Study of bimetallic Pd–Pt clusters in both free and supported phases

Rousset, Jean; Cadrot, A. M.; Aires, F.J. Cadete Santos; Renouprez, A.J.; Mélinon, P.; Pérez, A.; Pellarin, M.; Vialle, Jean; Broyer, M.

doi:10.1063/1.468847

Cited by 77 publications

(36 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 that the Pd atoms are enriched in the surface shell covering the Pt atoms, which implies the surface segregation phenomenon of Pd atoms. This observation is in good agreement with the results from the experimental [13,14] and theoretical methods [15][16][17]. The richer Pd atoms on the surface enables the cluster surface energy to be minimized, due to the lower surface energy of Pd (125 $ 131 meV Å À2 ), compared with Pt (155 $ 159 meV Å À2 ) [16].…”

Section: Resultssupporting

confidence: 87%

“…It is reported that the catalytic activity depends on the structure of the bimetallic clusters. Rousset and coworkers observed a sequential evaporation of Pd atoms in the Pd-Pt bimetallic clusters consistent with a Pd segregation process by experimental methods [13]. Fiermans and coworkers evidenced Pd segregation to the surface of the supported bimetallic clusters with X-ray photoelectron spectroscopy [14].…”

Section: Introductionmentioning

confidence: 88%

“…The sequential evaporation of Pd atoms in the Pd-Pt bimetallic clusters is consistent with a Pd segregation process. However, they did not predict whether the segregation occurs in the solid phase or in the liquid phase of small clusters [13]. In this work, we observed the segregation phenomenon in the solid phase of 55-atom Pd-Pt bimetallic clusters by using Monte Carlo simulation.…”

Section: Comparison Of Simulation and Experimentsmentioning

confidence: 95%

See 2 more Smart Citations

Structures of small Pd–Pt bimetallic clusters by Monte Carlo simulation

Cheng¹,

Huang²,

Wang³

2006

Chemical Physics

View full text Add to dashboard Cite

Section: Resultssupporting

confidence: 87%

Section: Introductionmentioning

confidence: 88%

Section: Comparison Of Simulation and Experimentsmentioning

confidence: 95%

See 1 more Smart Citation

Structures of small Pd–Pt bimetallic clusters by Monte Carlo simulation

Cheng¹,

Huang²,

Wang³

2006

Chemical Physics

View full text Add to dashboard Cite

“…In particular, there has been a significant amount of work at the level of sophisticated electronic structure calculations, 1,2,3 but these were often limited to small sizes due to the numerical effort involved. On a different scale of chemical complexity, many studies have been carried out using explicit, empirical force fields 4,5,6,7,8,9,10,11,12 in order to investigate the segregation properties of these clusters.…”

Section: Introductionmentioning

confidence: 99%

Composition-induced structural transitions in mixed rare-gas clusters

Calvo

Yurtsever

2004

Phys. Rev. B

View full text Add to dashboard Cite

The low-energy structures of mixed Ar-Xe and Kr-Xe Lennard-Jones clusters are investigated using a newly developed parallel Monte Carlo minimization algorithm with specific exchange moves between particles or trajectories. Tests on the 13-and 19-atom clusters show a significant improvement over the conventional basin-hopping method, the average search length being reduced by more than one order of magnitude. The method is applied to the more difficult case of the 38-atom cluster, for which the homogeneous clusters have a truncated octahedral shape. It is found that alloys of dissimilar elements (Ar-Xe) favor polytetrahedral geometries over octahedra due to the reduced strain penalty. Conversely, octahedra are even more stable in Kr-Xe alloys than in Kr38 or Xe38, and they show a core-surface phase separation behavior. These trends are indeed also observed and further analysed on the 55-atom cluster. Finally, we correlate the relative stability of cubic structures in these clusters to the glassforming character of the bulk mixtures.

show abstract

“…In particular, the calculated surface energies are somewhat underestimated [56] and the deviation increases with decreasing Z. This is also the case for Pd [57].…”

Section: Second Moment Approximation For Pd-pd Interactionsmentioning

confidence: 71%

Non‐reactive metal/oxide interfaces: from model calculations towards realistic simulations

Goniakowski¹,

Mottet

Noguera

2006

Physica Status Solidi (b)

View full text Add to dashboard Cite

International audienceIn the last decade two principal factors have stimulated the progressive regain of interest for non-reactive metal/oxide interfaces. On one hand, the efforts invested by the community of model catalysis in analyzing the reactivity properties of supported metal nano-clusters have resulted in an abundance of high quality experimental data. They have also risen several precise questions on the direct and indirect role played by the substrate in the determination of catalytic properties of deposited metal particles, and have thus reiterated the interrogations concerning the nature of interactions at the metal/oxide interfaces. On the other hand, conceptual improvements of first-principles calculations, such as implementations of various GGA functionals, have added enormously to the reliability of these methods, and have enlarged considerably their field of application. However, most ab initio simulations are sooner or later confronted to the constrains on the computational cost, inherent of this kind of approaches. It concerns principally the limited size of systems which can be treated in practice, a factor which turns out to be particularly limiting in realistic studies of interfaces, where the mismatch of lattice parameters is at the origin of incommensurate interface structures, long-range reconstructions, or/and complex structural deformations and dislocations. In this context, the goal of this paper is two-fold. First, we give an overview of essential metal/oxide interface characteristics as obtained from ab initio calculations on model systems, with a special focus on late transition metals, such as Pd, and on a highly ionic oxide substrate, such as MgO. It includes results on the relation between the strength of interfacial interaction and the type of deposited metal (transition, noble), the nature of metal deposit (isolated atoms, constituted interface), and the character of the substrate (non-polar, polar). We also comment on effects due to defects at the oxide surface. Secondly, we describe an effective approach to simulate non-reactive deposition of nano-scale metal objects on a surface of highly ionic oxide. The core of this approach is a many-body potential energy surface (PES) constructed on the basis of results of ab initio calculations for model metal/oxide interface structures. We present its application to studies on the deposition of late transition metals (Pd, Ag) on the MgO(100) surface, including the determination of substrate-induced change of equilibrium atomic structure and morphology of metal nano-clusters, the analysis of stress release at the interface, and the investigation of the role of the oxide substrate on the melting properties of supported clusters. (c) 2006 WILEYNCH Verlag GmbH & Co. KGaA, Weinheim

show abstract

Study of bimetallic Pd–Pt clusters in both free and supported phases

Cited by 77 publications

References 30 publications

Structures of small Pd–Pt bimetallic clusters by Monte Carlo simulation

Structures of small Pd–Pt bimetallic clusters by Monte Carlo simulation

Composition-induced structural transitions in mixed rare-gas clusters

Non‐reactive metal/oxide interfaces: from model calculations towards realistic simulations

Contact Info

Product

Resources

About