多孔莫来石纤维陶瓷负载La 1-x Sr x CoO 3(x =0.2~0.8)的NO+CO催化研究
Catalytic Activity of La 1-x Sr x CoO 3 (x=0.261566;0.8) Supported on Porous Mullite Fiber Ceramics for NO and CO
Received date: 2006-06-23
Revised date: 2006-08-21
Online published: 2007-05-20
采用真空浸渍法制备了多孔莫来石纤维陶瓷负载La1-xSrxCoO3(x=0.2、0.4、0.6、0.8)钙钛矿型催化剂. 利用XRD、SEM、BET等对样品进行了表征. 通过XRD发现, 所制备的La1-xSrxCoO3催化剂除了存在典型的钙钛矿结构外, 图谱中还发现了La(OH)3峰, 而且随着x值的减小La(OH)3 的衍射峰越来越尖锐. 由SEM可以观察到载体具有立体网状结构并且负载在载体上的催化剂颗粒分散性较好. BET表明随着 x 增加, 比表面积相应增加. 利用一氧化氮(NO)和一氧化碳(CO)对所制备的La1-xSrxCoO3系列载体催化剂的催化活性进行了测试比较, 发现当Sr取代量为x=0.2时, La1-xSrxCoO3整体催化活性较好.
关键词: La1-xSrxCoO3钙钛矿催化剂; 莫来石纤维多孔陶瓷; 载体; 催化活性
段碧林 , 曾令可 , 李秀艳 , 刘平安 , 税安泽 , 刘艳春 . 多孔莫来石纤维陶瓷负载La 1-x Sr x CoO 3(x =0.2~0.8)的NO+CO催化研究[J]. 无机材料学报, 2007 , 22(3) : 483 -488 . DOI: 10.3724/SP.J.1077.2007.00483
Perovskite La 1-x SrxCoO3 ( x=0.2,0.4,0.6,0.8) catalysts based on porous mullite fiber ceramic were prepared by a vacuum impregnation method. The samples were characterized by XRD, SEM and BET, respectively. The La(OH)3 crystal phase was detected besides the perovskite structures in La1-x SrxCoO3 catalysts, and the La(OH)3 peaks become sharp as x decreases. Tridimensional netshape of support and the good dispersing particles of catalysts based on support were detected by SEM. Specific surface area of La 1-xSrxCoO3 increases with the degree of substitution x of Sr for La via BET tests. Catalytic activity of La 1-x Sr x CoO3 catalysts prepared for CO+NO was tested. The results indicate that La 1-x Sr x CoO 3 catalysts have a best catalytic activity, when partial substitution of Sr for La reaches the optimal substitution fraction ( x=0.2).
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