Three-dimensionally ordered macroporous LaCoxFe1−xO3 perovskite-type complex oxide catalysts for diesel soot combustion
Three-dimensionally ordered macroporous LaCoxFe1−xO3 perovskite-type complex oxide catalysts for diesel soot combustion
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DOI：
10.1016/j.cattod.2010.01.063
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发表时间：
2010-08
期刊：
影响因子：
5.3
通讯作者：
Junfeng Xu;Jian Liu;Zhen Zhao;Jianxiong Zheng;Guizhen Zhang;A. Duan;Guiyuan Jiang
中科院分区：
文献类型：
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作者：
Junfeng Xu;Jian Liu;Zhen Zhao;Jianxiong Zheng;Guizhen Zhang;A. Duan;Guiyuan Jiang
以水油两相双引发剂为引发剂，采用改进的无皂乳液聚合工艺制备了粒径为300~500 nm的聚甲基丙烯酸甲酯(PMMA)微球。以−微球为模板，采用胶体晶体模板法制备了一系列具有三维有序结构的LaCoxFe1PMAxO3型钙钛矿型催化剂。采用X射线衍射仪、红外光谱、扫描电子显微镜和激光粒度仪对微球和3DOM催化剂进行了表征，并通过程序升温氧化(TPO)反应考察了催化剂对柴油机碳烟燃烧的催化性能。结果表明，制得的PMMA微球没有团聚，其固含量(即聚合物微球在整个乳液聚合物中的质量分数)达到9%。它们的粒径分布较窄，可以在不同的条件下设计不同尺寸的微球。除LaCo0.7Fe0.3O3外，其余催化剂均形成3DOM结构，并具有六方有序排列。它们的大孔直径在250-300 nm之间。3DOM催化剂对柴油机碳烟燃烧的催化性能优于非大孔颗粒催化剂。在所研究的催化剂中，3DOM LaCo0.5Fe0.5O3型催化剂的催化活性最高，其T50和[式：见正文]分别为397℃和99.7%。
Polymethyl methacrylate (PMMA) microspheres with diameters of 300–500nm were prepared by using a modified emulsifier-free emulsion polymerization technique with water–oil biphase double initiators. A series of three-dimensionally ordered macroporous (3DOM) LaCoxFe1−xO3(x=0–0.5) perovskite-type catalysts were synthesized by using colloid crystal template (CCT) method with the PMMA microspheres as template. The microspheres and 3DOM catalysts were characterized by means of XRD, FT-IR, SEM and Laser particle size analyzer, and the catalytic performances of the catalysts for diesel soot combustion were investigated by temperature-programmed oxidation (TPO) reaction. The results indicated that the obtained PMMA microspheres did not aggregate and their solid content (i.e., the mass percentage of polymer microspheres in the whole emulsion polymer) reached 9%. Their size distribution was narrow and the microspheres with different sizes can be designed under different conditions. Except LaCo0.7Fe0.3O3, all the catalysts formed 3DOM structure and possessed a hexagonally well-ordered array. Their macroporous diameters were in the range of 250–300nm. The 3DOM catalysts had better catalytic performances than the nonmacroporous particle catalysts for diesel soot combustion. Among the studied catalysts, the 3DOM LaCo0.5Fe0.5O3catalyst had the highest catalytic activity, and its T50and [Formula: see text] were 397°C and 99.7%, respectively.