Catalyst for hydrogen combustion reaction, catalyst composition using the same, method for hydrogen combustion or methane production using the same, and method for producing the catalyst composition

Abstract

To provide a novel catalyst for hydrogen combustion reaction.SOLUTION: A catalyst for hydrogen combustion reaction comprises at least one kind selected from the group consisting of silver carbonate (Ag2CO3), silver acetate (CH3COOAg), and silver oxide (Ag2O).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a catalyst for hydrogen combustion reaction, a catalyst composition using the same, a hydrogen combustion method or a methane production method using them, and a method for producing the catalyst composition.

Background Art

[0002] The combustion reaction of hydrogen is represented by the following formula (1). H 2 + 1 / 2O 2 = H 2 O + 284kJ ··· (1)

[0003] As shown in formula (1), high energy can be obtained by burning hydrogen.

[0004] In order to burn hydrogen more efficiently, the use of a catalyst is considered. Patent Document 1 discloses a catalyst composition including a hydrogen oxidation catalyst (HOC) that dissociates surface molecular hydrogen into hydrogen radicals and an oxygen reduction catalyst (ORC) that dissociates surface molecular oxygen into oxygen radicals.

Prior Art Documents

Non-Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the technology disclosed in Patent Document 1, in addition to the carrier, two materials, HOC and ORC, are essential, and HOC is palladium or platinum, etc., and there are concerns such as insufficient supply and / or high cost, and a new catalyst for hydrogen combustion reaction to replace it is required.

[0007] The present disclosure has been made in view of such a situation, and one of its objects is to provide a novel catalyst for hydrogen combustion reaction.

Means for Solving the Problems

[0008] Aspect 1 of the present invention is a catalyst for hydrogen combustion reaction containing at least one selected from the group consisting of silver carbonate (Ag 2 CO 3 ), silver acetate (CH 3 COOAg), and silver oxide (Ag 2 O).

[0009] Aspect 2 of the present invention is a catalyst for hydrogen combustion reaction containing at least one selected from the group consisting of silver carbonate (Ag 2 CO 3 ) and silver acetate (CH 3 COOAg).

[0010] Aspect 3 of the present invention is a catalyst composition including a metal oxide carrier and the catalyst for hydrogen combustion reaction according to Aspect 1 or 2 in contact with the metal oxide carrier.

[0011] Aspect 4 of the present invention is the catalyst composition according to Aspect 3, further including a catalyst for CO 2 reduction reaction containing at least one selected from the group consisting of nickel, iron, cobalt, and copper in contact with the metal oxide carrier.

[0012] Aspect 5 of the present invention is the catalyst composition according to Aspect 3 or 4, wherein the metal oxide carrier includes at least one selected from the group consisting of alumina, zirconia, titania, and zinc oxide.

[0013] Aspect 6 of the present invention is a step of disposing the catalyst for hydrogen combustion reaction according to Aspect 1 or 2, or the catalyst composition according to Aspect 3, in a container; A step of heating the container to a temperature of 80°C or higher and lower than 450°C; A step of supplying hydrogen and oxygen into the container, which is a hydrogen combustion method.

[0014] Aspect 7 of the present invention is A step of disposing the catalyst composition described in Aspect 4 in a container; A step of heating the container to a temperature of 80°C or higher and 350°C or lower; A step of supplying hydrogen, oxygen, and carbon dioxide into the container, which is a method for producing methane.

[0015] Aspect 8 of the present invention is A step of disposing the catalyst composition described in Aspect 4 in a container; A step of heating the container to a temperature of 80°C or higher and 350°C or lower; A step of supplying hydrogen, oxygen, and carbon dioxide into the container so that the pressure inside the container becomes 0.1 to 20 MPa, which is a method for producing methanol.

[0016] Aspect 9 of the present invention is A step of disposing the catalyst composition described in Aspect 4 in a container; A step of heating the container to a temperature of 80°C or higher and 350°C or lower; A step of supplying hydrogen, oxygen, and carbon dioxide into the container so that the pressure inside the container becomes 0.1 to 10 MPa, which is a method for producing formaldehyde.

[0017] Aspect 10 of the present invention is A step of disposing the catalyst composition described in Aspect 4 in a container; A step of heating the container to a temperature of 80°C or higher and 350°C or lower; A step of supplying hydrogen, oxygen, and carbon dioxide into the container so that the pressure inside the container becomes 0.1 to 10 MPa, which is a method for producing formic acid.

[0018] Aspect 11 of the present invention is ​​​​A method for producing the catalyst composition according to Aspect 4, comprising: A CO reduction reaction catalyst oxide containing at least one oxide selected from the group consisting of nickel, iron, cobalt, and copper, which is in contact with a metal oxide support 2 heating and reducing the CO reduction reaction catalyst oxide to 100 to 650 ° C in a hydrogen-containing gas atmosphere; after the reducing step, mixing the metal oxide support and the catalyst for hydrogen combustion reaction; A method for producing a catalyst composition comprising:

[0019] Aspect 12 of the present invention is The method for producing a catalyst composition according to Aspect 11, wherein the metal oxide support contains at least one selected from the group consisting of alumina, zirconia, titania, and zinc oxide.

