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Abstract：
The mechanism of Y on H/H2 adsorption performance of Mg17Al12 were studied by the density functional theory. We obtained that for the Y-adsorbed systems, Y tended to occupy on the bridge site between adjacent Mg atoms. For the Y-substituted surfaces, Y atoms inclined to replace Mg atoms on the surfaces. We found that hydrogen (H/H2) absorption on the Mg17Al12(110) systems were improved by adding Y, the order of adsorption energy was as follows: clean Mg17Al12(110) > the Y-substituted surfaces > the Y-adsorbed surfaces. In addition, H2 molecules could dissociate on the Y-containing systems without barrier energy. Electronic properties showed that for H2 adsorption, the s states of atomic H mainly hybridized with the d states of Y. The formations of the Y-H bonds and the interactions between Y and H atoms could expound the mechanism for the promoted hydrogenation performance of the Y-containing surfaces.
摘要：
利用密度泛函理论研究了Y对Mg17Al12的H/H2吸附性能的机理。我们得到了对于Y吸附系统，Y倾向于占据相邻Mg原子之间的桥位置。对于Y取代的曲面，Y原子倾向于取代表面上的Mg原子。我们发现，在Mg17Al12（110）系统上的氢（H/H2）吸收通过添加Y得到改善，吸附能的顺序如下：清洁Mg17Al12（110）>Y取代表面>Y吸附表面。此外,H2分子可以在含Y的系统上解离而没有势垒能。电子性质表明，对于H2的吸附，原子H的s态主要与Y的d态杂化。Y-H键的形成以及Y和H原子之间的相互作用可以阐明含Y表面促进氢化性能的机理。
