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ZSM-5 zeolite was in-situ synthesized from metakaolin or spinel by incorporating additional silica and alumina sources,respectively.The ZSM-5 zeolite was characterized by X-ray diffractometry(XRD),scanning electron microscopy(SEM),Fourier transform infrared(FT-1R) spectroscopy and N_2 adsorption measurement. This supported zeolite was tested on the methanol to propylene(MTP) processes.Experimental results showed that the ZSM-5 zeolite exhibited high selectivity for propylene.The yield of propylene on ZSM-5 zeolite made from metakaolin was increased by 17.73%,while that on ZSM-5 zeolite made from spinel was raised by 9.90%,compared to that achieved with the commercial ZSM-5 zeolite.The significant increase in propylene production is probably due to the distinctive morphology of the ZSM-5 zeolite,which possessed a rough external surface covered with sphere-like particles and distribution of small crystals sized at around 400—500 nm.This morphology could help to generate more crystal defects so that more active centers could be exposed to the reaction mixture.In addition,the zeolite product had a gradient pore distribution and many medium Bronsted acid sites,both of which might also contribute to the increased propylene production.
ZSM-5 zeolite was in-situ synthesized from metakaolin or spinel by incorporating additional silica and alumina sources, respectively.The ZSM-5 zeolite was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared This supported zeolite was tested on the methanol to propylene (MTP) processes. Experimental results showed that the ZSM-5 zeolite exhibited high selectivity for propylene. The yield of propylene on ZSM-5 zeolite made from metakaolin was increased by 17.73%, while that on ZSM-5 zeolite made from spinel was increased by 9.90%, compared to that achieved with the commercial ZSM-5 zeolite.The significant increase in propylene production is probably due to the distinctive morphology of the ZSM-5 zeolite, which possessed a rough external surface covered with sphere-like particles and distribution of small crystals sized around around 400-500 nm. Here we could help to generate more crystal de fects so that more active centers could be exposed to the reaction mixture. In addition, the zeolite product had a gradient pore distribution and many medium Bronsted acid sites, both of which might also contribute to the increased propylene production.