Advantages of the Invention

[0020] According to an embodiment of the present invention, it is possible to provide a novel catalyst for hydrogen combustion reaction.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0022] The present inventors have studied from various angles in order to realize a novel catalyst for hydrogen combustion reaction. As a result, silver carbonate (Ag 2 CO 3 ), silver acetate (CH 3 COOAg) and silver oxide (Ag 2It has been found for the first time that a catalyst containing at least one selected from the group consisting of (O) can be used as a catalyst for hydrogen combustion reaction. This is considered to be due to the fact that the catalyst can generate highly active hydrogen ions (for example, hydride ions). This novel catalyst, unlike the prior art disclosed in Patent Document 1, does not require two kinds of materials such as HOC and ORC in addition to the carrier, nor does it require palladium or platinum, etc. It uses an Ag compound that is superior in supplyability and can be made at low cost. Further, this novel catalyst is suitable as a catalyst for hydrogen combustion reaction and can efficiently burn hydrogen (for example, at a lower temperature than usual). Further, by this hydrogen combustion reaction, the temperature can rise by 20°C or more with respect to the temperature of the container in which the catalyst is disposed, for example, and the heat can be used for other reactions or the like. Details of each requirement defined by the embodiments of the present invention are shown below.

[0023] <1. Catalyst for hydrogen combustion reaction> The catalyst for hydrogen combustion reaction according to the embodiment of the present invention contains at least one selected from the group consisting of silver carbonate (Ag 2 CO 3 ), silver acetate (CH 3 COOAg), and silver oxide (Ag 2 O). The above catalyst is a novel catalyst for hydrogen combustion reaction that is excellent in supplyability and can be made at low cost. The above catalyst can be preferably used as a catalyst for hydrogen combustion reaction and can efficiently burn hydrogen (for example, at a lower temperature than usual). Further, by this hydrogen combustion reaction, the temperature can rise by 20°C or more with respect to the temperature of the container in which the catalyst is disposed, for example, and the heat can be used for other reactions or the like. Preferably, it contains at least one selected from the group consisting of silver carbonate and silver acetate. Thereby, hydrogen can be burned more efficiently (for example, at a lower temperature). This is considered to be due to the fact that the decomposition temperature of silver oxide is about 300°C, which is higher than that of silver acetate (about 210°C) and silver carbonate (about 150°C), and a more stable surface state is formed compared to other compounds, resulting in fewer active sites on the surface than silver acetate and silver carbonate.

[0024] The inventors have found that the catalyst for hydrogen combustion reaction according to the embodiment of the present invention has the effect of dissociating hydrogen molecules in the supplied oxygen-containing gas into highly active hydrogen ions (for example, hydride ions). First, as a result of calculations by the molecular orbital method (restricted Hartree-Fock method calculations (see A. Szabo and N. S. Ostlund, “Modern Quantum Chemistry”, (USA), McGraw-Hill publishing company, New York, 1989)), silver carbonate (Ag 2 CO 3 ) and silver acetate (CH 3 COOAg), it has been found that highly active hydrogen ions (for example, hydride ions) can be generated by the dissociation of hydrogen molecules. An example of the above calculation results is shown in FIG. 1. FIG. 1 shows the changes in the most stable structures and electrostatic potential maps of carbonates and acetates in the gas phase with and without hydrogen (upper figure and lower figure). In FIG. 1, in addition to Rb and Cs, which are generally considered to have high catalytic activity in the reaction with hydrogen, Ag is selected as the metal species, and the changes in the electrostatic potential maps of its carbonates (Rb, Cs, and Ag) and acetate (only Ag) are shown. Regarding FIG. 1, in order to better understand the changes with and without hydrogen, the color original drawing has been submitted simultaneously with this application and the basic application (Japanese Patent Application No. 2023-202513) as a property submission document. Please refer to this original drawing as needed. In the color original drawing, the red region indicates that it is charged with a negative charge, the blue region indicates that it is charged with a positive charge, and the green region indicates that it is not charged. As shown in FIG. 1, in the gas phase, when comparing the same carbonates, only when the metal species is Ag, the electrostatic potential map changes from without hydrogen (upper figure) to with hydrogen (lower figure), suggesting the decomposition of hydrogen and the generation of highly active hydrogen ions (for example, hydride ions). Similarly, in the acetate of Ag (the rightmost figure), the generation of highly active hydrogen ions was also suggested.

[0025] The present inventors have found that, similar to silver carbonate and silver acetate, in silver oxide as well, the dissociation of hydrogen molecules can generate highly active hydrogen ions (e.g., hydride ions). An example of the calculation results for silver oxide is shown in FIG. 2. FIG. 2 shows the changes in the most stable structures and electrostatic potential maps of carbonates and acetates in the gas phase with (bottom figure) and without (top figure) hydrogen. Regarding FIG. 2 as well, in order to better understand the changes with and without hydrogen similar to FIG. 1, the color original drawing has been submitted simultaneously with this application as a property submission document. Please refer to this original drawing as needed. As shown in FIG. 2, in silver oxide as well, the electrostatic potential map changes when going from without hydrogen (top figure) to with hydrogen (bottom figure), suggesting the decomposition of hydrogen and the generation of highly active hydrogen ions (e.g., hydride ions).

