NOx decomposition catalyst and exhaust gas purifier using said catalyst

摘要

The present invention provides an NOx decomposition catalyst which can decompose NOx in exhaust gas to decrease the amount of NOx in exhaust gas and is improved in durability through suppression of thermal decomposition thereof, and an exhaust gas purifier wherein said catalyst is used. This NOx decomposition catalyst is a compound having a brownmillerite type structure represented by the general formula: A3-XBXC4-YDYOZ, the carbon content of which compound may be at most 1.25 wt. %. This NOx decomposition catalyst can be used in an exhaust gas purifier applicable to an internal combustion engine.