柠檬酸溶胶凝胶法制备CuO-CeO2催化剂及其CO氧化活性对比研究

摘要：本实验以柠檬酸为络合剂，CeO2为载体，采用溶胶-凝胶法来制备制备了一系CuO-CeO2催化剂，并在不同的温度(500，650和800℃)下进行焙烧。对所制备的催化剂通进行了H2-TPR表征，并考察了其低温催化氧化CO的活性。H2-TPR结果表明,小颗粒高分散的CuO是催化剂的活性中心,有利于催化活性的提高，大颗粒CuO阻碍催化剂的催化活性。CO活性评价结果表明：在焙烧温度同为500℃和650℃的情况下，使用掺入PEG的柠檬酸溶胶凝胶法的活性最高，采用PEG隔离法所制备的最差。而在800℃焙烧下的催化剂样品活性则为：EiCuCe1>EiCuCe2>EiCuCe3。且对制备方法相同、焙烧温度不同的催化剂样品的活性评价结果则显示：高温焙烧使大部分氧化铜都被烧结而进入载体氧化铈中，催化剂表面几乎不存在小颗粒氧化铜，故不易与氢气发生还原反应。无论何种制备方法，其催化活性都随着焙烧温度的增高而降低。50503

毕业论文关键词：CO催化氧化；柠檬酸溶胶凝胶法；CuO-CeO2

The research on CuO-CeO2 catalysts prepared by citric acid sol gel method and their CO oxidation activity

Abstract: A series of CuO-CeO2 catalysts were prepared by sol-gel method with CeO2 as the support, citric acid as the complexing agent,and were alcined at different temperature(500,650,and 800℃). These catalysts were characterized by H2-TPR,and their catalytic activities for low temperature CO oxidation were investigated. H2-TPR results showed that the high dispersion of CuO was the active center of the catalyst, which was beneficial to the improvement of the catalytic activity, and the catalytic activity of the catalyst was hindered by the large particle CuO.CO activity evaluation results show that: in the case of the calcination temperature of 500℃ and 650℃, using the citric acid sol gel method with the incorporation of PEG was the highest, and the lowest was prepared by the PEG isolation method. The activity of the catalyst calcined at 800℃ was:EiCuCe1>EiCuCe2>EiCuCe3. The activity evaluation results of catalyst calcined at different temperatures with the same preparation method show that high temperature sintered most CuO into the ceria support and catalyst surface hardly exist small particles of copric oxide, which made the reduction reaction difficult to occur. Besides,the catalytic activity decreased with the increase of the calcination temperature no matter produced by which preparation method.

Keywords: CO catalytic oxidation; sol-gel method with citric acid; CuO-CeO2

1 前言 1

1.1 一氧化碳低温催化氧化研究背景 1

1.2 文献综述 1

1.3 方案论证 3

2 实验部分 4

2.1 实验仪器、原料与试剂 4

2.1.1 实验试剂 4

2.1.2 实验气体 4

2.1.3 实验仪器和设备 5

2.2 催化剂的制备 5

2.2.1 柠檬酸溶胶-凝胶法 5

2.2.2 掺入PEG的柠檬酸溶胶-凝胶法 6

2.2.3 采用PEG隔离法 7

2.3 催化剂CO活性的评价实验 7

2.4 程序升温还原实验（TPR） 10

3 实验分析 13

3.1 程序升温还原分析 13

3.1.1 不同制备方法所制得催化剂的TPR分析柠檬酸溶胶凝胶法制备CuO-CeO2催化剂及其CO氧化活性对比研究:http://www.youerw.com/huaxue/lunwen_53860.html