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ID 32009
本文ファイル
著者
Yamane, Aki
Shimojo, Fuyuki
NDC
物理学
抄録(英)
The hydrogen storage system LiH + NH_3 <-> LiNH_2 + H_2 is one of the most promising hydrogen storage systems, where the reaction yield can be increased by replacing Li in LiH with other alkali metals (Na or K) in order of Li < Na < K. In this paper, we have studied the alkali metal M (M = Li, Na, K) dependence of the reactivity of MH with NH_3 by calculating the potential barrier of the H_2 desorption process from the reaction of an M_2H_2 cluster with an NH_3 molecule based on the ab initio structure optimization method. We have shown that the height of the potential barrier becomes lower in order of Li, Na, and K, where the difference of the potential barrier in Li and Na is relatively smaller than that in Na and K, and this tendency is consistent with the recent experimental results. We have also shown that the H-H distance of the H_2 dimer at the transition state takes larger distance and the change of the potential energy around the transition state becomes softer in order of Li, Na, and K. There are almost no M dependence in the charge of the H atom in NH_3 before the reaction, while that of the H atom in M_2H_2 takes larger negative value in order of Li, Na, and K. We have also performed molecular dynamics simulations on the M_2H_2-NH_3 system and succeeded to reproduce the H_2 desorption from the reaction of Na_2H_2 with NH_3.
掲載誌名
Journal of Chemical Physics
134巻
12号
開始ページ
124515-1
終了ページ
124515-8
出版年月日
2011-03-29
出版者
American Institute of Physics
ISSN
0021-9606
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
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権利情報
Copyright (c) 2011 American Institute of Physics.
関連情報URL
部局名
総合科学研究科
先端物質科学研究科
先進機能物質研究センター