Hydrothermal conversion of FAU zeolite into LEV zeolite in the presence of non-calcined seed crystals

作者：Yashiki Ayako; Honda Koutaro; Fujimoto Ayumi; Shibata Shohei; Ide Yusuke; Sadakane Masahiro; Sano Tsuneji^*

来源：Journal of Crystal Growth, 2011, 325(1): 96-100.

DOI：10.1016/j.jcrysgro.2011.04.040

• Hydrothermal crystal growth
• Seed crystals
• Interzeolite conversion
• LEV type zeolite

Hydrothermal conversion of Faujasite-type (FAU) zeolite into Levynite (LEV) zeolite without the use of an organic structure-directing agent (OSDA) was successfully achieved in the presence of non-calcined seed crystals. The interzeolite conversion depended strongly upon the alkalinity (OH(-)/SiO(2)) of the starting gel, the Si/Al ratio of the starting FAU zeolite and the type of alkaline metal employed. Successful conversion of FAU zeolites into pure LEV zeolite was achieved only for FAU zeolites with Si/Al ratios in the range of 19-26, under highly alkaline conditions (OH(-)/SiO(2)=0.6) by using NaOH as an alkali source. Although the yield of LEV zeolite prepared by this method was lower (18-26%) than that of the conventional hydrothermal synthesis with the use of SDA, the obtained LEV zeolite exhibited a unique core/shell structure.

• 出版日期2011-6-15