Synthesis and excellent catalytic properties of hierarchical ZSM-5 zeolite by organosilanized doubleterminal amino polyetheramine template method

Hierarchical ZSM-5 zeolites had been synthesized by using organosilanized doubleterminal-amino polyetheramine template as a novel mesoporous agent, which subsequently displayed outstanding efficiency in creating mesoporosity. With the increase of templating agent in the mixed gel, the total BET surface areas of as-synthesized samples presented a clear trend of first increasing and then decreasing, in contrast, the external BET surface area and the microporous surface area of the samples varied greatly. When 7.5 mL mesoporogen was added, the resulting ZSM-5 sample showed the largest external BET surface area of 435 m2/g. The obtained hierarchical ZSM-5 zeolites were characterized with X-ray diffraction (XRD), N2 sorpotion, scanning electron microscopy (SEM), transmission electron microscopy (TEM), NH3 temperature programmed desorption (NH3-TPD) and pyridine adsorption Fourier-transform infrared (Py-IR). Due to greater external surface area and larger number of external surface acid sites, the hierarchical ZSM-5 zeolites displayed an obvious advantage in the thiophene alkylation reaction compared to the conventional ZSM-5 zeolite.