Destabilization of Li-based complex hydrides
Destabilization of Li-based complex hydrides
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DOI：
10.1016/j.jallcom.2003.08.089
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发表时间：
2004-05
影响因子：
6.2
通讯作者：
Y. Nakamori;S. Orimo
中科院分区：
文献类型：
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作者：
Y. Nakamori;S. Orimo
近年来，对络合氢化物的基础研究对于开发具有比常规材料更高的重氢密度的实用储氢材料具有重要意义。首先，本文阐明了[BH_4]−-阴离子的B-H原子振动与MBH_4(M=Li，Na，K)的熔融温度之间的关系，作为氢的脱附(分解)温度的指标。这一研究表明，使用具有较高电负性的较小尺寸和/或较高价态阳离子的部分阳离子取代可能提供较高的拉曼光谱的能量模式，从而降低氢的脱附(分解)温度。接下来，以LiNH_2为例，初步考察了LiNH_2及其部分阳离子取代物的放氢性能。Li被Mg部分阳离子取代后，氢脱附反应的开始和结束温度实际上降低了约50K。
Fundamental researches on complex hydrides are recently of great importance to develop practical hydrogen storage materials with higher gravimetric hydrogen densities than those of conventional materials. First, in this paper, we clarify the correlation between B–H atomistic vibrations in [BH4]−-anion and melting temperatures of MBH4(M=Li, Na, and K) as indexes of hydrogen desorption (decomposition) temperatures. This investigation implies that partial cation substitutions using smaller sized- and/or higher valenced-cations with higher electronegativities might provide higher energy modes of Raman spectra, and then, lower hydrogen desorption (decomposition) temperatures. Next, as an example, the hydrogen desorption properties of LiNH2and its partial cation substitution are preliminary examined. The starting and ending temperatures for the hydrogen desoprtion reaction are actually lowered about 50K by the partial cation substitution of Li by Mg.