In Situ Assembly of Nanoparticles into Hierarchical Beta Zeolite with Tailored Simple Organic Molecule

A hierarchically structured beta zeolite with intercrystalline mesopores was successfully synthesized via in situ assembly of nanoparticles by employing a simple organic molecule N₂-p-N₂, tailored from polyquaternium surfactant, with no hydrophobic long chain. The generated samples were studied by using powder X-ray diffraction (XRD) and nitrogen adsorption/desorption isotherms. Computer simulation, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) technologies were also used. The characterized results show that the tailored template molecule N₂-p-N₂ without hydrophobic long-chain tail still can direct the zeolite crystallization, while the hydrophobic long-chain tail is not necessary during the mesoporous Beta zeolite formation. The catalytic performances of the sample were studied using alkylation of benzene with propene reaction to evaluate the relationship between the structure and property. The results apparently suggested an overall improved resistance against deactivation as compared to conventional beta zeolite in reactions. Furthermore, this tailored simple organic molecule strategy from dual-functional surfactant for making mesoporous zeolite would offer a new method of synthesizing other hierarchically structured zeolites.