JP2002126535A - Catalyst for selective oxidation of carbon monoxide and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a carbon monoxide selective oxidation catalyst capable of selectively oxidizing CO in a CO-containing gas mixture and excellent in selective oxidation and provide a production method of the oxidation catalyst. SOLUTION: The method for producing a carbon monoxide selective oxidation catalyst for selectively oxidizing CO in a CO-containing gas mixture comprises a sep of adding a catalyst carrier in a solvent and further adding a catalytic active species to the solvent to produce a carbon monoxide selective oxidation catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catalyst for selective oxidation of carbon monoxide and a method for producing the same.

[0002]

2. Description of the Related Art Polymer electrolyte fuel cells (hereinafter sometimes referred to as PEFC devices) have low pollution and high thermal efficiency, so that they can be used as power sources in a wide range of fields such as power sources for automobiles and distributed power sources. Expected. A platinum catalyst is mainly used for the electrodes of this polymer electrolyte fuel cell. Since the platinum catalyst is easily poisoned by carbon monoxide (CO), it is necessary to remove as much CO as possible from the fuel gas containing hydrogen as a main component.

Here, a method for producing this fuel gas will be described. First, a fuel such as methanol is reformed by a steam reforming reaction or a partial oxidation reaction to generate hydrogen, and CO produced as a by-product of the reforming reaction is subjected to a CO shift reaction (reaction formula: CO
+ H ₂ O → CO ₂ + H ₂ ). The CO shift reaction alone has a limit in reducing CO due to restrictions on chemical equilibrium. Therefore, in addition to the CO shift reaction, it is necessary to adopt a method for reducing the CO concentration so that the polymer electrolyte fuel cell is not poisoned. Taking an example of a component of the gas after CO-shift reaction for reference (methanol as fuel), H ₂ is 40 to 60%, CO ₂ is about 10%, H ₂ O is about 20% and CO of about 0.5%. If CO could be selectively oxidized by adding oxygen to the gas after the CO shift reaction, it would be the most efficient and inexpensive method among various methods for removing CO.

[0004] However, according to the conventional combustion catalyst,
Oxygen added to the source gas reacts only with hydrogen, that is, hydrogen, which is the main component in the source gas, burns, so that CO remains. Therefore, in order to realize the selective oxidation of CO, the combustion of hydrogen is suppressed and
A catalyst that selectively promotes the combustion of O has been desired.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a wide range of temperatures.
CO in the mixed gas containing O can be selectively oxidized,
An object of the present invention is to provide a carbon monoxide selective oxidation catalyst having excellent selective oxidation properties and a method for producing the same. In the present invention, CO 2
Is a mixed gas containing CO, hydrogen (H ₂ ), oxygen (O ₂ )
It is a gas containing such.

[0006]

In order to achieve the above object, the present invention relates to a method for producing a carbon monoxide selective oxidation catalyst for causing a selective oxidation reaction of CO in a mixed gas containing CO. It was intended to include adding the carrier into the solvent and further adding the catalytically active species into the solvent. In the present invention, the selective oxidation reaction of CO refers to a reaction that selectively oxidizes CO even if an element (eg, H ₂ ) that is more easily oxidized than CO is contained in a mixed gas containing CO. The solvent only needs to dissolve the catalytically active species used in the present invention, and is not limited to water (H ₂ O). For example,
Organic solvents such as methanol and ethanol may be used.

Further, a zeolite-based carrier is used as a catalyst carrier, water is used as a solvent, a zeolite carrier is added to the water, and a metal salt, which is a catalytically active species, is added to the water. It is preferable that the production method includes ion exchange between the alkali metal or H element and the metal element in the metal salt. In the present invention, the zeolite-based carrier is a crystalline silicate, a Y-type zeolite,
Those containing at least one selected from the group consisting of A-type zeolite, β-type zeolite, mordenite, and ferrierite are preferable. However, the carrier is not limited as long as it can support the catalytically active species. This crystalline silicate is (1 ± 0.8) R ₂ O.
[AM ₂ O ₃ · bLO · cAl ₂ O ₃ ] · ySiO ₂ , wherein R is an alkali metal and H
At least one element selected from the group consisting of: wherein M is a group 8 (VIII) element, a rare earth element, Ti,
At least one element selected from the group consisting of V, Cr, Nb, Sb and Ga, wherein L is Mg, C
at least one element selected from the group consisting of a, Sr and Ba, and having a molar ratio of a, b, c and y
Are 0 ≦ a, 0 ≦ b ≦ 20, a + b = 1 and 11 ≦ y ≦
3000, and a lattice spacing of 3.65 ± 0.1 °, 3.75 ± 0.1 ° in powder X-ray diffraction using CuKα ray,
3.85 ± 0.1 °, 10.0 ± 0.3 ° and 11.
It is preferable that peaks from the strongest peak to the fifth place appear at 2 ± 0.3 °. However, any crystalline silicate that can carry the catalytically active species may be used, and is not limited.

