EXHAUST PURIFICAION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

An exhaust purification system of an internal combustion engine is provided with an exhaust purification catalyst which includes an upstream side catalyst and a downstream side catalyst and removes NO X . The upstream side catalyst has an oxidation ability, while the downstream side catalyst has catalyst particles of precious metals and basic exhaust flow surface parts. The system makes the concentration of hydrocarbons which flow into the exhaust purification catalyst vibrate by within a predetermined range of amplitude and by within a predetermined range of period and reduces the NO X . The upstream side catalyst includes an upstream side substrate and an upstream side container, while the downstream side catalyst includes a downstream side substrate, a downstream side container, and a channel of exhaust between the downstream side substrate and the downstream side container. The exhaust is divided toward a plurality of directions at the inside of the downstream side container, runs through the channel between the downstream side substrate and the downstream side container, then merges.