PURIFYING MATERIAL AND METHOD; FOR EXHAUST GAS

摘要

PURPOSE:To provide the purifying material for exhaust gas and a purifying method therefor wherein nitrogen oxide is efficiently removed in a wide temperature range from combustion exhaust gas containing excess oxygen. CONSTITUTION:A first catalytic layer is formed on the base body of exhaust gas purifying material in the inflow side of exhaust gas. A second catalyst layer is formed on the outflow side of exhaust gas. The first and second catalytic layers are constituted of the purifying material for exhaust gas having different compositions. Exhaust gas mixed with hydrocarbon is brought into contact with the purifying material at 300-600 deg.C in the upstream side thereof. Thereby nitrogen oxide is removed by reaction with hydrocarbon.