CATALYST FOR TREATING EXHAUST GAS OF INTERNAL COMBUSTION ENGINE AND ITS PRODUCTION

摘要

PURPOSE: To obviate the degradation in the economical activity of catalyst by providing a portion of the length from one end of the catalyst with a first catalytically active phase and another portion of the length with a second catalytically active phase, thereby forming the exhaust gas treatment catalyst. CONSTITUTION: A monolithic support is adhered or impregnated with the catalytically active phases to form the catalyst for the treatment of internal combustion engine exhaust gases. The one portion of the length from the one end of the catalyst is provided with the first catalytically active phase and the another portion of the length is provided with the second catalytically active phase. The monolithic support preferably comprises a rigid monolithic base body having a conduit and a porous material layer on the surface of this base body. The first and/or second catalytically active phase is adequately formed of >=1 kind of the noble metals selected from platinum, palladium, rhodium and iridium.