SYSTEM FOR AFTER-TREATMENT OF EXHAUST GAS FOR DIESEL ENGINE INCLUDING THE FILTER COATED WITH DENITRIFICATION CATALYST

The present invention provides an exhaust gas post-treatment system including a denitrification catalyst-coated filter. The exhaust gas post-treatment system including a diesel oxidation catalyst (DOC) and mounted on an exhaust pipe of a combustion engine to oxidize hydrocarbon (HC) or carbon monoxide (CO) included in exhaust gas or to oxidize a soluble organic fraction (SOF) included in a particulate matter, further comprises a selective catalyst reduction on diesel particulate filter (SCR on DPF) coated with a denitrification catalyst for purifying nitrogen oxide (NO_x) on a diesel particulate matter filter (DPF) for purifying exhaust gas by collecting the particulate matter, wherein the diesel particulate matter filter is coated with the denitrification catalyst in a slurry state having a particle size of 2-4 ㎛, a pH of 5-7, and a viscosity of 150-300 cp. Therefore, provided is an exhaust gas post-treatment system for a diesel engine including a denitrification catalyst-coated filter, wherein back pressure increase and total nitrogen oxide emission can be minimized. 본 발명은 내연기관의 배기관에 장착되어, 배기가스에 포함된 탄화수소(HC)나 일산화탄소(CO)를 산화시키거나 입자상 물질에 포함된 용해성유기성분(SOF; Soluble Organic Fraction)을 산화시키는 디젤산화촉매장치(DOC; Diesel Oxidation Catalyst)를 포함하는 배기가스 후처리 시스템에 있어서, 입자상물질을 포집하여 배기가스를 정화하는 미립자포집장치(DPF; Diesel Particulate matter Filter)에 질소 산화물(NOx)을 정화하기 위한 탈질촉매가 코팅된 SDPF(SCR on DPF; Selective Catalyst Reduction - on - Diesel Particulate Filter)를 더 포함하되, 상기 탈질촉매는 입도 2~4 ㎛, pH 5~7, 그리고 점도 150~300 cp의 슬러리(slurry) 상태로 상기 미립자포집장치에 코팅되는 것을 특징으로 하는 탈질촉매가 코팅된 필터를 포함한 배기가스 후처리 시스템을 제공한다.