NOx SELECTIVE REDUCTION CATALYST AND NOx PURIFICATION METHOD USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a NOx selective reduction catalyst having sufficient high NOx purification activity under a high temperature condition at 400°C or more and sufficient high NOx purification activity even in a transient condition.SOLUTION: There is provided a NOx selective reduction catalyst used when reducing nitrogen oxide (NOx) by a reductant and containing a first zeolite having a CHA crystal structure carrying at least one of Cu and Fe and a second zeolite having a MOR crystal structure.