초록 ▼

A system for reducing NOx gases found in the exhaust stream of the internal combustion engine is provided which includes an internal combustion engine having associated therewith a means for supplying fuel and oxygen to the engine, a manifold system for directing or channeling the exhaust gases from

A system for reducing NOx gases found in the exhaust stream of the internal combustion engine is provided which includes an internal combustion engine having associated therewith a means for supplying fuel and oxygen to the engine, a manifold system for directing or channeling the exhaust gases from the engine, and an NOx reducing catalyst assembly communicating with the manifold which includes a housing having an NOx reducing catalytic structure of apertured thin metal foil positioned therein which comprises a durable, chromium containing corrosion resistant metal substrate having bonded thereto an effective amount of a NOx reducing catalyst selected from the group consisting of iron, nickel, cobalt, copper, manganese and mixtures thereof. In addition, an article composed of a catalytic material for reducing the oxides of nitrogen in exhaust gases from an internal combustion engine is also provided. The article includes a self-supporting catalytic structure in the form of an apertured, thin metal foil having a ratio of low mass to high surface area. In its preferred form, the foil is an expanded metal foil, and the article is formed by tightly winding the foil into a plural layer helical coil. The catalytic structure is produced by a method which comprises providing a thin sheet of metal foil, expanding the sheet of metal foil to thereby form a plurality of strands defining openings therebetween, depositing a metal on at least a part of the surface of the expanded metal foil which when alloyed with the metal foil increases its resistance to corrosion, alloying the deposited metal with the metal foil, and coating at least a part of the surface of the expanded metal foil with an adherent layer of a catalyst material which is capable of catalytically reducing the oxides of nitrogen (NOx) found in the exhaust gases emanating from an internal combustion engine.

대표청구항 ▼

A catalytic structure capable of reducing the concentration of undesirable gases in the exhaust gases of an internal combustion engine by chemically reducing oxides of nitrogen, said structure having high NOx reducing activity and comprising a thin, expanded metal foil structure having a plurality o

A catalytic structure capable of reducing the concentration of undesirable gases in the exhaust gases of an internal combustion engine by chemically reducing oxides of nitrogen, said structure having high NOx reducing activity and comprising a thin, expanded metal foil structure having a plurality of strands defining openings therebetween said structure consisting essentially of a metallic reinforcing member and a metallic catalytic surface layer metallurgically bonded thereto, said layer comprising an NOx reducing catalyst comprising a mixture of nickel and copper, said metallic reinforcing member comprising: i. from about 50 to 85 weight percent of a first metal selected from the group consisting of nickel, mixtures of nickel and cobalt, mixtures of nickel and iron, and mixtures of nickel, iron and cobalt, said iron and cobalt individually not exceeding about 1 weight percent of said member and said nickel being present in said mixtures in an amount of at least about 48 weight percent of said member, and ii. from about 15 to about 50 weight percent of a second metal selected from the group consisting of chromium and mixtures of chromium and aluminum, said aluminum not exceeding about 10 weight percent of said member and said chromium being present in said mixtures in an amount of at least about 5 weight percent of said member.