JP2003164764A - Catalyst for oxidizing carbon monoxide, method for manufacturing the same and method for oxidizing carbon monoxide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high performance catalyst having selective oxidation capacity with respect to a very small amount of carbon monoxide. <P>SOLUTION: The catalyst for oxidizing carbon monoxide comprises a noble metal/alumina having iron supported thereon. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a catalyst for oxidizing carbon monoxide, a method for producing the same, and a method for oxidizing carbon monoxide.

[0002]

2. Description of the Related Art A polymer electrolyte fuel cell (PEFC) is
Since the polymer membrane is used as the electrolyte, there is no problem with the dissipation and retention of the electrolyte, and maintenance is easy. Also,
Since it can be operated at 100 ° C or below, it has the principle superior features such as a short starting time. As fuel gas,
Although hydrogen gas obtained by reforming methane or methanol is used, it is known that the electrode catalyst is poisoned by a small amount of carbon monoxide contained in the fuel gas, and the cell performance is significantly reduced. To solve this problem, a method of selectively reducing carbon monoxide in advance before supplying the reformed gas to the battery is effective. Therefore, there is a demand for the development of a high-performance catalyst capable of selectively oxidizing and removing a trace amount of carbon monoxide without oxidizing hydrogen.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a high-performance catalyst having a selective oxidizing ability for a trace amount of carbon monoxide, a method for producing the catalyst, and a method for oxidizing carbon monoxide using the catalyst. The task is to do.

[0004]

The present inventors have completed the present invention as a result of extensive studies to solve the above-mentioned problems. That is, according to the present invention, the following method is provided. (1) A carbon monoxide oxidation catalyst characterized in that iron is supported on a noble metal / alumina. (2) The ratio of the iron is 0.00 per mol of the noble metal.
The carbon monoxide oxidation catalyst according to (1) above, wherein the amount is 5 to 0.2 mol. (3) The carbon monoxide oxidation catalyst according to (1) or (2), wherein the noble metal is platinum or ruthenium. (4) A method for producing a carbon monoxide oxidation catalyst, which comprises adding an iron carbonyl complex to a noble metal / alumina and then thermally decomposing the iron carbonyl in a hydrogen stream. (5) A method for producing a carbon monoxide oxidation catalyst, which comprises adding an iron salt to a noble metal / alumina, followed by firing in an air stream and hydrogen reduction. (6) A method for selectively oxidizing carbon monoxide, characterized in that the catalyst according to any one of (1) to (3) is used as the catalyst.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The catalyst of the present invention is an iron-noble metal / alumina catalyst in which iron is supported on a noble metal / alumina. As the noble metal / alumina in this catalyst, a commercially available noble metal / alumina catalyst can be used. In that case,
The amount of precious metal supported is 0.1 to 5% by weight with respect to alumina.
Is preferable, and 0.1 to 0.5% by weight is more preferable. The noble metal / alumina can be prepared as an alumina gel containing a noble metal according to the following method. Examples of the noble metal used in the present invention include rhodium, palladium, osmium, iridium, platinum and ruthenium.
More preferred is the use of platinum, rhodium, palladium or ruthenium.

To prepare the noble metal / alumina gel,
First, an aqueous solution of a noble metal salt is added to an organic solvent containing a surfactant and stirred to form a water-in-oil (W / O) microemulsion. In this case, the diameter of the water droplet particles is 10
It is 100Å, and the number of noble metal ions contained in one water droplet is preferably 5 to 50, and more preferably 5 to 20. In order to obtain this microemulsion stably, it is important to select the surfactant and the organic solvent. The surfactant is preferably a nonionic surfactant, alkyl polyethylene ether, and further,
The use of polyoxyethylene nonyl phenyl ether is preferred. In the polyoxyethylene group of the polyoxyethylene nonylphenyl ether, the average added mole number of oxyethylene is preferably 3 to 10, and more preferably 4 to 6.

