title: Shape-dependent hydrogen-storage properties in Pd nanocrystals: which does hydrogen prefer, octahedron (111) or cube (100)?
abstract: Pd octahedrons and cubes enclosed by {111} and {100} facets, respectively, have been synthesized for investigation of the shape effect on hydrogen-absorption properties. Hydrogen-storage properties were investigated using in situ powder X-ray diffraction, in situ solid-state (2)H NMR and hydrogen pressure-composition isotherm measurements. With these measurements, it was found that the exposed facets do not affect hydrogen-storage capacity; however, they significantly affect the absorption speed, with octahedral nanocrystals showing the faster response. The heat of adsorption of hydrogen and the hydrogen diffusion pathway were suggested to be dominant factors for hydrogen-absorption speed. Furthermore, in situ solid-state (2)H NMR detected for the first time the state of (2)H in a solid-solution (Pd + H) phase of Pd nanocrystals at rt.
authors.affiliation: Division of Chemistry, Graduate School of Science, Kyoto University , Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Guangqin
authors.initials: G
authors.lastname: Li
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Shun
authors.initials: S
authors.lastname: Dekura
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Ikeda
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kubota
authors.forename: Kenichi
authors.initials: K
authors.lastname: Kato
authors.forename: Masaki
authors.initials: M
authors.lastname: Takata
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Syo
authors.initials: S
authors.lastname: Matsumura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kitagawa
mesh_terms: D065966:Absorption, Physicochemical; D006859:Hydrogen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008968:Molecular Conformation; D010165:Palladium / Q000737:chemistry*; D013499:Surface Properties
chemical_list: C032391:palladium hydride; D010165:Palladium; D006859:Hydrogen