| abstract |
An exhaust purification device for an internal combustion engine capable of efficiently purifying NOx in a wide temperature range from a low temperature region to a high temperature region near room temperature. In an exhaust purification device 2 of an engine 1 that is provided in an exhaust system of the engine 1 and purifies NOx in the exhaust of the engine 1, it is carried on a carrier and provided in an exhaust pipe 5 of the engine 1, It includes a NOx purifying catalyst 3 for reducing the trapped NOx with capturing the NOx and NH 3 as a reducing agent, a NH 3 supply unit 4 for supplying NH 3 to the upstream side of the NOx purifying catalyst 3, a, NOx purifying catalyst 3 Includes a first catalyst layer that captures NOx when the air-fuel ratio of the exhaust gas is lean, and a second catalyst layer that retains NH 3 supplied by the NH 3 supply unit 4 and reduces NOx using NH 3 as a reducing agent. And comprising. [Selection] Figure 1 |