中文摘要：

采用溶胶-凝胶法制备了K^＋掺杂的La1-xKx3oO3系列钙钛矿结构柴油车尾气炭烟氧化催化剂，用XRD，TG-DTA及程序升温反应等技术详细研究了心掺杂量及焙烧温度对催化剂结构和炭烟燃烧性能的影响，初步探讨了催化剂结构与性能之间的相关性．实验结果表明，以蔗糖为络合剂在600℃下可以得到纯钙钛矿结构的La1-xKx3oO3纳米晶，其中菱方相为LaCoO3系钙钛矿的高温稳定相，升高焙烧温度及增加心掺杂量都会促进钙钛矿结构由立方相转变为菱方相．K^＋的掺杂可以降低炭烟的燃烧温度，一定量的K可以提高炭烟的燃烧速率．700℃焙烧的具有菱方相钙钛矿结构的La0.9K0.1CoO3具有最好的催化性能，对炭烟的起燃点和燃尽温度分别为240及387℃，可以通过柴油车自身的排气热量来实现炭烟的催化燃烧过程．

英文摘要：

Diesel engines are currently facing serious challenges to reduce exhaust pollution, especially the particulate soot, which is harmful to human beings. Simultaneous removal of NOx and soot has been studied for the past two decades and perovskite-type LaMO3 （M= Co, Mn） proved to be an effective catalyst. In this work, a series of nanostructured K^＋-doped perovskite-type La1-xKxCoO3 catalysts were prepared by sol-gel method using sucrose as complex agent. The influences of K^＋ doping and high temperature calcining on the structure and soot oxidation activity of the catalyst were studied by XRD and TPR techniques. The results indicated that nanostructured perovskite catalyst with single phase formed at the temperature higher than 600 ℃, and it showed much higher activity for soot oxidation in the mixed gas of NO and 02. K^＋ could be inserted into perovskite lattices, enhancing the phase transformation from cubic to rhombohedral structure. The resulting phase was more stable at high temperatures. The catalyst of La0.90K0.10CoO3 （about 30 nm） calcined at 700 ℃ with rhombohedral structure exhibited the highest activity for soot oxidation in 0.5% NO and 5% O2, which led to the low Tig and Tend as 240 and 387 ℃ respectively, almost 200 ℃ lower than the temperature of soot combustion without the catalyst. In the reaction system of soot-NO-O2, both the crystal structure and particle size of the perovskite catalysts were most influential, and the rhombohedral structure together with small size perhaps was beneficial to soot oxidation.