Exploration of the nature of active Ti species in metallic Ti-doped NaAlH(4)

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	Exploration of the nature of active Ti species in metallic Ti-doped NaAlH(4)
	P. Wang; X. D. Kang; H. M. Cheng
	2005
发表期刊	Journal of Physical Chemistry B
ISSN	1520-6106
卷号	109 期号:43 页码:20131-20136
摘要	Clarification of the nature of active Ti species has been a key challenge in developing Ti-doped NaAlH(4) as a potential hydrogen storage medium. Previously, it has been greatly hindered by the invisibility of Ti-containing species in conventional analysis techniques. In the present study, for the first time, the catalytically active Ti-containing species have been definitely identified by X-ray diffraction in the hydrides doped with metallic Ti. It was found that mechanical milling of a NaH/Al mixture or NaAlH(4) with metallic Ti powder resulted in the formation of nanocrystalline Ti hydrides. The variation of the preparation conditions during the doping process leads to a slight composition variation of the Ti hydrides. The catalytic enhancement arising upon doping the hydride with commercial TiH(2) was quite similar to that achieved in the hydrides doped with metallic Ti. Moreover, the cycling stability that was previously established in metallic Ti-doped hydrides was also observed in the hydrides doped with TiH(2). These results clearly demonstrate that the in situ formed Ti hydrides act as active species to catalyze the reversible dehydrogenation of NaAlH(4). The mechanism by which Ti hydrides catalyze the reversible de-/hydrogenation reactions of NaAlH(4) was discussed.
部门归属	chinese acad sci, met res inst, shenyang natl lab mat sci, shenyang 110016, peoples r china.;wang, p (reprint author), chinese acad sci, met res inst, shenyang natl lab mat sci, shenyang 110016, peoples r china;pingwang@imr.ac.cn
关键词	Sodium Aluminum-hydride Hydrogen-storage Material X-ray-diffraction Thermal-decomposition Titanium Alanates State Zirconium Powder Behavior
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/35087
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	P. Wang,X. D. Kang,H. M. Cheng. Exploration of the nature of active Ti species in metallic Ti-doped NaAlH(4)[J]. Journal of Physical Chemistry B,2005,109(43):20131-20136.
APA	P. Wang,X. D. Kang,&H. M. Cheng.(2005).Exploration of the nature of active Ti species in metallic Ti-doped NaAlH(4).Journal of Physical Chemistry B,109(43),20131-20136.
MLA	P. Wang,et al."Exploration of the nature of active Ti species in metallic Ti-doped NaAlH(4)".Journal of Physical Chemistry B 109.43(2005):20131-20136.