层状复合氧化物La~4BaCu~5~-~xMn~xO~1~2的表征及在催化消除NO中活性的研究

采用柠檬酸配合法合成了结构呈层状ABO~3的La~4BaCu~5O~1~2复合氧化物, 并以它为基体合成了一系列Mn取代Cu的样品(La~4BaCu~5~-~xMn~xO~1~2, x=1-5)并利用XRD, IR进行了结构表征, 结果表明其均为5层的ABO~3结构。利用H~2-TPR考查了掺杂Mn以后样品的氧化还原性能的变化, 发现由于Mn的掺杂使Cu明显的容易还原。还考查了样品对NO+CO反应的催化活性, 结果表明反应的活性中心是Cu离子,但加入适量的Mn离子可以使活性提高。

Synthesis, characterization and catalytic behavior of layered mixed oxides La~4BaCu~5~-~xMn~xO~1~2 in NO reduction by CO

A series of sample having the stoichiometry La4BaCu5-xMnxO12(x = 0-5) were prepared,characterized by XRD,IR and H2 - TPR and used as catalyst for NO + CO reaction. It was found that they have 5-layered ABO3-type structure. The results of H2 - TPR showed that the Cu ion was more easily reduced while a part of them was replaced by Mn ions. Their catalytic behavior to NO + CO reaction was investigate, La4BaCu2Mn3O12 showed the highest catalyst activity for the reaction than the others. The reaction mechanism is discussed: the activity of the catalysts could be attributed to the Cu ions,but it was improved when Mn ions took the place of some Cu ions.