La1-xKxMnO3钙钛矿型催化剂同时去除碳烟颗粒物和NOx的性能研究

Catalytic Properties of Perovskite Catalysts La1-xKxMnO3 (x=0~0.5) for Simultaneous Removal of Soot Particles and NOx

中文关键词: 去除NOx  碳烟颗粒物  La_1-xKxMnO3  钙钛矿型催化剂  K掺杂

英文关键词: Removal of NOx  Soot particles  La_1-xKxMnO3  perovskite catalysts  K-doping

中文摘要:

      通过柠檬酸络合法制备了一系列钙钛矿型催化剂La_1-xKxMnO3 (x=0~0.5)。通过程序升温氧化反应测试了催化剂同时去除碳烟颗粒物和NOx的性能。采用X射线衍射（XRD）、扫描电镜（SEM）、氢气程序升温还原（H2-TPR）以及X射线光电子能谱（XPS）等表征技术分析了经过A位掺杂的催化剂与基础催化剂产生活性差异的原因。结果表明：所制备的催化剂均具有钙钛矿结构；K的掺杂使得催化剂拥有更加均匀的纳米颗粒且颗粒粒度减小；同时掺杂还改变了B位金属的化学状态，使得被掺杂的催化剂中高价态的Mn4+和氧空位的含量增加。其中La0.7K0.3MnO3具有较好催化活性，碳烟颗粒物的特征温度T50和最大燃烧速率温度分别为344℃和349.8℃，NO的转化率为39.1%。

英文摘要:

      A series of La_1-xKxMnO3 (x=0~0.5) perovskite catalysts were prepared by citric acid sol-gel method. X - ray diffraction (XRD), scanning electron microscopy (SEM), hydrogen temperature-programmed reduction (H2-TPR) and X - ray photoelectron spectroscopy (XPS) were used to investigate the reasons for the difference in activity between A - doped catalyst and the normal bulk catalyst. The results show that the prepared catalysts have perovskite structure. K-doping reduces the particle size of the catalyst and makes it more uniform. At the same time, doping also changes the chemical state of B-site metal, which increases the content of Mn4+ and oxygen vacancy in the doped catalyst. Among them, La0.7K0.3MnO3 has good catalytic activity, the characteristic temperature T50 and maximum burning rate temperature of soot particles are 344℃ and 349.8℃, respectively. The conversion rate of NO is 39.1%.