介孔La_(1-x)Sr_(x)MnO_(3)催化剂的COK-12纳米浇铸法制备  

Preparation of Mesoporous La_(1-x)Sr_(x)MnO_(3)Catalysts via COK-12 Nano-Casting Method

作　　者：黄学辉[1] 胡祥奥 陈文臻 邓鹏辉 HUANG Xuehui;HU Xiang’ao;CHEN Wenzhen;DENG Penghui(School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《硅酸盐通报》2024年第8期3079-3088,共10页Bulletin of the Chinese Ceramic Society

摘　　要：钙钛矿型催化剂在汽车尾气净化方面具有良好的应用潜力。本文以表面活性剂P123为软模板剂,廉价的硅酸钠为硅源,在近中性条件下制备了介孔材料COK-12。并以此为基础,以对二甲苯为扩容剂对COK-12进行改性,得到了大孔径、有序的介孔材料。随后以改性介孔材料为模板剂,采用纳米浇铸法结合溶胶-凝胶法制备了介孔La_(0.8)Sr_(0.2)MnO_(3)催化剂。结果显示,在550℃下合成的催化剂具有较大的比表面积(72.11 m^(2)/g),表面Mn^(4+)/Mn^(3+)和O_(ads)/O_(lat)摩尔比最高。此外,样品的CO催化性能测试转化表明,550℃下合成的样品具有最好的催化活性和优秀的高温稳定性,其特征温度T_(50)和T_(90)分别为180和218℃。Perovskite-type catalysts show promising potential in the purification of automobile exhaust.This paper discussed the synthesis of mesoporous material COK-12 using surfactant P123 as a soft template and inexpensive sodium silicate as the silicon source under nearly neutral conditions.Building on this,the mesoporous COK-12 was modified with p-xylene as a swelling agent,resulting in large-pore,ordered mesoporous materials.Subsequently,for the first time,modified mesoporous materials were used as templates for the preparation of mesoporous La_(0.8)Sr_(0.2)MnO_(3)catalysts through nano-casting combined with the sol-gel method.The results demonstrate that the catalyst synthesized at 550℃possesses a larger specific surface area(72.11 m^(2)/g)and the highest molar ratio of Mn^(4+)/Mn^(3+)and O ads/O lat on the surface.Additionally,CO catalytic performance tests of samples indicate that those synthesized at 550℃exhibit the best catalytic activity and excellent high-temperature stability.Their characteristic temperatures T_(50)and T_(90)are 180 and 218℃,respectively.

关 键 词：COK-12 介孔材料 纳米浇铸法 溶胶-凝胶法 CO催化 

分 类 号：O643.36[理学—物理化学]