| abstract |
A optimizes the pores of the support itself, and NO x storage-and-reduction type catalyst and high the NO x purification performance and resistance to sulfur poisoning has both. SOLUTION: It consists of an aggregate of secondary particles in which a plurality of types of oxide particles are mixed at the nano level, and has macropores having a pore diameter of 1 to 20 μm. By including ZrO 2 —TiO 2 or the like, high sulfur poisoning resistance is exhibited. The macropores are excellent in gas diffusibility, and the exhaust gas can reach the inside of the catalyst even in a short rich spike, so that high NO x purification ability is expressed. [Selection] Figure 2 |