Patent ID: 6025296
Filing Date: 2000-02-15
Classification: B01D,B01J,Y02T,Y10S

Abstract:
A process for production of a catalyst applied to a structural support member for cleaning exhaust gas formed by an engine operated under a continuous lean mode, comprising:(1) supporting at least two catalytic metals as active components on a metal-containing silicate by a supporting treatment comprising:(a) mixing the metal containing silicate with an aqueous solution comprising one of said at least two catalytic metals and an alcohol dispersion comprising another of said at least two catalytic metals to form mixture and(b) then depositing said at least two catalytic metals by a deposition method consisting essentially of evaporating off water and alcohol as volatile components from said mixture to obtain a catalyst powder comprising said metal-containing silicate and said at least two catalytic metals supported thereon,(2) then activating said catalyst powder by an activation treatment comprising heating said catalyst powder to a temperature of 150-300.degree. C. for a period of time effective to drive off at least one material adsorbed in pores of said catalyst powder to make said catalyst powder catalytically active so as to provide said catalyst, said catalyst being capable of removing NOx from exhaust gas formed by the engine operated under the continuous lean mode; and(3) subsequently mixing said catalyst with a binder and water to form a slurry, and coating the slurry on said support member.