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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (13): 1447-1454. 上一篇    下一篇

研究论文

掺杂元素Ti和Ni对NaAlH4放氢性能影响的第一原理研究

代建红 李成桂 宋 岩

  

  1. (哈尔滨工业大学(威海)材料科学与工程学院 威海 264209)

  • 投稿日期:2008-09-17 修回日期:2009-01-16 发布日期:2009-07-14
  • 通讯作者: 宋岩

First-Principles Study of Influence of Dopants Ti and Ni on the Dehydrogenation Properties of NaAlH4

Dai, Jianhong Li, Chenggui Song, Yan   

  1. (School of Materials Science and Engineering, Harbin Institute of Technology, Weihai 264209)
  • Received:2008-09-17 Revised:2009-01-16 Published:2009-07-14
  • Contact: Song, Yan

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被引次数

3

利用第一性原理方法研究了掺杂元素Ti, Ni对NaAlH4放氢性能的影响. 计算表明: Ti在NaAlH4中倾向于替代Al原子, 而Ni则倾向于占据间隙位置. 电子结构分析显示Ti替代NaAlH4中的Al位置时与近邻的Al原子产生强烈的相互作用, 破坏[AlH4]基团的结构, 从而改善NaAlH4的放氢性能. Ti替代Na或占据间隙位置时Ti与H原子间存在较强的相互作用, 有可能诱发TiH2相而改善NaAlH4的放氢性能. 与Ti相比Ni对NaAlH4放氢性能的影响较小, 仅当Ni占据间隙位置时才可能对[AlH4]基团产生一定影响. 总体而言, Ti对NaAlH4放氢性能的影响强于Ni的作用, 这与实验观测相吻合.

关键词: 第一原理, NaAlH4, 放氢性能

The influence of dopants Ti and Ni on the dehydrogenation properties of NaAlH4 was studied by means of first principles. It was shown that Ti tended to occupy the Al site in NaAlH4, while the interstitial site was favourite for Ni to occupy. Analysis of the electronic structure reveals that the [AlH4] ligand was distorted by the strong interaction between the dopant Ti and its nearest neighbouring Al atoms when Ti occupied the Al site. Therefore, the dehydrogenation properties of NaAlH4 were improved. The influence of Ni on the dehydrogenation properties of NaAlH4 was relatively small than that of Ti. The stability of the [AlH4] ligand was affected only if the Ni occupied the interstitial site. In general, the influence of Ti on the dehydrogenation properties of NaAlH4 is stronger than that of Ni, which is consistent with the experimental findings.

Key words: first-principles, NaAlH4, dehydrogenation property

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