物理化学学报 >> 2006, Vol. 22 >> Issue (09): 1126-1131.doi: 10.1016/S1872-1508(06)60052-1

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NO双分子在Cu2O(111)面吸附与解离的理论研究

孙宝珍;陈文凯;徐香兰   

  1. (福州大学化学系, 福州 350002)
  • 收稿日期:2006-03-27 修回日期:2006-05-18 发布日期:2006-09-04
  • 通讯作者: 陈文凯 E-mail:qc2008@fzu.edu.cn

Theoretical Studies of the Adsorption and Dissociation of Two NO Molecules on Cu2O(111) Surface

SUN Bao-Zhen;CHEN Wen-Kai;XU Xiang-Lan   

  1. (Department of Chemistry, Fuzhou University, Fuzhou 350002, P. R. China)
  • Received:2006-03-27 Revised:2006-05-18 Published:2006-09-04
  • Contact: CHEN Wen-Kai E-mail:qc2008@fzu.edu.cn

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摘要： 采用广义梯度密度泛函理论结合周期平板模型方法, 在DNP基组下, 研究了NO双分子在三重态和单重态两种电子组态下在Cu2O(111)完整表面的吸附情况. 考虑了Cu+(NO)(NO)、Cu+(NO)(ON)及Cu+(ON)(ON)这三种构型, 计算了它们的吸附能和Mulliken电荷, 分析并预测了吸附后可能产生的物种. 结果表明, 当两个NO分子都以O端吸附在Cu2O(111)表面时即Cu+(ON)(ON)构型, N—N键长很短, 只有124.4 pm, 吸附的两个NO分子形成了二聚体形式, 这种吸附构型有利于进一步离解产生N2或N2O并形成Cu-O表面物种.

关键词: 密度泛函理论, 周期平板模型, NO, Cu2O(111), 吸附, 二聚体, 离解

Abstract: The adsorption and dissociation of two NO molecules on Cu2O(111) surface have been studied with periodic slab model by DFT method using the generalized gradient approximation(GGA) with the Perdew-Burke-Emzerhof(PBE) exchange-correlation functional. Three kinds of structures, Cu+(NO)(NO), Cu+(NO)(ON), and Cu+(ON)(ON), with singlet and triplet states, were considered. Their corresponding adsorption energies and Mulliken charges were calculated. The calculated results indicate that in the optimized Cu+(ON)(ON) configuration, two adsorbed NO molecules form a dimeric species with a much shorter N—N bond length (about 124.4 pm). Such a configuration contributes to the dissociation of NO to Cu-O surface species, with elimination of N2 or N2O.

Key words: Density functional theory, Periodic slab model, NO, Cu2O(111), Adsorption, Dimer, Dissociation