Modification of Nano Spherical-Like MnO<sub>x</sub>/TiO<sub>2</sub> Catalysts with F-Doped

Abstract

A series of spherical-like MnOx/TiO2 catalysts with F-doped were prepared by using sol-gel method and investigated for low-temperature selective catalytic reduction (SCR) of NOx with NH3 at the temperature ranging from 100 °C to 200 °C. The 0.07Ce-MnOx/TiO2 catalyst shows the highest activity and yields 95% NO conversion at 200 °C. With the help of XRD, TGA, H2-TPR, NH3-TPD, BET and TEM, the structures and properties of the catalysts were characterized. The results show that it is a fine modifier for TiO2 support with appropriate amounts of F doping, and F ions can enter into TiO2 lattice, reducing the formation of rutile TiO2 and the crystallization of MnOx. However, MnTiO3 was generated in the catalysts with excess F doping. This would cause larger diameter of spherical particle and smaller surface area. But the amounts of the surface acid sites increased, and the reduction ability of catalysts was enhanced, which is beneficial for catalytic activity of the catalysts.