Effect of the Partial Replacement of CaH2 with CaF2 in the Mixed System CaH2 + MgB2

• Published in: Journal of physical chemistry. C Vol. 118; no. 49; pp. 28409 - 28417
• Main Authors: Pistidda, C, Karimi, F, Garroni, S, Rzeszutek, A, Bonatto Minella, C, Milanese, C, Le, T. T, Rude, L. H, Skibsted, J, Jensen, T. R, Horstmann, C, Gundlach, C, Tolkiehn, M, Pranzas, P. K, Schreyer, A, Klassen, T, Dornheim, M
• Format: Journal Article
• Language: English
• Published: American Chemical Society 11-12-2014
• Subjects: Fysik; Natural Sciences; Naturvetenskap; Physical Sciences
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp508780b

In this work the effect of a partial replacement of CaH2 with CaF2 on the sorption properties of the system CaH2 + MgB2 has been studied. The first five hydrogen absorption and four desorption reactions of the CaH2 + MgB2 and 3CaH2 + CaF2 + 4MgB2 systems were investigated by means of volumetric measurements, high-pressure differential scanning calorimetric technique (HP-DSC), 11B and 19F MAS NMR spectroscopy, and in situ synchrotron radiation powder X-ray diffraction (SR-PXD). It was observed that already during the mixing of the reactants formation of a nonstoichiometric CaF2–x H x solid solution takes place. Formation of the CaF2–x H x solid solution sensibly affects the overall hydrogen sorption reactions of the system CaH2 + MgB2.