Pt-based cluster have received much attention for their catalytic applications, while its stability property and phase diagram remain unclear. In this work, the structural, thermal and phase stability of Pt–Cu nanoclusters, with various atomic arrangement, morphologies and sizes, are studied by both atomistic simulations and theoretical model. Pt atoms tend to distribute around the surface and Cu atoms prefer occupying inner core, derived from the surface energies, lattice parameters and the binding energy of the metal bond. Furthermore, we focus on the melting points and phase diagrams of Pt–Cu nanoalloys with different morphologies and sizes. The melting point of Pt–Cu nanoparticles rises with the increasing size. The distribution of Pt atoms along surface enhances the structural and thermal stability of the Pt–Cu nanoalloys. This theoretical work serve as a case to explore the stability and segregation properties of nanoalloys by combining atomistic simulations and theoretical model, which provides a deep insight into the effect on the stability and segregation properties of bimetallic nanoparticles.

中文翻译：

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Pt-Cu合金团簇的结构，热和相稳定性的理论研究

铂基团簇由于其催化应用而受到广泛关注，但其稳定性和相图尚不清楚。在这项工作中，通过原子模拟和理论模型研究了具有各种原子排列，形态和尺寸的Pt-Cu纳米团簇的结构，热和相稳定性。根据表面能，晶格参数和金属键的结合能，Pt原子倾向于分布在表面周围，而Cu原子则更倾向于占据内核。此外，我们关注具有不同形态和尺寸的Pt-Cu纳米合金的熔点和相图。Pt-Cu纳米粒子的熔点随尺寸的增加而增加。Pt原子沿表面的分布增强了Pt-Cu纳米合金的结构和热稳定性。