计算物理 ›› 2012, Vol. 29 ›› Issue (2): 297-302.

• 论文 • 上一篇    下一篇

掺杂元素Fe对LiAlH4放氢性能影响的第-性原理研究

王青1,2, 党文强2, 杜瑞2, 戴剑锋1,2, 李维学1,2   

  1. 1. 兰州理工大学 甘肃省有色金属新材料省部共建国家重点实验室, 甘肃 兰州 730050;
    2 兰州理工大学 理学院, 甘肃 兰州 730050
  • 收稿日期:2011-04-02 修回日期:2011-09-16 出版日期:2012-03-25 发布日期:2012-03-25
  • 作者简介:王青(1965-),女,硕士,教授,主要从事纳米材料研究,E-mail:wangqing@lut.cn
  • 基金资助:
    国家自然科学基金(50873047);甘肃省教育厅(0903-12)资助项目

First-principles Study of Dehydrogenation Characteristics of LiAlH4 with Dopant Fe

WANG Qing1,2, DANG Wenqiang2, DU Rui2, DAI Jianfeng1,2, LI Weixue1,2   

  1. 1. Lanzhou University of Technology, State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou 730050, China;
    2. School of Science, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2011-04-02 Revised:2011-09-16 Online:2012-03-25 Published:2012-03-25

摘要: 采用第-性原理赝势平面波方法研究掺杂元素Fe对LiAlH4放氢性能的影响及其作用机理.计算杂质形成能、电子态密度、氢原子分解能,分析原子间的成键情况和结构的稳定性.结果表明:Fe在LiAlH4中占据间隙位置或者替代Al或者Li时,都能改善LiAlH4的放氢性能.Fe在LiAlH4中倾向于占据间隙位置,电子结构分析显示Fe占据间隙位置时与近邻的Al原子产生强烈的相互作用;另-方面,Fe与近邻的H也有较强相互作用.两个因素共同的结果是破坏了[AlH4]基团的稳定性,从而改善LiAlH4的放氢性能.结果与实验相吻合.

关键词: 第-性原理, LiAlH4, Fe, 放氢性能

Abstract: With plane-wave pseudo-potential method of first-principles,effect of dopant Fe on dehydrogenation characteristics of LiAlH4 and mechanism were studied.Dopant formation energy,electronic density of states and dissociation energy of H were investigated.Bonding state and structure-stability of the crystal were analyzed.It indicates that as Fe occupied an interstitial site,an Al site or an Li site,dehydrogenation properties of LiAlH4 were improved.Fe tended to occupy the interstitial site.Analysis on electronic structure reveals that there exist strong interactions between a dopant Fe and its nearest neighbouring Al atoms as Fe occupied an interstitial site.Meanwhile,interaction between a dopant Fe and its nearest neighbouring H atoms is also considerably strong.Stability of the [AIH4] ligand is distorted.Therefore,dehydrogenation properties of LiAlH4 are improved.In general,dopant Fe improve dehydrogenation properties of LiAlH4,which is consistent with experimental observations.

Key words: first-principles, LiAlH4, Fe, dehydrogenation

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