Hydrogen kinetics in magnesium hydride: On different catalytic effects of niobium

被引：40

作者：

Bazzanella, N. ^{[1
]}

Checchetto, R.

Miotello, A.

Sada, C.

Mazzoldi, P.

Mengucci, P.

机构：

[1] Univ Trent, Dipartimento Fis, I-38050 Trento, Italy

[2] Univ Padua, Dipartimento Fis, I-35131 Padua, Italy

[3] Univ Politecn Marche, Dipartimento Fis & Ingn Mat & Terr, I-60131 Ancona, Italy

来源：

APPLIED PHYSICS LETTERS | 2006年 / 89卷 / 01期

关键词：

D O I：

10.1063/1.2218328

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The hydrogen desorption kinetics from pure and Nb-doped MgH2 samples was studied as function of the Nb concentration (6x10(-4)<[Nb/Mg]< 5x10(-2)). Structural and kinetics analyses indicate that Nb acts as catalyst both when Nb atoms aggregate forming NbH clusters dispersed in the MgH2 and also when Nb is contained as atomic impurity. It is suggested that the local atomic environment around the Nb atom acts as seed for h-Mg phase nucleation which constitutes the rate limiting step for the hydrogen kinetics while, when the Nb concentration exceeds about 1 at. %, the rate limiting step is hydrogen diffusion. (c) 2006 American Institute of Physics.

引用

页数：3

共 14 条

[1] Catalytic effect on hydrogen desorption in Nb-doped microcrystalline MgH2 [J].