Patent ID: 6221804
Filing Date: 2001-04-24
Classification: B01D,B01J

Abstract:
A method of manufacturing an exhaust gas purifying catalyst, which comprises the steps of:preparing a powdered first catalyst carrying Pt on a mixture of Al.sub.2 O.sub.3 and CeO.sub.2, but not containing Rh;preparing a powdered second catalyst carrying Rh on at least one metal oxide selected from a group consisting of oxides of Mn, Co, Ti, and Fe, but not containing Pt;preparing a powdered third catalyst carrying Pt and Rh on a zeolite,coating a mixture of said powdered first catalyst and said powdered second catalyst as a catalyst inner layer on a substrate;coating said powered third catalyst over said catalyst inner layer as a catalyst outer layer on said substrate; andimpregnating said catalyst inner and outer layers with a solution of NOx adsorbent comprising at least one of metals selected from a group consisting of alkaline metals, alkali earth metals, and rare earth metals, which is operative to adsorb NOx in an exhaust gas from an engine to carry said NOx adsorbent in said catalyst inner and outer layers.