Abstract:
ZnO/SiO
2/ZSM-5 zeolites were prepared from ZSM-5 by vacuum metal impregnation of metallic oxides and silicon deposition. The resulted zeolite were characterized by XRD, BET, NH
3-TPD, SEM and TEM. Furthermore, the influence of silicon deposition time and the content of impregnated ZnO to the selectivity and yield of
p-xylene (PX) on the reaction of aromatization of methanol was investigated. The results indicated that by twice silicon deposition and 2.0% ZnO, the modified ZSM-5 had the highest PX selectivity. The yield of PX could reach up to 28% at 420 ℃, 0.2 MPa and 1.25 h
-1 of methanol WHSV.