物理化学学报 >> 1995, Vol. 11 >> Issue (03): 234-241.doi: 10.3866/PKU.WHXB19950310

研究论文 上一篇    下一篇

外延定向生长氧化铌模型催化剂的制备

谢磊, 王德峥, 魏绪明, 曹玉明, 郭燮贤, Ushikubo T, Wada K   

  1. 中国科学院大连化学物理研究所催化剂出国家重点实验室|大连 116023|Mitsubishi Kasei Corporation,Research Center 1000,Kamoshida-cho,Midori-ku,Yokohama 227,Japan
  • 收稿日期:1994-02-09 修回日期:1994-06-04 发布日期:1995-03-15
  • 通讯作者: 魏绪明

The Preparation of A |Model Nb Oxide Catalyst Epitaxially Grown

Xie Lei, Wang De-Zheng, Wei Xu-Ming, Cao Yu-Ming, Guo Xie-Xian, Ushikubo T, Wada K   

  1. State Key Laboratory on Catalysis,Dalian Institute of Chemical Physics Chinese Academy of Sciences,Dalian 116023|Mitsubishi Kasei Corporation,Research Center 1000,Kamoshida-cho,Midori-ku,Yokohama 227,Japan
  • Received:1994-02-09 Revised:1994-06-04 Published:1995-03-15
  • Contact: Wei Xu-Ming

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摘要：

为用现代表面科学技术研究金属氧化物催化剂，在Pt（111）上于超高真空系统中原位蒸镀制备了NbO、NbO2、NbO2、单晶薄膜（＞2nm）．通过AES、ISS、LEED、ILS等手段研究了单晶薄膜的成长模式、化学计量和几何结构．表明通过选择合适的废物和控制制备条件，可制备出确定结构的金属氧化物单晶薄膜表面作为体相氧化物催化剂的模型表面．这种方法克服了电子能谱技术研究金属氧化物表面的困难，为研究金属氧化物催化剂的表面化学物理性质提供了方法

关键词: 定向生长, 氧化铌, 模型催化剂, 单晶薄膜

Abstract:

Metal oxides are useful catalytic materials but are not well understood due to a scarcity of fundamental studies. They are rarely available as single crystals and their insulator nature causes charging problems when electrons or ions are probes. We report the use of a technique to overcome these problems by anepitaxial growth onto a dissimilar metal to study the solid add niobium oxide. The model niobium oxide grew epitaxially on a single crystal Pt(111) substrate. The growth mode of the niobium oxide overlayers indicates that the overlayer grows as a 2D monolayer on the Pt substrate followed by the development of a high density of small 3D crystallites. LEED patterns from the niobium oxide overlayer indicate that the small crystallites of niobium oxide grew with the (111) structure of the Pt(111) substrate. The valence states of Nb of our model niobium oxide were determined from AES and ILS (ionization loss spectroscopy, which gives information similar to XPS) chemical shifts. Nb oxide overlayers could segregate into bulk Pt and decompose at high tempetature. This Nb oxide overlayers will be used as a model Nb oxide catalyst.

Key words: Eqitaxial growth, Nb oxide, Model catalyst, Crystal film