Acta Phys. -Chim. Sin. ›› 1992, Vol. 8 ›› Issue (05): 613-618.doi: 10.3866/PKU.WHXB19920508

• ARTICLE • Previous Articles     Next Articles

The Studies of Pore Structures of High-Silica Y Zeolites by N2 Adsorption

Pei Zhan-Fen; Liu Xing-Yun; Li Xuan-Wen   

  1. Department of Chemistry, Peking University, Beijing 100871
  • Received:1991-05-09 Revised:1991-12-09 Published:1992-10-15
  • Contact: Pei Zhan-Fen

Abstract: The properties of pore structure of high-silica Y zeolites prepared by combined hydrothermal-chemical treatments have been characterized by measuring N_2 adsorption-desorption isotherms at 77.4 K. The surface area and micropore volume for the sam-ples have been calculated by means of t-method and MP method. It has been found that two zeolites Y samples dealuminated by different chemical agents have apparent differences in their pore structures. But, when these two samples are further submitted to hydrothermal treatments combined chemical treatments, an evolution with similar tendencies in pore structure has been observed, namely, their total surface area, the surface area of micropores and micropore volume have reduced after hydrothermal treatments and increased after chemical treatments. On the contrary, the surface area of the secondary pore systems has been increased after hydrothermal treatments and reduced after chemical treatments. This evolution of pore structure may be related to the formation and elimination of non-framework aluminium species.

Key words: Zeolite Y, Mordification, N2 adsorption, Pore structure, Secondary pore system