Graphyne and graphdiyne : versatile catalysts for dehydrogenation of light metal complex hydrides
Graphyne and graphdiyne : versatile catalysts for dehydrogenation of light metal complex hydrides
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DOI：
10.1021/jp406081v
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发表时间：
2013-09
期刊：
影响因子：
--
通讯作者：
Hui-Yeol Yu;A. Du;Y. Song;D. Searles
中科院分区：
文献类型：
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作者：
Hui-Yeol Yu;A. Du;Y. Song;D. Searles
用结合长程范德华色散修正的密度泛函理论(DFT)研究了新的二维碳同素异形体--石墨烯(GP)和石墨二炔(GD)与轻金属络合物氢化物LiAlH4、LiBH4和NaAlH4之间的相互作用。由于具有良好的孔结构，轻金属络合物氢化物与GP和GP的相互作用比与富勒烯的相互作用强得多。这种强烈的相互作用极大地影响了碱金属原子对AlH4或BH4的电荷给予程度，从而破坏了Al-H或B-H键的稳定。与单独的轻金属络合物氢化物相比，GP或Gd的存在可以显著降低脱氢能量。最有趣的是，LiBHx在GP和GD上的脱氢能在所有阶段(x从4到1)都降低了，而在第三阶段，LiBH4在富勒烯上的脱氢能增加了。此外，GP和GD上均匀分布的孔的存在有望促进轻金属络合物氢化物的脱氢。这些结果突出了催化轻金属络合物氢化物作为储氢介质的新的有趣的材料。由于最近的一次实验已经成功地合成了GD，我们希望本工作将促进这一方向的进一步实验研究。
The interaction between new two-dimensional carbon allotropes, i.e. graphyne (GP) and graphdiyne (GD), and light metal complex hydrides LiAlH4, LiBH4, and NaAlH4 was studied using density functional theory (DFT) incorporating long range van der Waals dispersion correction. The light metal complex hydrides show much stronger interaction with GP and GP than that with fullerene due to the well defined pore structure. Such strong interactions greatly affect the degree of charge donation from the alkali metal atom to AlH4 or BH4, consequently destabilizing the Al-H or B-H bonds. Compared to the isolated light metal complex hydride, the presence of GP or GD can lead to a significant reduction of the hydrogen removal energy. Most interestingly, the hydrogen removal energies for LiBHx on GP and with GD are found to be lowered at all the stages (x from 4 to 1) whereas the H-removal energy in the third stage is increased for LiBH4 on fullerene. In addition, the presence of uniformly distributed pores on GP and GD is expected to facilitate the dehydrogenation of light metal complex hydrides. The present results highlight new interesting materials to catalyze light metal complex hydrides for potential application as media for hydrogen storage. Since GD has been successfully synthesized in a recent experiment, we hope the present work will stimulate further experimental investigations in this direction.