大孔SiO_2载体制备La_(0.8)Sr_(0.2)CoO_3及其对NO+CO的催化性能

以具有高比表面积的大孔SiO_2为载体,采用浸渍法,通过控制浸渍液浓度的不同原位制备不同负载率的稀土钙钛矿型复合氧化物La_(0.8)Sr_(0.2)CoO_3/SiO_2样品。利用X射线衍射、比表面积、扫描电镜和X射线光电子能谱等分析方法对样品进行表征,结果表明,载体表面均匀负载La_(0.8)Sr_(0.2)CoO_3,且随着负载率增加,样品比表面积下降。考察不同负载率的La_(0.8)Sr_(0.2)CoO_3/SiO_2样品对NO+CO的催化活性,结果表明,与比表面积和结晶度相比,负载率在该催化实验体系中是影响最大的因素,综合催化效果最好的样品负载La_(0.8)Sr_(0.2)CoO_3质量分数为50.47%。

Catalytic properties of La0.8Sr0.2CoO3 prepared on macroporous SiO2 support for NO and CO

Using macroporous SiO2 with high specific surface area as the support and controlling the different concentration of impregnation solution,lanthanon perovskite oxide La0.8Sr0.2CoO3/SiO2 samples with different loading rate of La0.8Sr0.2CoO3 were prepared in-situ by the impregnation method.The samples were characterized by X-ray diffraction,specific surface area,scanning electron microscopy and X-ray photoelectron spectroscopy.The results showed that La0.8Sr0.2CoO3 were uniformly loaded on the support surface, and the specific surface area of the samples decreased with the increase of the loading rate of La0.8Sr0.2CoO3.The catalytic activity of La0.8Sr0.2CoO3/SiO2 samples with different loading rate for NO＋CO was investigated.The results indicated that the effects of loading rate on catalytic activity was stronger than that of specific surface area and crystallinity.The sample with La0.8Sr0.2CoO3 loading rate of 50.47wt% had the best catalytic activity.