It is preferable to use a water-insoluble solvent as the organic solvent, and a hydrocarbon solvent such as cyclohexene,
It is more preferable to use cyclohexane or toluene. The stirring speed for preparing the microemulsion is preferably 200 to 500 rpm, more preferably 300 to 500 rpm. The stirring temperature is 20 to
The temperature is preferably 60 ° C, more preferably 40 to 50 ° C. The concentration of the noble metal salt in the aqueous solution is 0.1 to 1 mol /
dm ³ is preferable, and more preferably 0.2 to 0.8 mol / dm ³ .

Cetyltrimethylammonium chloride (CTAC) is added to the microemulsion and reacted with the noble metal salt to form ultrafine particles of a complex of the noble metal and CTAC. Then, aluminum triisopropoxide is added and hydrolyzed,
Polycondensate. The hydrolysis temperature in this case is 40 to 60 ° C.
Is preferable, and more preferably 50 ° C. By this operation, ultrafine particles of noble metal / alumina are obtained. The ultrafine particles are separated from the liquid by filtration, washed with 2-propanol, dried, and then calcined under air flow.
The firing temperature is preferably 300 to 700 ° C, more preferably 350 to 600 ° C. By this firing,
The surfactant adhering to the ultrafine particles is burned out. As a result, an ultrafine particle noble metal / alumina gel is obtained. In this precious metal / alumina, the average particle size is 3 to 20n
m, preferably 3 to 10 nm.

The precious metal salt compound is not particularly limited as long as it is a water-soluble salt. Such substances include, for example, halides such as chlorides and bromides, nitrates and the like.

The catalyst of the present invention can be prepared by loading iron on the commercially available precious metal / alumina or the precious metal / alumina gel prepared by the above method. In one preferable method for supporting iron, an iron-noble metal / alumina catalyst is prepared by adding a predetermined amount of iron carbonyl complex to the noble metal / alumina and then thermally decomposing the iron carbonyl complex in a hydrogen stream. You can As the iron carbonyl complex, conventionally known ones are used, but iron pentacarbonyl is particularly preferable in the present invention. The thermal decomposition temperature is preferably 200 to 300 ° C, more preferably 250 to 300 ° C.

In another method for supporting iron, an aqueous iron salt solution is added to the noble metal-alumina, stirred, allowed to stand, and then dried. Then, it is fired under air circulation. The firing temperature is preferably 300 to 700 ° C., more preferably 3
It is 50 to 600. As a result, an iron-noble metal / alumina catalyst can be prepared. The iron-noble metal / alumina catalyst thus prepared is molded with a molding machine to adjust the particle size. In this case, the particle size can be appropriately adjusted depending on the reaction device used. Subsequently, the iron-noble metal / alumina catalyst can be prepared by reduction under a hydrogen stream. The reduction temperature is preferably 150 to 300 ° C,
Furthermore, 200-300 degreeC is preferable. In the catalyst of the present invention, the proportion of iron is 0.005-0.2 mol, preferably 0.05-0.2 mol, per mol of the noble metal contained therein.
It is 0.1 mol.

The iron salt is not particularly limited as long as it is a water-soluble salt. Such substances include, for example, halides such as chlorides and bromides, nitrates and the like. The iron salt concentration in the aqueous solution is preferably 0.2 to 4.0 mol%, more preferably 0.2 to 2.0 mol%.

The iron-noble metal / alumina catalyst of the present invention can be used in various shapes such as a spherical shape, a cylindrical shape, and a cylindrical shape, in addition to the powder shape. In the case of powder, the average particle size is 10 to 500 μm, preferably 300 to 500
μm. In the catalyst of the present invention, the iron form is usually in the metallic state, and the noble metal state is also usually in the metallic state.

In order to oxidize carbon monoxide contained in a gas using the catalyst of the present invention, the gas may be contacted with the catalyst of the present invention in the presence of oxygen. The ratio of carbon monoxide contained in the gas is usually 0.4 to 2.0 mol%,
It is preferably 0.4 to 1.0 mol%. The molar ratio of oxygen to carbon monoxide is 0.5 to 3.0, preferably 1.0 to 3.0. Reaction temperature is 120-250
C., preferably 150 to 200.degree.

