Facile Preparation of Aluminosilicate RTH across a Wide Composition Range Using a New Organic Structure-Directing Agent

Abstract

RTH type zeolite (aluminosilicate) is a potentially useful catalytic material that is limited by the inability to easily prepare the material over a wide composition range. Here, we report the use of pentamethylimidazolium to prepare aluminosilicate RTH across a wide range of compositions in both fluoride and hydroxide inorganic systems. RTH type zeolites are crystallized with a calcined product Si/Al of 7–27 from fluoride media and 6–59 from hydroxide media. The use of this new, simple organic structure-directing agent that can be prepared in one step allows for dramatic improvement in the compositional space where aluminosilicate RTH can be formed. RTH is tested as a catalyst for the methanol-to-olefins reaction and at complete conversion shows a high propylene/ethylene ratio of 3.9 at a propylene selectivity of 43%.