Energies (Aug 2019)

Hydrogen Desorption in Mg(BH<sub>4</sub>)<sub>2</sub>-Ca(BH<sub>4</sub>)<sub>2</sub> System

  • Erika M. Dematteis,
  • Marcello Baricco

DOI
https://doi.org/10.3390/en12173230
Journal volume & issue
Vol. 12, no. 17
p. 3230

Abstract

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Magnesium borohydride, Mg(BH4)2, and calcium borohydride, Ca(BH4)2, are promising materials for hydrogen storage. Mixtures of different borohydrides have been the subject of numerous researches; however, the whole Mg(BH4)2-Ca(BH4)2 system has not been investigated yet. In this study, the phase stability and the hydrogen desorption were experimentally investigated in the Mg(BH4)2-Ca(BH4)2 system, by means of XRD, ATR-IR, and HP-DSC. Mg(BH4)2 and Ca(BH4)2 are fully immiscible in the solid state. In the mechanical mixtures, thermal decomposition occurs at slightly lower temperatures than for pure compounds. However, they originate products that cannot be identified by XRD, apart from Mg and MgH2. In fact, amorphous phases or mixtures of different poorly crystalline or nanocrystalline phases are formed, leading to a limited reversibility of the system.

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