The gas containing carbon monoxide may be hydrogen, hydrocarbon, alcohol, water vapor, carbon dioxide or the like. According to the present invention, carbon monoxide contained in these gases can be selectively oxidized. Oxides produced by this reaction are carbon dioxide, water vapor and the like. According to the present invention, a lower hydrocarbon having 1 to 3 carbon atoms such as methane or an alcohol such as methanol or ethanol is reformed with steam or carbon dioxide gas, and a trace amount (usually, contained in hydrogen gas obtained by purification (usually, It is possible to oxidize and remove carbon monoxide (about 0.4 to 2.0 mol%). In this case, hydrogen is not substantially oxidized, and only carbon monoxide is selectively oxidized. The purified hydrogen gas thus obtained is suitable as a hydrogen gas for polymer electrolyte fuel cells.

[0016]

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A beaker having an internal volume of 1000 ml was charged with 400 ml of 0.2 M polyoxyethylene (average addition mole number: 5)) nonylphenyl ether / cyclohexane solution, and a beaker of 0.
2 ml of 5M chloroplatinic acid solution and purified water, 17
Add ml, stir at 300 rpm at a temperature of 50 ° C,
A water-in-oil microemulsion was made. The diameter of the water droplet was calculated to be 79Å, and the average number of platinum ions contained in one water droplet was calculated to be eight. To this microemulsion, 4 g of cetyltrimethylammonium chloride (CTAC) was mixed in advance with 50 ml of cyclohexane and stirred, and well stirred at 50 ° C. for 30 minutes to form ultrafine particles of platinum and CTAC complex. next,
170 g of aluminum triisopropoxide was mixed in 400 ml of cyclohexene with stirring and added,
The hydrolysis was performed for 1 hour. Subsequently, the beaker contents were cooled to room temperature, the mother liquor was separated by centrifugation, and the obtained precipitate was washed with 2-propanol three times. The purified precipitate was dried at 80 ° C for 12 hours and then calcined at 500 ° C for 2 hours. As a result, 39.8 g of an alumina gel (catalyst I) containing 0.5 wt% of platinum was obtained. To 3.0 g of the platinum / alumina (catalyst I) prepared as described above, iron pentacarbonyl was added in a predetermined amount according to the amount of iron supported, and 25
Iron pentacarbonyl was pyrolyzed at 0 ° C. As a result,
An iron-platinum / alumina catalyst (catalysts A, B, and C) having iron: platinum = 1: 50 to 200 (molar ratio) was obtained. The iron-platinum / alumina catalysts A, B and C were molded by a molding machine to obtain a particle size:
16-18 mesh pellets were made. 0.2 g of this shaped catalyst was loaded into a reaction tube having an inner diameter of 8 mm, and hydrogen reduction was carried out at 500 ° C. for 2 hours in a hydrogen stream. Table 1 shows the physical properties of each catalyst after hydrogen reduction. After reduction with hydrogen, a selective oxidation reaction of carbon monoxide was performed. That is, a reaction tube is installed in an electric furnace whose temperature can be controlled within a temperature range of 1 ° C., and carbon monoxide: oxygen: hydrogen: carbon dioxide: steam = 0.5: 0.5: 40: A mixed gas of 9:50 (molar ratio) was fed in and reacted. The reaction pressure was normal pressure, the reaction temperature was 200 ° C., and the mixed gas flow rate was 60 ml / min. The experimental results are shown in Table 2.

Example 2 A 0.05 M iron nitrate aqueous solution and ion-exchanged water were prepared and put in an evaporating dish according to the amount of iron supported, and 3.0 g of the catalyst I prepared in Example 1 was added thereto and stirred. It was left for 1 hour. After leaving it for 3 hours in a vacuum dryer, and then in a dryer,
It was dried at 80 ° C. for 12 hours. After that, firing was performed under the same conditions as in Example 1, and subsequently hydrogen reduction was performed. This results in iron:
An iron-platinum / alumina catalyst (catalysts D, E, F) having platinum = 1: 10 to 100 (molar ratio) was obtained. The physical properties of the catalyst are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was performed. The experimental results are shown in Table 2.

