| abstract |
The invention relates to the technical field of automobile exhaust gas purification, in particular to a localized coating of an automobile exhaust gas purification catalyst and a preparation method thereof. This coating is applied to the inner wall of the cell channel of the honeycomb ceramic carrier set at the outlet end of the automobile engine. The honeycomb ceramic carrier includes a front half area and a back half area with a height wall of 1:(1-4), and the coating of the front half area The inner coating layer, the middle coating layer and the outer coating layer are included in sequence, and the coating layer in the second half zone includes the inner coating layer and the outer coating layer in sequence; the components of the inner coating layer, the middle coating layer and the outer coating layer all include Rare earth composite oxides, modified alumina, additives and precious metals. By partitioning the carrier and coating different areas with coatings of different components, different thicknesses and different noble metal contents, the invention can reduce the amount of noble metals on the entire honeycomb ceramic carrier on the premise of ensuring the conversion efficiency of exhaust gas, thereby reducing the The cost of automobile exhaust purification catalysts. |