氢原子与Fe(111)表面相互作用的理论研究

Theoretical investigation on the interaction between hydrogen atom and Fe(111)

氢自由基在Fe表面的吸附是典型的表面吸附反应。本文首先对α-Fe体相开展研究,再对Fe(111)的周期性平板模型进行了参数测试,确定了7层模型可以有效表示Fe(111)表面。研究了氢原子在Fe的刚性表面和柔性表面上的吸附情况,发现弛豫效应主要集中在上3层表面,而底层4层原子几乎未发生驰豫。发现氢原子在Fe(111)表面的吸附稳定顺序为Bridge>Hcp>Fcc>Top。还考察了不同的泛函结合不同的色散校正方法对吸附的影响。本文提供了H@Fe(111)体系详细的模型测试结果,为今后H@Fe体系构建精细势能面的研究提供初步指导和参考。

The adsorption of the hydrogen atom on the Fe surface is an important surface reaction for adsorption.Both the bulk α-Fe and the periodic plate model of Fe(111)were tested using various calculation parameters.After testing,we found that a seven-layer surface model is sufficiently reliable for representing the clean Fe(111)surface.The test results showed that the relaxation effect mainly takes place on the upper three layers.The stable order of the hydrogen adsorption sites on the Fe(111)surface is Bridge>Hcp>Fcc>Top.We also investigated the influence of different functions combined with different dispersion correction methods on the adsorption characterizations.Our test not only provided detailed results of the H@Fe(111)system,but also offered preliminary guidance and support for constructing full-dimensional reliable potential energy surface in the future.