The Ti-modified sepiolite （Ti-Sep）-supported Mn-Cu mixed oxide （yMn5Cu/Ti-Sep） catalysts were synthesized using the co-precipitation method. The materials were characterized by the X-ray diffraction scanning elect...The Ti-modified sepiolite （Ti-Sep）-supported Mn-Cu mixed oxide （yMn5Cu/Ti-Sep） catalysts were synthesized using the co-precipitation method. The materials were characterized by the X-ray diffraction scanning electron microscope, N2 adsorption-desorption, H2-TPR, O2-TPD, and XPS techniques, and their catalytic activities for CO oxidation were evaluated. It was found that the catalytic activities ofyMn5Cu/Ti-Sep were higher than those of 5Cu/Ti-Sep and 30Mn/Ti-Sep, and the Mn/Cu molar ratio had a distinct influence on catalytic activity of the sample. Among the yMn5Cu/Ti- Sep samples, the 30Mn5Cu/Ti-Sep catalyst showed the best activity （which also outperformed the 30Mn5Cu/Sep catalyst）, giving the highest reaction rate of 0.875 × 10^- 3 mmol· g^-1· s^-1 and the lowest T50%and T100% of 56℃ and 86℃, respectively. Moreover, the 30Mn5Cu/Ti-Sep possessed the best low-temperature reducibility, the lowest 02 desorption temperature, and the highest surface Mn3＋/ Mn4＋ atomic ratio. It is concluded that factors, such as the strong interaction between the copper or manganese oxides and the Ti-Sep support, good low-temperature reducibility, and good mobility of ehemisorbed oxygen species, were responsible for the excellent catalytic activity of 30Mn5Cu/Ti-Sep.展开更多
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 21277008 and 20777005） and Natural Science Foundation of Beijing （No. 8082008）.
文摘The Ti-modified sepiolite （Ti-Sep）-supported Mn-Cu mixed oxide （yMn5Cu/Ti-Sep） catalysts were synthesized using the co-precipitation method. The materials were characterized by the X-ray diffraction scanning electron microscope, N2 adsorption-desorption, H2-TPR, O2-TPD, and XPS techniques, and their catalytic activities for CO oxidation were evaluated. It was found that the catalytic activities ofyMn5Cu/Ti-Sep were higher than those of 5Cu/Ti-Sep and 30Mn/Ti-Sep, and the Mn/Cu molar ratio had a distinct influence on catalytic activity of the sample. Among the yMn5Cu/Ti- Sep samples, the 30Mn5Cu/Ti-Sep catalyst showed the best activity （which also outperformed the 30Mn5Cu/Sep catalyst）, giving the highest reaction rate of 0.875 × 10^- 3 mmol· g^-1· s^-1 and the lowest T50%and T100% of 56℃ and 86℃, respectively. Moreover, the 30Mn5Cu/Ti-Sep possessed the best low-temperature reducibility, the lowest 02 desorption temperature, and the highest surface Mn3＋/ Mn4＋ atomic ratio. It is concluded that factors, such as the strong interaction between the copper or manganese oxides and the Ti-Sep support, good low-temperature reducibility, and good mobility of ehemisorbed oxygen species, were responsible for the excellent catalytic activity of 30Mn5Cu/Ti-Sep.
