CO在Fe3O4(111)表面吸附的密度泛函理论研究。

Density function theory study of CO adsorption on Fe3O4(111) surface.

作者信息

Huang Dong-Mei, Cao Dong-Bo, Li Yong-Wang, Jiao Haijun

机构信息

State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, People's Republic of China.

出版信息

J Phys Chem B. 2006 Jul 20;110(28):13920-5. doi: 10.1021/jp0568273.

DOI:10.1021/jp0568273

PMID:16836342

Abstract

Density functional theory calculations have been carried out for CO adsorption on the Fe(oct2)- and Fe(tet1)-terminated Fe(3)O(4)(111) surfaces, which are considered as active catalysts in water-gas shift reaction. It is found that the on-top configurations are most stable on these two surfaces. Some bridge configurations are also stable in which the new C-O bond formed between the surface O atom and the C atom of CO. The adsorption on the Fe(oct2)-terminated surface is more stable than on the Fe(tet1)-terminated surface. The density of state reveals the binding mechanism of CO adsorption on the two surfaces. Our calculations have also shown that the absorbed CO can migrate from the on-top site to the bridge site or 3-fold site. The oxidation of CO via surface oxygen atoms is feasible, which is in good agreement with experimental results.

摘要

已对CO在Fe(oct2) - 和Fe(tet1) - 终止的Fe₃O₄(111)表面上的吸附进行了密度泛函理论计算，这两种表面被认为是水煤气变换反应中的活性催化剂。研究发现，顶位构型在这两个表面上最稳定。一些桥式构型也很稳定，其中表面O原子与CO的C原子之间形成了新的C - O键。在Fe(oct2) - 终止表面上的吸附比在Fe(tet1) - 终止表面上更稳定。态密度揭示了CO在这两个表面上的吸附结合机制。我们的计算还表明，吸附的CO可以从顶位迁移到桥位或三重位。通过表面氧原子对CO的氧化是可行的，这与实验结果高度一致。