Exhaust Gas Filter with Localized Catalyst for HC Purification

The patent applies local quality by creating non-uniform catalyst distribution within the partition pores. The catalyst layer is concentrated in specific regions (such as near the pore openings or at specific depth ranges) rather than being uniformly distributed throughout the entire partition thickness. This localized catalyst placement ensures effective HC removal at critical interfaces while minimizing the total catalyst quantity and reducing pressure loss compared to uniform thick coating.

The patent utilizes the porous structure of the partition walls to support the catalyst layer. The pores provide a high surface area framework that allows efficient catalyst utilization. By forming the catalyst layer on or within the porous partition structure, the patent achieves high purifying performance with reduced catalyst loading, thereby minimizing pressure loss while maintaining effective HC removal.

The patent implements local quality by concentrating the catalyst in specific zones within the partition structure rather than uniform distribution. This strategic localization ensures that the catalyst is positioned where it is most effective for HC removal (such as near gas-catalyst interface regions), maximizing purifying performance per unit of catalyst while minimizing total catalyst quantity required.

The porous partition structure serves as a high-surface-area support that enables efficient catalyst utilization. The pore network provides extensive contact area between the exhaust gas and catalyst with minimal catalyst material, achieving high HC removal efficiency while reducing the quantity of expensive catalyst substance required.