Selective Reduction of NOx over Ir/Metallosilicate Catalyst for a Lean Burn Gasoline Engine

摘要

Recently, some catalysts capable of reducing NOx with hydrocarbons contained in the exhaust gases of lean burn gasoline engines have been proposed. However, these catalysts suffer deterioration problems due to heat, water vapor and sulfur dioxide in the exhaust gas. We have made various efforts to overcome the disadvantages of prior art catalysts and have found that indium catalysts supported on MFI-type metal-losilicate with activation treatment have had high NOx reduction activity and have deteriorated very little even in an atmosphere of high temperatures. In this study, we report on catalytic performance and durability of NOx reduction activity for a lean burn gasoline engine exhaust gas.