Abstract
The high-silica mordenite zeolite (MOR) was synthesized by adding NaF as a fluoride source to the synthesis gel in the middle of crystallization process. The addition of NaF into the synthesis gel enhanced the nucleation and crystal growth of MOR zeolite, and depressed the nucleation of beta zeolite (BEA). When NaF was added in the middle of crystallization process, the fluoride content and the Na/Al ratio markedly decreased although the crystallinity and the Si/Al ratio of as-synthesized MOR zeolite were independent of the time at which NaF was added. The decrease in the fluoride content considerably improved the thermal stability of the as-synthesized MOR zeolite.
