Alliedsignal Inc.

Asec Manufacturing General Partnership

Michael G Henk

Jack C Summers

John Gerard Nunan

Karl C Kharas

Heinz J Robota

Removal of carbon monoxide, hydrocarbons, and nitrogen oxides from the exhaust gas from lean-burn, diesel and other engines which produce exhaust gases containing oxygen in substantial excess of stoichiometric is provided by catalysts containing platinum alloyed with cobalt, nickel, copper, rhodium, palladium, silver or gold. Alloying is accomplished by thermal treatment or by colloidal methods. The catalysts are capable of reducing nitrogen oxides (NO.sub.x) within a predetermined range of engine operating temperatures.

Alloyed metal catalysts for the reduction of NO.sub.x in the exhaust

This invention relates to a catalytic composite for treating an exhaust gas comprising a first support which is a refractory inorganic oxide having dispersed thereon at least one noble metal component and having dispersed immediately thereon an overlayer comprising at least one oxygen storage component and optionally a second support which is a refractory inorganic oxide. The first 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, ruthernium 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. Cerium oxide is a preferred oxygen storage component. Finally, the second support may be selected from the group consisting of alumina, silica, titania, zirconia and aluminosilicates, with alumina preferred. This invention also relates to a process for minimizing the content of hydrogen sulfide in an automotive exhaust gas which comprises contacting said exhaust gas with a catalytic composite comprising a first support which is a refractory inorganic oxide having dispersed thereon at least one noble metal component and having dispersed immediately thereon an overlayer comprising at least one oxygen storage component and optionally a second support which is a refractory inorganic oxide.

Layered automotive catalytic composite

This invention relates to a catalytic composite for treating an exhaust gas comprising a first support which is refractory inorganic oxide having dispersed thereon at least one noble metal component and having dispersed immediately thereon an overlayer comprising at least one oxygen storage component and optionally a second support which is a refractory inorganic oxide. The first 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. Cerium oxide is a preferred oxygen storage component. Finally, the second support may be selected from the group consisting of alumina, silica, titania, zirconia and aluminosilicates, with alumina preferred. This invention also relates to a process for minimizing the content of hydrogen sulfide in an automotive exhaust gas which comprises contacting said exhaust gas with a catalyst composite comprising a first support which is a refractory inorganic oxide having dispersed thereon at least one noble metal component and having dispersed immediately thereon an overlayer comprising at least one oxygen storage component and optionally a second support which is refractory inorganic oxide.

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Tulsa, OK, United States of America

Michael G Henk