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制备了一系列金属离子改性的SO42-/ZrO2固体超强酸(SZ)。用N2吸附比表面积测定、X射线衍射、透射电子显微镜、扫描电子显微镜、差热分析等方法对固体超强酸进行表征。以正己烷的裂解为探针反应,考察了固体超强酸催化剂的催化活性和乙烯选择性。实验结果表明,不同金属离子改性的SZ均为纳米粒子(粒径小于40nm),但其催化剂的催化活性不同。金属离子和SO42-的共同作用使得ZrO2由四方晶形向单斜晶形转化的温度升高,晶粒粒度减小,比表面积增大,催化活性提高。催化剂催化正己烷裂解的活性由高到低的顺序为:N i/SZ>A l/SZ>Sn/SZ>SZ>Ag/SZ。
A series of metal ion-modified SO42- / ZrO2 solid superacids (SZ) were prepared. The solid superacids were characterized by N2 adsorption specific surface area, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and differential thermal analysis. Using n-hexane cracking as the probe reaction, the catalytic activity and ethylene selectivity of the solid superacid catalyst were investigated. The experimental results show that the SZ modified by different metal ions are nanoparticles (particle size less than 40nm), but the catalytic activity of the catalyst is different. The combined effect of metal ions and SO42- causes the temperature of ZrO2 transformation from tetragonal to monoclinic to increase, the grain size decreases, the specific surface area increases and the catalytic activity increases. The order of catalytic activity of n-hexane cracking from high to low is Ni / SZ> Al / SZ> Sn / SZ> SZ> Ag / SZ.