[0008] The metal salt is Pt, Ru, Pd, R
Preferably, at least one metal selected from the group consisting of h, Ir, Cr, Co, Ni, Cu, Fe and Sn is contained in the form of nitrate, sulfate, chloride, acetate or hydroxide. It is. The form of the metal salt is preferably at least one selected from the group consisting of nitrate, sulfate, chloride, acetate and hydroxide. However, as long as the object of the present invention of selectively oxidizing carbon monoxide is achieved, any combination including two or more kinds may be used without any limitation.

Further, by the method for producing a selective oxidation catalyst for carbon monoxide under various conditions, a selective oxidation catalyst for carbon monoxide capable of selectively causing oxidation reaction of carbon monoxide in a mixed gas containing CO is provided. You.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION [Exchange of an alkali metal or hydrogen element in a zeolite-based carrier with a metal element of a catalytically active species by ion exchange] The method for producing a carbon monoxide selective catalyst according to the present invention will be described below. Will be described in more detail. The zeolite-based carrier is added to a solution that has been heated and held at 40 ° C. to 100 ° C. in advance, and is uniformly dispersed in the solution by stirring. Thereafter, the catalytically active species is added to the alkali metal concentration of the zeolite carrier of 1 to 100.
A metal salt solution containing a concentration equivalent to mol times is added. Thereafter, the mixture is stirred in the range of 40 to 100 ° C for 0.5 to 48 hours,
Allow ion exchange to proceed. After ion exchange, the resultant is filtered, washed, and dried at a temperature of 60 to 150 ° C. for 1 to 120 hours to obtain a catalyst powder. The zeolite-based carrier may be, but is not limited to, crystalline silicate, Y-type zeolite, A-type zeolite, β-type zeolite, mordenite, or ferrierite. As a solution of a metal salt in which a catalytically active species is present, a tetraammine platinum hydroxide solution,
Tetraammine platinum chloride solution, tetraammine platinum nitrate solution, hexaammine platinum hydroxide solution, hexaammine platinum chloride solution, hexaammine platinum nitrate solution, ruthenium nitrate, hexaammine ruthenium hydroxide solution, hexaammine ruthenium chloride solution,
Hexamin ruthenium nitrate solution, palladium nitrate, tetraammine palladium hydroxide solution, tetraammine palladium chloride solution, tetraammine palladium nitrate solution, hexaammine iridium hydrochloride solution, hexaammine iridium chloride solution, hexaammine iridium nitrate solution, rhodium nitrate, hexa Ammine rhodium hydroxide solution, hexaammine rhodium chloride solution, hexaammine rhodium nitrate solution,
Chromium chloride, cobalt chloride, nickel chloride, copper chloride, iron chloride or tin chloride can be used, but is not limited as long as it contains a metal salt that is a catalytically active species. Among these, hydroxides (hydrates), which tend to easily exchange ions with the catalytically active species, are particularly preferred.

[Preparation of catalyst] 1 part by weight of silica sol (containing SiO ₂ ) to 100 parts by weight of the obtained catalyst powder
After adding 50 parts by weight and ion-exchanged water to prepare a slurry having a solid content concentration of 1 wt% to 50 wt%, wash-coat and prepare, for example, a honeycomb-shaped catalyst.

[Preparation of Crystalline Silicate] A method of preparing the above-mentioned crystalline silicate as a zeolite-based carrier will be described. 100 parts by weight of Water Glass No. 1 (containing SiO ₂ ) is dissolved in 100 parts by weight of water. On the other hand, aluminum sulfate, ferric chloride, calcium acetate, sodium chloride, and concentrated hydrochloric acid are dissolved in water. The solution A and the solution B are supplied at a constant ratio to form a precipitate, and the mixture is sufficiently stirred to obtain a PH8 slurry. This slurry was charged into an autoclave, and tetrapropylammonium bromide was further added.
Hydrothermal synthesis at 00 ° C for 1 hour to 100 hours, after synthesis, washing with water, drying, and further firing at 300 ° C to 600 ° C for 1 hour to 12 hours to obtain crystalline silicate in a dehydrated state Get.

