【摘要】 通过水热合成的方法合成纳米ZSM-5分子筛，并采用等体积浸渍法制备ZnO,MgO和P₂O₅复合改性分子筛，用于催化甲醇高选择性制对二甲苯反应中。采用XRD、SEM、氮气吸附-脱附以及NH₃-TPD等手段对催化剂进行表征分析，并在固定床微型反应装置上进行甲醇直接制对二甲苯（MTPX）反应性能评价。结果表明：相比于常规微米ZSM-5分子筛，纳米分子筛具有大量晶间介孔，提高总芳烃选择性；Zn改性减少强酸量，增加中强酸酸量，有利于芳烃产物的生成；分子筛上进一步引入适量的MgO和P₂O₅可以有效覆盖分子筛的部分孔口和外表面的酸性位，对孔道扩散限制产生影响，对位选择性提高至81.1%,对二甲苯选择性提高至23.3%。更多还原

【Abstract】 Nano ZSM-5 zeolites was synthesized by hydrothermal synthesis method, and the compositely modified nano ZSM-5zeolites by ZnO,MgO,and P₂O₅ was prepared by equal volume impregnation method, which was used to catalyze the highly selective reaction of preparing p-xylene using methanol.The synthesized modified nano-sized ZSM-5 zeolites was characterized by XRD,SEM,N₂ adsorption-desorption and NH₃-TPD.Furthermore, the catalytic performance of different ZSM-5 zeolites for using methanol to prepare p-xylene was investigated.The results indicated that, nano-sized samples exhibited higher aromatic selectivity than micro-sized ZSM-5,owing to the more inter-mesopores.The introduction of Zn could increase the medium acid sites, which enhanced the aromatic production.The modification of Mg and P could optimise both the acidic properties and shape selectivity, which is beneficial to the formation of p-xylene.The modified nano-sized ZSM-5 zeolite gave the p-xylene selectivity of 23.3%,with the para-selectivity of 81.1%.更多还原