title: In situ characterization of the decomposition behavior of Mg(BH4)2 by X-ray Raman scattering spectroscopy.
abstract: We present an in situ study of the thermal decomposition of Mg(BH4)2 in a hydrogen atmosphere of up to 4 bar and up to 500 °C using X-ray Raman scattering spectroscopy at the boron K-edge and the magnesium L2,3-edges. The combination of the fingerprinting analysis of both edges yields detailed quantitative information on the reaction products during decomposition, an issue of crucial importance in determining whether Mg(BH4)2 can be used as a next-generation hydrogen storage material. This work reveals the formation of reaction intermediate(s) at 300 °C, accompanied by a significant hydrogen release without the occurrence of stable boron compounds such as amorphous boron or MgB12H12. At temperatures between 300 °C and 400 °C, further hydrogen release proceeds via the formation of higher boranes and crystalline MgH2. Above 400 °C, decomposition into the constituting elements takes place. Therefore, at moderate temperatures, Mg(BH4)2 is shown to be a promising high-density hydrogen storage material with great potential for reversible energy storage applications.
authors.affiliation: ESRF-The European Synchrotron, Grenoble Cedex 9, France. christoph.sahle@esrf.fr.
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Sahle
authors.forename: Simon
authors.initials: S
authors.lastname: Kujawski
authors.forename: Arndt
authors.initials: A
authors.lastname: Remhof
authors.forename: Yigang
authors.initials: Y
authors.lastname: Yan
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Stadie
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Zein
authors.forename: Metin
authors.initials: M
authors.lastname: Tolan
authors.forename: Simo
authors.initials: S
authors.lastname: Huotari
authors.forename: Michael
authors.initials: M
authors.lastname: Krisch
authors.forename: Christian
authors.initials: C
authors.lastname: Sternemann