MCM-41 was synthesized by a soft template technique.The specific surface area and pore volume of the MCM-41 were 805.9 m2/g and 0.795 cm3/g,respectively.MCM-41-supported manganese and cobalt oxide catalysts were prepa...MCM-41 was synthesized by a soft template technique.The specific surface area and pore volume of the MCM-41 were 805.9 m2/g and 0.795 cm3/g,respectively.MCM-41-supported manganese and cobalt oxide catalysts were prepared by an impregnation method.The energy dispersive X-ray spectroscopy clearly confirmed the existence of Mn,Co,and O,which indicated the successful loading of the active components on the surface of MCM-41.The structure and function of the catalysts were changed by modulating the molar ratio of manganese to cobalt.The 10%MnCo(6:1)/MCM-41(Mn/Co molar ratio is 6:1)catalyst displayed the best catalytic activity according to the activity evaluation experiments,and chlorobenzene(1000 ppm)was totally decomposed at 270°C.The high activity correlated with a high dispersion of the oxides and was attributed to the exposure of more active sites,which was demonstrated by X-ray diffraction and high-resolution transmission electron microscopy.The strong interactions between MnO2,Co3O4,MnCoOx,and MCM-41 indicated that cobalt promoted the redox cycles of the manganese system.The bimetal-oxide-based catalyst showed better catalytic activity than that of the single metal oxide catalysts,which was further confirmed by H2 temperature-programmed reduction.Chlorobenzene temperature-programmed desorption results showed that 10%MnCo(6:1)/MCM-41 had higher adsorption strength for chlorobenzene than that of single metal catalysts.And stronger adsorption was beneficial for combustion of chlorobenzene.Furthermore,10%MnCo(6:1)/MCM-41 was not deactivated during a continuous reaction for 1000 h at 260°C and displayed good resistance to water and benzene,which indicated that the catalyst could be used in a wide range of applications.展开更多
文摘MCM-41 was synthesized by a soft template technique.The specific surface area and pore volume of the MCM-41 were 805.9 m2/g and 0.795 cm3/g,respectively.MCM-41-supported manganese and cobalt oxide catalysts were prepared by an impregnation method.The energy dispersive X-ray spectroscopy clearly confirmed the existence of Mn,Co,and O,which indicated the successful loading of the active components on the surface of MCM-41.The structure and function of the catalysts were changed by modulating the molar ratio of manganese to cobalt.The 10%MnCo(6:1)/MCM-41(Mn/Co molar ratio is 6:1)catalyst displayed the best catalytic activity according to the activity evaluation experiments,and chlorobenzene(1000 ppm)was totally decomposed at 270°C.The high activity correlated with a high dispersion of the oxides and was attributed to the exposure of more active sites,which was demonstrated by X-ray diffraction and high-resolution transmission electron microscopy.The strong interactions between MnO2,Co3O4,MnCoOx,and MCM-41 indicated that cobalt promoted the redox cycles of the manganese system.The bimetal-oxide-based catalyst showed better catalytic activity than that of the single metal oxide catalysts,which was further confirmed by H2 temperature-programmed reduction.Chlorobenzene temperature-programmed desorption results showed that 10%MnCo(6:1)/MCM-41 had higher adsorption strength for chlorobenzene than that of single metal catalysts.And stronger adsorption was beneficial for combustion of chlorobenzene.Furthermore,10%MnCo(6:1)/MCM-41 was not deactivated during a continuous reaction for 1000 h at 260°C and displayed good resistance to water and benzene,which indicated that the catalyst could be used in a wide range of applications.
