Ab initio studies of hydrogen desorption from low index magnesium hydride surface

被引：74
作者：
Du, A. J.
Smith, Sean C.
Yao, X. D.
Lu, G. Q.
机构：
[1] Univ Queensland, Ctr Computat Mol Sci, Brisbane, Qld 4072, Australia
[2] Univ Queensland, Sch Engn, ARC Ctr Funct Nanomat, Brisbane, Qld 4072, Australia
[3] James Cook Univ N Queensland, Sch Engn, Townsville, Qld 4811, Australia
来源：
SURFACE SCIENCE | 2006年 / 600卷 / 09期
基金：
澳大利亚研究理事会;
关键词：
ab initio density functional calculations; desorption; surface relaxation;
D O I：
10.1016/j.susc.2006.02.019
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
The low index Magnesium hydride surfaces, MgH2(001) and MgH2(110), have been studied by ab intio Density Functional Theory (DFT) calculations. It was found that the MgH2(110) surface is more stable than MgH2(001) surface, which is in good agreement with the experimental observation. The H-2 desorption barriers vary depending on the crystalline surfaces that are exposed and also the specific H atom sites involved-they are found to be generally high, due to the thermodynamic stability of the MgH2, system, and are larger for the MgH2(001) surface. The pathway for recombinative desorption of one in-plane and one bridging H atom from the MgH2(110) surface was found to be the lowest energy barrier amongst those computed (172 KJ/mol) and is in good agreement with the experimental estimates. (c) 2006 Elsevier B.V. All rights reserved.
引用
收藏
页码：1854 / 1859
页数：6
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