How Local Order Leads to Shape Selectivity in Disordered Materials: The Case of FAU-FER Interzeolite Transformation Intermediates

Abstract

This study presents a series of Interzeolite Transformation Intermediates (ITIs) derived from FAU-to-FER interconversion. These hybrid materials, obtained through precise control of the interconversion process, exhibit both large mesoporosity and FER topology-type pore confinement, resulting in high conversion and remarkable shape selectivity despite their disordered structure at the long range. We demonstrated this unique combination of properties in three different catalytic tests. The local order within these ITIs is sufficient to create pore confinement, which not only produces remarkable shape selectivity but also enhances conversion by increasing accessibility. Specifically, the ITIs show a 10-fold increase in activity for Friedel-Crafts alkylation, a 16-fold increase in activity for triisopropylbenzene (TiPBz) cracking, and a two-fold increase in methanol dehydration to dimethyl ether (DME) compared to commercial ferrierite all while maintaining the selectivity of FER. These results highlight the potential of FAU-to-FER ITIs as high-performance catalysts that combine the accessibility of disordered structures with the selectivity typically associated with well-ordered zeolites, opening avenues in zeolite-based catalysis.