Highly active La1-xKxCoO3 perovskite-type complex oxide catalysts for the simultaneous removal of diesel soot and nitrogen oxides under loose contact conditions
Highly active La1-xKxCoO3 perovskite-type complex oxide catalysts for the simultaneous removal of diesel soot and nitrogen oxides under loose contact conditions
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DOI：
10.1007/s10562-008-9429-1
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发表时间：
2008-08-01
影响因子：
2.8
通讯作者：
Liu, Jian
中科院分区：
文献类型：
--
作者：
Wang, Hong;Zhao, Zhen;Liu, Jian
采用柠檬酸配位法制备了La（1-x）K（x）CoO（3）（x = 0-0.30）钙钛矿型纳米氧化物。采用XRD、IR、BET、XPS、SEM等手段对催化剂进行了表征。采用程序升温氧化反应技术对催化剂同时脱除碳烟和氮氧化物的活性进行了评价。在LaCoO（3）催化剂中，碱金属K（+）对La（3+）A位的部分取代提高了催化剂对碳烟颗粒氧化和NO（X）还原的活性。La（0.70）K（0.30）CoO（3）氧化物是同时脱除碳烟颗粒和NO（X）的良好候选催化剂。碳烟颗粒在La（0.70）K（0.30）CoO（3）催化剂上的燃烧温度范围为289 - 461 ℃，在松接触条件下CO（2）的选择性为98.4%，NO转化为N（2）的转化率为34.6%。给出了导致K取代样品比未取代样品（LaCoO（3））活性增强的可能原因。颗粒尺寸对其同时去除柴油机碳烟和氮氧化物的催化性能有很大影响。
The nanometric La(1-x) K(x) CoO(3) (x = 0-0.30) perovskite-type oxides were prepared by a citric acid-ligated method. The catalysts were characterized by means of XRD, IR, BET, XPS and SEM. The catalytic activity for the simultaneous removal of soot and nitrogen oxides was evaluated by a technique of the temperature-programmed oxidation reaction. In the LaCoO(3) catalyst, the partial substitution of La(3+) at A-site by alkali metal K(+) enhanced the catalytic activity for the oxidation of soot particle and reduction of NO(X). The La(0.70)K(0.30)CoO(3) oxides are good candidate catalysts for the simultaneous removal of soot particle and NO(X). The combustion temperatures for soot particles over the La(0.70)K(0.30)CoO(3) catalyst are in the range from 289 to 461 C, the selectivity of CO(2) is 98.4% and the conversion of NO to N(2) is 34.6% under loose contact conditions. The possible reasons that can lead to the activity enhancement for the K-substitution samples compared to the unsubstituted sample (LaCoO(3)) were given. The particle size has a large effect on its catalytic performance for the simultaneous removal of diesel soot and nitrogen oxides.