Formation of Pt islets on facets of Ru nanoparticles: First-principles study

被引：6

作者：

Ortigoza, Marisol Alcantara ^{[1
]}

Stolbov, Sergey ^{[1
]}

Rahman, Talat S. ^{[1
]}

机构：

[1] Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA

来源：

PHYSICAL REVIEW B | 2008年 / 78卷 / 19期

关键词：

adsorbed layers; anodes; catalysts; density functional theory; diffusion; direct methanol fuel cells; island structure; nanoparticles; platinum; ruthenium;

D O I：

10.1103/PhysRevB.78.195417

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have carried out density-functional-theory-based calculations of the size-dependent formation energy and geometry of Pt islands on Ru(0001) to model Pt-Ru nanocatalysts which have been recently proposed as fuel cell anode. The Pt islands are found to prefer two-dimensional (2D) structures. Furthermore, a monotonic decrease in the formation energy per Pt atom suggests a propensity of Pt atoms to wet the Ru(0001) surface. Calculated energy barriers for the diffusion of Pt monomers and dimers on the facets and through the edges of a superstructure modeling a Ru nanoparticle indicate that these edges help reduce considerably the diffusion rates across them such that the Pt atoms prefer to remain in the facet on which they were adsorbed originally and form 2D islands.

引用

页数：9

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