Hydrogen sorption properties of MgH2-LiBH4 composites
Hydrogen sorption properties of MgH2-LiBH4 composites
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DOI：
10.1016/j.actamat.2007.03.010
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发表时间：
2007-06-01
期刊：
影响因子：
9.4
通讯作者：
Bormann, Ruediger
中科院分区：
文献类型：
--
作者：
Boesenberg, Ulrike;Doppiu, Stefania;Bormann, Ruediger
使用高压差示扫描量热法 (HP-DSC) 测量和原位同步加速器粉末 X 射线衍射 (XRD) 测量以及使用 Sievert 型装置的动力学研究，对反应性氢化物复合材料 (RHC) MgH2 + 2LiBH(4) MgB2 + 2LiH + 4H(2) 的反应机理进行了详细分析。对于解吸，观察到以下两步反应：MgH2 + 2LiBH(4) Mg + 2LiBH(4) + H-2 MgB2 + 2LiH + 4H(2)。然而，该反应在动力学上受到限制并且仅在高温下进行。与解吸反应相反，LiBH4 和 MgH2 在 250-300 摄氏度的温度范围内、50 bar 氢气压力的相当温和的条件下同时形成。正如在纯轻金属氢化物中所发现的那样，如果使用合适的添加剂，则可以显着改善吸附动力学。 (c) 2007 Acta Materialia Inc. 由 Elsevier Ltd 出版。保留所有权利。
A detailed analysis of the reaction mechanism of the reactive hydride composite (RHC) MgH2 + 2LiBH(4) MgB2 + 2LiH + 4H(2) was performed using high-pressure differential scanning calorimetry (HP-DSC) measurements and in situ synchrotron powder X-ray diffraction (XRD) measurements along with kinetic investigations using a Sievert-type apparatus. For the desorption the following two-step reaction has been observed: MgH2 + 2LiBH(4) Mg + 2LiBH(4) + H-2 MgB2 + 2LiH + 4H(2). However, this reaction is kinetically restricted and proceeds only at elevated temperatures. In contrast to the desorption reaction, LiBH4 and MgH2 are found to form simultaneously under fairly moderate conditions of 50 bar hydrogen pressure in the temperature range of 250-300 degrees C. As found in pure light metal hydrides, significant improvement of sorption kinetics is possible if suitable additives are used. (c) 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.