Catalyst for purifing exhaust gases
Patent 4921829 Issued on May 1, 1990. Estimated Expiration Date: 
December 21, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 21, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3905918 Catalyst Catalytic perovskites on perovskite supports and process for preparing them Patent #: 4151123 InventorsAssigneeApplicationNo. 287019 filed on 12/21/1988US Classes:502/302, Of lanthanide series (i.e., atomic number 57 to 71 inclusive)423/213.5, Group VIII element502/303, Lanthanum502/304, Cerium502/525PEROVSKITEExaminersPrimary: Shine, W. J.Attorney, Agent or FirmForeign Patent References
International ClassesB01J 021/06B01J 023/10 B01J 023/58 Foreign Application Priority Data1987-12-22 JPAbstractA catalyst for purifying exhaust gases comprises: a perovskite-type complex oxide represented by the general formula Ln1-x Ax MO3, wherein Ln represents at least one rare earth metal, A presents at least one alkaline earth metal and M represents at least one transition metal, and 0<x<1; at least one heat resistant complex oxide; and at least one precious metal. The heat resistant complex oxide is one of ABO3, LnAlO3 or Ln2 B2 O7, wherein A represents at least one alkaline earth metal, B represents at least one of Ti, Zr and Hf, and Ln represents at least one rare earth metal, and the precious metal is at least one of Pt, Pd, Rh, Ir, Ru and Os. The catalyst is usable as a temperature of 900° C. or above without sintering or reduction of a catalytic activity. |
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