Rapid Synthesis of Nine-Membered-Ring STT Aluminosilicate Zeolite from Chain Rearrangement of Lamella MWW Zeolite and Its Catalytic Performance in the Methanol-to-Olefin Reaction

Nine-membered-ring (9-MR) STT zeolites hold immense potential in studying the impact of pore structure on catalytic performance. However, synthesizing pure-phase STT zeolites with tunable acid sites has been challenging. This study presents a rational approach for the rapid synthesis of STT zeolites from lamella Si-MWW zeolite via a chain rearrangement process, leveraging their structural similarities and the flexibility in manipulating MWW's layer structure. Both zeolites share a common chain comprising ordered arrangements of 4-, 5-, and 6-membered rings, facilitating robust and rapid (10 h) STT growth, with a broad Si/Al ratio range. The resulting Al-STT zeolites exhibited an olefin product distinct from the 8-MR CHA and 10-MR MFI zeolites in the methanol-to-olefin reaction, underscoring the pivotal role of 9-MR pore structure. The findings not only advance the understanding of zeolite synthesis but also demonstrate the potential of tailoring pore structures to enhance the catalytic efficiency in industrially relevant processes.