electronic structures of Pt-Rh icosahedral nanoparticles based on first-principles calculations. We find that Pt atom energetically prefers vertex and edge sites at the surface rather than subsurface and core sites, which is a tendency similar to PtRh cuboctahedral nanoparticles. This can be attributed to lower surface energy of Pt compared with Rh. Edges of nanoparticles with secondlowest coordination number are the most favorable sites for Pt atom. This could be attributed to the enhanced interatomic distance at the edge site. 1st order moment of d-state electronic contribution for Pt atom exhibits almost negative dependence in terms of Pt coordination number. This can be qualitatively interpreted by positive dependence of 2nd order moment of the density of states for the Pt atom on the coordination number. Pt surface segregation is expected mainly due to contribution from Pt on-site segregation energy compared with weak ordering tendency of Pt-Rh unlike-atom pairs. [doi:10.2320/matertrans.M2011055]