| 摘要 |
PROBLEM TO BE SOLVED: To suppress the degradation in durability by the grain growth of Pt, to prevent the degradation in the NOx occluding and releasing capability of a NOx occluding material and to improve durability by allowing first power deposited with Rh on porous particles and second powder deposited with Pt and the NOx occluding material on the porous particles to coexist. SOLUTION: The catalyst for purification of exhaust gases which purifies the exhaust gases discharged from an automobile, etc., is produced by allowing the first power deposited with the Rh on the porous particles and the second powder deposited with the Pt and the NOx occluding material on the porous particles to coexist. At the time of purification of the exhaust gases, the catalyst is arranged in the exhaust gases to occlude NOx in the NOx occluding material in an oxygen excessive lean atmosphere. This atmosphere is temporarily changed from the stoichiometric to rich atmosphere, by which the NOx released from the NOx occluding material is reduced and the gases are purified. The grain sizes of the porous particles are preferably in the range of 1 to 100μm for both of the first and second powders. The amt. of the Rh deposited on the first powder is preferably in a range of 0.1 to 10g per 120g porous particles. |