[Polymer-type fuel cell (PEFC device)] Next, PEF using the low-temperature oxidation catalyst according to the present invention.
An embodiment of the C apparatus will be described. FIG.
1 is a block diagram illustrating an outline of an embodiment of a PEFC device to which a low-temperature oxidation catalyst is suitably applied.
The PEFC device 1 includes an LTS device 2, a PROx device 3, a fuel cell 4, an evaporator 5, and an exhaust gas combustor 6.
These devices function according to the steady state gas flow shown by the bold solid line. The function will be described together with the outline of each device. Incidentally, the carbon monoxide selective oxidation catalyst according to the present invention,
Used in the PROx device 3.

LTS (low temperature)
shift) device is provided by a methanol reforming catalyst,
This is a device for performing methanol reforming, receives methanol and water, and obtains hydrogen from methanol by the following reaction. CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ (1) CH ₃ OH + 1 / 2O ₂ → CO + H ₂ + H ₂ O (2) CO + H ₂ O → CO ₂ + H ₂ (3) The reaction (1) reforms methanol. This is a reaction for obtaining hydrogen. This reaction (1) is an endothermic reaction. Therefore, heat for maintaining the reforming reaction is obtained by the reaction (2) which is an exothermic reaction. However, in this reaction (2), CO is generated. CO hinders the operation of the fuel cell 4. Therefore, CO is removed by the reaction (3).

The gas from the LTS device 2 adds air,
It is sent to the PROx device 3. The PROx device 3 is a device for selectively removing CO by the carbon monoxide selective oxidation catalyst according to the present invention.
O is removed. CO + ／ O ₂ → CO ₂ (4) CO generated in the LTS device 2 is removed by the reaction (3). However, in the LTS device 2, 0.3 to 0.
It has been removed to 4%. The PROx device 3 further removes CO to 20 ppm or less. Note that the carbon monoxide selective catalyst according to the present invention is preferably used for this device.

The gas containing hydrogen from the PROx device 3 is:
It is sent to the fuel cell 4. The fuel cell 4 includes an anode electrode 7
In the above, the following reaction is caused by the anode electrode catalyst. H ₂ → 2H ⁺ + 2e ⁻ (5) H ⁺ generated by this reaction (5) diffuses. on the other hand,
The following reaction is caused in the cathode electrode 8 by the cathode electrode catalyst. 2H ⁺ + 2e ⁻ + ／ O ₂ → H ₂ O (6) These reactions (5) and (6) constitute a battery reaction, and an electromotive force can be obtained.

The off-gas from the fuel cell 4 is sent to an evaporator 5. The evaporator 5 has a function of gasifying water and methanol by using an attached combustor to burn about 20% of hydrogen contained in the off-gas with the low-temperature oxidation catalyst (low-temperature combustion catalyst) according to the present invention. . Gasified water,
The methanol is sent to the LTS device 2 as described above. Further, the exhaust gas combustor 6 completely combusts the remaining hydrogen with the low-temperature oxidation catalyst (low-temperature combustion catalyst) according to the present invention.

Heat exchangers 9, 10 and 11 are provided at the inlet of the fuel cell 4, the fuel cell 4 and the exhaust gas combustor 6, and cooling water is circulated from a cooling water source 12 by a circulation pump 13. The cooling water flows in the circulation line 14 (dotted line), and the temperature in the line 14 is detected by a temperature sensor (not shown). The temperature information from the temperature sensor is sent to the control system, and the temperature in the PROx device 3 and the fuel cell 4 is appropriately maintained by appropriately controlling the flow rate.

Further, the PEFC device 1 has an activation system. First, water and methanol are heated and evaporated by the electric heater 20 in advance, and are sent to the burner 21. Add air here to burn some of the methanol,
Raise the temperature to 250 ° C. Air is further added to the heated gas and sent to the LTS device 2. In the LTS device 2, the above-described reaction occurs. Then, as described above, the PROx device 3 also selectively oxidizes and removes CO. The PROx device 3 cannot sufficiently reduce the CO concentration unless the temperature exceeds 100 ° C. The PROx device 3 is operated on the starting route until the temperature inside the PROx device 3 becomes 100 ° C. or more. When the operation is switched to the steady operation, the use of the burner 21 and the like is stopped. The gas from the PROx device 3 is sent to the fuel cell 4 to be in a state of obtaining electricity.

