Accelerated crystallization of all-silica TON-type zeolite: mechanistic insights into methanol as a dual-function agent

Abstract

Rapid and straightforward synthesis of all-silica zeolites is essential for scaling up their industrial applications in adsorption and separation. However, the synthesis typically necessitates the use of complex organic structure-directing agents (OSDAs) and/or fluoride, presenting challenges in the development of straightforward strategies. Herein, a siliceous TON zeolite, referred to as Si-TON, is successfully obtained without the need for any costly OSDAs, utilizing seeds and methanol as facilitating agents. Various analyses validate that methanol acts as both a dynamic stabilizer and a solvent, which can be totally removed without high-temperature calcination. This approach circumvents the requirement for high-temperature calcination to achieve open channels in the TON zeolite, distinguishing it from traditional synthesis method. Additionally, metal species (Co, Fe, and Zr) can be incorporated into the TON zeolite to form heteroatom-substituted TON samples, thereby offering a viable strategy for the preparation of heteroatom doping catalysts that exhibit excellent performance in various catalytic reactions. Furthermore, the as-synthesized Si-TON zeolite exhibits high methanol adsorption capacity, making it a promising candidate adsorbent for methanol removal.