CLOSE COUPLED CATALYST FOR PURIFICATION OF EXHAUST GAS AND THE PREPARATION THEREOF

摘要

A close coupled three-way catalyst for purification of exhaust gas and the preparation thereof. The support is selected from the cordierite honeycomb ceramic materials having a pore volume of 0.25-0.35ml/g. The coating layer is the mixture of hexaaluminates and perovskite type composite oxides, ceria-zirconia solid solutions, rare-earth oxides and alumina, alkali-earth metals and zeolites having a high Si/Al ratio. The active components are palladium-rhodium, rare-earth oxides and transition metals in the hexaaluminates and perovskite type composite oxides. The catalyst has not only the function of low-temperature catalytic oxidation of hydrocarbons, but also the function of reduction of nitrogen oxides, and can be used for purifying the exhaust gas of motor vehicles using gasoline, liquid gas, or CNG as fuel.