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

Bimetallic Pd(1−x)Pt(x) 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 diffract...

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Detalles Bibliográficos
Autores principales: Kumara, Loku Singgappulige Rosantha, Sakata, Osami, Kobayashi, Hirokazu, Song, Chulho, Kohara, Shinji, Ina, Toshiaki, Yoshimoto, Toshiki, Yoshioka, Satoru, Matsumura, Syo, Kitagawa, Hiroshi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5668347/
https://www.ncbi.nlm.nih.gov/pubmed/29097810
http://dx.doi.org/10.1038/s41598-017-14494-7
Descripción
Sumario:Bimetallic Pd(1−x)Pt(x) 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 L(III)-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 Pd(1−x)Pt(x) solid-solution NPs with a Pt content of 8-21 atomic percent.