Stability of Au–Pd Core–Shell Nanoparticles

Abstract

The stability of Au−Pd alloys with sizes close to 3 nm and icosahedral, decahedral, and truncated octahedral geometries with Au core Pd shell and Pd core Au shell elemental distributions have been studied using canonical molecular dynamics simulations. The analysis of excess energy show that the Pd core Au shell ordering is more stable than the Au core Pd shell for particles of this size, while the analysis of the order parameter Q 6 revealed that some of the particles with Au core Pd shell ordering exhibited geometric and structural changes previous to melting of the particles. Analysis of the local density of the species revealed that these changes are due to diffusion of Pd atoms into the inner core of the particles. The geometry and structure of all of the particles with Pd core Au shell were preserved until just before the solid−liquid transition, as well as showing a lower melting temperature than the Au core Pd shell particles.

Bonding and properties of superatoms. Analogs to atoms and molecules and related concepts from superatomic clusters

“…In accordance with this, the Au@Pd nanoparticle appears as a suitable candidate for long‐term hydrogen storage. In this sense, calculated by Fernández‐Navarro and Mejía‐Rosales, accounting for the stability of Au@Pd core‐shell nanoparticles with nuclearities of 561 and 586 owing to the respective icosahedral, decahedral, and truncated octahedral structures.…”

Bimetallic Au–Pd nanoparticles supported on silica with a tunable core@shell structure: enhanced catalytic activity of Pd(core)–Au(shell) over Au(core)–Pd(shell)

“…On the contrary, anti-galvanic core-shell nanoparticles with Pdcore-Aushell structures are relatively few and limited in scope. 20,21 In fact, a number of theoretical studies involving molecular dynamics simulation 22,23 and density functional theory (DFT) 24 have envisaged that in a core-shell structure, the Pdcore-Aushell arrangement is deemed more stable than the Aucore-Pdshell arrangement. This theoretical outcome is further reinforced by a few experimental works that demonstrated the synthesis of stable Au-Pd coreshell nanoparticles with Pdcore-Aushell arrangement and their application as catalysts for different organic transformations like hydrogenation, 20 selective oxidation of alcohol, 21 photocatalytic oxidation, 25 etc.…”

Molecular Dynamics Investigation on Thermal Stability and Shape Evolution of Pd-Au Heterostructured Nanorods: Implications for Catalysis

“…As a novel heterostructure, fcc -2H- fcc Pd@Au nanorods synthesized recently not only have a unique morphology but also exhibit excellent catalytic properties . Although there are existing simulations performed to investigate the thermal stability of Pd@Au and Au@Pd core-shell polyhedron structures, a fundamental understanding of the fcc -2H- fcc Pd@Au nanorod thermal stability is still lacking. Therefore, in this work, we addressed these fcc -2H- fcc Pd-Au heterostructured nanorods and explored their structural and shape evolutions during heating by using molecular dynamics (MD) simulations.…”