Method and apparatus of purifying exhaust gas from internal combustion engine

摘要

A catalyst body having carried in a carrier a three way conversion catalyst is disposed inside an exhaust pipe near an exit to the atmosphere. An internal combustion engine is operated in a rich range of air/fuel ratio. Reducing reaction of the exhaust gas takes place in a front portion of the catalyst body. Oxidizing reaction takes place in a rear portion of the catalyst body by intermittently introducing atmospheric air into the catalyst body through pulsations of the exhaust gas.