On the nucleation step in the Mg-MgH2 phase transformation

被引：45
作者：
Antisari, M. Vittori [1 ]
Aurora, A. [1 ]
Gattia, D. Mirabile [1 ]
Montone, A. [1 ]
机构：
[1] ENEA, FIM Dept, Res Ctr Casaccia, I-00123 Rome, Italy
来源：
SCRIPTA MATERIALIA | 2009年 / 61卷 / 11期
关键词：
Hydrogen storage; Magnesium; Nanocomposite; Scanning electron microscopy (SEM); Phase transformation kinetics; HYDROGEN SORPTION; MAGNESIUM HYDRIDE; KINETICS; DESORPTION; DIFFUSION; MG; NI;
D O I：
10.1016/j.scriptamat.2009.08.030
中图分类号：
TB3 [工程材料学];
学科分类号：
0805 ; 080502 ;
摘要：
Scanning electron microscopy was used to support kinetic analysis in order to ascertain the physical mechanisms involved in the Mg-MgH2 phase transformation. Kinetic asymmetry in hydrogen absorption and desorption was explained by the different requirements for fast nucleation in the two reactions. In particular, MgH2 nucleation in Mg is assisted by crystal defects, while free surface is the only nucleation site in the reverse reaction. This explains, for the first time, the different role of the metal catalyst in the two reactions. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
引用
收藏
页码：1064 / 1067
页数：4
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