Patent ID: 10150082

Abstract:
A catalyst and system for an internal combustion engine exhaust gas purification includes a first catalyst component region (a) having a catalyst component layer containing Rh at a concentration of 0.1 to 3.0 g/L at a length of 3 to 30 mm on an upstream side, a second catalyst component region (b) having a catalyst component layer containing Pd at a concentration of 1.0 to 20.0 g/L at a length of 10 to 100 mm on a downstream side, and a third catalyst region (c) containing rhodium at a concentration of 0.05 to 1.0 g/L and an oxygen storage material at a concentration of 30 to 150 g/L at a length of 25 to 150 mm on a monolithic support. The catalyst suppresses the formation and discharge of N2O from the exhaust gas with a small amount of a noble metal from the time of cold starting.