Mixed transition metal oxide catalysts for conversion of carbon monoxide and method for producing the catalysts

Claim 2

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.

Claim 3

The catalyst of claim 1, wherein the catalyst consists of two metal oxide layers and the ratio of weight of the second metal oxide to the weight of the first metal oxide is from about 1:50 to about 1:4.

Claim 4

The catalyst of claim 1, wherein the catalyst consists of two metal oxide layers and the ratio of weight of the second metal oxide to the weight of the first metal oxide is form about 2:50 to about 1:10.

Claim 5

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.

Claim 6

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.

Claim 7

The catalyst of claim 1, further comprising one or more noble metals, the noble metal or mixture being layered upon the other metal oxide layer.

Claim 8

The catalyst of claim 5, wherein the ratio of the weight of the noble metals to the weight of the metal oxides is from about 0.1% to about 5.0%.

Claim 9

The catalyst of claim 5, wherein the ratio of the weight of the noble metals to the weight of the metal oxides is from about 0.1% to about 1.0%.

Claim 10

The catalyst of claim 5, wherein the noble metal is selected from the group consisting of gold, silver, platinum, palladium, rhodium, ruthenium and iridium, and mixtures thereof.

Claim 11

The catalyst of claim 1 or 5, further comprising a support material upon which the first metal oxide is layered.

Claim 12

The catalyst of claim 9, wherein the support material is selected from the group consisting of a ceramic, a zeolite, porous carbon, porous paper, and a metal mesh.

Claim 13

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.

Claim 14

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.

Claim 15

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.

Claim 16

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.

Claim 17

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.

Claim 18

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.

Claim 19

The method of claim 13, wherein in step (a) the base solution is added to the salt of the first metal oxide.

Claim 20

The method of claim 13 or 14, wherein the salt of the first metal is selected from the group consisting of cobalt(II)nitrate and iron(III)nitrate and the salt of the second metal is selected from the group consisting of cobalt(II)nitrate and tin(II)chloride, wherein the second metal salt is different from the first metal salt.

Claim 21

The method of claim 13 or 14, wherein the base is selected from the group consisting of sodium bicarbonate, sodium hydroxide, potassium carbonate and lithium hydroxide.

Claim 22

The method of claim 13 or 14, wherein a suspension of a support is first added to the aqueous solution of the base.

Claim 23

The method of claim 17, wherein the support is selected from the group consisting of a ceramic, a zeolite, porous carbon, porous paper, and a metal mesh.

Claim 24

The method of claim 13 or 14, comprising the additional step of isolating the precipitate resulting from step (a) and adding it to the solution of step (b).

Claim 25

The method of claim 13 or 14, wherein the precipitate is heated to a temperature between about 95° C. and about 500° C.

Claim 26

The method of claim 13 or 14, wherein the precipitate is heated to a temperature between about 300° C. and about 400° C.

Claim 27

The method of claim 13 or 14, wherein the precipitate is heated for a period of between about 1 hour and about 12 hours.

Claim 30

The method of claim 23, wherein in step (a) the base solution is added to the salt of the first metal oxide.

Claim 31

The method of claim 23 or 24, wherein the salt of the first metal is selected from the group consisting of cobalt(II)nitrate and iron(III)nitrate and the salt of the second metal is selected from the group consisting of cobalt(II)nitrate and tin(II)chloride, wherein the second metal salt is different from the first metal salt.

Claim 32

The method of claim 23 or 24, wherein the base is selected from the group consisting of sodium bicarbonate, sodium hydroxide, potassium carbonate and lithium hydroxide.

Claim 33

The method of claim 23 or 24, wherein a suspension of a support is first added to the aqueous solution of the base.

Claim 34

The method of claim 27, wherein the support is selected from the group consisting of a ceramic, a zeolite, porous carbon, porous paper and a metal mesh.

Claim 35

The method of claim 23 or 24, comprising the additional step of isolating the precipitate resulting from step (a) and adding it to the solution of step (b).

Claim 36

The method of claim 23 or 24, wherein the precipitate is heated to a temperature between 95° C. and 500° C.

Claim 37

The method of claim 23 or 24, wherein the precipitate is heated to a temperature between 300° C. and 400° C.

Claim 38

The method of claim 23 or 24, wherein the precipitate is heated for a period of between about 1 hour and about 12 hours.

Claim 39

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.

Claim 40

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.

Claim 41

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.

Claim 42

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.

Claim 43

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.

Claim 44

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.

Claim 45

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.

Claim 46

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.

Claim 47

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.

Claim 48

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.