CATALYST FOR CLEANING AUTOMOBILE EXHAUST GASES RESISTANT TO POISONING, AND METHOD FOR CLEANING AUTOMOBILE EXHAUST GASES

摘要

1. The catalyst for cleaning automotive exhaust gases, including:! (a) a substrate coated with at least two coating layers containing one or more precious metal components; and! (b) an outer layer comprising a porous refractory oxide and one or more base metal oxides selected from the group consisting of barium oxide and strontium oxide, wherein said outer layer does not contain precious metals; ! and also:! i) the specified at least two layers of precious metals in the coating layer are adjacent to each other and covered by the specified outer layer or! ii) said outer layer is sandwiched between a pair of precious metal-containing coating layers comprising a lower coating layer and an upper coating layer, and in which said outer layer is coated on said lower coating layer. ! 2. The catalyst for purifying automobile exhaust gases according to claim 1, wherein said at least two precious metal-containing coating layers are adjacent to each other and said outer layer is deposited on the ascending portion of said catalyst from the ascending edge of said catalyst, thereby creating a zone capture poisons, and in which the specified zone capture poisons includes a length within 10-60% of the length of the specified catalyst from the specified ascending edge. ! 3. The catalyst for cleaning automobile exhaust gases according to claim 1, in which said at least two precious metal-containing coating layers are adjacent to each other and said outer layer is deposited on the ascending portion of said catalyst