Synthesis and characterization of zeolite ZSM-25

摘要

The synthesis of the intermediate-silica zeolite ZSM-25 in the presence of sodium andtetraethylammonium cations is described. The crystallization of pure ZSM-25 was found to besensitive not only to the oxide composition of synthesis mixtures, but also to the choice of the aluminasource. The overall characterization results of this study suggest that ZSM-25 is probably an 8-ringor constrained 10-ring pore material containing 4-rings as the smallest structural unit. However, theproton form of ZSM-25 has a poor thermal stability, revealing a serious drawback in its applicationsas a shape-selective catalyst for acid-catalyzed hydrocarbon conversions.