| 摘要 |
Provided is a catalyst that is for internal combustion engine exhaust gas purification and that is formed on a monolithic support along the exhaust gas flow from the following regions, which serve as metal catalyst active components: (a) a first catalyst component region formed by supporting, at the upstream end, 3-30mm length of a catalyst component layer containing a concentration of 0.1-3.0g/L of Rh; (b) a second catalyst component region formed by providing, at the downstream end, 10-100mm length of a catalyst component layer containing a concentration of 1.0-20.0g/L of Pd; and, if required, (c) a third catalyst component region provided at a length of 25-150mm and having, as the main components, a concentration of 0.05-1.0g/L of rhodium and a concentration of 30-150g/L of an oxygen storage material. Further provided is an internal combustion engine exhaust gas purification system formed using said catalyst. The catalyst and system restrict the generation and discharge of N2O during the purification of exhaust gas, and enable the purification of NOx and HC from cold starts and with a small amount of noble metal. |
