Patent ID: 7820123

Claim:
A method for the catalytic purification of exhaust gases from an internal combustion engine, which comprises: (a) conducting exhaust gases from an internal combustion engine first into contact with a catalyst A comprising a honeycomb carrier and a three-way catalyst formed thereon; (b) next causing all of the exhaust gases contacted with catalyst A to flow out of the catalyst A; (c) next causing all of the exhaust gases flowing out of the catalyst A to flow directly into an adsorption catalyst B only a single time in a single pass system, at all time during operation of the catalyst A and the catalyst B during the method, wherein the catalyst B comprises: a honeycomb carrier; an adsorption layer formed thereon for the effective adsorption of hydrocarbons; and a catalyst layer consisting essentially of a noble metal selected from the group consisting of platinum, palladium and rhodium and at least one of ceria and alumina, wherein the catalyst layer is a separate layer applied to the adsorption layer and coats the adsorption layer, and wherein the adsorption catalyst B is located downstream of the catalyst A in the direction of the exhaust gas directly; and (d) during the method, heating the catalyst B by a heat source for supplying heat to the adsorption catalyst B from outside of the adsorption catalyst B, the heat source consisting essentially of engine combustion heat carried by the exhaust gases and heat generated by reactions occurring at the catalyst A.