| Structure and hydrogen absorbing properties of ScCrMn alloy |
| W. H. Li; E. D. Wu
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| 2012
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| 发表期刊 | Journal of Alloys and Compounds
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| ISSN | 0925-8388
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| 卷号 | 511期号:1页码:169-175 |
| 摘要 | The crystal structures of ScCrMn alloy and its hydride are determined by XRD Rietveld analysis and TEM examination. The ScCrMn alloy exhibits a rarely ideal close-packed C14 type hexagonal Laves phase structure with lattice parameters a = 5.064(1), c = 8.263(2) angstrom, deviating from the ANOE dependent rule on Laves phase structure. The hydrogenation of the alloy to ScCrMnH(3.9) results in significant lattice expansion of 27%, but does not alter the matrix lattice structure. The XRD pattern of the hydride also shows close-packed structure with little line broadening, comparable to that of the alloy, indicating a high degree of crystallinity, where the hydrogen atoms are homogeneously distributed in evenly distributed interstitials with minimal defects. The alloy demonstrates extremely easy activation property. The alloy can be activated at a low pressure of 0.46 kPa and exhibit very fast absorption rate at sub-atmosphere at room temperature. The hydrogenation thermodynamics of the alloy are evaluated by P-C-T measurements at different temperatures. At hydrogen concentration H/M = 0.66 corresponding to a defined room temperature plateau pressure, the relative partial molar enthalpy Delta H and entropy Delta S derived by Van't Hoff equation are -63 kJ/mol and -111 J/mol K, respectively. These results manifest that the hydride stability of the ScCrMn alloy is comparable to those of the hydrogen isotope storage alloys of ZrCo and ZrTi(0.2)V(1.8), and would be superior on relevant applications. The DSC-TG measurements of the hydride reveal that the total release of hydrogen can basically be achieved at 653 K, accompanied by an oxidation reaction with residual oxygen to form water vapor. The results indicate that the alloy is an effective catalyst for the dissociation of hydrogen and combination of oxygen. (C) 2011 Elsevier B.V. All rights reserved. |
| 部门归属 | [li, wuhui; wu, erdong] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china.;wu, ed (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china.;ewu@imr.ac.cn
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| 关键词 | Sc-based Laves Phase Alloy
Crystal Structure
Hydrogen Activation
Hydrogen Absorption/desorption
Thermodynamics
Laves Phase Alloys
Crystal-structure
Equilibrium
Systems
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| URL | 查看原文
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| 文献类型 | 期刊论文
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| 条目标识符 | http://ir.imr.ac.cn/handle/321006/60071
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| 专题 | 中国科学院金属研究所
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推荐引用方式
GB/T 7714 |
W. H. Li,E. D. Wu. Structure and hydrogen absorbing properties of ScCrMn alloy[J]. Journal of Alloys and Compounds,2012,511(1):169-175.
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| APA |
W. H. Li,&E. D. Wu.(2012).Structure and hydrogen absorbing properties of ScCrMn alloy.Journal of Alloys and Compounds,511(1),169-175.
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| MLA |
W. H. Li,et al."Structure and hydrogen absorbing properties of ScCrMn alloy".Journal of Alloys and Compounds 511.1(2012):169-175.
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