A new synthesis method for zeolites

Abstract

A new methodology for the synthesis of zeolites and molecular sieves that utilizes structure-directing agents (SDA) that can be cleaved into pieces within zeolite pore spaces for easy removal of these fragements is demonstrated. The method provides an alternative to the normal high temperature treatment used to remove organic structure-directing agent within the synthesized zeolites. One example of the methodology is provided and involves a dimethylated ammonium derivative of 1,4-dioxa-8-azaspiro[4,5]decane as a SDA for the formation of ZSM-5. This organic molecule is cleaved into smaller pieces inside the zeolite pores of the as-synthesized ZSM-5, and the fragments Successfully removed by ion-exchange. The ZSM-5 after the removal of the organic molecules showed an equivalent catalytic activity with vendor sample of ZSM-5.