AMMONIA OXIDATION CATALYST EXHAUST GAS PURIFICATION DEVICE USING SAME AND EXHAUST GAS PURIFICATION METHOD

摘要

2Provided are: an ammonia oxidation catalyst having excellent heat resistance and capable of suppressing NO by production and ammonia leakage despite a low precious metal content when purifying nitrogen oxide discharged from a boiler etc. by spraying urea water or the like on a selective reduction catalyst; an exhaust gas purification device using same; and an exhaust gas purification method. The present invention is provided by using the ammonia oxidation catalyst (AMOX) or the like for removing by oxidation surplus ammonia when adding urea or ammonia to an exhaust gas and using a selective reduction catalyst (SCR) to selectively reduce the nitrogen oxide the ammonia oxidation catalyst comprising at least two catalyst layers covering the surface of an integrally structured carrier said catalyst layers having a catalyst layer (lower layer) including a catalyst carrying a precious metal element in a complex oxide (A) having titania and silica as the main components thereof and a catalyst layer (upper layer) including a complex oxide (C) comprising tungsten oxide ceria and zirconia. The composition of the complex oxide (C) is 1 50 wt% tungsten oxide 1 60 wt% ceria and 30 90 wt% zirconia.