LAUSR

Abstract Loose aggregates of superfine ZSM-5 crystals (S-ZSM-5) were synthesized by a seed-induced method in the presence of cetyltrimethylammonium bromide (CTAB), characterized by XRD, SEM, N2 adsorption and desorption, XRF, NH3-TPD, 27Al MAS NMR, TG analysis, FTIR and TEM, and studied for the methanol to propylene (MTP) reaction. The results showed that CTAB played a curial role in the formation of S-ZSM-5 zeolites; NaOH concentration had a significant effect on the textural properties of S-ZSM-5 zeolites, with the morphology being controllable from cuboid to sphere by varying the NaOH/SiO2 ratios from 0 to 0.27. Compared with the catalysts synthesized by the conventional seed-induced method without CTAB, all S-ZSM-5 catalysts showed much higher stability and higher propylene selectivity in the MTP reaction. The excellent catalytic performance can be attributed to the aggregates of superfine ZSM-5 crystals with abundant mesopores and more weak acid sites, which hinder various side reactions such as hydrogen-transfer reactions.