物理化学学报 >> 2012, Vol. 28 >> Issue (01): 51-57.doi: 10.3866/PKU.WHXB20122851

理论与计算化学 上一篇    下一篇

一氧化碳分子在Pt/t-ZrO2(101)表面的吸附性质

满梅玲1, 陆春海2, 陈文凯1, 李奕1, 章永凡1   

  1. 1. 福建省光催化重点实验室—省部共建国家重点实验室培育基地, 福州大学化学系, 福州 350002;
    2. 成都理工大学核技术与自动化工程学院, 成都 610059
  • 收稿日期:2011-08-25 修回日期:2011-09-16 发布日期:2011-12-29
  • 通讯作者: 陈文凯 E-mail:qc2008@fzu.edu.cn
  • 基金资助:

    国家自然科学基金(90922022)和福建省高等学校新世纪优秀人才计划(HX2006-103)资助项目

Adsorption Properties of CO Molecules on Pt/t-ZrO2(101) Surfaces

MAN Mei-Ling1, LU Chun-Hai2, CHEN Wen-Kai1, LI Yi1, ZHANG Yong-Fan1   

  1. 1. State Key Laboratory Breeding Base of Photocatalysis, Department of Chemistry, Fuzhou University, Fuzhou 350002, P. R. China;
    2. College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, P. R. China
  • Received:2011-08-25 Revised:2011-09-16 Published:2011-12-29
  • Contact: CHEN Wen-Kai E-mail:qc2008@fzu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (90922022) and New Century Excellent Talents Program in University of Fujian Province, China (HX2006-103).

摘要: 运用广义梯度密度泛函理论(GGA-PW91)结合周期平板模型方法, 研究了CO分子在完整与Pt 负载的四方ZrO2(101)表面的吸附行为. 结果表明: 表面第二层第二氧位和表面第二桥位分别为CO分子和Pt 原子在完整ZrO2(101)表面的稳定吸附位, 且覆盖度为0.25 ML (monolayer)时均为稳定吸附构型, 吸附能分别为56.2和352.7 kJ·mol-1. CO分子在负载表面的稳定吸附模式为C-end吸附, 吸附能为323.8 kJ·mol-1. 考察了CO分子在负载表面吸附前后的振动频率、态密度和轨道电荷布居分析, 并与CO分子和Pt 原子在ZrO2表面的结果进行比较. 结果表明, C端吸附CO分子键长为0.1161 nm, 与自由的和吸附在ZrO2表面后的CO相应值(0.1141和0.1136 nm)相比伸长. 吸附后C―O键伸缩振动频率为2018 cm-1, 与自由CO分子相比发生红移; 吸附后CO带部分正电荷, 电子转移以Pt 5d→CO 2ππ反馈机理占主导地位.

关键词: 密度泛函理论, 四方型二氧化锆, 一氧化碳, 吸附,

Abstract: We studied the adsorption of CO molecules on perfect and Pt-adsorbed t-ZrO2(101) surfaces using a periodic slab model by PW91 of generalized gradient approximation (GGA) within the framework of density functional theory. The results indicated that the second sub-surface oxygen and the second bridge sites are the most stable adsorbed sites for CO and Pt on the ZrO2(101) surface, respectively. When the coverage is 0.25 ML (monolayer) the most stable models were obtained with adsorption energies of 56.2 and 352.7 kJ·mol-1. The most stable model of CO adsorbed on the Pt/t-ZrO2(101) surface was obtained by C-end adsorption with an adsorption energy of 323.8 kJ·mol-1. We considered vibrational frequency calculations, density of states and the Mulliken population of the adsorption systems before and after adsorption and these were compared for CO and Pt adsorption onto the ZrO2 surface. The results indicate that the C―O bond length of 0.1161 nm after adsorption at the C-end is elongated compared with the 0.1141 and 0.1136 nm of free and adsorbed on ZrO2. The vibrational frequency of CO at 2018 cm-1 is red-shifted compared with free CO. CO has some positive charge after adsorption and charge transfer is predominantly by the π back-donation bonding mechanism of the Pt 5d→CO 2π orbital.

Key words: Density functional theory, Tetragonal zirconia, CO, Adsorption, Pt

MSC2000: 

  • O641