摘要
采用基于密度泛函理论的第一性原理方法研究了氢原子和氢分子在纯铁表面和锰原子掺杂表面的吸附与解离行为.研究结果表明,氢原子可在纯铁(001)表面稳定吸附,吸附能按照顶位,桥位和心位依次增强;而溶质原子锰降低了氢原子距离表面的位置并强化了氢原子的吸附行为.氢分子在纯铁表面的吸附解离行为取决于氢分子距离模型表面的初始距离和初始空间构型.氢分子平行于纯铁(001)表面时,距离心位1.2Å发生解离,而桥位、顶位均不会发生解离;氢分子垂直放置时,距离桥位0.6Å、顶位1.0Å发生解离,心位不会发生解离.氢分子平行于锰掺杂纯铁(001)表面时,距离桥位0.6Å、顶位0.7Å、心位1.2Å发生解离;氢分子垂直放置时,距离桥位、心位0.8Å发生解离,而顶位放置氢分子不发生解离.归纳可知,锰溶质原子掺杂会增加铁基体表面氢原子和氢分子的吸附作用并促进氢分子发生分解.
The adsorption and dissociation behaviors of H atom and Hon pure Fe and Mn doped Fe surfaces were studied by first-principles method based on density functional theory(DFT).The results show that hydrogen atom can be adsorbed stably on the surface of Fe(001),and the adsorption energy increases according to the top site,bridge site and hollow site.The solute atom Mn reduces the position of hydrogen atom from the surface and strengthens the adsorption behavior of hydrogen atom.The adsorption and dissociation behavior of Hon Fe surface depends on the initial distance and initial spatial configuration of Hfrom the model surface.When His parallel to the surface of Fe(001),the dissociation occurs 1.2Å away from the hollow site,but the bridge and top sites do not dissociate.When Hare placed vertically,dissociation occurs 0.6Å from the bridge and 1.0Å from the top,but dissociation does not occur at the hollow site.When hydrogen molecules are parallel to the surface of Mn doped Fe,dissociation occurs 0.6Å from the bridge,0.7Å from the top and 1.2Å from the hollow site.When Hare placed vertically,dissociation occurs 0.8Å from the bridge and hollow site,while no dissociation occurs when Hare placed at the top site.It can be concluded that the doping of Mn solute atoms will increase the adsorption of hydrogen and Hon the surface of iron matrix and promote the decomposition of hydrogen molecules.
作者
王诚
成林
许泽岷
吴开明
WANG Cheng;CHENG Lin;XU Ze-Min;WU Kai-Ming(Collaborative Innovation Center for Advanced Steels,International Research Institute for Steel Technology,Wuhan 430081,China;Metals Valley and Band(Foshan)Metallic Composite Co.,Ltd.,Foshan 528000,China)
出处
《原子与分子物理学报》
CAS
北大核心
2023年第5期1-10,共10页
Journal of Atomic and Molecular Physics
基金
国家自然科学基金(52071238)。
关键词
锰溶质原子
表面吸附
氢分子吸附
第一性原理
Medium-high manganese steel
Surface adsorption
Molecular hydrogen adsorption
First principles
