Micron ZSM-11 microspheres seed-assisted synthesis of hierarchical submicron ZSM-11 with intergrowth morphology

•Hierarchical submicron ZSM-11 was prepared by using micron ZSM-11 microspheres as seeds.•Product zeolites possessed the similar intergrowth morphology with that of seeds.•Submicron ZSM-11 exhibited enhanced external surface area and mesopore volume than micron seeds.•In the presence of seeds, crystallization could be completed at a much faster rate.•In the seeded synthesis, the used template amount ((TBA)2O/SiO2) could be reduced to a very low level of 0.005 (molar ratio).

Hierarchical submicron ZSM-11 particles with intergrowth morphology and intercrystalline mesopores were prepared by adding micron ZSM-11 microspheres (6.5–7.5 μm) to the TBA-gel precursors. The particle size of products could be feasibly adjusted from 700 to 200 nm with the increase of seeds content from 1 wt% to 10 wt%. Compared to seed particles, the obtained submicron product particles exhibited both enhanced external surface area by 10–30 m2/g and increased mesopore volume by 0.09–0.20 cm3/g. According to the follow-up investigation, the existence of seed particles was found to induce the nucleation, which was responsible for the fast crystallization rate as well as the small particle size of products. In addition, the amount of template ((TBA)2O/SiO2) used in the seeded system was able to be reduced as low as 0.005 (molar ratio).