Exhaust gas purifying device for diesel engine

An exhaust gas purifying device disposed in an exhaust passage of a diesel engine, wherein a nitrogen oxide reduction (DeNOx) catalyst part carrying a silver (Ag) component and a platinum (Pt) group catalyst component for reducing nitrogen oxides and a diesel particulate filter (DPF) part carrying a platinum (Pt) group catalyst component are provided sequentially from an upstream for a flow of the exhaust gas;

• a diesel fuel injector is mounted at a front of the nitrogen oxide reduction catalyst part;
• a pluralily of nitrogen oxide reduction catalyst parts are arranged adjacently in multi-layer;
• the nitrogen oxide reduction catalyst part has a support body made of heat-resisting ceramic or metal material and at least one carrier coated on the support body selected from alumina, silica, titania, ceria, zirconia or zeolite;
• and the nitrogen oxide reduction catalyst part carries 0.1 to 10 weight percent of silver (Ag) component and 0.0001 to 0.5 weight percent of platinum group catalyst component;
• and the diesel fuel injector is positioned upstream of the nitrogen oxide reduction (DeNOx) catalyst part to be able to supply a reducing agent to the nitrogen oxide reduction (DeNOx) catalyst part.