The carbon monoxide selective catalyst according to the present invention comprises H ₂
Carbon monoxide can be selectively oxidized and burned in the mixed gas containing CO and CO.
H ₂ in oxidizing the is never hindered that oxidizes earlier.

[0021]

EXAMPLES Example 1 Preparation of Crystalline Silicate, Preparation of Catalyst by Ion Exchange Method Next, the result of preparing a catalyst by an ion exchange method using crystalline silicate as a raw material will be described. Water glass No. 1 (containing 30 wt% of SiO ₂ )
5616 g was dissolved in 5429 g of water.
And On the other hand, aluminum sulfate 71 was added to 4175 g of water.
8.9 g, ferric chloride 110 g, calcium acetate 47.
2 g, 262 g of sodium chloride and 2020 g of concentrated hydrochloric acid were dissolved. Solution A and solution B are supplied at a constant rate to form a precipitate, and the mixture is sufficiently stirred to adjust the pH to 8
Was obtained. This slurry was charged into a 20-liter autoclave, and 500 g of tetrapropylammonium bromide was further added. Hydrothermal synthesis was performed at 160 ° C. for 72 hours. H
₂ O [0.25Fe ₂ O ₃ .0.8Al ₂ O ₃ .0.2Ca
A crystalline silicate 1 having a composition of [O] 27SiO ₂ was obtained.

With respect to the obtained crystalline silicate 1, C
The powder X-ray diffraction measurement using uKα ray was performed, and the lattice spacing (d value) and the relative intensity of the peaks from the strongest line to the 15th position are shown in Table 1 below. As is clear from Table 1, the crystalline silicate 1 has a lattice spacing of 3.65 ± 0.1 ° and 3.75 ± in powder X-ray diffraction measurement using CuKα radiation.
The peaks from the strongest peak to the fifth place are shown at 0.1 °, 3.85 ± 0.1 °, 10.0 ± 0.3 ° and 11.2 ± 0.3 °, and the lattice spacing is 3.0 ± 0.1 °. 3.3 ±
0.1 °, 4.25 ± 0.1 °, 5.6 ± 0.2 °,
The peaks from the 6th position to the 11th position are shown at 6.0 ± 0.2 ° and 6.4 ± 0.2 °, and 3.05 ± 0.1 °,
4.6 ± 0.1%, 5.7 ± 0.2 ° and 6.7 ± 0.
The peaks from the twelfth to the fifteenth are shown in FIG. Further, the amount of Na ⁺ in the obtained crystalline silicate 1 was measured by ICP and found to be 1.0 mmol / g.

[Table 1]

The crystalline silicate 1 is heated at 75.degree.
Was immersed in a solution of 10 mmol of tetraammine platinum hydroxide and stirred for 12 hours to carry out Pt ion exchange. After ion exchange, the resultant was filtered, washed with water, and dried at 110 ° C. overnight to obtain a catalyst powder 1. Obtained catalyst powder 1
100 parts by weight of silica sol (SiO ₂ : 20 wt%)
50 parts and ion-exchanged water to prepare a slurry having a solid content concentration of 20 wt%, and then 62 cells / cm ²
A honeycomb catalyst 1 was prepared by wash-coating such that the solid content per unit surface area of the cordierite honeycomb substrate (400 cells / inch ² ) was 60 g / m ² .

[Example 2: Preparation by ion exchange method using another zeolite as a carrier] Instead of the crystalline silicate 1 of Example 1, Y-type zeolite, A-type zeolite, β-type zeolite, mordenite, and ferrierite are used. Except for the above, the powder catalysts 2 to 6 were the same as in Example 1 described above.
I got Next, honeycomb catalysts 2 to 6 were obtained in the same manner as in Example 1 except that powder catalysts 2 to 6 were used. (See Table 2)

[Table 2]

