Decomposition kinetics of metal hydrides: Experiments and modeling
Decomposition kinetics of metal hydrides: Experiments and modeling
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DOI：
10.1016/j.jallcom.2013.03.205
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发表时间：
2013-12-15
影响因子：
6.2
通讯作者：
Voyt, A. P.
中科院分区：
文献类型：
--
作者：
Gabis, I. E.;Chernov, I. A.;Voyt, A. P.
该研究的目的是了解金属氧化物的分解，并确定最重要的限制反应。我们使用的功能，描述真实的物理过程，如氢化物相的分解，氢的解吸和扩散，和相的形态。将氢化物材料分为两类，这取决于键合的类型（金属或非金属），允许解释脱氢动力学的细节。我们发现，对于非金属陶瓷的分解形态的“形核和生长”是典型的，而对于金属的“收缩核”形态是更常见的。在这两种情况下，氢通过金属相相当快地从晶界-金属边界扩散到外表面，因此扩散不影响分解动力学。最可能的限制因素是氢从金属相解吸的速率。对于“收缩核”形态，氢化物分解的速率也可以影响过程的最后阶段期间的动力学。(C)2013爱思唯尔有限公司版权所有。
The aim of the research was to understand decomposition of hydrides of metals and determine the most significant limiting reactions. We used functions that describe real physical processes, such as decomposition of hydride phase, desorption and diffusion of hydrogen, and morphology of phases. Dividing hydride materials to two classes depending on the type of bonding (metallic or non-metallic) allowed to explain details of kinetics of dehydriding. We show that for decomposition of non-metallic hydrides morphology of "nucleation and growth" is typical; while for metallic ones the "shrinking core" morphology is more common. In both cases hydrogen diffuses from the hydride-metal boundary to the outer surface through the metal phase rather quickly, so diffusion does not influence on the decomposition kinetics. The most probable limiting factor is the rate of hydrogen desorption from the metal phase. For the "shrinking core" morphology rate of hydride decomposition can also influence on the kinetics during the final stages of the process. (C) 2013 Elsevier B.V. All rights reserved.