期刊
SURFACE SCIENCE
卷 601, 期 12, 页码 2426-2437出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.susc.2007.04.059
关键词
hematite surface; adsorption; hydroxylation; density functional
The adsorption modes of HO on a Fe-terminated hematite(0001) surface have been investigated by first principles Density Functional theory within a periodic slab model and the generalized gradient approximation. Molecular adsorption and dissociative adsorption in monolayer coverage, one H2O per surface Fe, were both considered. Five plausible orientations were studied to determine the most favorable adsorption position. Molecular adsorption is shown to have a small effect on the underlying surface structure, while hydroxylation has a strong effect on the surface geometry. Electronic densities of state calculations reveal details of these different interactions. The heterolytic dissociation, which produces two types of surface hydroxyls, is the preferable adsorption mode, being slightly favored energetically over the molecular adsorption. Homolytic dissociative adsorption, forming a single hydroxyl on surface Fe, is energetically unfavored, even though strong binding interaction (similar to 3 eV) is found between the OH radical and surface. Dissociative adsorption on an oxidized ferryl site was also studied to investigate suggested local reactivity enhancement. (c) 2007 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据