EXHAUST GAS TREATMENT APPARATUS FOR SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDE UNDER LEAN EXHAUST GAS CONDITION, AND METHOD FOR REMOVING NITROGEN OXIDE FROM LEAN EXHAUST GAS OF INTERNAL-COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust gas treatment apparatus which includes at least one catalyst having a catalytically active component for selective catalytic reduction (SCR component) and is used for subjecting nitrogen oxides to selective catalytic reduction under the lean exhaust gas condition. SOLUTION: The catalyst to be used in this exhaust gas treatment apparatus contains at least one storage component for storing nitrogen oxides (NOX component) in addition to the SCR component.