| abstract |
This honeycomb catalyst is provided with a honeycomb unit in which a plurality of through holes are arranged in parallel in a longitudinal direction with being separated by partition walls, wherein the honeycomb unit contains a zeolite and an inorganic binder, the zeolite satisfies all of conditions (A) to (D): (A) having a CHA structure in which the composition ratio of SIO 2 /Al 2 O 3 is less than 15; (B) having Cu being carried by 3.5 to 6.0 mass% with respect to zeolite; (C) having an average particle diameter of 0.05 to 1 µm; and (D) being contained by 150 to 350 g/L with respect to the whole of the honeycomb unit, and excellent NOx purifying performance, reduction of water absorption and displacement, and inhibition of crack occurrence can be exerted. |