Example 3 A 0.05 M aqueous solution of iron chloride and ion-exchanged water were prepared and put in an evaporation dish according to the amount of iron supported, and 3.0 g of the catalyst I prepared in Example 1 was added thereto, and the mixture was stirred. It was left for 1 hour. After leaving it for 3 hours in a vacuum dryer, and then in a dryer,
It was dried at 80 ° C. for 12 hours. After that, firing was performed under the same conditions as in Example 1, and subsequently hydrogen reduction was performed. This results in iron:
An iron-platinum / alumina catalyst (catalysts G, H, I) having platinum = 1: 10 to 100 (molar ratio) was obtained. The physical properties of the catalyst are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was performed. The experimental results are shown in Table 2.

Example 4 A commercially available 0.5 wt% platinum / alumina catalyst (catalyst II) was added to
A predetermined amount of iron pentacarbonyl was added according to the amount of iron supported, and iron pentacarbonyl was thermally decomposed at 250 ° C. in a hydrogen stream. As a result, iron: platinum = 1: 50 to 200
(Molar ratio) iron-platinum / alumina catalyst (catalysts J, K,
L) was obtained. The physical properties of each catalyst are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was performed. The experimental results are shown in Table 2.

Example 5 A 0.05 M aqueous solution of iron nitrate and ion-exchanged water were prepared and placed in an evaporating dish according to the amount of iron supported, and the catalyst II of Example 4 was placed therein.
Was added, and the mixture was left for 1 hour after stirring. After leaving it to stand, it is dried in a vacuum dryer for 3 hours and then in a dryer at 80 ° C for 1 hour.
It was dried for 2 hours. After that, firing was performed under the same conditions as in Example 1, and subsequently hydrogen reduction was performed. As a result, iron: platinum =
An iron-platinum / alumina catalyst (catalysts M, N, O) of 1:10 to 100 (molar ratio) was obtained. The physical properties of the catalyst are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was performed. The experimental results are shown in Table 2.

Example 6 A 0.05 M aqueous solution of iron chloride and ion-exchanged water were prepared and placed in an evaporation dish according to the amount of iron supported, and the catalyst II of Example 4 was added thereto.
Was added, and the mixture was left for 1 hour after stirring. After standing, after drying in a vacuum dryer for 3 hours, further in the dryer at 80 ° C,
It was dried for 12 hours. After that, firing was performed under the same conditions as in Example 1, and subsequently hydrogen reduction was performed. As a result, iron: platinum =
An iron-platinum / alumina catalyst (catalysts P, Q, R) of 1:10 to 100 (molar ratio) was obtained. The physical properties of the catalyst are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was performed. The experimental results are shown in Table 2.

Example 7 5 ml of a 0.1 M ruthenium chloride aqueous solution and 15 ml of ion-exchanged water were placed in an evaporation dish, 10.0 g of alumina gel prepared in advance in a microemulsion was added thereto, and the mixture was left standing for 1 hour after stirring. After standing, it was dried in a vacuum dryer for 3 hours, and further dried in a dryer at 80 ° C. for 12 hours. Then, firing and hydrogen reduction were performed under the same conditions as in Example 1. An alumina gel (catalyst III) having a ruthenium supported amount of 0.5 wt% was prepared. Iron pentacarbonyl was added to 3.0 g of the ruthenium / alumina catalyst (catalyst III) prepared as described above, and iron pentacarbonyl was thermally decomposed at 250 ° C. in a hydrogen stream. As a result, an iron-ruthenium / alumina catalyst (catalyst S) having iron: ruthenium = 1: 80 (molar ratio) was obtained. The physical properties of each catalyst are shown in Table 1.
It was shown to. Using this catalyst, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Example 8 An evaporation dish was charged with 1.5 ml of a 0.01 M iron nitrate aqueous solution and 4.5 ml of ion-exchanged water, 3.0 g of the catalyst III of Example 7 was added thereto, and the mixture was left standing for 1 hour after stirring. After left to stand, it is dried in a vacuum dryer for 3 hours, and then in a dryer at 80 ° C for 12 hours.
Allowed to dry for hours. After that, firing was performed under the same conditions as in Example 1, and subsequently hydrogen reduction was performed. As a result, an iron-ruthenium / alumina catalyst (catalyst T) having iron: ruthenium = 1: 10 (molar ratio) was obtained. The physical properties of the catalyst are shown in Table 1. Using this catalyst, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Example 9 To an evaporation dish, 1.5 ml of a 0.01 M aqueous solution of iron chloride and 4.5 ml of ion-exchanged water were placed, 3.0 g of the catalyst III of Example 7 was added thereto, and the mixture was left standing for 1 hour after stirring. After left to stand, it is dried in a vacuum dryer for 3 hours, and then in a dryer at 80 ° C for 12 hours.
Allowed to dry for hours. After that, firing was performed under the same conditions as in Example 1, and subsequently hydrogen reduction was performed. As a result, an iron-ruthenium / alumina catalyst (catalyst U) having iron: ruthenium = 1: 10 (molar ratio) was obtained. The physical properties of the catalyst are shown in Table 1. Using this catalyst, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Example 10 Commercially available 0.5 wt% rhodium / alumina catalyst (Catalyst IV)
Iron pentacarbonyl was added to and the iron pentacarbonyl was thermally decomposed at 250 ° C. As a result, iron: rhodium =
An iron-rhodium / alumina gel catalyst (catalyst V, W, X) of 1:50 to 200 (molar ratio) was obtained. The catalyst physical properties are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.
Shown in.

