Acta Phys. -Chim. Sin. ›› 1999, Vol. 15 ›› Issue (11): 1053-1056.doi: 10.3866/PKU.WHXB19991119

• Note • Previous Articles    

The Study of Dehydration from the Secondary Pore in USY Zeolite by the Positron Annihilation Pectroscopy

Zhu Jun, Wang Shao-Jie, Ma Li, Chen Zhi-Quan   

  1. Department of Physics,Wuhan University,Wuhan 430072
  • Received:1999-04-13 Revised:1999-07-07 Published:1999-11-15
  • Contact: Wang Shao-Jie

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Abstract:

The positron lifetime spectra were measured as a function of dehydration time for the ultra stable Y zeolite(USY) samples unheated, heated at 180 ℃in air and at 500 ℃in vacuum respectively. All spectra were resolved into five components. The intensity of the fifth component I5 is sensitive to the structure of the second pore in USY. The experimental results indicate that long time pumping with 0.5 Pa vacuum can dehydrate, but heating the sample at 500 ℃is a more effective method of dehydration for the second pore in USY zeolite.

Key words: Positron annihilation, USY zeolite, Dehydration