Rapid High-temperature Synthesis of Nanosized ZSM-22 Zeolite

Nanosized ZSM-22 with high crystallinity was synthesized rapidly by a high-temperature hydrothermal synthesis method. The effects of synthesis conditions such as crystallization temperature, crystallization time, Si/Al ratios and crystallinity of ZSM-22 were investigated, and the relationship between crystallization temperature and crystallization time was calculated by Arrhenius equation. Meanwhile, the rapid high-temperature synthesis method was effective to synthesize ZSM-22 with Si/Al ratio from 35 to 70. The nanosized ZSM-22 exhibited high light olefin selectivity and a long lifetime in the MTO reaction. Nanosized ZSM-22 with high crystallinity was synthesized rapidly and efficiently by conventional hydrothermal method at 240 °C for 2 h, which exhibited needle-like morphology (410 nm in length and 55 nm in diameter) with grain aggregation and good catalytic performance in MTO reaction with a long catalytic lifetime and high light olefin selectivity.