【摘要】 采用低温-高温二步晶化法动态水热合成制备了椭球形貌纳米HBeta分子筛，采用金属盐溶液等体积浸渍制备了La₂O₃、Cr₂O₃以及NiO负载HBeta分子筛，采用XRD、N₂吸附-脱附、SEM、NH₃-TPD及Py-FTIR等手段对样品的结构、酸性进行表征，并对其催化2-甲萘与甲醇烷基化反应的催化性能进行了研究。结果表明，金属氧化物改性降低了HBeta的结晶度、比表面积和平均孔径。Cr₂O₃和La₂O₃改性保持了酸强度分布而明显降低了Cr₂O₃/HBeta的中强酸酸量；NiO/HBeta上Lewis酸量增加且酸强度降低。La₂O₃和Cr₂O₃改性样品的三甲基萘副产物选择性增加，2,6-二甲基萘（2,6-DMN）选择性下降。NiO/HBeta上初始催化活性下降，但产物中二甲基萘（DMNs）选择性增加，2,6-DMN收率由2.52%提高至3.31%。随着反应时间延长，样品的催化活性均下降而2,6-DMN选择性提高，La₂O₃/HBeta在反应5 h获得4.41%的2,6-DMN收率。更多还原

【Abstract】 Nano-HBeta molecular sieves with ellipsoid morphology were prepared via two-step crystallization dynamic hydrothermal method.La₂O₃、Cr₂O₃ and NiO modified HBeta catalysts were prepared by equal volume impregnation of metal salt solution.The structure and acidity of the samples were characterized by XRD,N₂ adsorption-desorption, SEM、NH₃-TPD and Py-FTIR,and the catalytic performance of the samples on the alkylation of 2-methylnaphthalene with methanol was studied.The results show that metal oxide modification reduced the crystallinity, specific surface area and average pore size of HBeta.Cr₂O₃ and La₂O₃ kept the distribution of acid strength but decreased the amounts of medium strength acid on Cr₂O₃/HBeta.The acid strength of NiO/HBeta decreased and the Lewis acid amounts increased significantly.The selectivity to trimethyl naphthalene by-products over La₂O₃ and Cr₂O₃ modified HBeta increased, while the selectivity to 2,6-dimethylnaphthalene（2,6-DMN）decreased.The initial catalytic activity of NiO/HBeta decreased, however the selectivity to dimethylnaphthalene（DMNs） increased, and the yield of 2,6-DMN increased from 2.52% to 3.31%.With the increase of reaction time, the catalytic activity of the samples decreased while the selectivity to 2,6-DMN increased, and the yield of 2,6-DMN reached to 4.41% over La₂O₃/HBeta on 5 h.更多还原