초록 ▼

This invention relates to an improved catalytic composite for treating an exhaust gas comprising a first support which is a refractory inorganic oxide, having dispersed thereon at least one oxygen storage component and at least one noble metal component and having dispersed immediately thereon an ov

This invention relates to an improved catalytic composite for treating an exhaust gas comprising a first support which is a refractory inorganic oxide, having dispersed thereon at least one oxygen storage component and at least one noble metal component and having dispersed immediately thereon an overlayer comprising lanthanum oxide and optionally a second support which is a refractory inorganic oxide. The first and second support may be selected from the group consisting of alumina, silica, titania, zirconia and aluminosilicates with alumina being preferred. Additionally, the noble metal component may be selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium. The oxygen storage component is an oxide of a metal which includes cerium, iron, nickel, cobalt lanthanum, neodymium, praesodymium, etc. and mixtures thereof. This invention also relates to a process for treating automotive exhaust comprising contacting the exhaust with the catalytic composite described above. The catalytic composite shows improved activity, especially for eliminating NOx, after extensive durability testing and also minimizes the formation of H2S.

대표청구항 ▼

A catalytic composite for treating an exhaust gas, said catalytic composite a first support having dispersed thereon an oxygen storage component and at least one noble metal component selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium and having dispersed immed

A catalytic composite for treating an exhaust gas, said catalytic composite a first support having dispersed thereon an oxygen storage component and at least one noble metal component selected from the group consisting of platinum, palladium, rhodium, ruthenium and iridium and having dispersed immediately thereon an overlayer comprising lanthanum oxide and optionally a second support, said first and second support both being a refractory inorganic oxide selected from the group consisting of alumina, silica, titania, zirconia, aluminosilicates and mixtures thereof. The catalytic composite of claim 1 where said oxygen storage component is an oxide of a metal selected from the group consisting of iron, nickel, cobalt, the rare earths and mixtures thereof. The catalytic composite of claim 1 where said second support is selected from the group consisting of alumina, silica, titania, zirconia, and aluminosilicates.