Experimental observation of polymerization from BH4− to B12H122 in mixed-anion A3BH4B12H12 (A = Rb+, Cs+)

Schouwink, Pascal; Sadikin, Yolanda; van Beek, W.; Cerny, Radovan

doi:10.1016/j.ijhydene.2015.06.022

Scientific article

English

Experimental observation of polymerization from BH₄⁻ to B₁₂H₁₂² in mixed-anion A₃BH₄B₁₂H₁₂ (A = Rb⁺, Cs⁺)

Contributors

Schouwink, Pascal; Sadikin, Yolanda; van Beek, W.; Cerny, Radovan

Published in

International journal of hydrogen energy, vol. 40, no. 34, p. 10902-10907

Publication date

2015

Abstract

It has often been suggested that reversible hydrogen storage is hampered by the formation of higher boranes MpBnHm (M = alkaline or earth alkaline metal), acting as a boron sink in the solid state during decomposition processes of the borohydride. The thermodynamic stability of these materials poses high barriers for rehydrogenation. Though assumed to be key component in storage system optimization, the ultimate proof, being the crystal structure, has never been determined on a higher borane in-situ during thermal decomposition. We herein present a case study on a double-perovskite, significantly substantiating such assumptions and providing thorough experimental evidence based on synchrotron X-ray diffraction. It is shown on the basis of thermogravimetric measurements (TGA), in-situ mass spectroscopy and ex-situ nuclear magnetic resonance (NMR) spectroscopy that the double perovskites Cs3Y(BH4)6Cs3Y(BH4)6 and Cs2LiY(BH4)6Cs2LiY(BH4)6 release 2.9 mol H2 during polymerization to the inverse perovskite, Cs3BH4B12H12Cs3BH4B12H12, containing both closo and borohydride anions. Novel phases are solved ab-initio and in-situ Raman and mass spectroscopy are employed to follow the polymerization reaction.

Keywords

Closoborane
Borohydride
Polymerization
Hydrogen storage
Powder diffraction

UNIGE affiliation entities

Faculté des sciences / Section de physique / Département de physique de la matière quantique

UNIGE research groups

Groupe Cerny

Citation (ISO format)

SCHOUWINK, Pascal et al. Experimental observation of polymerization from BH₄⁻ to B₁₂H₁₂² in mixed-anion A₃BH₄B₁₂H₁₂ (A = Rb⁺, Cs⁺). In: International journal of hydrogen energy, 2015, vol. 40, n° 34, p. 10902–10907. doi: 10.1016/j.ijhydene.2015.06.022

Article (Published version)

Identifiers

PID : unige:75459
DOI : 10.1016/j.ijhydene.2015.06.022

Additional URL for this publication

http://linkinghub.elsevier.com/retrieve/pii/S0360319915015049

Journal ISSN

0360-3199

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Creation

24/09/2015 11:17:00

First validation