【摘要】 以含有少量稀土的Y型分子筛为原料，柠檬酸/柠檬酸盐为脱铝剂，对Y型分子筛进行改性，考察了柠檬酸/柠檬酸盐的加入量对改性分子筛物化性质、表面形貌、孔结构及酸性的影响，并采用XRF、XRD、XPS、SEM、N₂吸附-脱附、NH₃-TPD、Py-IR等方法对制备的样品进行表征。结果表明，随着柠檬酸/柠檬酸盐投加量的增加，改性分子筛的硅铝比逐渐增大；改性后分子筛的相对结晶度提高，晶胞略有收缩。改性后分子筛的比表面积和总孔体积均增大，其中，柠檬酸/柠檬酸盐与分子筛的质量比为0.30时，具有最大的比表面积969 m²/g和总孔体积0.425 cm³/g。改性后分子筛的总酸量减少，酸强度变弱，B酸量增多，L酸量减少，大分子可接近性酸中心数量增多。更多还原

【Abstract】 Using Y zeolite containing a small amount of rare earth as raw material and citric acid/citrate as dealumination agent, Y zeolite was modified.The effects of the addition of citric acid/citrate on the physicochemical properties, surface morphology, pore structure and acidity of modified zeolites were investigated.The prepared samples were characterized by XRF,XRD,XPS,SEM,N₂ adsorption-desorption, NH₃-TPD,Py-IR and so on.The results showed that the Si/Al ratio of the modified zeolite increased with the increase of citric acid/citrate dosage, and the relative crystallinity of the modified zeolite increased and the unit cell contracted slightly.The specific surface area and total pore volume of the modified zeolites increased.When the mass ratio of citric acid/citrate to zeolite is 0.30,it has the largest specific surface area 969 m²/g and total pore volume 0.425 cm³/g.After modification, the total acid content of the zeolite decreased, the acid strength became weaker, the amount of B acid increased, the amount of L acid decreased, and the number of accessible acid sites of macromolecules increased.更多还原