La-Ce-Cu复合金属氧化物的结构表征及催化性能

Structure Characterization and Catalytic Performance of the Multiple Metal Oxides of La-Ce-Cu Series

本文用ＮＨ４ＮＯ３共熔法合成Ｌａ－Ｃｅ－Ｃｕ系列样品。用ＸＲＤ分析了ＣｅＯ２在铜酸镧盐中的溶解度，发现大量ＣｅＯ２存在时，Ｌａ２Ｏ３、ＣｕＯ的加入导致原晶体结构发生变形，生成少量铜酸镧盐。ＸＲＦ分析了系列样品组成均为氧缺陷型化合物。ＸＰＳ研究发现，含大量ＣｅＯ２的样品高温焙烧后在ＣｅＯ２表面生成复合金属氧化物Ｌａ２ＣｕＯ４，最表面一层为少量Ｌａ２Ｏ３，并确定了其中Ｏ的属性。利用ＴＥＭ研究了部分样品的表面结构，同时研究了其ＣＯ催化氧化活性。

The samples of La-Ce-Cu series were prepared with ammonium nitrate (NH 4NO 3) co melted method.The solubility of cerium dioxide (CeO 2) in lanthanum cuprate was analyzed by XRD.XRD analysis also showed that when CeO 2 is sufficient,the addition of La 2O 3,CuO causes the distortion of the original crystal structure and some lanthanum cuprate is formed.The samples,which were analyzed by XRF,were found to be O defect compounds.XPS results showed that when there is plenty of CeO 2,the multiple metal oxides of lanthanum cuprate and La 2O 3 are formed at the surface of CeO 2 after calcination at elevated temperature,the La 2O 3 is located on the surface,the lanthanum cuprate is located in the intermediate,the property of oxygen was also defined.The superficial structures of some samples were analyzed by TEM and the activities for CO catalytic oxidation were studied.