EXHAUST GAS PURIFICATION APPARATUS OF HEAT ENGINE AND EXHAUST GAS PURIFICATION METHOD

摘要

PROBLEM TO BE SOLVED: To purify to a high degree an NOx component in exhaust gas, even when a temperature of the exhaust gas in an oxygen excessive atmosphere discharged from a heat engine is fluctuated, in an exhaust gas purification apparatus of the heat engine utilizing an NOx purification catalyst containing a zeolite component.SOLUTION: In an exhaust gas purification apparatus of a heat engine including an exhaust gas passage for discharging exhaust gas in a more excessive oxygen atmosphere than a stoichiometric amount in an oxidation reaction of CO and HC, an NOx purification catalyst arranged in the exhaust gas passage and containing a zeolite component, for purifying NOx in the exhaust gas is provided, and a COamount in the exhaust gas is reduced before the exhaust gas flows into the NOx purification catalyst.