Studies on the Dual-Templating Function of TBA for the Formation of ZSM-11 Intergrowth Morphology

Hierarchically structured ZSM-11 microspheres with an intergrowth morphology have been hydrothermally synthesized using only one organic templating molecule (TBABr). An investigation of the effects of the structure-directing agent on the zeolite particle morphology and textural properties was performed. It was found that the template tetraalkylammonium ions TBA(+) (or TPA(+)) not only were located in the channel intersections of ZSM-11 (or ZSM-5), but were also attached to the external surface of the precursors, which prevented these precursors from further condensation. Finally, a morphology of numerous nanocrystals inserting into each other was formed, and the voids among these intergrowth crystals endowed these materials with mesoporosity.