Promoting effect of Ru-doped Mn/TiO2 catalysts for catalytic oxidation of chlorobenzene

Mn/TiO2 catalysts were synthesized using a deposition-precipitation method. Ru-doped Mn/TiO2 catalysts were prepared by an incipient-wetness impregnation method. To investigate the interaction between Ru and Mn species, the catalytic performance of Mn/TiO2 and Ru-Mn/TiO2 catalysts in the catalytic oxidation of chlorobenzene (CB) was evaluated. The physicochemical properties of the catalysts were characterized by XRD, HRTEM, XPS, EPR, H-2-TPR, O-2-TPD and so on. The results showed that the 0.8% Ru-10% Mn/TiO2 catalyst exhibited the best catalytic activity with 99% CB conversion at 250 degrees C and showed an excellent CO2 yield (95% at 300 degrees C) and stability. In comparison with the 10% Mn/TiO2 catalyst, the T90 of the Ru-Mn/TiO2 catalyst decreased by 60 degrees C, which was attributed to the interaction between Ru and Mn species at the interfaces of Ru/Mn. The Ru species increased the concentration of Mn4+ and Ru4+ and reduced the H-2 reduction temperature, which was conducive to improving the redox performance of the catalysts. Ru species were highly dispersed on the Mn/TiO2 catalyst surfaces, forming a large number of Ru/Mn interfaces. The interaction between Ru and Mn species at the interfaces of Ru/Mn promoted the formation of oxygen vacancies and surface reactive oxygen species, thus enhancing the catalytic activity.

Automated summary

Mn/TiO2 and Ru-Mn/TiO2 catalysts were prepared and their catalytic performance in the oxidation of chlorobenzene was evaluated. The results showed that the Ru-Mn/TiO2 catalyst exhibited better activity compared to the Mn/TiO2 catalyst. The interaction between Ru and Mn species at the interfaces of Ru/Mn promoted the formation of oxygen vacancies and surface reactive oxygen species, enhancing the catalytic activity.