Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (04): 503-507.doi: 10.3866/PKU.WHXB20070410

• ARTICLE • Previous Articles     Next Articles

Crystal Transformation among ZSM-5, ZSM-57 andMordenite

LIU Bai-Jun; ZENG Xian-Jun; WANG Hui; HUANG Yong; WANG Mei   

  1. Key Laboratory of Catalysis of CNPC, China University of Petroleum, Beijing 102249, P. R. China
  • Received:2006-09-26 Revised:2006-11-08 Published:2007-04-05
  • Contact: LIU Bai-Jun

Abstract: The crystal transformation among ZSM-5, ZSM-57, and mordenite was studied under different conditions, such as SiO2/Al2O3 molar ratio, alkalinity, n-butylamine template, crystallization time, and temperature. The results showed that higher alkalinity and longer crystallization time were of benefit to mordenite; lower alkalinity and higher induction temperature of crystallization were in favor of ZSM-57 with low n(SiO2)/n(Al2O3) ratio; alkalinity was required to be adjusted accurately to synthesize ZSM-5 with low n(SiO2)/n(Al2O3) ratio, shortening of crystallization time, decrease in induction temperature of crystallization, and the addition of seed crystal were all in favor of ZSM-5 with low n(SiO2)/n(Al2O3) ratio. A slight change in the above conditions would result in the transformation among the three crystals, and two or more crystal phases could be observed in the products.

Key words: Zeolite ZSM-5, Zeolite ZSM-57, Mordenite, Crystal transformation