Recrystallization of Zeolite Y to Analcime and Zeolite P with D-Methionine as Structure-Directing Agent (SDA)

In this study, the synthesis of template free zeolite Y and its recrystallization to two types of pure zeolite P and analcime in the presence of the amino acid d-methionine as structure-directing agent were investigated. The recrystallization occurred solely when specific heating cycles were applyed. A completely crystallized phase of zeolite Y for the mixture of zeolite P and analcime was observed in the presence of cl-methionine at a concentration of 0.015 M. The effect of different Si/Al ratios (2.3-9.3), crystallization temperatures (40-160 degrees C), and crystallization times (28-96 hours) on the achievement of two different zeolite types were studied as well. Pure zeolite P was obtained during conventional heating to 100 degrees C for 42 hours, whereas pure analcime zeolite was achieved by heating the mixture to 160 degrees C for 96 hours. The products were characterized by X-ray diffraction, scanning electron microscopy, and IR spectroscopy.