Method for operation of combined cycle power plant using denitrification catalyst

The present invention relates to an operation method for a combined cycle power plant using a denitrification catalyst. The operation method for a combined cycle power plant using a denitrification catalyst comprises the steps of: performing a denitrification process by contacting an exhaust gas generated during combined cycle power generation with a denitrification catalyst; and performing a CO oxidation process by contacting the denitrified exhaust gas with a CO oxidation catalyst. The exhaust gas is NO_2/NO_x >= 0.5 or more and the denitrification catalyst contains vanadium/tungsten/titania and manganese, wherein the manganese contains both α-Mn_2O_3 and Mn_3O_4 structures, thereby reducing the formation of ammonium nitrate (NH_4NO_3) and the generation of nitrous oxide (N_2O). According to the present invention, it is possible to provide an operation method for a new combined cycle power plant using a denitrification catalyst for a thermoelectric power plant, which does not deteriorate denitrification efficiency by repressing the formation of ammonium nitrate (NH_4NO_3) and the generation of nitrous oxide (N_2O). 탈질촉매를 이용한 복합화력발전 운전방법으로, 복합화력 발전시 발생하는 배가스를 탈질촉매에 접촉시켜 탈질공정을 진행하는 단계; 및 상기 탈질된 배가스를 CO 산화 촉매에 접촉시켜 CO 산화공정을 진행하는 단계를 포함하는 것을 특징으로 하는 탈질촉매를 이용한 복합화력발전 운전방법이며, 상기 배가스는 NO2/NOx≥0.5 이상이며, 상기 탈질촉매는 바나듐/텅스텐/티타니아 및 망간을 포함하며, 상기 망간은 α-Mn2O3 및 Mn3O4 구조를 모두 포함하며, 이로써 질산암모늄(NH4NO3)의 형성 및 아산화질소(N2O) 발생이 억제되는 것을 특징으로 하는 탈질촉매를 이용한 복합화력발전 운전방법이 제공된다.