Example 3 Preparation by Ion Exchange Method Using Another Active Metal as an Active Species Next, the catalyst of Example 1 in which the raw material of the active metal to be ion-exchanged was changed will be described. As a raw material of the active metal to be ion-exchanged in Example 1, in addition to a tetraammine platinum hydroxide solution, a tetraammine platinum chloride solution, a tetraammine platinum nitrate solution, a hexaammine platinum hydroxide solution, a hexaammine platinum chloride solution, and a hexaammine platinum nitrate solution Solution, ruthenium nitrate, hexaammine ruthenium hydroxide solution, hexaammine ruthenium chloride solution, hexaammine ruthenium nitrate solution, palladium nitrate, tetraammine palladium hydroxide solution, tetraammine palladium chloride solution, tetraammine palladium nitrate solution, hexaammineiridium hydroxide Salt solution, hexaammine iridium chloride solution, hexaammine iridium nitrate solution, rhodium nitrate, hexaammine rhodium hydroxide solution, hexaammine iridium chloride solution Rhodium chloride solution, hexamine rhodium nitrate solution, chromium chloride, cobalt chloride, nickel chloride, copper chloride, but using iron chloride or tin chloride to obtain a powder catalyst 7-32 in the same manner as in Example 1 described above. Next, a honeycomb catalyst 7 was prepared in the same manner as in Example 1 except that the powder catalysts 7 to 32 were used.
~ 32 were obtained. (See Table 2)

Comparative Example 1: Preparation by impregnation method Next, as a comparative example, preparation of a catalyst by an impregnation method instead of an ion exchange method will be described. The carrier made of crystalline silicate 1 was impregnated with an aqueous solution of chloroplatinic acid to obtain a Pt of 1 m per 1 g of the carrier.
After being supported by mol, dried and calcined at 500 ° C., Comparative Powder Catalyst 1 was obtained. Next, a comparative honeycomb catalyst 1 was obtained in the same manner as in Example 1 except that the comparative powder catalyst 1 was used. (See Table 2) The impregnation method used here is a preparation in which a chloroplatinic acid solution is added to a carrier, and then the water is gradually removed by evaporation to dryness while kneading to obtain a dry powder. That's how.

[Measurement of ion exchange capacity] Next, the results of confirming the ion exchange capacity of the obtained ion exchange powder catalysts 1 to 32 and the filtrate after the ion exchange by ICP analysis will be described. As shown in Table 2, the Pt concentration in the powder catalyst after the ion exchange and the Na concentration in the filtrate were almost the same as the Na concentration in the powder catalyst before the ion exchange. You can see that it is. In the comparative powder catalyst 1, although Pt is supported in a predetermined amount,
a is also present in the same amount as before impregnation, indicating that ion exchange has not progressed.

[CO selective oxidation test] Honeycomb catalysts 1 to 3
The CO selective oxidation test in Comparative Catalyst 2 and Comparative Honeycomb Catalyst 1 will be described. The test conditions are described in Table 3. During the test, the CO concentration of the gas discharged from the outlet of the reaction tube was continuously monitored by a CO analyzer of an ND-IR system, and then the stabilized CO concentration was measured, and the measured value was regarded as the CO selective oxidation performance of the catalyst. . As shown in Table 4, the honeycomb catalysts 1 to 32 prepared by the ion exchange method can lower the CO concentration in the processing gas in a wide temperature range of 110 ° C. to 230 ° C. at the inlet of the reaction tube. I understand. On the other hand, it can be seen that the comparative honeycomb catalyst 1 prepared by the impregnation method had insufficient removal of CO in the processing gas when the reaction tube inlet temperature was 230 ° C. The reason that the carbon monoxide selective oxygen catalyst prepared by this ion exchange method was superior to the catalyst prepared by the impregnation method in the effect of reducing the CO concentration was that the catalytically active species was coordinated to the carrier by ion exchange. This is because the specific surface area of the catalyst is increased, and the reaction of the catalytically active species is improved.

[Table 3]

[Table 4]

[0029]

As is apparent from the above description, according to the present invention, CO is selectively oxidized and burned in a mixed gas containing H ₂ and CO in a PROx device of a polymer electrolyte fuel cell device. A method for producing a carbon monoxide selective oxidation catalyst is provided. The carbon monoxide selective oxidation catalyst provided by the present invention is particularly suitable for use in a PROx device of a polymer electrolyte fuel cell device of a hydrogen fueled vehicle. In addition, since the method for producing the carbon monoxide selective oxidation catalyst of the present invention is based on the ion exchange method, the calcination step required for the production by the impregnation method is unnecessary. For this reason, the production of the carbon monoxide selective oxidation catalyst can be simple and inexpensive. Further, carbon monoxide can be selectively oxidized in a wide temperature range as compared with a catalyst prepared by the impregnation method.

