CATALYST FOR THE PURIFICATION OF ESCAPE GASES WITH AN IMPROVED CONVERSION FOR HYDROCARBONS.

摘要

The invention is related to a catalyst for the purification of escape gases with an improved conversion for hydrocarbons containing metal active catalysts as components from the platinum group and that presents two superposed function layers applied on a carrier body. The catalyst is characterized in that the first function layer contains a mixture of a first catalyst with at least a zeolite and the second function layer applied on the first function layer contains a mixture of a second catalyst with at least a zeolite, where the zeolites present a molar relation betwen the aluminum silicone/oxide dioxide of more than 40 and because as metals of the platinum group are present at lease paladium and radium which separated between them are contained in only one of the two catalysts. The catalyst is characterized in that it presents a very good suppression of the hydrocarbon emissions during the starting up cold and because it is especially stable during the storage.