“Burr Puzzle”-Like Hierarchical Beta zeolite composed of crisscrossed nanorods

Abstract

Hierarchical Beta zeolite (named ECNU-41) was directly synthesized with commercially available ionic liquid 1-butyl-1-methylpyrrolidinium hydroxide as organic structure-directing agent (OSDA) in the absence of any surfactants or polymers. The ECNU-41 crystals were composed of nanorods through a unique stacking manner, exhibiting a morphology resembling the Chinese traditional toy “burr puzzle”. The orderly crisscrossed stacking ECNU-41 possesses high hydrothermal stability, abundant intercrystal mesoporosity, and enriched phase of polymorph B. In comparison to conventional nanosized Beta zeolites, ECNU-41 aluminosilicate and titanosilicate exhibited more remarkable and competitive catalytic performances in a variety of reactions, including benzene alkylation, methanol to propylene, and alkenes epoxidation. With improved diffusion rate and mass transfer due to the hierarchical structure, ECNU-41 is expected to serve as promising catalysts for those reactions involving bulky molecules. The hierarchical Beta zeolite (named ECNU-41) was synthesized using a small ionic liquid molecule, 1-butyl-1-methylpyrrolidinium hydroxide as the organic structure-directing agent in the absence of any surfactants or polymers. ECNU-41 shows an unusual “interlaced” morphology, and the individual crystal is orderly knitted by nanorods, forming an intersected model like the “burr puzzle”. In comparison to conventional nanosized Beta zeolites, ECNU-41 aluminosilicate and titanosilicate exhibited more remarkable and competitive catalytic performances in a variety of reactions than the commerical nanosized counterparts. With stable and abundant hierarchical pores as well enhanced diffusion rate and mass transfer, ECNU-41 is expected to serve as a promising catalyst for processing the reactions especially involving bulky molecules. • A hierarchical Beta zeolite (ECNU-41) was synthesized in the absence of any mesoporogen additives. • ECNU-41 showed an unusual crisscrossed morphology resembling burr puzzle, which resulted in abundant intercrystal mesopores. • ECNU-41 aluminosilicate and titanosilicate exhibited remarkable and competitive catalytic performances in reactions.