| 摘要 |
PURPOSE:To obtain an exhaust gas purifying catalyst preventing the sudden lowering of leak NH3 decomposing activity caused by volatile compds. of As, Se, Re or the like contained in coal combustion gas and capable of realizing a high denitration rate, low leak NH3 decomposing activity and high CO oxidizing activity and to provide an excellent exhaust gas purifying method using this exhaust gas purifying catalyst. CONSTITUTION:A catalyst compsn. consists of a first component consisting of TiO2 and oxide of one or more kinds of elements selected from Mo, W and V, a second component obtained by preliminarily supporting Pt, Pd and Rh on a porous material such as silica, alumina or zeolite and a third component of sulfate of one or more kinds of elements selected from Al, Mn and Mg, and its characteristic comprises that the mixing wt. ratio of the second and first components is 20/80-0.5/99.5 and the content of the third component is 0-20wt.%. This exhaust gas purifying catalyst having NOx reducing function, unreacted NH3-decomposing function and CO oxidizing function in the presence of NH3 is composed of the above compsn. and adapted to the purification of exhaust gas. |
