Interplay of diffusion and dissociation mechanisms during hydrogen absorption in metals
Interplay of diffusion and dissociation mechanisms during hydrogen absorption in metals
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DOI：
10.1103/physrevb.78.094106
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发表时间：
2008-09-01
影响因子：
3.7
通讯作者：
Griessen, R.
中科院分区：
文献类型：
--
作者：
Borgschulte, A.;Gremaud, R.;Griessen, R.
气固反应的动力学测量，特别是氢吸附动力学，通常根据单限速步骤模型进行解释。然而，最近的研究提供了明确的证据，证明氢吸附所涉及的根本不同步骤之间的相互依赖性。在一维连续模型中探索这种相互依赖性，以估计吸附动力学的时间、温度和压力依赖性以及该过程中涉及的几个材料参数的相关性。给出了各种场景下物理参数提取的定量描述。该模型已成功测试了多个实验案例，范围从模型系统（薄膜）到实际系统（LaNi(5)H(x) 和 MgH(2) 粉末样品）。
Kinetic measurements of gas-solid reactions, in particular hydrogen-sorption kinetics, are usually interpreted according to single rate-limiting step models. However, recent studies gave clear evidence for the interdependence of fundamentally different steps involved in hydrogen sorption. This interdependence is explored in a one-dimensional continuum model in order to estimate the time, temperature, and pressure dependences of the sorption kinetics and the relevance of several materials parameters involved in the process. Quantitative descriptions of the extraction of physical parameters for various scenarios are given. The model is successfully tested for several experimental cases, ranging from model systems (thin films) to practical systems (LaNi(5)H(x) and MgH(2) powder samples).