Synthesis of Nano EU-1 Zeolite and Its Catalytic Performance in Toluene Methylation
TONG Weiyi
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208, China
Abstract Nano EU-1 molecular-sieve/zeolite with high crystallinity was successfully synthesized by using hexamethyldiammonium bromide (HMBr2) and hexamethyldiammonium hydroxide [HM(OH)2] aqueous solution with mass fraction of 25% as mixed organic structure-directing agents (OSDAs/templates). The samples were characterized by X-ray diffraction (XRD), 27Al MAS nuclear magnetic resonance (27Al MAS NMR), scanning electron microscopy (SEM), N2 adsorption-desorption and NH3 temperature programmed desorption (NH3-TPD). The results showed that the crystallinity of EU-1 zeolites synthesized by the synergistic action of the mixed OSDAs was better than that by the only HMBr2 template. Different from the conventional shuttle like aggregates, the morphology of the obtained EU-1 zeolites (S1) presented highly uniformly dispersed nano-blocks and self-assembled plate-like morphology, with a larger microporous specific surface area. Above these, there were more medium/strong acid sites in these EU-1 samples. The conversion of toluene and the yield of xylene were significantly improved in the alkylation of toluene and methanol catalyzed by the as-synthesized EU-1 zeolites, and maintain a high selectivity of xylene products at the same time, compared with the commercial ZSM-5 zeolite. All these results showed that the reaction performance of toluene methylation was affected both by the pore-structure and acid-distribution of zeolites. Hence, EU-1 zeolite would be an ideal catalytic material for toluene methylation.
TONG Weiyi. Synthesis of Nano EU-1 Zeolite and Its Catalytic Performance in Toluene Methylation [J]. Chemical Reaction Engineering and Technology, 2022, 38(1): 48-55.
TONG Weiyi. Synthesis of Nano EU-1 Zeolite and Its Catalytic Performance in Toluene Methylation [J]. Chemical Reaction Engineering and Technology, 2022, 38(1): 48-55.
