Patent ID: 9732648
Date: 2017-08-15
CPC Classifications: B01D,B01J,F01N

Claim:
1. An exhaust gas purification catalytic device which is disposed in an exhaust gas passage of an engine comprising: a plurality of catalytic layers to purify an exhaust gas discharged from the engine, wherein Pt is contained as a catalytic metal, the catalytic metal Pt is loaded on silica-alumina which serves as a support and in which alumina is modified by silicon, the plurality of catalytic layers form a stack, Pt-loaded silica-alumina obtained by loading the Pt on the silica-alumina is contained in an uppermost one of the plurality of catalytic layers with which the exhaust gas contacts first, the Pt-loaded silica-alumina is also contained in at least one catalytic layer of the stack of catalytic layers other than the uppermost catalytic layer, and the uppermost catalytic layer is higher in content of the Pt-loaded silica-alumina than the at least one catalytic layer other than the uppermost catalytic layer.