Hydrogen Cycling of Niobium and Vanadium Catalyzed Nanostructured Magnesium.
The reaction of hydrogen gas with magnesium metal, which is important for hydrogen storage purposes, is enhanced significantly by the addition of catalysts such as Nb and V and by using nanostructured powders. In situ neutron diffraction on MgNb and Mg V powders give a detailed insight on the magnes...
| Publicado en: | Journal of the American Chemical Society Vol. 127; no. 41; pp. 14348 - 14355 |
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| Autores principales: | , , , , |
| Formato: | Artículo |
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American Chemical Society
10/19/2005
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=18880636&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 18880636 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 10/19/2005 vid: 127 iid: 41 pid: 997 pub: American Chemical Society artinfo: ui: 18880636 10.1021/ja051508a ppf: 14348 ppct: 7 formats: tig: atl: Hydrogen Cycling of Niobium and Vanadium Catalyzed Nanostructured Magnesium. aug: au: Schimmel, H. Gijs Huot, Jacques Chapon, Laurent C. Tichelaar, Frans D. Mulder, Fokko M. affil: Department of Radiation, Radionuclides and Reactors, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629J8 Delf, The Netherlands. Institut de recherche sur I'hydrogène, Université dii Québec à Trois-Rivières, (Qc)G9A 5H7 Canada. ISIS facility, Rutherford Appleton. Laboratory, Chilton, Didcot, United Kingdom, and the National Centre for HREM, Delft University of Technology, The Netherlands. su: Nanostructured materials Vanadium catalysts Niobium Transition metals Chemical inhibitors Magnesium sug: subj: Nanostructured materials Vanadium catalysts Niobium Transition metals Chemical inhibitors Magnesium ab: The reaction of hydrogen gas with magnesium metal, which is important for hydrogen storage purposes, is enhanced significantly by the addition of catalysts such as Nb and V and by using nanostructured powders. In situ neutron diffraction on MgNb and Mg V powders give a detailed insight on the magnesium and catalyst phases that exist during the various stages of hydrogen cycling. During the early stage of hydriding (and deuteriding), a MgH phase is observed, which does not occur in bulk MgH and, thus, appears characteristic for the small particles. The abundant H vacancies will cause this phase to have a much larger hydrogen diffusion coefficient, partly explaining the enhanced kinetics of nanostructured magnesium. It is shown that under relevant experimental conditions, the niobium catalyst is present as NbH. Second, a hitherto unknown Mg-Nb perovskite phase could be identified that has to result from mechanical alloying of Nb and the MgO layer of the particles. Vanadium is not visible in the diffraction patterns, but electron micrographs show that the V particle size becomes very small, 2-20 nm. Nanostructuring and catalyzing the Mg enhance the adsorption speed that much that now temperature variations effectively limit the absorption speed and not, as for bulk, the slow kinetics through bulk MgH layers. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2005 holdings: @attributes: islocal: N |
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