| 摘要 |
PROBLEM TO BE SOLVED: To provide a honeycomb catalyst having sufficiently high NOx removal performance in a wide temperature range from low temperature to high temperature or when the NOratio in exhaust gas becomes high by the usage state or time of an internal combustion engine.SOLUTION: There is provided a honeycomb catalyst which has a TiO/VO/WOcomponent composed of a titanium oxide, a vanadium oxide and a tungsten oxide and a CHA structure and comprises two types of catalyst components of zeolite carrying copper, wherein the average particle diameter of primary particles of the zeolite is 0.1 to 1.0 μm and the average particle diameter of secondary particles of the titanium oxide is 0.5 to 1.5 μm, which is larger than the average particle diameter of primary particles of the zeolite.SELECTED DRAWING: Figure 2 |
