A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH(2) through adding Ti catalysts

IMR OpenIR

	A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH(2) through adding Ti catalysts
	H. Zhang; G. L. Liu; K. Z. Qi; G. Y. Zhang; M. Z. Xiao; S. L. Zhu
	2010
发表期刊	Chinese Physics B
ISSN	1674-1056
卷号	19 期号:4
摘要	Experiments on a ball milled mixture with a 1:1 molar ratio of LiNH(2) and LiH with a small amount (1 mol %) of Ti(nano), TiCl(3) and TiO(2)(nano) have revealed a superior catalytic effect on Li-N-H hydrogen storage materials. In the x-ray diffraction profiles, no trace of Ti(nano), TiCl(3) and TiO(2)(nano) was found in these doped composites, by which we deduced that Ti atoms enter LiNH(2) by partial element substitution. A first-principles plane-wave pseudopotential method based on density functional theory has been used to investigate the catalytic effects of Ti catalysts on the dehydrogenating properties of LiNH(2) system. The results show that Ti substitution can reduce the dehydrogenation reaction activation energy of LiNH(2) and improve the dehydrogenating properties of LiNH(2). Based on the analysis of the density of states and overlap populations for LiNH(2) before and after Ti substitution, it was found that the stability of the system of LiNH(2) is reduced, which originates from the increase of the valence electrons at the Fermi level (E(F)) and the decrease of the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap (Delta E(H-L)) near E(F). The catalytic effect of Ti on the dehydrogenating kinetics of LiNH(2) may be attributed to the reduction of average populations between N-H per unit bond length (nm(-1)), which leads to the reduction of the chemical bond strength of N-H.
部门归属	[zhang hui; qi ke-zhen; zhang guo-ying; xiao ming-zhu] shenyang normal univ, coll phys sci & technol, shenyang 110034, peoples r china. [liu gui-li] shenyang univ technol, coll construct engn, shenyang 110023, peoples r china. [zhu sheng-long] chinese acad sci, inst met res, state key lab corros & protect, shenyang 110016, peoples r china.;zhang, h (reprint author), shenyang normal univ, coll phys sci & technol, shenyang 110034, peoples r china;huizhangking@sina.com
关键词	Linh(2) First-principles Calculation Dehydrogenating Properties Ti Catalytic Mechanism Density-functional Theory Hydrogen Storage Properties Destabilization Clusters Nitride
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/31688
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	H. Zhang,G. L. Liu,K. Z. Qi,et al. A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH(2) through adding Ti catalysts[J]. Chinese Physics B,2010,19(4).
APA	H. Zhang,G. L. Liu,K. Z. Qi,G. Y. Zhang,M. Z. Xiao,&S. L. Zhu.(2010).A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH(2) through adding Ti catalysts.Chinese Physics B,19(4).
MLA	H. Zhang,et al."A first-principles study of the catalytic mechanism of the dehydriding reaction of LiNH(2) through adding Ti catalysts".Chinese Physics B 19.4(2010).