The Study of the MnOx/TiO2-ZrO2 used in the Sintering flue gas low-temperature Selective Catalytic Reaction

摘要

TiO2,50％TiO2-ZrO2 and 80％TiO2-ZrO2 were prepared by sol-gel method.The manganese oxides were impregnated on the carrier and the catalysts were used for low-temperature selective catalytic reduction of NOx with ammonia (NH3-SCR) in the presence of excess O2.The samples were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM).The results showed that the particle size of 80％TiO2-ZrO2 is the smallest among the three kind of carrier and the particles are highly dispersed.By adding the ZrO2,the Zr4+ ions replaced the lattice Ti4+ ions,and thus caused lattice distortion in the TiO2 and an increase of the active point amount on the carrier.Furthermore,the Zr also promoted the dispersion of the active ingredients carried on the carder,increased the surface concentration of Mn.The most active catalyst was obtained with a mass MnOx/80％TiO2-ZrO2 ratio of 0.1.The best MnOx/80％TiO2-ZrO2 catalyst yielded nearly 92.6％ NO conversion at 130°C at a high space velocity of 67,000 h-1.