| 摘要 |
An exhaust system for treating an exhaust gas from an internal combustion engine is disclosed. The system comprises a modified lean NOx trap (LNT), a urea injection system, and an ammonia-selective catalytic reduction (NH3-SCR) catalyst. The modified LNT comprises platinum, palladium, barium, and a ceria-containing material, and has a platinum:palladium molar ratio of at least 3:1. The modified LNT stores NOx at temperatures below about 200° C. and releases the stored NOx at temperatures above about 200° C. The urea injection system injects urea at temperatures above about 180° C. |
