EXHAUST GAS CLEANING SYSTEM AND EXHAUST GAS CLEANING CATALYST

摘要

PROBLEM TO BE SOLVED: To provide a exhaust gas cleaning system capable of cleaning NOx, HC and CO in an excess oxygen-containing exhaust gas even under a high temperature condition of >=250 deg.C and excellent in fuel consumption saving performance. SOLUTION: The cleaning system of the excess oxygen-containing exhaust gas is formed by arranging a NOx cleaning catalyst for cleaning NOx using at least hydrogen as a reducing agent in an exhaust gas passage of an internal engine or a combustion device, platinum and cesium are carried on the porous carried of the NOx cleaning catalyst and cleans NOx in the exhaust gas by supplying the exhaust gas containing hydrogen to the NOx cleaning catalyst and bringing them into contact with each other under a condition that the temperature of the NOx cleaning catalyst and/or the hydrogen enriched exhaust gas is 250-600 deg.C.