物理化学学报 >> 2012, Vol. 28 >> Issue (05): 1063-1069.doi: 10.3866/PKU.WHXB201203021

理论与计算化学 上一篇    下一篇

H2在WO3表面解离吸附反应的第一性原理研究

田相桂, 张跃, 杨泰生   

  1. 北京航空航天大学材料科学与工程学院, 北京 100191
  • 收稿日期:2011-10-31 修回日期:2012-02-22 发布日期:2012-04-26
  • 通讯作者: 张跃 E-mail:zhangy@buaa.edu.cn
  • 基金资助:

    教育部长江学者和创新团队发展计划(IRT0805)资助项目

First-Principles Study of H2 Dissociative Adsorption Reactions on WO3 Surfaces

TIAN Xiang-Gui, ZHANG Yue, YANG Tai-Sheng   

  1. School of Materials Science and Engineering, Beihang University, Beijing 100191, P. R. China
  • Received:2011-10-31 Revised:2012-02-22 Published:2012-04-26
  • Contact: ZHANG Yue E-mail:zhangy@buaa.edu.cn
  • Supported by:

    The project was supported by the Cheung Kong Scholars of China and Innovative Research Team Program in University from Ministry of Education, China (IRT0805).

摘要: 采用第一性原理方法对H2在WO3表面的解离吸附反应进行了研究. 首先通过清洁表面模型的计算, 证明了c(2×2)重构表面是最稳定的WO3(001)表面构型; 进而研究了4 种可能的H2解离吸附模型, 结果表明最可能的吸附反应为两个氢原子吸附在表面O1c原子上, 氢原子被氧化在表面形成水, 同时伴随着产生一个表面氧空位. 态密度结果表明氢的吸附导致体系能带下移, 导带部分填充电子, 从而阐明了实验中WO3吸附H2后电导率上升的微观机理.

关键词: 三氧化钨, 第一性原理计算, 气体传感器, 氢气吸附

Abstract: The reaction mechanism of H2 dissociative adsorption on WO3 surfaces was studied by a first-principles method. Calculations for the clean surface indicated that the c(2×2) reconstruction was the most stable surface geometry. Four H2 dissociative adsorption models were investigated. The optimal configuration was for two H atoms adsorbed at the terminal O1c site, followed by water formation and an oxygen vacancy on the surface. The density of states (DOS) results revealed that H2 dissociative adsorption led to partial filling of the conduction band, which accounted for the increase of WO3 electrical conductivity upon H2 exposure.

Key words: WO3, First-principles calculation, Gas sensor, Hydrogen adsorption

MSC2000: 

  • O647