【作者】 曹自平；

【导师】 陈庆华；

【作者基本信息】 昆明理工大学 ， 材料学， 2002， 硕士

【摘要】 本文首先寻找出合适的催化剂制备了乙醇铝，在一定条件将乙醇铝进行水解得到假薄水铝石溶胶，随之经过溶胶-凝胶转变、干燥和热处理得到了多孔氧化铝。实验中发现：在中低温度时氧化铝为分形结构，比表面积极高；在高温时分形特征丧失，比表面积急剧下降，相对于600℃在800℃时下降了39.9％，1000℃时下降了56.5％。分析了产生这种情况的原因。 通过在假薄水铝石溶胶中加入造孔剂聚乙二醇（PEG）来改变了氧化铝中晶粒的堆垛方式，改变了氧化铝中的孔结构，从而提高氧化铝的比表面积。在800℃时PEG使得氧化铝比表面积提高了18.3％，但是到了1000℃时这种效果极不明显。这是因为到高温时氧化铝发生晶型转变和孔结构烧结，削弱了PEG的作用。 选用Sr（NO₃）₂·2H₂O作热稳定剂希望能够使得氧化铝高温时仍具有高比表面积。实验发现硝酸锶能阻碍和推迟氧化铝的相变，减少烧结，使氧化铝在1000和1200℃高温时仍具有分形特征，从而氧化铝在高温时仍具有极高的比表面积。添加硝酸锶后氧化铝在1000℃时比表面积相对800℃时下降只有5.4％ 综上所述，结合造孔剂PEG和热稳定剂Sr（NO₃）₂·2H₂O的使用，运用Sol-Gel法制备的氧化铝水洗涂层，能够获得较高热稳定性和比表面积，性能明显优于当前车用净化器载体的水洗涂层。更多还原

【Abstract】 Firstly, in this dissertation the precursor-ethoxyl aluminate was fabricated via direct reaction between aluminum and ethanol with present of a proper catalyst; then porous alumina was gained through sol-gel processing, eg. hydrolysis, condensation, drying and heat treatment. The experimental result shows that alumina with high specific area has a fractal structure under low or medium temperature(500). However, the specific area of porous alumina decreases sharply and the fractal character vanishes as temperature increases. It decreases by 39.9% at 800 and by 56.5% at 1000. The causes of this decrease have been analyzed.The stack of crystal particles and the pores in alumina were changed through adding PEG to the pseudo-boehmite sol. The specific area of alumina was enhanced by 18.3% at 800. However, this effect was not distinct at 1000 These phenomena resulted from the transformation of the crystal type and the sintering of the pore structure, as a result the PEG effect was weakened.Sr (NO3) 2 2H2O was selected as the thermostable reagent to enhance the specific area of alumina under high temperature. It was found that Sr (NO3) 2 2H2O could counteract the transformation of phase, defer the alteration of the stack of crystal particles, and weaken the sintering ofpores in alumina. Through adding Sr (NO3) 2 2H2O, the specific area of alumina decreased by 5.4% at 1000 and alumina remains a still good fractal structure at 1200.In conclusion, after adding PEG and Sr (NOs) 2 2H2O ,alumina carrier coating that is fabricated by Sol-Gel has high thermostaility and large specific area. It’s property surpasses evidently the carrier coating used ordinarily in the automobile exhaust gas catalytic converters.更多还原