The Study of the MnOx/TiO sub(2)-ZrO sub(2) Used in the Sintering Flue Gas Low-Temperature Selective Catalytic Reaction

TiO sub(2), 50%TiO sub(2)-ZrO sub(2) and 80%TiO sub(2)-ZrO sub(2) 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 O sub(2). The samples were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The results showed that the particle size of 80%TiO sub(2)-ZrO sub(2) is the smallest among the three kind of carrier and the particles are highly dispersed. By adding the ZrO sub(2), the Zr super(4+) ions replaced the lattice Ti super(4+) ions, and thus caused lattice distortion in the TiO sub(2) 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 carrier, increased the surface concentration of Mn. The most active catalyst was obtained with a mass MnOx/80%TiO sub(2)-ZrO sub(2) ratio of 0.1. The best MnOx/80%TiO sub(2)-ZrO sub(2) catalyst yielded nearly 92.6% NO conversion at 130[degrees]C at a high space velocity of 67,000 h super(-1).