关键词: 碱处理改性;Zn/HZSM-5催化剂;甲醇制芳烃;多级孔ZSM-5分子筛

Abstract: The HZSM-5 zeolite was alkali treated with NaOH solution at different concentrations,and the hierarchical ZSM-5 zeolite was prepared as the active component for the catalyst of methanol to aromatics,the catalysts were characterized by XRD,SEM,NH3-TPD and N2 adsorption-desorption,the effects of alkali treatment on the structure,acid properties,pore structure and catalytic performance of the zeolite catalyst were investigated.The results show that the size of mesoporous distribution and acid properties of the HZSM-5 zeolite can be changed with the treatment of appropriate concentration of NaOH solution but the Microporous structure of the HZSM-5 zeolite can be maintained.With the increasing concentration of NaOH solution,the amount of acid sites,mesopore volume,and specific surface area increase,the pore size distribution become broader.Therefore,the catalytic performance for the reaction is effectively improved.As the HZSM-5 was treated by the suitable NaOH concentration of 0.4 mol/L,the yield of aromatics increase from 25.07％ to 32.22％,and the stability of catalyst increase from 8 d to 16 d.When the NaOH concentration is over 0.6 mol/L,the framework of HZSM-5 zeolite is found to be severely destroyed and catalytic activity decrease rapidly.

Key words: alkali treatment modification;Zn/HZSM-5 catalyst;aromatization of methanol;hierarchical ZSM-5 zeolite