Thermal decomposition of Mg(AlH4)2 studied by in situ synchrotron X-ray diffraction

被引：26

作者：

Fossdal, A

Brinks, HW

Fichtner, M

Hauback, BC

机构：

[1] Inst Energy Technol, Dept Phys, NO-2027 Kjeller, Norway

[2] Forschungszentrum Karlsruhe, Inst Nanotechnol, D-76021 Karlsruhe, Germany

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2005年 / 404卷

关键词：

hydrogen storage materials; crystal structure; neutron diffraction; synchrotron radiation; alanates;

D O I：

10.1016/j.jallcom.2004.12.169

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The thermal decomposition of Mg(AlH4)(2) was studied by in situ synchrotron X-ray diffraction. The reaction proceeds in two steps. The first reaction step involves decomposition of magnesium alanate to magnesium hydride and the solid solution Al1-x/2Mgx/2: (1-x/2)Mg(AlH4)(2) -> (1 - (3/2)x)MgH2 + 2Al(1-x/2)Mg(x/2) + (3 + (3/2)x)H-2. No evidence of intermediate phases was found. The second step proved to be more complex. For simplicity this step can be written as: (1 - (3/2)x)MgH2 + 2Al(1-x/2)Mg(x/2) -> Al1-x/2Mgx/2 -> AlxMgy + (1 - (3/2)x)H-2, where AlxMgy represents either two cubic Al-Mg solid solution phases or the ordered beta-Al3Mg2 phase. (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：752 / 756

页数：5

共 15 条

[1] Solid-phase solvate-free formation of magnesium hydroaluminates Mg(AlH4)2 and MgAlH5 upon mechanochemical activation or heating of magnesium hydride and aluminum chloride mixtures [J].