摘要
To improve their thermal stability, La0.8Sr0.2MnO3 cordierite monoliths are washcoated with mayenite, which is a novel Al-based material with the crystal structure of 12MO 7Al2O3 （M= Ca, Sr）. The monoliths are characterized by means of nitrogen adsorp- tion/desorption, scanning electron microscopy, and X-ray diffraction. Catalytic performances of the monoliths are tested for methyl methacrylate combustion. The results show that mayenite obviously improves both the physic- chemical properties and the catalytic performance of the monoliths. Because mayenite improves the dispersity of Lao.sSro.2MnO3 and also prevents the interaction between La0.8Sr0.2MnO3 and cordierite or γ-A1203, both crystal structure and surface morphology of La0.8Sr0.2MnO3 phase can thereby be stable on the mayenite surface even at high temperature up to 1050 ℃. Under the given reaction conditions, La0.8Sr0.2MnO3 monolith washcoated with 12SrO. γ-A1203 shows the best catalytic activity for methyl methacrylate combustion among all the tested monoliths.
To improve their thermal stability, La0.8Sr0.2MnO3 cordierite monoliths are washcoated with mayenite, which is a novel Al-based material with the crystal structure of 12MO 7Al2O3 （M= Ca, Sr）. The monoliths are characterized by means of nitrogen adsorp- tion/desorption, scanning electron microscopy, and X-ray diffraction. Catalytic performances of the monoliths are tested for methyl methacrylate combustion. The results show that mayenite obviously improves both the physic- chemical properties and the catalytic performance of the monoliths. Because mayenite improves the dispersity of Lao.sSro.2MnO3 and also prevents the interaction between La0.8Sr0.2MnO3 and cordierite or γ-A1203, both crystal structure and surface morphology of La0.8Sr0.2MnO3 phase can thereby be stable on the mayenite surface even at high temperature up to 1050 ℃. Under the given reaction conditions, La0.8Sr0.2MnO3 monolith washcoated with 12SrO. γ-A1203 shows the best catalytic activity for methyl methacrylate combustion among all the tested monoliths.