[Brief description of the drawings]

FIG. 1 shows a PEFC using a low-temperature oxidation catalyst according to the present invention.
It is a conceptual diagram explaining one Embodiment of an apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PEFC apparatus 2 LTS apparatus 3 PROx apparatus 4 Fuel cell 5 Evaporator 6 Exhaust gas combustor 7 Anode electrode 8 Cathode electrode 9, 10, 11 Heat exchanger 12 Cooling water source 13 Circulation pump 14 Circulation line 20 Electric heater 21 Burner

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B01J 29/76 B01J 29/76 M 5H027 29/78 29/78 M C10K 1/34 C10K 1/34 H01M 8 / 06 H01M 8/06 G 8/10 8/10 // C01B 3/32 C01B 3/32 A (72) Inventor: Toshinobu Yasutake 4-6-22 Kanon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Research by Mitsubishi Heavy Industries, Ltd. Hiroshima In-plant F-term (reference) 4G040 EA02 EA06 EA07 EB31 4G069 AA01 AA08 BA07A BA07B BC01A BC09A BC10A BC12A BC13A BC17A BC22A BC22B BC26A BC31A BC31B BC38A BC50A BC54A BC55A BC58A BC68 BC66 BCA BC66 BCA BC66 BCBC ZA01A ZA01B ZA02A ZA02B ZA04A ZA04B ZA06A ZA06B ZA13A ZA13B ZA19A ZA19B ZC02 ZC04 ZD01 4G140 EA02 EA06 EA07 EB31 4H060 AA04 BB11 B B33 DD01 EE03 FF02 GG02 5H026 AA06 5H027 AA06 BA09 BA17

Claims (6)

[Claims] 1. A method for producing a carbon monoxide selective oxidation catalyst for causing a selective oxidation reaction of CO in a mixed gas containing CO, wherein a catalyst carrier is added to a solvent, and a catalytically active species is further added to the solvent. A method for producing a carbon monoxide selective oxidation catalyst, which comprises adding the catalyst to the inside. 2. A zeolite-based support is used as the catalyst support, and after the zeolite-based support is further added to water used as the solvent, the metal salt that is the catalytically active species is added to water to form a zeolite-based support. 2. The method for producing a carbon monoxide selective oxidation catalyst according to claim 1, comprising ion-exchanging the alkali metal or H element of the above with the metal element in the metal salt. 3. The zeolite-based carrier is at least one selected from the group consisting of crystalline silicate, Y-type zeolite, A-type zeolite, β-type zeolite, mordenite, and ferrierite. 3. The method for producing a carbon monoxide selective oxidation catalyst according to item 1. 4. The method according to claim 1, wherein the crystalline silicate is (1 ± 0.
8) R_TwoO ・ [aM_TwoO _Three・ BLO ・ cAl_TwoO_Three] ・ YS
iO_TwoWherein R is an alkali gold
At least selected from the group consisting of the genus and H
M is a group VIII element, a rare earth element, T
a group consisting of i, V, Cr, Nb, Sb and Ga
L is at least one element selected from
g, Ca, Sr and Ba.
At least one element, and the molar ratios a, b, c and
And y is 0 ≦ a, 0 ≦ b ≦ 20, a + b = 1 and 11
≦ y ≦ 3000, and a powder X-ray cycle using CuKα ray
3.65 ± 0.1Å, 3.75 ± 0.1
{3.85 ± 0.1}, 10.0 ± 0.3} and 1
Peak from strongest peak to fifth place at 1.2 ± 0.3
4. The carbon monoxide according to claim 3, wherein
A method for producing a selective oxidation catalyst. 5. The method according to claim 1, wherein the metal salt is Pt, Ru, Pd, R
at least one metal selected from the group consisting of h, Ir, Cr, Co, Ni, Cu, Fe and Sn, in the form of nitrate, sulfate, chloride, acetate or hydroxide. The method for producing a carbon monoxide selective oxidation catalyst according to any one of claims 2 to 4. 6. A carbon monoxide selective oxidation catalyst for causing a selective oxidation reaction of CO in a mixed gas containing CO, the monoxide being produced by the production method according to any one of claims 1 to 6. Carbon selective oxidation catalyst.