摘要
The effects of support materials on catalytic performance were investigated in catalytic removal of toluene.And the Mn–Ce binary oxides as active components were supported on ZrO_(2),SiO_(2),γ-Al_(2)O_(3) and TiO_(2) support materials.Many techniques,including X-ray diffraction(XRD),Brunauer–Emmett–Teller method(BET),X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction(TPR)and NH_(3)-temperature-programmed desorption(NH_(3)-TPD),were used to characterize physicochemical properties.Among the different catalysts,the MnCe/ZrO_(2) catalyst with the lowest specific surface area(39.7 m^(2)/g)shows the best catalytic activity.In terms of toluene conversion,the activity order is as follows:MnCe/ZrO_(2)>MnCe/TiO_(2)≈MnCe/SiO_(2)>MnCe/Al_(2)O_(3).The better performance of MnCe/ZrO_(2) should be attributed to the low-temperature reducibility,and abundant surface species(Mn^(4+)and lattice oxygen).And XPS and TPR results reveal that more surface abundant Mn and Ce elements generate good interaction in MnCe/ZrO_(2).The weak interaction between metal oxide and support also boosts the dispersion and complete reduction of MnCe oxides at low temperature.In addition,the in-situ DRIFTS results clarify that the carbonate species are main intermediates in MnCe/ZrO_(2) sample during surface reaction process.
基金
Project supported by the National Natural Science Foundation of China (21503184)
the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (18KJA610004)。