Example 11 A 0.05 M iron nitrate aqueous solution and ion-exchanged water were placed in an evaporation dish, 3.0 g of the catalyst IV of Example 10 was added thereto, and the mixture was left standing for 1 hour after stirring. After standing, it was dried in a vacuum dryer for 3 hours and then in a dryer at 80 ° C. for 12 hours. afterwards,
Firing and hydrogen reduction were performed under the same conditions as in Example 1. As a result, an iron-rhodium / alumina gel catalyst (catalyst Y) having iron: rhodium = 1: 10 (molar ratio) was obtained. The catalyst physical properties are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Example 12 A 0.05 M aqueous solution of iron chloride and ion-exchanged water were put in an evaporation dish, 3.0 g of the catalyst IV of Example 10 was added thereto, and the mixture was left standing for 1 hour after stirring. After standing, it was dried in a vacuum dryer for 3 hours and then in a dryer at 80 ° C. for 12 hours. afterwards,
Firing and hydrogen reduction were performed under the same conditions as in Example 1. As a result, an iron-rhodium / alumina gel catalyst (catalyst Z) containing iron: rhodium = 1: 10 (molar ratio) was obtained. The catalyst physical properties are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Example 13 Iron pentacarbonyl was added to a commercially available 0.5 wt% palladium / alumina catalyst (catalyst V), and iron pentacarbonyl was thermally decomposed at 250 ° C. As a result, an iron-palladium / alumina gel catalyst (catalyst a) of iron: palladium = 1: 50 (molar ratio) was obtained. The catalyst physical properties are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Example 14 A 0.05 M aqueous solution of iron nitrate and ion-exchanged water were placed in an evaporation dish, 3.0 g of the catalyst IV of Example 10 was added thereto, and the mixture was left standing for 1 hour after stirring. After standing, it was dried in a vacuum dryer for 3 hours and then in a dryer at 80 ° C. for 12 hours. afterwards,
Firing and hydrogen reduction were performed under the same conditions as in Example 1. As a result, an iron-palladium / alumina gel catalyst (catalyst b) of iron: rhodium = 1: 10 (molar ratio) was obtained. The catalyst physical properties are shown in Table 1. Using these catalysts, the same catalyst performance evaluation test as in Example 1 was conducted. The experimental results are shown in Table 2.

Comparative Example 1 Catalyst I prepared in Example 1, Catalyst II used in Example 4,
Catalyst III prepared in Example 7 and catalyst I used in Example 10
V and the catalyst V used in Example 13 are noble metal-alumina catalysts that do not support iron. As a comparative example, these catalysts I, II, III and IV were subjected to a catalyst performance evaluation test in the same manner as in Example 1. The catalyst physical properties are shown in Table 1, and the experimental results are shown in Table 2.

Table 1 shows the physical properties of the catalysts obtained in Examples and Comparative Examples.

[Table 1]

Table 2 shows the results of the carbon monoxide selective oxidation reaction of the catalysts obtained in Examples and Comparative Examples.

