Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (2): 329-336.doi: 10.3866/PKU.WHXB201412082

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

In situ Synthesis of Cu-SSZ-13/Cordierite Monolithic Catalyst for the Selective Catalytic Reduction of NO with NH3

ZHANG Yu, WANG Hong-Ning, CHEN Ruo-Yu   

  1. School of Petrochemical Engineering, Changzhou University, Changzhou 213164, Jiangsu Province, P. R. China
  • Received:2014-10-09 Revised:2014-12-08 Published:2015-01-26
  • Contact: CHEN Ruo-Yu E-mail:chry@cczu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21101017).

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Abstract:

SSZ-13 molecular sieves were synthesized in situ on the surface of a honeycomb-shaped cordierite support using a hydrothermal method, and the resulting material was characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The process for preparing SSZ-13/cordierite was optimized in detail. Furthermore, the ion exchange levels of the 50% Cu-SSZ-13/cordierite and Cu-SSZ-13 catalysts were tested in the ammonia-selective catalytic reduction (NH3-SCR) of NO both before and after the hydrothermal treatment process using a fixed-bed reactor. The results of these experiments showed that the Cu-SSZ-13/cordierite prepared in situ by hydrothermal synthesis had good catalytic activity, and gave an NO conversion of more than 80% at temperatures in the range of 200-500 ℃, with the highest NO conversion of 96.4%being reached at 300 ℃. After being aged hydrothermally at 850 ℃ for 12 h, the SCR activity of the Cu- SSZ-13 catalyst was significantly reduced, whereas that of Cu-SSZ-13/cordierite remained largely unchanged with an NO conversion of 91% at 300 ℃. Analysis of the catalysts framework both before and after the hydrothermal treatment by X-ray diffraction and solid state 27Al NMR revealed a significant reduction in the intensities of the X-ray diffraction and tetrahedral aluminumpeaks for Cu-SSZ-13, whereas those of the Cu-SSZ- 13/cordierite material remained unchanged. These results indicated that the Cu-SSZ-13/cordierite prepared by in situ hydrothermal synthesis was less prone to deactivation by hydrothermal aging.

Key words: Cu-SSZ-13 molecular sieve, Hydrothermal aging, In situ synthesis, Cordierite, NH3-selective catalytic reduction