Patent ID: 7560079

Claim:
An exhaust gas-purifying apparatus, comprising: an NO x sorbing-and-reducing first catalyst disposed on a downstream side of an exhaust manifold of an engine, said exhaust manifold carrying exhaust gases away from the engine, said first catalyst, comprising a straight-flow structure support substrate having cells and cellular walls demarcating the cells, and a catalytic layer formed on a surface of the cellular walls, and including a catalytic ingredient and an NO x sorbing member loaded thereon; a second catalyst disposed on an upstream side of the exhaust gases with respect to the first catalyst, comprising a wall-flow structure honeycomb substrate having inlet cells clogged on a downstream side of the flow of the exhaust gases, outlet cells neighboring the inlet cells, and clogged on an upstream side of the flow of the exhaust gases, and porous cellular walls demarcating the inlet cells and the outlet cells and having pores, and a catalytic layer formed on a surface of the cellular walls and an inner surface of the pores of the second catalyst, and including an oxide support and a catalytic ingredient loaded on the oxide support; an NO x sorbing-and-reducing third catalyst disposed on an upstream side of the exhaust gases with respect to the second catalyst, comprising a straight-flow structure support substrate having cells and cellular walls demarcating the cells, and a catalytic layer formed on a surface of the cellular walls and including a catalytic ingredient and an NO x sorbing member loaded thereon; and a fuel injector intermittently supplying a liquid reducing agent directly into said third catalyst; wherein the second catalyst further comprises an NOx sorbing member loaded on the catalytic layer; and wherein the first catalyst exhibits a loading density of the catalytic ingredient higher than that of the third catalyst.