Abstract
To improve their thermal stability, La Sr MnO cordierite monoliths are washcoated with mayenite, which is a novel Al-based material with the crystal structure of 12MO·7Al O (M= Ca, Sr). The monoliths are characterized by means of nitrogen adsorption/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 La Sr MnO and also prevents the interaction between La Sr MnO and cordierite or -Al O , both crystal structure and surface morphology of La Sr MnO phase can thereby be stable on the mayenite surface even at high temperature up to 1050 oC. Under the given reaction conditions, La Sr MnO monolith washcoated with 12SrO·7Al O shows the best catalytic activity for methyl methacrylate combustion among all the tested monoliths.