Preparation of Mesoporous La1-xSrxMnO3 Catalysts via COK-12 Nano-Casting Method
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 La0.8Sr0.2MnO3 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 m2/g)and the highest molar ratio of Mn4+/Mn3+and Oads/Olat 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 T50 and T90 are 180 and 218℃,respectively.
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