物理化学学报 >> 2010, Vol. 26 >> Issue (10): 2679-2685.doi: 10.3866/PKU.WHXB20101013

催化和表面结构 上一篇    下一篇

NOx分子在[Ag]-MAPO-5 (M=Si, Ti) 分子筛中的吸附

刘洁翔1, 张晓光2, 段中余1, 刘晓莉1   

  1. 1. 河北工业大学化工学院, 天津300130;
    2. 南开大学化学学院, 天津300071
  • 收稿日期:2010-04-20 修回日期:2010-07-06 发布日期:2010-09-27
  • 通讯作者: 刘洁翔 E-mail:jxliu@hebut.edu.cn
  • 基金资助:

    河北省科技支撑计划(06215124)和天津市自然科学基金(08JCYBJC00700)资助项目.

NOx Molecule Adsorption in [Ag]-MAPO-5 (M=Si, Ti)Molecular Sieves

LIU Jie-Xiang1, ZHANG Xiao-Guang2, DUAN Zhong-Yu1, LIU Xiao-Li1   

  1. 1. School of Chemical Engineering, Hebei University of Technology, Tianjin 300130, P. R. China;
    2. College of Chemistry, Nankai University, Tianjin 300071, P. R. China
  • Received:2010-04-20 Revised:2010-07-06 Published:2010-09-27
  • Contact: LIU Jie-Xiang E-mail:jxliu@hebut.edu.cn
  • Supported by:

    The project was supported by the Science and Technology Project of Hebei Province, China (06215124) and Natural Science Foundation of Tianjin, China (08JCYBJC00700).

摘要:

采用密度泛函理论(DFT) 研究了银离子交换的硅磷酸铝([Ag]-SAPO-5)和钛磷酸铝([Ag]-TAPO-5)分子筛结构及其对NOx 分子的吸附, 获得吸附复合物的平衡几何结构参数和吸附能. 结果表明, NOx 分子以η1-N 模式吸附在[Ag]-SAPO-5 和[Ag]-TAPO-5 分子筛中的结构更稳定, 其吸附作用强度的次序为NO2>NO>N2O.[Ag]-SAPO-5 和[Ag]-TAPO-5 对NO 和NO2 分子的活化程度要比N2O 大. 相比[Ag]-AlMOR,[Ag]-SAPO-5 和[Ag]-TAPO-5 对NOx 分子的活化程度较大. 还对[Ag]-SAPO-5 和[Ag]-TAPO-5 分子筛的抗硫、抗水及抗氧化性能进行了研究和分析. 另外, 通过自然键轨道(NBO) 计算, 分析了NOx 分子与平衡离子Ag+之间的作用机理.

关键词: 氮氧化物, 磷酸铝分子筛, 银, 吸附, 密度泛函理论

Abstract:

NOx adsorption in silver-exchanged aluminophosphate molecular sieves ([Ag]-SAPO-5 and [Ag]-TAPO-5) was investigated using the density functional theory (DFT). Equilibrium structure parameters and adsorption energies were obtained and compared. The results indicated that the η1-N mode was more stable than the η1-O mode. The adsorption energy values of NOx followed the order: NO2>NO>N2O. Compared to the free gas state, the bond parameters of NO and NO2 in the adsorbed state changed more than that of N2O in [Ag]-SAPO-5 and [Ag]-TAPO-5. Moreover, [Ag]-SAPO-5 and [Ag]-TAPO-5 had a higher activation for the NOx molecule compared to [Ag]-AlMOR. The resistance capabilities of [Ag]-SAPO-5 and [Ag]-TAPO-5 to SO2,H2O, and O2 were also studied and analyzed. In addition, the interaction mechanism of NOx in silver-exchanged aluminophosphate molecular sieves was investigated using natural bond orbital (NBO) analysis.

Key words: Nitrogen oxide, Aluminophosphate molecular sieves, Silver, Adsorption, Density functional theory

MSC2000: 

  • O643