Soot Combustion over Lanthanum Cobaltites and Related Oxides for Diesel Exhaust Treatment
Soot Combustion over Lanthanum Cobaltites and Related Oxides for Diesel Exhaust Treatment
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DOI：
10.1021/ef901279w
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发表时间：
2010-02
期刊：
影响因子：
5.3
通讯作者：
Runduo Zhang;Na Luo;Biaohua Chen;S. Kaliaguine
中科院分区：
文献类型：
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作者：
Runduo Zhang;Na Luo;Biaohua Chen;S. Kaliaguine
本文报道了一系列La_1-−_x(M)_xCoO_3(M=Ce和Sr)钙钛矿及其相关的M‘O_x(M’=La，Co，Ce和Sr)样品氧化物的比较研究。采用氮气吸附、X-射线衍射仪(XRD)、氧气程序升温脱附(TPD)、氢气程序升温还原(TPR)和碳烟程序升温燃烧(TPC)等方法对催化剂进行了表征。在钙钛矿型催化剂的存在下，碳烟的氧化被促进，与非催化过程相比，CO2峰向更低的温度移动。此外，这些钙钛矿的催化活性遵循La0.8Ce0.2CoO_3&Gt；La0.9Ce0.1CoO_3&Gt；La0.9Sr0.1CoO_3&Gt；La0.8Sr0.2CoO_3&≈LaCoO_3的趋势。提出了从钙钛矿表面迁移的表面氧物种对碳烟的攻击机理。还讨论了作为中间体的CO(或羰基)的生成以及在大多数碱性化合物上可能形成的碳酸盐物种。
This paper reports a comparative study of a series of La1−x(M)xCoO3 (M = Ce and Sr) perovskites and the related M′Ox (M′ = La, Co, Ce, and Sr) sample oxides. These catalysts were characterized by N2 adsorption, X-ray diffraction (XRD), temperature-programmed desorption (TPD) of oxygen, temperature-programmed reduction (TPR) by hydrogen, and temperature-programmed combustion (TPC) of soot. In the presence of perovskite-type catalysts, the soot oxidation was promoted, showing a shift of CO2 peaks toward lower temperature compared to the non-catalytic process. In addition, the catalytic activity of these perovskites was found to follow the trend La0.8Ce0.2CoO3 > La0.9Ce0.1CoO3 > La0.9Sr0.1CoO3 > La0.8Sr0.2CoO3 ≈ LaCoO3. A mechanism was proposed with an attack of soot by surface oxygen species, which migrate from the perovskite surface. The generation of CO (or carbonyl groups) as an intermediate and the possible formation of carbonate species over the most basic compounds are also discussed.