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中文摘要：
γ-Al2O3是常用的催化剂载体，具有比表面积大和价廉易得等优点．它也是汽车尾气净化催化剂常用的载体．满足欧Ⅱ及欧Ⅲ排放标准以上的汽车尾气净化催化剂是由密偶催化剂和三效催化剂（TWC）组成的，由于密偶催化剂靠近发动机，因此对载体的抗老化性能要求非常高．汽车尾气净化催化剂是在高空速的反应条件下工作的，要求载体的孔容和孔径较大，因此提高氧化铝的稳定性，改变其孔结构是提高密偶催化剂和TWC催化性能的重要条件．
英文摘要：
Alumina prepared by peptizing method with a high specific surface area, moderate pore structure and pore size distribution was studied. Furthermore, the effects of additives La and PEG on thermal stability, particle size, structure and texture of alumina were investigated. The results of characterization of BET and XRD show that the addition of La greatly, inhibits the loss of specific surface area and α phase transformation of alumina under the hydrothermal and high temperature conditions. At the same time, PEG as an additive can apparently increase pore volume and pore diameter of alumina. The more the La and PEG content is, the larger the surface area, pore volume and average diameter of alumina are. However, when the quantity ratio of La2O3 to Al2O3 or PEG to Al2O3 is excessive, the negative action of La and PEG are stronger. When the quantity ratio of La2O3/Al2O3 is 2.5%-3.0% , thermal stability of γ-Al2O3 is the best and specific surface area of alumina is more than 140 m^2/g after hydro thermally being aged at 1000 ℃ for 5 h. Though PEG plays a good role on making pore and aggregation when the value of quantity ratio of PEG/Al2O3 is 80%, the thermal stability of alumina is worse and specific surface area is only 136.4 m^2/g, pore volume is 0. 41 mL/g and pore diameter is 9.38 nm under the same aging condition. Fortunately, after hydro thermally being aged at 1000 ℃ for 5 h, the alumina containing 2. 5% La2O3 and 80% PEG of quantity of alumina has the best thermal stabilization and the largest specific surface area, pore volume and pore diameter that are 156.2 m^2/g, 0. 57 mL/g and 11 nm, respectively.
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