Patent ID: 7732368

Claim:
An exhaust system for an internal combustion engine, comprising: an exhaust gas conduit in communication with said engine, said exhaust gas conduit for passing a stream of exhaust gases from said engine; and a catalyst system in communication with said exhaust gas conduit, said catalyst system comprising: a substrate; a binder layer formed on the substrate; and a plurality of particulate catalyst structures affixed to a surface of said binder layer wherein: the binder layer is interposed between the substrate and the particulate catalyst structures; said plurality of particulate catalyst structures protrude from said surface of said binder layer such that at least about 70% of the surface area of said plurality of particulate catalyst structures is directly exposed to said stream of exhaust gases when said stream of exhaust gases passes over said catalyst system; said particulate catalyst structures have diameters of from about 5μ to 100μ and said particulate catalyst structures are arranged as a substantially uniform layer with adjacent particulate catalyst structures spaced apart from each other on said binder layer; said binder layer comprises a ceramic coating bound to said substrate, said binder layer having a thickness in the range of from about 0.5 to 10 microns; said binder layer being impervious to the exhaust gases so that the substrate is not in contact with the exhaust gases; and said particulate catalyst structures form a catalytic layer that does not contain components other than said particulate catalyst structures.