Sorption properties and reversibility of Ti(IV) and Nb(V)-fluoride doped-Ca(BH<inf>4</inf>)<inf>2</inf>-MgH<inf>2</inf> system

Christian Bonatto Minella, Sebastiano Garroni, Claudio Pistidda, Maria Dolors Baró, Oliver Gutfleisch, Thomas Klassen, Martin Dornheim

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

© 2014 Elsevier B.V. In the last decade, alkaline and alkaline earth metal tetrahydroborates have been the focuses of the research due to their high gravimetric and volumetric hydrogen densities. Among them, Ca(BH4)2 and the Ca(BH4)2 + MgH2 reactive hydride composites (RHC), were calculated to have the ideal thermodynamic properties which fall within the optimal range for mobile applications. In this study, the addition of NbF5 or TiF4 to the Ca(BH4)2 + MgH2 reactive hydride composite system was attempted aiming to obtain a full reversible system with the simultaneous suppression of CaB12H12. Structural characterization of the specimens was performed by means of in-situ Synchrotron Radiation Powder X-ray diffraction (SR-PXD) and 11B{1H} Solid State Magic Angle Spinning-Nuclear Magnetic Resonance (MAS-NMR). The evolution of the chemical state of the Nb- and Ti-based additives was monitored by X-ray Absorption Near Edge Structure (XANES). The addition of NbF5 or TiF4 to the Ca(BH4)2 + MgH2 system have not suppressed completely the formation of CaB12H12 and only a slight improvement concerning the reversible reaction was displayed just in the case of Nb-doped composite material.
Original languageEnglish
Pages (from-to)989-994
JournalJournal of Alloys and Compounds
Volume622
DOIs
Publication statusPublished - 15 Feb 2015

Keywords

  • (XANES)
  • 11 1 B H} Solid State Magic Angle Spinning-
  • Hydrogen storage
  • In-situ Synchrotron Radiation Powder X-ray
  • Nuclear Magnetic Resonance (MAS-NMR)
  • Tetrahydroborate
  • Transition metal fluorides
  • X-ray Absorption Near Edge Structure
  • diffraction (SR-PXD)

Fingerprint Dive into the research topics of 'Sorption properties and reversibility of Ti(IV) and Nb(V)-fluoride doped-Ca(BH<inf>4</inf>)<inf>2</inf>-MgH<inf>2</inf> system'. Together they form a unique fingerprint.

Cite this