期刊
PHYSICAL REVIEW B
卷 74, 期 19, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.74.195120
关键词
-
资金
- Engineering and Physical Sciences Research Council [GR/S52636/01] Funding Source: researchfish
The Li-N-H system holds great promise for on-board hydrogen storage applications, particularly due to reversible interactions among lithium amide (LiNH2), imide (Li2NH), and hydride (LiH). However, practical applications of the system are hindered by the relatively high stabilities of the compounds and uncertainty of their reaction paths. Understanding the mechanism of hydrogen interactions with the host structures is essential for further development. Here, we calculated the electronic structures and total energies of lithium hydride (LiH), lithium imide (Li2NH), and lithium amide (LiNH2) using a first-principles full potential approach. The estimated formation enthalpies for the two-step reactions, Li3N+2H(2)<-> Li2NH+LiH+H-2 <-> LiNH2+2LiH are -162.05 and -40.94 kJ/mol, comparable to the experimental values of -165 and -45.5 kJ/mol, respectively. The bonding interaction characteristics and the stability of these materials were further analyzed from the electronic structures. It is noted that the N atom bonds unequally with the two H atoms in lithium amide. As a result, the amide LiNH2 can dissociate in two almost equivalent transient steps: Li++(NH2)(-); and (LiNH)(-)+H+. The reaction of the relevant species may evolve NH3 as a transient gas in the (LiNH2+LiH) system.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据