Methanol to Aromatic Reaction over HZSM-5: Co-Effect Desilication and SiO2 Deposition

In this work Si/HZSM-5-0.09M catalyst was prepared using desilication and regrowth of SiO2 method, which was characterized by XRF, XRD, SEM, NH3-TPD, and N2 adsorption/desorption. Meanwhile, the structure–activity relationship was comprehensively discussed. The results revealed that the aromatics total selectivity of Si/HZSM-5-0.09M catalyst was significantly improved, from 33 to 54.8% compared to HZSM-5 under the optimal conditions. Also, the selectivity of p-xylene over Si/HZSM-5-0.09M catalyst increased from 4.6 to 19.8% compared to HZSM-5. The total selectivity of benzene, toluene, and xylene over Si/HZSM-5-0.09M catalyst was significantly improved by 66.1% compared to that of HZSM-5. Thus, an excellent catalytic effect has been found, which indicates that the SiO2 deposition on the surface favors the enhancement of the p-xylene selectivity in the methanol aromatization reaction.