摘要
Fluoride mediated nano-sized ZSM-5(ZSM-5-F) with a high Si/Al ratio of 181 was fabricated using a seed-induction method and evaluated the catalysis of the methanol to propylene(MTP) reaction. High propylene selectivity(45%) was similar to ZSM-5-OH synthesized via a hydroxide route. However, ZSM-5-F showed much longer lifetime(305 h) compared with ZSM-5-OH(157 h) in spite of similar crystal size and aluminum content. Characterization by NH_3-TPD, Py-IR, OH-IR, SEM, TG-DTA, XRD and ~1H MAS NMR techniques indicated that the enhanced catalytic performance of ZSM-5-F is attributed to the fewer structural defects in the form of internal silanol groups and silanol nests.
Fluoride mediated nano-sized ZSM-5 （ZSM-5-F） with a high Si/AI ratio of 181 was fabricated using a seed-induction method and evaluated the catalysis of the methanol to propylene （MTP） reaction. High propylene selectivity （45%） was similar to ZSM-5-OH synthesized via a hydroxide route. However, ZSM- 5-F showed much longer lifetime （305 h） compared with ZSM-5-OH （157 h） in spite of similar crystal size and aluminum content. Characterization by NH3-TPD. Py-IR, OH-IR, SEM, TG-DTA, XRD and 1H MAS NMR techniques indicated that the enhanced catalytic performance of ZSM-S-F is attributed to the fewer structural defects in the form of internal silanol groups and silanol nests.
