期刊
CATALYSIS TODAY
卷 126, 期 3-4, 页码 400-405出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.cattod.2007.06.032
关键词
perovskite; NO oxidation; La(1-x)CexCoO(3); TPD; DRIFTS; nitrate
This paper presents an investigation on the NO oxidation properties of perovskite oxides. La1-xCexCoO3 (x = 0, 0.05, 0.1, 0.2, 0.3, 0.4) perovskite-type oxides were synthesized through a citrate method and characterized by XRD, BET and XPS. The catalytic activities were enhanced significantly with Ce substitution, and achieved the best when x was 0.2, but decreased at higher x values. The performed characterizations reveal that the adsorbed oxygen on the surface plays an important role in the oxidation of NO into NO2. The surface compounds after the co-adsorption of NO and O-2 at room temperature, were investigated by DRIFTS and TPD experiments: Three species: the bridging nitrate, the hyponitrites and the monodentate nitrate, were formed on the surface. The order of thermal stabilities was as follows: monodentate > hyponitrite > bridging. Among them, only the monodentate nitrate which decomposed at above 300 degrees C, would desorb NO2 into the gas phase. When Cc was added, the temperature of monodentate nitrate desorption became low and the adsorption of the other two species decreased. This might be related to the oxidation state of Co on the surface. Analysis by synthesizing the characterization results and catalytic activity data shows that large amounts of adsorbed oxygen, small amount of inactive compounds on the surface and low NO2 desorption temperature are favorable for the oxidation of NO. (C) 2007 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据