NH3 Mediated or Ion Migration Reaction: The Case Study on Halide–Amide System

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• 作者：Hujun Cao ; Jianhui Wang ; Yongshen Chua ; Han Wang ; Guotao Wu ; Zhitao Xiong ; Jieshan Qiu ; Ping Chen
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：February 6, 2014
• 年：2014
• 卷：118
• 期：5
• 页码：2344-2349
• 全文大小：426K
• ISSN：1932-7455

文摘

Lively debates on hydrogen desorption from the amide鈥揾ydride system via either ion migration or NH₃ mediated mechanisms have been ongoing since the discovery of the amide鈥揾ydride system for hydrogen storage. In this work, we employed kinetic analyses to demonstrate that the mechanism of hydrogen desorption depends on the sample morphology and desorption conditions. Upon the formation of Li amide bromide (Li₂NH₂Br), the LiNH₂ unit is confined in the cage of Br, resulting in less mobility of ion. Hydrogen desorption from the Li₂NH₂Br鈥?LiH system appears to follow the NH₃ mediated mechanism even if the two starting chemicals have been intensively ball milled. On the other hand, the migrations of Li⁺ and H⁺ play important roles leading to H₂ formation from the direct combination of H⁺ (from 鈭扤H₂) and H^{鈥?/sup> (from LiH) when LiNH₂ and LiH are intimately in contact.}