Patent ID: 6087295
Filing Date: 2000-07-11
Classification: B01D,B01J,C40B,Y02T

Abstract:
A multi-component catalyst for removing carbon monoxide, hydrocarbons, and nitrogen oxides contained in exhaust gases from a lean-burn internal combustion engine, said engine operating with an air-fuel ratio above about 18, comprising:(a) a first catalytic component comprising a catalyst selected from the group consisting of:(i) alumina having dispersed thereon a catalytically effective amount of a material selected from the group consisting of Pt/Au alloys and mixtures, oxidized Cu, oxidized Ag, Ga.sub.2 O.sub.3, In.sub.2 O.sub.3, and dispersed SnO.sub.2 ;(ii) zeolite having dispersed thereon a catalytically effective amount of Cu and Ag; and,(iii) .gamma.-alumina having dispersed thereon a catalytically effective amount of CoO;(b) a second catalytic component comprising a catalyst selected from the group consisting of alumina having dispersed thereon a catalytically effective amount of Pt/Ag alloys and/or mixtures and molecular sieves having dispersed thereon a catalytically effective amount of Rh; and(c) a third catalytic component comprising a catalytically effective amount of Pt dispersed on a support selected from the group consisting of .alpha.-alumina and Y-zeolite.