La_2O_3-ZrO_2缺陷萤石型燃烧催化剂的制备

PREPARATION OF La_2O-3-ZrO_2 OXIDE COMBUSTIONAL CATALYST WITH DEFECTIVE FLUORITE STRUCTURE

缺陷萤石型La_2Q_3-ZrO_2固溶体的催化燃烧活性受制备条件的影响,本文通过对其共沉淀前体的表面结构和热分解过程的分析,发现共沸蒸馏的办法可以有效地控制前体表面羟基的缩合过程,减少团聚,保持前体中金属离子均匀分散,为生成缺陷有序的烧绿石型的La_2Zr_2O_7复氧化物提供了可能,复合氧化物固溶体的表面阳离子配置情况与样品的催化氧化性能密切相关,软团聚前体的烧结产物对甲烷燃烧反应具有更高的催化活性。

One of the most important factors which affect the catalytic performances of complex oxide used in catalytic combustion is the preparative process of samples. Combined with several spectrum techniques, the study on the thermal decomposing procedure of the coprecipated precursors illustrates that the catalytic activity of La2O3-ZrO2 composite oxide solid solution is intimately concerned with drying condition, due to the different crystallization therein. The codistillation involved n-butanol could keep the uniform distribution of metal cations in precursor intact, and facilitates acquiring the well-crystallized sample by following thermal treatment. These crystalline with regular lattice will supply more anion defects on the surface, which act as the active sites for the complete oxidation of hydrocarbon.