| 摘要 |
PURPOSE:To eliminate efficiently nitrogen oxide from an exhaust combustion gas contg. at last the theoretical amt. of reaction of oxygen to unburnt part by a method wherein a specified decontaminating material for exhaust gas is used and a hydrocarbon is incorporated as a reducing agent and nitrogen oxide in the exhaust as is reduced at a specified temp. CONSTITUTION:In a decontaminating material for exhaust gas wherein the first catalyst is set on an exhaust gas inlet side and the second catalyst is set on the exhaust gas outlet side, the first catalyst carried 0.2-15wt.% (in terms of the element) silver or silver oxide as an active species on a porous inorg. oxide and the second catalyst carries more than 2wt.% and less than 5wt.% at least one of elements selected from the group of Pt, Pd, Ru, Rh and Ir as an active species on a porous inorg. oxide. In addition, silver or silver oxide has a mean diameter of 10-500nm and a hydrocarbon is incorporated as a reducing agent in the exhaust gas from the outside to reduce nitrogen oxide in the exhaust gas at 200-650 deg.C. |
