Abstract

Nanosized ZSM-5 zeolites (NZ5(x) series) with different SiO2/Al2O3 ratios as well as samples isomorphously substituted by Fe ([Fe,Al]NZ5(x) series) with various SiO2/(Al2O3+Fe2O3) ratios were synthesized by an in situ seed-induced hydrothermal method. The structure, morphology, textural and acidity of catalysts were characterized via XRD, SEM, 27Al and 29Si MAS NMR, UV–vis spectroscopy, XPS, N2 physical adsorption, NH3-TPD and Py-IR. The catalytic performance was assessed by methanol-to-olefins (MTO) reaction and the effect of the textural and acidity of the two series of samples on the catalytic performance was also investigated. The results showed that the catalyst acidity is closely related to the product selectivity in the MTO reaction. Compared with NZ5(x), the [Fe,Al]NZ5(x) samples with smaller particle size, weaker acid strength and fewer Brønsted acid sites displayed a higher selectivity towards C2∼C4 light olefins. Highest selectivity of 82.7% for C2∼C4 light olefins and lowest coke amount of 0.71% after reaction for 50 h was obtained for the [Fe,Al]NZ5(300) catalyst due to the appropriate acidity and improved diffusion properties.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.