Synthesis of mesoporous ZSM-5 by one-pot method in the presence of polyethylene glycol

Mesoporous ZSM-5 was synthesized by using dual templates and one step hydrothermal crystallization method under alkali conditions. Mesopores were created by using cetyltrimethylammonium bromide (CTAB) as the template and the crystallized pore wall framework was formed by using tetrapropylammonium bromide (TPAB) as the template. The specific influences of the polyethylene glycol (PEG) and ammonium fluoride (NH4F) addition, hydrothermal crystallization temperature, TPAB/Si and Al/Si ratio to the mesostructure and crystallinity of the obtained samples were carefully studied. In this system, PEG plays an important role in the maintenance of the mesoporous pore ordering and the zeolite crystallinity. Moreover, the study on the hydrothermal stability of the sample with best mesoporous pore ordering and zeolite crystallinity showed this kind mesoporous zeolite has extremely high hydrothermal stability in boiling water.