One‐pot Synthesis of Phosphorus‐modified ZSM‐5 Zeolite by Solid‐state Method and its MTO Catalytic Performance

A green and efficient strategy for synthesizing phosphorus modified ZSM-5 zeolite is proposed by grinding phosphorus source, silicon source and aluminum source with the solvent-free conditions. Phosphorus-modified ZSM-5 zeolites exhibited higher light olefin selectivity and longer catalytic lifetime (33 h) in methanol to olefin reaction when the weight hourly space velocity was 4 h⁻¹.

Abstract

The traditional hydrothermal synthesis strategy of ZSM-5 zeolite is energy-consumption accompanying by pollution issues. Herein, phosphorus-modified layered ZSM-5 zeolites (PZ) were obtained by one-pot synthesis under solvent-free conditions. The synthesized samples were fully characterized by XRD, SEM, BET, NH₃-TPD and FTIR. The effect of phosphorus addition on the morphology and catalytic activity of ZSM-5 was investigated. The results showed that phosphorus-modified ZSM-5 zeolites exhibited higher light olefin (ethylene and propylene) selectivity (above 50 %) and longer catalytic lifetime (33 h) in methanol to olefin (MTO) reaction when the weight hourly space velocity was 4 h⁻¹. Phosphorus-modified ZSM-5 zeolite synthesized by in situ solvent-free method, which not only reduced the discharge of sewage but also showed a simple method to realize the introduction of phosphorous species, which provided a new idea for phosphorus modification of ZSM-5 zeolite.

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