发明授权
US5234881A Binary LA-PA oxide catalyst and method of making the catalyst 失效
二元LA-PA氧化物催化剂及其制备方法

Binary LA-PA oxide catalyst and method of making the catalyst
摘要:
A catalyst having high temperature (800.degree.-1050.degree. C.) stability and improved three-way automotive exhaust gas catalyst activity at high temperatures, comprising an outer catalytic coating of binary La-Pd oxide (La.sub.2 Pd.sub.2 O.sub.5 or La.sub.4 PdO.sub.7) calcined and supported on a catalyst-supporting substrate, the oxide being present in an amount to provide 15-150 g of Pd per cubic foot of the substrateA method of making binary La-Pd oxides useful as an automotive exhaust catalyst operative at high temperatures, comprising heating in an oxidizing atmosphere a mixture containing La compounds and Pd compounds in a La:Pd ratio of 1:1 or 4:1, the heating being staged to first heat slowly from about 50.degree. C. to start decomposition of the compounds and thereafter retaining the residue at an elevated temperature to stimulate growth of crystalline binary La-Pd oxides and to calcine the crystalline oxides.A method of making an automotive catalyst by suspending binary La-Pd oxides in a sol (preferably alumina sol) and depositing and fixing such sol suspension on a substrate coated with conventional washcoats.
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