The palladium-platinum phase diagram

Bharadwaj, S.R.; Kerkar, A.S.; Tripathi, S. N.; Dharwadkar, S.R.

doi:10.1016/0022-5088(91)90245-y

Cited by 40 publications

(26 citation statements)

References 5 publications

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“…This is a clear indication of the formation of PtPd alloy . This is consistent to the fact that the Pt‐Pd system shows no (or negligible) miscibility gap for the whole range of concentrations, forming continuous and homogeneous solid solutions across the entire range of composition by alloying …”

Section: Resultssupporting

confidence: 83%

Self‐Organization Based Fabrication of Bimetallic PtPd Nanoparticles on Transparent Conductive Oxide Substrates

Censabella

Ruffino

Zimbone

et al. 2017

Physica Status Solidi (a)

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Bimetallic PtPd nanoparticles are of special interest for their tunable properties in a wide range of applications as plasmonics, energy storage, catalysis. So, in this work we present a simple and versatile method for the production of bimetallic PtPd nanoparticles on a transparent and conductive substrate, such as fluorine-doped tin oxide/glass (FTO/glass) substrate. The method is based on the deposition of thin Pt/Pd bilayers on the FTO substrate. Then, we induced the melting, alloying, and dewetting process of the Pt and Pd layers by nanosecond laser irradiation with the consequent formation of the bimetallic PtPd nanoparticles. We characterized the nanoparticles by Scanning Electron Microscopy, Rutherford backscattering spectrometry, and X-Ray Diffraction measurements. In particular, the microscopic analysis showed that the average diameter of the nanoparticles is independent on the thickness of the deposited bilayers and on the layers sequence. On the other hand, the X-ray diffraction measurements confirmed that the structure of the nanoparticles consists in a PtPd alloy structure. The formation process of the nanoparticles is, finally, discussed on the basis of the general microscopic mechanisms involved in the laser-induced melting, alloying, and dewetting of the metallic films.

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Section: Resultssupporting

confidence: 83%

Self‐Organization Based Fabrication of Bimetallic PtPd Nanoparticles on Transparent Conductive Oxide Substrates

Censabella

Ruffino

Zimbone

et al. 2017

Physica Status Solidi (a)

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“…Compared with monometallic NPs, bimetallic NPs present various complex structural forms, such as core-shell 1 – 3 , multi-shell 4 and ordered/random mixed solid-solution alloy NPs 5 – 7 . Furthermore, face-centred cubic (fcc) packed palladium and platinum noble metals can form a continuous solid-solution alloy for all compositions at high temperatures above 1043 K 8 . Density functional theory studies have shown that a Pd 1− x Pt x solid-solution phase is thermodynamically stable in the nanoparticle phase at 373 K, although Pd and Pt are immiscible in their bulk phases 9 .…”

Section: Introductionmentioning

confidence: 99%

Hydrogen storage and stability properties of Pd–Pt solid-solution nanoparticles revealed via atomic and electronic structure

Kumara

Sakata

Kobayashi

et al. 2017

Sci Rep

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Bimetallic Pd1−xPtx solid-solution nanoparticles (NPs) display charging/discharging of hydrogen gas, which has relevance for fuel cell technologies; however, the constituent elements are immiscible in the bulk phase. We examined these material systems using high-energy synchrotron X-ray diffraction, X-ray absorption fine structure and hard X-ray photoelectron spectroscopy techniques. Recent studies have demonstrated the hydrogen storage properties and catalytic activities of Pd-Pt alloys; however, comprehensive details of their structural and electronic functionality at the atomic scale have yet to be reported. Three-dimensional atomic-scale structure results obtained from the pair distribution function (PDF) and reverse Monte Carlo (RMC) methods suggest the formation of a highly disordered structure with a high cavity-volume-fraction for low-Pt content NPs. The NP conduction band features, as extracted from X-ray absorption near-edge spectra at the Pd and Pt LIII-edge, suggest that the Pd conduction band is filled by Pt valence electrons. This behaviour is consistent with observations of the hydrogen storage capacity of these NPs. The broadening of the valence band width and the down-shift of the d-band centre away from the Fermi level upon Pt substitution also provided evidence for enhanced stability of the hydride (ΔH) features of the Pd1−xPtx solid-solution NPs with a Pt content of 8-21 atomic percent.

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“…For the former, the existence of miscibility gaps at T ϳ 1000 K has first been proposed by Raub et al, 3 though subsequent attempts to observe these miscibility gaps have consistently failed. [4][5][6] Later in 1995, first-principles-based study 7 predicted the Pt-Rh to be an ordering system: Pt 50 Rh 50 alloys form "40" ordered structure below T = 210 K. A recent diffuse x-ray scattering study 8 has confirmed the presence of local order in Pt-47 at. % Rh at T = 923 K, and measured the position of the diffuse maximum at 1 1 2 0, which satisfies the corresponding position of predicted structure "40."…”

Section: Introductionmentioning

confidence: 99%

First-principles study of bulk ordering and surface segregation in Pt-Rh binary alloys

et al. 2006

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The cluster expansion technique in conjunction with first-principles calculations has been applied in Monte Carlo simulations to derive the configurational thermodynamics of the bulk and ͑111͒ surface of Pt-Rh alloys. Lattice-dynamics calculations reveal that the vibrational contribution to Pt-Rh bulk phase stability is fairly negligible. Calculated short-range-order parameter, ground state, and ordering transition temperature T c of bulk Pt 50 Rh 50 are in satisfactory agreement with experimental values in the literature. Calculated composition profiles of the ͑111͒ surface at T = 1373 K show the enrichment of Pt at the top layer and Pt depleted at the second layer for the entire composition, which is in agreement with experimental observations. At low temperatures, a significant difference is found in the temperature dependence of the layer composition profile between Pt 25 Rh 75 and Pt 50 Rh 50. While Pt composition of the Pt 25 Rh 75 subsurface shows positive temperature dependence, that of Pt 50 Rh 50 has a minimum at T ϳ 300 K. The former can be qualitatively interpreted by taking account of the on-site energy only. The latter is due to the occurrence of sublayer-confined phase transition from ͑ ͱ 3 ϫ ͱ 3͒R30°order to disorder alloys.

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The palladium-platinum phase diagram

Cited by 40 publications

References 5 publications

Self‐Organization Based Fabrication of Bimetallic PtPd Nanoparticles on Transparent Conductive Oxide Substrates

Self‐Organization Based Fabrication of Bimetallic PtPd Nanoparticles on Transparent Conductive Oxide Substrates

Hydrogen storage and stability properties of Pd–Pt solid-solution nanoparticles revealed via atomic and electronic structure

First-principles study of bulk ordering and surface segregation in Pt-Rh binary alloys

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