Exhaust gas cleaning catalysts and method of producing same
AssigneeHitachi Shipbuilding & Engineering Co., Ltd.
InventorsSo Takeoka, Hideya Inaba, Masayoshi Ichiki
Life of this patent
Estimating the term…
Abstract
Exhaust gas cleaning catalysts are produced by alloying copper and aluminum with at least one of the elements, nickel and chromium, and eluting by alkali or acid means aluminum from the cooled alloy surface. Small amounts of other metals from the fourth or fifth period V.about. VIII groups, may be added to the catalysts by alloying, or by impregnation, for enhanced catalytic properties. The catalysts exhibit improved reduction of NO and oxidation of CO in an exhaust gas stream, in the presence of Pb, SO.sub.2, moisture and hydrocarbons (H.C) and at relatively low temperatures.
Claims16
A method of producing an exhaust gas cleaning catalyst comprising the steps of
- forming an alloy composed of 20 to 50% by weight of Cu;
- at least one of the metals Ni in an amount of 1 to 20% by weight, and Cr in an amount of 0.5 to 8% by weight;
- and Al as the remaining percent by weight;
- adding at least one additional metal selected from the group consisting of V, Mn, Fe, Co, Nb, Mo, Ru, Rh and Pd;
- and
- eluting Al from the surface of said alloy to activate the surface of said catalyst.
An exhaust gas cleaning catalyst comprising an alloy composed of 20 to 50% by weight of Cu, at least one of the metals Ni in an amount of 1 to 20% by weight and Cr in an amount of 0.5 to 8% by weight, and Al as the remaining percent by weight;
- said catalyst including at least one additional metal selected from the group consisting of V, Mn, Fe, Co, Nb, Mo, Ru, Rh and Pd;
- and the surface of said catalyst being activated by the removal of Al therefrom.
A method of producing an exhaust gas cleaning catalyst consisting of forming an alloy composed of 20 to 50% by weight of copper;
- at least one of the metals Ni in an amount of 3 to 7% by weight and Cr in an amount of 0.5 to 85 by weight;
- and Al as the remaining percent by weight;
- and eluting Al from the surface of said alloy to activate the surface of said catalyst.
An exhaust gas cleaning catalyst comprising an alloy composed of 20 to 50% by weight of copper;
- at least one of the metals Ni in an amount of 3 to 7% by weight and Cr in an amount of 0.5 to 8% by weight;
- and Al as the remaining percent by weight;
- the surface of said alloy being activated by the removal of Al therefrom.
Dependencies are inferred from the claim text.