摘要:
采用溶胶-凝胶法和超临界干燥技术制备出CeO2和Ce1-xMnxO2(x分别为0.05, 0.10, 0.15,0.20)气凝胶。以硝酸锰浸渍制得的氧化铈气凝胶Mn/CeO2,用TEM、BET、一氧化碳催化氧化活性评价和H2-TPR对所制备的催化剂进行了研究。TEM、BET的结果表明，随着锰含量的增加，氧化铈气凝胶的粒度减小，表面积增大。一氧化碳催化氧化活性评价显示,氧化铈中添加锰制得的催化剂的一氧化碳低温催化氧化的活性比未添加锰的氧化铈提高。且锰加入量为15 mol%时，气凝胶的催化活性最高。锰的引入方式不同，气凝胶的催化活性不同。浸渍方式负载锰所制备的Mn/CeO2气凝胶的一氧化碳催化氧化活性低于Ce1-xMnxO2(x分别为0，0.05, 0.10, 0.15,0.20)气凝胶。TPR实验发现，与氧化锰相同，氧化铈上负载的锰的还原也分三步进行。
Abstract:
In this paper, CeO2 aerogel and Ce1-xMnxO2 aerogel (x=0.05, 0.10, 0.15,0.20) were prepared by sol-gel method and super critical fluid drying technology- Mn/CeO2 was prepared by impregnating CeO2 aerogel with the solution of manganese nitrate. The prepared aerogels were characterized by TEM, BET, CO oxidation reaction and H2-TPR. The experimental results of TEM and BET showed that with the increase of manganese content, the particle size of ceria aerogel decreased and the surface area increased. Reaction of CO oxidation showed that the oxidation activity was improved by adding Mn to the ceria aerogel. The best result was gained when the Mn content is 15 mol%. Ce1-xMnxO2 aerogel (x=0.05, 0.10, 0.15,0.20) and Mn/CeO2 show different carbon monoxide oxidation activities. Catalyst prepared by impregnation method (Mn/CeO2) shows lower catalyst activity than CeO2 and Ce1-xMnxO2(x=0.05, 0.10, 0.15,0.20) areogel. TPR experiment shows Mn species on ceria are also reduced through three steps as MnO2.
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