Phosphorus-modified b-axis oriented hierarchical ZSM-5 zeolites for enhancing catalytic performance in a methanol to propylene reaction

In this work, a b-axis oriented hierarchical ZSM-5 zeolite was prepared with glucose as an additive and further modified by phosphorus to improve the propylene selectivity and prolong the lifetime of the catalyst in a methanol to propylene (MTP) reaction. The physiochemical properties were characterized by XRD, low-temperature N-2 sorption, SEM, TEM, XPS, solid-state NMR, FTIR, and NH3-TPD analyses. The b-axis oriented ZSM-5 (Z5C) zeolite exhibited a microsized hexagonal lamellar structure with a thickness of approximately 220 nm. Analyzing the MTP reactions revealed that the newly prepared Z5-C catalyst exhibited a higher propylene selectivity of 53.01 % and a longer lifetime of 45 h compared to those of a conventional nanosized ZSM-5 catalyst (propylene selectivity of 43.97 % and lifetime of 10 h). In addition, the phosphorus modification remarkably increased the lifetime of the b-axis-oriented ZSM-5 catalyst to 79 h.