Matsunaga, Tomoya Buchter, Florian Mauron, Phillipe Bielmann, Michael Nakamori, Y. Orimo, S. Ohba, N. Miwa, K. Towata, S. Züttel, Andreas 2007-05-18 Among the large variety of possible complex hydrides only few exhibit a large gravimetric hydrogen density and stability around 40 kJ mol⁻¹H₂. Mg[BH₄]₂ is based on theoretical approaches a complex hydride with an equilibrium hydrogen pressure of approximately 1 bar at room temperature and a hydrogen content of 14.9 mass%. The reaction of Li[BH₄] with MgCl₂ at elevated temperatures was investigated as a possible route to synthesize Mg[BH₄]₂. Li[BH₄] reacts with MgCl₂ at a temperature >523 K at a pressure of 10 MPa of hydrogen, where the product contains LiCl and Mg[BH₄]₂. The desorption pc-isotherm of the product obtained at 623 K shows two flat plateaus, which indicates that the decomposition of the product consists of a two-step reaction. The products of the first and the second decomposition reaction were analyzed by means of X-ray diffraction and found to be MgH₂ and Mg, respectively. The enthalpy for the first decomposition reaction was determined to be Δ<i>H</i> = −39.3 kJ mol⁻¹H₂ by the Van’t Hoff plot of the equilibrium measurements between 563 K and 623 K, which is significantly lower than that for pure Li[BH₄] (Δ<i>H</i> = −74.9 kJ mol⁻¹H₂). However, only the second reaction step (MgH₂ → Mg) is reversible at the condition up to 623 K at 10 MPa of hydrogen. application/pdf https://folia.unifr.ch/global/documents/300800 https://folia.unifr.ch/documents/300800/files/zuettel_hsp.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jallcom.2007.05.054 info:eu-repo/semantics/openAccess License undefined Journal of Alloys and Compounds. - 2008, vol. 259, no. 1-2, p. 583-588 Hydrogen absorbing materials thermodynamic properties thermal analysis info:eu-repo/classification/udc/53 Hydrogen storage properties of Mg[BH₄]₂ http://purl.org/coar/resource_type/c_6501