多级孔 Zn-La／HZSM-5制备及在甲醇芳构化中的应用

摘要

采用NaO H溶液对ZSM-5分子筛进行碱处理，制备了多级孔径ZSM-5分子筛。采用浸渍法制备了多级孔Zn-La/HZSM-5分子筛，并采用XRD、BET、SEM和N H3-T PD等方法进行了表征，在固定床反应器中进行甲醇芳构化反应。结果表明，经过碱处理，ZSM-5分子筛的平均孔径、孔容和比表面积增大，孔径呈微孔和介孔多级孔分布。Zn和La的负载量均为0．5％时，Zn-La/ZSM-5分子筛具有较好的芳构化活性。在反应温度475℃、反应压力0．6 MPa、空速（LHSV）0．8 h-1条件下，芳烃（苯、甲苯和二甲苯）的收率可达32．3％。%The alkaline treatment of ZSM-5 zeolite with NaOH solution ,received the hierarchical porous ZSM-5 zeolite ,Zn and La by co-impregnation method of loading in the alkali treatment of the modified ZSM-5 zeolite ,the ZSM-5 molecular sieves were characterized by XRD ,BET ,SEM and NH3-TPD .The reaction of methanol aromatization was investigated in a fixed bed reactor .The results show that after alkali treatment modified ZSM-5 zeolite had a pore size increased and the acidity distribution was changed;Zn-La/HZSM-5 zeolite had the better catalytic ,Zn and La with the load capacity of each of 0 .5% , the reaction temperature was 475 ℃ ,the reaction pressure was 0 .6 MPa ,LHSV was 0 .8 h-1 ,the yield of aromatic hydrocarbons (benzene ,toluene and xylene) up to 32 .3% .