Lu Jun, Fang Zhigang Zak
Department of Metallurgical Engineering, University of Utah, 135 South 1460 East Room 412, Salt Lake City, UT 84112, USA.
J Phys Chem B. 2005 Nov 10;109(44):20830-4. doi: 10.1021/jp053954q.
Although there have been numerous materials systems studied as potential candidates for hydrogen storage applications, none of the materials known to date has demonstrated enough hydrogen capacity or efficiency at required operating temperature ranges. There are still considerable opportunities for discovery of new materials or material systems that could lead to advances in science as well as commercial technologies in this area. LiAlH(4) is one of the most promising materials owing to its high hydrogen content. In the present work, we investigated dehydrogenation properties of the combined system of LiAlH(4) and LiNH(2) under atmospheric argon. Thermogravimetric analysis (TGA) of 2LiAlH(4)/LiNH(2) mixtures without any catalysts indicated that a large amount of hydrogen (approximately 8.1 wt %) can be released between 85 and 320 degrees C under a heating rate of 2 degrees C/min in three dehydrogenation reaction steps. It is found that LiNH(2) effectively destabilizes LiAlH(4) by reacting with LiH during the dehydrogenation process of LiAlH(4).
尽管已经对众多材料体系作为储氢应用的潜在候选材料进行了研究，但迄今为止已知的材料中，没有一种在所需的操作温度范围内表现出足够的储氢容量或效率。在发现能够推动该领域科学以及商业技术进步的新材料或材料体系方面，仍有相当大的机会。LiAlH₄因其高氢含量而成为最有前景的材料之一。在本工作中，我们研究了LiAlH₄和LiNH₂的复合体系在常压氩气下的脱氢性能。对不含任何催化剂的2LiAlH₄/LiNH₂混合物进行热重分析（TGA）表明，在2℃/min的升温速率下，在三个脱氢反应步骤中，85至320℃之间可释放大量氢气（约8.1 wt%）。研究发现，在LiAlH₄的脱氢过程中，LiNH₂通过与LiH反应有效地使LiAlH₄失稳。
