The Difference between ZSM-5 Zeolites Manufactured from Various Synthesis Systems and Their Catalytic Performances

摘要

ZSM-5 zeolites with similar Si/Al ratio were synthesized successfully using various templates [nbutylamine (BTA), tetrapropylammonium bromide (TPABr) and no template (NT)] under hydrothermal conditions. The samples were characterized by XRD, SEM, Py-IR and BET surface area measurements in order to understand the template effects and the differences between the ZSM-5 samples. The synthesis of ZSM-5 with organic templates was relatively easier than those with inorganic templates and without template.SEM results revealed that ZSM-5 synthesized with different templates had different morphologies in similar particle size. Toluene disproportionation reaction was carried out over the catalyst samples to evaluate the catalytic properties. The results have shown that large crystals which have a correspondingly small external surface showed a high para-xylene selectivity, and the amount of C9+ and C5- was much less than that obtained from zeolite with small crystals.