EXHAUST GAS PURIFICATION CATALYST

PROBLEM TO BE SOLVED: To provide an exhaust gas purification catalyst having improved NOpurification ability, capable of generating actively a catalytic reaction even in an exhaust gas downstream part of a catalyst layer.SOLUTION: An exhaust gas purification catalyst in which a catalyst layer containing at least one kind of Pd and Pt is formed on a substrate 1 includes an OSC material which is an inorganic material having oxygen storage ability and having a pyrochlore type structure, and an OSC material having higher oxygen storage speed than the OSC material having the pyrochlore type structure, on a catalytic layer front stage 21 within the range of a length of 50% or less of the full length of the catalytic layer from the exhaust gas upstream side end 2a of the catalytic layer 2. 【課題】触媒層の排ガス下流部においても触媒反応を活発に起こす、NOx浄化能が向上した排ガス浄化触媒を提供する。【解決手段】Pd及びPtの少なくとも１種を含む触媒層が基材１上に形成された排ガス浄化触媒であって、触媒層２の排ガス上流側端部２ａから触媒層の全長の50%以下の長さの範囲内である触媒層前段２１に、パイロクロア型構造を有する酸素吸蔵能を有する無機材料であるOSC材及びパイロクロア型構造を有するOSC材よりも酸素吸蔵速度が速いOSC材を含む、排ガス浄化触媒。【選択図】図１