Three-way catalyst for treating exhaust gases
AssigneeARD Co., Pte. Ltd.
InventorsAndriy M. Bolshakov, Seow Boon Quek
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Abstract
A three-way conversion catalyst useful for the treatment of exhaust gas streams to accomplish the catalytic oxidation of carbon monoxide and hydrocarbons and the catalytic reduction of the oxides of nitrogen has a catalyst carrier such as cordierite coated with an oxygen reservoir layer, and a second layer of finely divided nickel needles obtained by reduction of Ni.sup.2+ in an autoclave and a platinum group metal.
Claims18
A catalyst for purification of exhaust gases comprising a catalyst carrier and first and second catalyst layers formed as discrete layers one over the other on the catalyst carrier with the first layer being formed between the catalyst carrier and the second layer, wherein
- the first layer comprises a material effective to provide an oxygen reservoir during catalysis;
- and
- the second layer comprises nickel and a platinum group metal, wherein the nickel is present as finely divided needles distributed over the surface of the catalyst.
A method for making a three-way conversion catalyst comprising the steps of:
- (a) applying a first catalytic coating to a catalyst carrier to form a coated catalyst carrier, said first catalytic coating acting as an oxygen reservoir during catalysis;
- (b) immersing the coated catalyst carrier in a solution containing Ni.sup.2+ ions to form a Ni-wash-coated catalyst carrier;
- (c) heating the Ni-wash-coated carrier in an autoclave to form a coating of nickel metal needles on the coated catalyst carrier;
- and
- (c) applying a coating of a platinum group metal over the nickel metal needles.
A catalyst for purification of exhaust gases having an active catalyst surface formed from finely divided nickel needles with a specific surface area of 100 m.sup.2 /g.
Dependencies are inferred from the claim text.