Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (10): 2679-2685.doi: 10.3866/PKU.WHXB20101013

• CATALYSIS AND SURFACE STRUCTURE • Previous Articles     Next Articles

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).

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