中文摘要：

以共沉淀法制备了LaFexMmAl12-x-yO19六铝酸盐催化剂，并用X射线衍射、扫描电镜、N2吸附-脱附、紫外-可见漫反射光谱和穆斯堡尔谱对催化剂进行了表征，考察了催化剂上高浓度N2O分解反应的性能．结果表明，在所考察的条件下，Mn比Fe更有利于促进六铝酸盐晶相的形成．LaFeXAl12-xO19（x=0．5，1）中Fe以Fe3＋位于六铝酸盐尖晶石结构中的四面体位和镜面层结构中的三角双锥位，其中后者为N2O分解的主要活性中心．LaMnyAl12-yO19（y=0．5，1）中Mn优先以Mn2＋进入四面体位，然后以Mn3＋进入尖晶石结构中的八面体位，并成为N2O分解的主要活性中心．

英文摘要：

LaFexMnyAl12-x-yO19 hexaaluminate catalyst samples were prepared by a coprecipitation method and tested for N2O decomposition with high concentration （30%, V/V）. The catalyst samples were characterized by X-ray diffraction, scanning electron microscopy, N2 adsorption-desorption, ultraviolet-visible spectroscopy, and Mossbaner spectroscopy. The results showed that the partial substitution by Mn led to easier formation of phase-pure hexaaluminate compared with that by Fe under the investigated conditions. Fe3＋ occupied both tetrahedral sites in spinel block and trigonal bipyramid sites in mirror plane for LaFexAl12-xO19 （x = 0.5, 1） hexaaluminate. Mn2＋ preferentially entered tetrahedral sites at low Mn content （y = 0.5） for LaMnyAl12-yO19 hexaaluminate, whereas Mn3＋ entered octahedral sites in spinel block aty = 1 The activity tests for N2O decomposition with high concentration demonstrated that Fe3＋ in trigonal bipyramid sites of LaFexAl12-xO19 and Mn3＋ in octahedral sites of LaMnyAl12-yO19 were the main active centers.