CATALYST FOR CLEANING EXHAUST GAS

摘要

PROBLEM TO BE SOLVED: To provide an NOX occlusion reduction type catalyst for cleaning an exhaust gas which has a still more enhanced durability. SOLUTION: The catalyst for cleaning exhaust gas is constituted of a core part 10 consisting of a first carrier and NOX occlusion material contained in the first carrier and of a catalyst-carrying layer 11 which consists of a second carrier and catalytic noble metal contained in the second carrier and is formed on the surface of the core part 10. A part of the NOX occlusion material is contained in the catalyst carrying layer 11. NOX cleaning activity in early stages is enhanced by the NOX occlusion material contained in the catalyst carrying layer 11 and the temperature window of NOX purification is spread. Further, SOX is inhibited from reaching the core part 10 by the catalyst carrying layer 11. Sintering of the catalytic noble metal is prevented because catalytic noble metal is separated from the NOX occlusion material.