Thermodynamics and reaction pathways of hydrogen sorption in Mg6(Pd,TM) (TM = Ag, Cu and Ni) pseudo-binary compounds
| Autor: | J. Bodega, J. F. Fernandez, Carlos Sánchez, M. Ponthieu, José R. Ares, Paloma Adeva, Fermin Cuevas |
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| Rok vydání: | 2014 |
| Předmět: |
Hydrogen sorption
Renewable Energy Sustainability and the Environment Hydride Chemistry Enthalpy Intermetallic Energy Engineering and Power Technology Thermodynamics Hydrogen storage Mg-based intermetallics Condensed Matter Physics Thermodynamic properties Fuel Technology Hydrogenation reaction Metal hydrides Solubility Ternary operation Phase diagram |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2014.09.034 |
| Popis: | © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. Mg6(Pd,TM) (TM = Ag, Cu and Ni) pseudo-binary compounds have been synthesized at the TM solubility limit to determine the influence of TM on the thermodynamics and reaction pathways of the Mg6Pd-H system. All compounds exhibit a two-plateau pressure behaviour, being the value of the high plateau pressure well above that of the Mg/MgH2 system. Such destabilization is explained by the formation of different Mg-(Pd,TM) intermetallics and/or Mg2NiH4 hydride phases during the hydrogenation reaction. The formation of these phases not only increases the enthalpy of hydrogenation but also enhances disorder leading to a limited destabilization of the hydrogenated state. This compensation effect is characterized by a linear correlation between enthalpy and entropy terms. In addition, this work also provides the assessment at 623 K of the ternary Mg-Pd-Cu phase diagram in the Mg-rich corner. |
| Databáze: | OpenAIRE |
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