| 摘要 |
PURPOSE:To obtain a catalyst for removing nitrogen oxides with high rate of removal by constituting the catalyst of a carrier comprising an acid type mordenite having a compsn. expressed by the specified formula, and depositing a metal oxide having <=80 enthalpy of formation (kcal/gram atom oxygen) as active component. CONSTITUTION:A base material comprising ceramic fiber is dipped in a slurry contg. acid type mordenite expressed by the composition formula (Hx- z).(Naz).[(AlO2)x.(SiO2)y].mH2O (wherein z/x is a molar ratio <=0.4, y/x is a molar ratio >=5), then the dipped product is dried after removing excess slurry, and the dried product is then calcined to prepare a carrier comprising the acid type mordenite. An active component comprising metal oxide having <=80 enthalpy of formation (kcal/gram atom oxygen) (i.e., V2O5, In2O3, Fe2O3, NiO, RuO2 and CuO) is impregnated into the carrier, and the product is dried and calcined. By producing a catalyst for removing nitrogen oxides by this method, high rate of removal of NOx is realized even if the temp. of exhaust gas is high. |
