Ti原子在Al(110)表面吸氢过程中催化作用的第一性原理研究

运用第一性原理方法对H₂分子在Ti掺杂和纯的Al(110)表面的吸附情况进行了研究,发现有Ti原子掺杂时,存在一个H₂分子的吸附路径,即位于Al(110)面顶位Ti原子上方的H₂分子会发生解离,并与Ti原子形成TiH₂分子,然后TiH₂分子向能量更低的空位移动并接近Al(110)表面.态密度与电荷布居分析显示,吸附完成后H原子与表面Al原子存在较强的共价键作用,这为Al-H类物质及Na_{3 关键词： 钛 吸附 解离能 第一性原理}

First-principles study on the catalytic role of Ti in the hydrogenation of Al(110)surfaces

First-principles calculation is used to study the hydrogen molecule adsorbed on Ti-doped Al(110) surface and pure Al(110) surface separately. We find an adsorption path of hydrogen molecule for decomposing hydrogen atoms and forming TiH₂ with Ti atoms on top site. Afterwards, the TiH₂ molecule moves to hollow site and approaches to the Al(110) surface. The analyses of density of state and Milliken overlap population show that there is covalence interaction between hydrogen atoms and Al atoms of surface, which gives rise to the formation of Al-H, Na₃AlH₆ and NaAlH₄. Hydrogen molecule is unable to decompose hydrogen atoms on pure Al(110) surface.These results contribute further towards the understanding of the improved observation in recycling of hydrogen with Ti-doped NaAlH₄.