Mixed transition metal oxide catalysts for conversion of carbon monoxide and method for producing the catalysts
AssigneePhilip Morris Incorporated
InventorsRobert L. Augustine, Setrak Tanielyan
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Abstract
This invention relates to improved catalysts for the oxidation of carbon monoxide and methods of preparing these catalysts. The catalysts of this invention are prepared using a sequential precipitation process which generates catalysts that contain substantially layered metal oxides, both supported and unsupported, and, in some embodiments of the invention, a noble metal or mixture of noble metals layered on the metal oxides. These catalysts are particularly useful in smoking articles.
Claims37
An oxidation catalyst for use in low temperature oxidation of carbon monoxide comprising a plurality of metal oxide layers, wherein at least one of said layers comprises cobalt(II,III)oxide and at least another one of said layers comprises a metal oxide selected from the group consisting of the oxides of iron, nickel, copper, zinc, molybdenum, tungsten, and tin.
A layered metal oxide catalyst for use in low temperature oxidation of carbon monoxide comprising a layer of cobalt(II,III)oxide and a layer of tin oxide.
A layered metal oxide catalyst for use in oxidizing carbon monoxide comprising a support material, two metal oxide layers and an outer noble metal layer, wherein the support material is silicon dioxide, the first metal oxide layer is cobalt(II,III)oxide, the second metal oxide layer is tin oxide, and the noble metal is selected from the group consisting of gold, platinum and mixtures thereof.
A layered metal oxide catalyst for use in oxidizing carbon monoxide comprising a support material, two metal oxide layers and an outer noble metal layer, wherein the support material is silicon dioxide, the first metal oxide layer is cobalt(II,III)oxide, the second metal oxide is copper oxide, and the noble metal comprises platinum and rhodium.
Method for producing a layered metal oxide catalyst for use in oxidizing carbon monoxide comprising the steps of:
- (a) adding an aqueous solution of a salt of a first metal to an aqueous solution of a base;
- (b) adding to the suspension of step (a) an aqueous solution of a salt of a second metal;
- (c) isolating the precipitate resulting from step (b);
- and
- (d) heating the precipitate, wherein the metal oxides are selected from the group consisting of the oxides of iron, cobalt, nickel, copper, zinc, molybdenum, tungsten, and tin.
A method for producing a layered metal oxide catalyst for use in oxidizing carbon monoxide comprising a noble metal layered upon a second metal oxide which is layered upon a first metal oxide, comprising the steps of:
- (a) adding an aqueous solution of a salt of a first metal to an aqueous solution of a base;
- (b) adding to the suspension of step (a) an aqueous solution of a salt of a second metal;
- (c) adding an aqueous solution of formaldehyde;
- (d) adding an aqueous solution of a salt of a noble metal;
- (e) isolating the precipitate resulting from step (d);
- and
- (f) heating the precipitate,
- wherein the metal oxide are selected from the group consisting of iron, cobalt, nickel, copper, zinc, molybdenum, tungsten, and tin, and wherein the noble metal is selected from the group consisting of gold, silver, platinum, palladium, rhodium, ruthenium and iridium, and mixtures thereof.
An oxidation catalyst for use in a smoking article comprising a plurality of metal oxide layers, wherein at least one of said layers comprises cobalt(II,III)oxide and at least another one of said layers comprises a metal oxide selected from the group consisting o the oxides of iron, nickel, copper, zinc, molybdenum, tungsten, and tin.
A layered metal oxide catalyst for use in a smoking article comprising a support material, two metal oxide layers and an outer noble metal layer, wherein the support material is silicon dioxide, the first metal oxide layer is cobalt(II,III)oxide, the second metal oxide layer is tin oxide, and the noble metal is selected from the group consisting of gold, platinum and mixtures thereof.
A layered metal oxide catalyst for use in a smoking article comprising a support material, two metal oxide layers and an outer noble metal layer, wherein the support material is silicon dioxide, the first metal oxide layer is cobalt(II,III)oxide, the second metal oxide layer is copper oxide, and the noble metal comprises platinum and rhodium.
A layered metal oxide catalyst for use in low temperature oxidation of carbon monoxide made by the method comprising the steps of:
- (a) adding an aqueous solution of a salt of a first metal to an aqueous solution of a base;
- (b) adding to the suspension of step (a) an aqueous solution of a salt of a second metal;
- (c) isolating the precipitate resulting from step (b);
- (d) heating the precipitate, wherein the metal oxides are selected from the group consisting of the oxides of iron, cobalt, nickel, copper, zinc, molybdenum, tungsten, and tin.
A layered metal oxide catalyst for use in low temperature oxidation of carbon monoxide comprising a noble metal layered upon a second metal oxide which is layered upon a first metal oxide made by the method comprising the steps of:
- (a) adding an aqueous solution of a salt of a first metal to an aqueous solution of a base;
- (b) adding to the suspension of step (a) an aqueous solution of a salt of a second metal;
- (c) adding an aqueous solution of formaldehyde;
- (d) adding an aqueous solution of a salt of a noble metal;
- (e) isolating the precipitate resulting from step (d);
- and
- (f) heating the precipitate,
- wherein the metal oxides are selected from the group consisting of the oxides of iron, cobalt, nickel, copper, zinc, molybdenum, tungsten, and tin, and wherein the noble metal is selected from the group consisting of gold, silver, platinum, palladium, rhodium, ruthenium, osmium and iridium, and mixtures thereof.
Dependencies are inferred from the claim text.