[Table 2]

Reaction conditions: 200 ° C., normal pressure, catalyst amount: 0.
2 g, mixed gas flow rate: 60 ml / min Test mixed gas composition; carbon monoxide: oxygen: hydrogen: carbon dioxide: steam = 0.5: 0.5: 40: 9: 50 (molar ratio)

The example catalysts shown in Tables 1 and 2 are:
(I) iron: platinum (molar ratio) = 1: 10-200 iron-platinum / alumina catalyst, (ii) iron: ruthenium (molar ratio) = 1: 10-80 iron-ruthenium / alumina catalyst, (Iii) Iron: rhodium (molar ratio) = 1: 10 to 5
An iron-rhodium / alumina catalyst which is 0 and (iv) iron:
It can be summarized as an iron-palladium / alumina catalyst in which palladium (molar ratio) = 1: 10 to 50. The carbon monoxide selective oxidation ability of the example catalysts is as shown in Table 2, iron-platinum / alumina catalysts (catalysts A to R), iron-ruthenium / alumina catalysts (catalysts S to U) iron-rhodium / alumina catalysts. (Catalyst V to X) and iron-palladium / alumina catalyst (catalysts Y and Z) are used in the selective oxidation reaction of carbon monoxide to obtain 200 ° C. and oxygen / carbon monoxide = 1.0.
Under the condition of (molar ratio), the residual concentration of carbon monoxide is 2 to 2
It could be reduced to 300 ppm. In particular, it has been found that the iron-platinum / alumina catalyst prepared by using iron pentacarbonyl has a high carbon monoxide selective oxidation ability.
On the other hand, the platinum / alumina catalysts (catalysts I and II) without addition of iron, the ruthenium / alumina catalysts (catalyst III), the rhodium / alumina catalysts (catalyst IV) and the palladium / alumina catalysts (catalyst V) shown in Comparative Examples are the same. In the test under the conditions, the residual concentration of carbon monoxide was as high as about 2400 to 4400.

[0036]

According to the present invention, a high performance catalyst capable of selectively oxidizing and removing a trace amount of carbon monoxide in hydrogen gas is provided. The hydrogen gas from which carbon monoxide has been removed according to the present invention is suitable as a hydrogen gas for fuel cells.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masahiro Kishida             5-29 Mai Matsubara, Higashi-ku, Fukuoka City, Fukuoka Prefecture             Ruby Kashii 8th Building Room 306 (72) Inventor Teruko Taiko             2-20-22 Harada, Higashi-ku, Fukuoka City, Fukuoka Prefecture             Zondor Miyake Room 302 (72) Inventor Hiroki Hayashi             2-28-16 Hakomatsu, Higashi-ku, Fukuoka City, Fukuoka Prefecture             Cattle Maison Room 101 F-term (reference) 4G069 AA01 AA03 AA08 BA01A                       BA01B BA27C BA38 BC32A                       BC33A BC66A BC66B BC66C                       BC69A BC70A BC70B BC71B                       BC72B BC75A BC75B BE42C                       CC40 DA05 FA01 FA02 FB14                       FB16 FB29 FB30 FB44 FC02                       FC08                 5H026 AA06                 5H027 AA06 BA01 BA17

Claims (6)

[Claims] 1. A catalyst for carbon monoxide oxidation, comprising iron supported on a noble metal / alumina. 2. The proportion of iron per mol of the noble metal is
The catalyst for carbon monoxide oxidation according to claim 1, wherein the amount is 0.005 to 0.2 mol. 3. The carbon monoxide oxidation catalyst according to claim 1, wherein the noble metal is platinum or ruthenium. 4. A method for producing a catalyst for carbon monoxide oxidation, which comprises adding an iron carbonyl complex to a noble metal / alumina and then thermally decomposing the iron carbonyl in a hydrogen stream. 5. After adding the iron salt to the precious metal / alumina,
A method for producing a carbon monoxide oxidation catalyst, which comprises calcination in an air stream and hydrogen reduction. 6. A method for oxidizing carbon monoxide in the presence of a catalyst, wherein the catalyst according to any one of claims 1 to 3 is used as the catalyst.