Alloying effects on the hydrogen-storage capability for Pd-TM-H (TM = Cu, Au, Pt, Ir) systems
Alloying effects on the hydrogen-storage capability for Pd-TM-H (TM = Cu, Au, Pt, Ir) systems
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合金对 Pd-TM-H（TM = Cu、Au、Pt、Ir）体系储氢能力的影响
DOI：
10.1016/j.jallcom.2014.06.118
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发表时间：
2014
影响因子：
6.2
通讯作者：
M. Matsuyama
中科院分区：
文献类型：
--
作者：
S. Akamaru;M. Hara;M. Matsuyama
在室温下测量了Pd-TM-H（TM = Cu，Au，Pt，Ir）体系的压力-组成等温线和磁化率，并从电子能带结构的角度研究了Pd与过渡金属合金化对Pd-TM合金储氢性能的影响。Pd-TM-H体系的磁化率均随吸氢量线性下降。对于Pd-Cu合金，磁化率在从压力-成分等温线获得的平台区域中的氢的末端成分处接近于零，并且末端成分随着Cu取代的增加而降低。这些结果表明，Pd-Cu合金的贮氢能力与其电子能带结构中未占据d态的数量成正比。Pd-Au-H体系表现出与Pd-Cu-H体系基本相同的行为。对于Pd-Pt和Pd-Ir合金，在平台中的氢的末端组成处的磁化率呈现有限的正值，这表明当最大量的氢存储在合金中时，Pd-Pt和Pd-Ir合金中未占据的d态未被填充。这些有限的磁导率在终端组成的氢在平台区解释了由于合金化的电子能带结构中的未占据的d态的结构修改。
Pressure–composition isotherms and the magnetic susceptibilities of Pd–TM–H (TM = Cu, Au, Pt, and Ir) systems were measured at ambient temperature, and the effects of alloying between Pd and transition metals on the hydrogen storage capability of these Pd–TM alloys were investigated by considering their electronic band structures. All of the magnetic susceptibilities for the Pd–TM–H systems decreased linearly with hydrogen uptake. For the Pd–Cu alloy, the magnetic susceptibility was nearly zero at the terminal composition of hydrogen in the plateau region obtained from the pressure–composition isotherm, and the terminal composition decreased with increasing Cu substitution. These results indicated that the hydrogen-storage capability was proportional to the amount of unoccupied d states in the electronic band structure of the Pd–Cu alloy. The Pd–Au–H system exhibited substantially the same behavior as the Pd–Cu–H system. For the Pd–Pt and Pd–Ir alloys, the magnetic susceptibility at the terminal composition of hydrogen in the plateau exhibited a finite positive value, indicating that the unoccupied d states in the Pd–Pt and Pd–Ir alloys were not filled when the maximum quantity of hydrogen was stored in the alloys. These finite magnetic susceptibilities at the terminal composition of hydrogen in the plateau region were explained by the structural modification of the unoccupied d states in the electronic band structures due to alloying.