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dc.contributor.author
Urretavizcaya, Guillermina
dc.contributor.author
Sarmiento Chavez, Ana Carolina
dc.contributor.author
Castro, Facundo
dc.date.available
2017-12-18T15:06:51Z
dc.date.issued
2014-05-22
dc.identifier.citation
Castro, Facundo; Sarmiento Chavez, Ana Carolina; Urretavizcaya, Guillermina; Hydrogen absorption and desorption in the Mg-Ag system; Elsevier Science Sa; Journal of Alloys and Compounds; 611; 2014; 22-5-2014; 202-209
dc.identifier.issn
0925-8388
dc.identifier.uri
http://hdl.handle.net/11336/30867
dc.description.abstract
We analyze hydrogen absorption and desorption in Mg and Mg?Ag compounds prepared by mechanical milling. The materials were obtained by processing mixtures of Mg or MgH2 with different proportions of Ag under Ar or H2 atmosphere.We observe that Ag and AgMg destabilize MgH2. In the first case the products of the reaction of Ag and MgH2 are AgMg and H2, in the second case MgH2 reacts with AgMg to give AgMg4 and H2. The first reaction was only observed in the forward direction, whereas the second one was registered in both directions. The impossibility to reverse the first reaction was attributed to poor kinetics and experimental limitations. The reversible destabilization induced by AgMg is low, MgH2 overall dehydriding enthalpy is reduced from 76.5 kJ/mol H2 to 69.1 kJ/mol H2. This last value allowed us to estimate the formation enthalpy of AgMg4 at _59.5 kJ/mol.
Besides destabilization, a slight improvement in hydrogen absorption kinetics and a more noticeable enhancement in desorption kinetics has been observed in samples containing Ag as an additive. During thermal desorption, the dehydriding temperature decreases by 20 _C. In isothermal desorption experiments at 325 _C, the characteristic induction period of MgH2 without additive practically disappears, and the time to reach 50% of conversion decreases from 17 min to 5.4 min when silver is present. The changes in desorption kinetics could be attributed to AgMg or the interfaces MgH2/AgMg acting as nucleation sites for Mg.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier Science Sa
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
Hydrogen Absorbing Materials
dc.subject
Intermetallics
dc.subject
Mechanical Milling
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Thermodynamic Destabilization
dc.subject
Reaction Pathway
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Kinetics
dc.title
Hydrogen absorption and desorption in the Mg-Ag system
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2017-12-14T20:13:40Z
dc.journal.volume
611
dc.journal.number
2014
dc.journal.pagination
202-209
dc.journal.pais
Países Bajos
dc.journal.ciudad
Amsterdam
dc.description.fil
Fil: Urretavizcaya, Guillermina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
dc.description.fil
Fil: Sarmiento Chavez, Ana Carolina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
dc.description.fil
Fil: Castro, Facundo. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
dc.journal.title
Journal of Alloys and Compounds
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0925838814011414?via%3Dihub
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1016/j.jallcom.2014.05.066
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