[0026] Moreover, based on the calculations of the present inventors, it is presumed that the above phenomenon also occurs in the aqueous phase. Generally, the presence of a large amount of water around the catalytic active site inhibits its catalytic activity, but the generation of water in the hydrogen combustion of the present disclosure is considered to advantageously act on the generation of highly active hydrogen ions (e.g., hydride ions) and the stabilization of the ionic state after generation. Note that as the basis function system for this calculation, 6-31G(d,p) obtained by adding a polarization function to 6-31G was used. As a similar calculation method, reference can be made to P.C. Hariharan and J.A. Pople, “Molecular Physics”, (English), 1974, vol. 27, p. 209-214. Also, the program used for the quantum chemical calculations in the present invention was “Spartan’20 for Windows (64-bit) Version 1.1.2” (Spartan’20 for Windows (64-bit) Version 1.1.2 (Wavefunction, Inc.)).

[0027] The catalyst for hydrogen combustion reaction according to an embodiment of the present invention is silver carbonate (Ag 2 CO 3 ), silver acetate (CH 3 COOAg) and silver oxide (Ag 2There is no particular limitation on the content of at least one selected from the group consisting of (O), and it can be, for example, 1% by mass or more. The said content is preferably 10% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more in order. The catalyst for hydrogen combustion reaction according to the embodiment of the present invention is silver carbonate (Ag 2 CO 3 ), silver acetate (CH 3 COOAg) and silver oxide (Ag 2 O) and more preferably consists of at least one selected from the group consisting of inevitable impurities.

[0028] The form and size of the catalyst for hydrogen combustion reaction according to the embodiment of the present invention are not particularly limited. For example, the catalyst for hydrogen combustion reaction according to the embodiment of the present invention may be a powder. If it is a powder, it is preferable to appropriately adjust the particle size and / or surface area, etc.

[0029] <2. Catalyst composition containing catalyst for hydrogen combustion reaction> The catalyst composition according to an embodiment of the present invention includes a metal oxide carrier and the catalyst for hydrogen combustion reaction described in Mode 1 that is in contact with the metal oxide carrier. The said catalyst composition can be preferably used as a catalyst composition for hydrogen combustion reaction. The said catalyst composition can efficiently utilize the heat generated by hydrogen combustion due to the far-infrared radiation characteristics of the metal oxide carrier.

[0030] Examples of the metal oxide include alumina (Al 2 O 3 ), silica (SiO 2 ), titania (TiO 2 ), zirconia (ZrO 2 ), cerium oxide (CeO 2 ), magnesia (MgO), lanthanum oxide (La 2 O 3 ), samarium oxide (Sm 2 O 3) Zinc oxide (ZnO) etc. can be used. From the viewpoint of far-infrared radiation characteristics, the metal oxide preferably contains at least one selected from the group consisting of alumina, zirconia, titania and zinc oxide. As the alumina, α-Al 2 O 3 is suitable. This α-Al 2 O 3 generally has a specific surface area of 0.8 to 15 m 2 / g and has a high surface area, so that the catalyst can be more easily adhered. In another embodiment, the metal oxide is preferably a single zinc oxide or a mixture of alumina and zinc oxide. Thereby, it becomes easier to promote the CO 2 reduction reaction (in particular, any one or more of methanol synthesis reaction, formaldehyde synthesis reaction and formic acid synthesis reaction). When it is a mixture of alumina and zinc oxide, the content of zinc oxide in the mixture is preferably 1% by mass or more, more preferably 25% by mass or more, still more preferably 50% by mass or more, and even more preferably 75% by mass or more.

[0031] The form and size of the metal oxide carrier are not particularly limited. For example, the catalyst for hydrogen combustion reaction according to the embodiment of the present invention may be in powder form. If it is in powder form, it is preferable to appropriately adjust the particle size and / or surface area etc.

[0032] The total content of the metal oxide carrier and the catalyst for hydrogen combustion reaction in the catalyst composition according to an embodiment of the present invention is not particularly limited, and can be, for example, 1% by mass or more, and preferably 10% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more in order. The catalyst composition according to an embodiment of the present invention more preferably consists of a metal oxide carrier, a catalyst for hydrogen combustion reaction and inevitable impurities.

[0033] In the catalyst composition according to an embodiment of the present invention, the mass ratio of the metal oxide carrier and the catalyst for hydrogen combustion reaction is not particularly limited. For example, the mass ratio of the metal oxide carrier to the catalyst for hydrogen combustion reaction can be 1:99 to 99:1. In order to utilize more efficiently the heat generated by hydrogen combustion at a lower cost, it is preferable to increase the ratio of the metal oxide carrier. For example, the mass ratio of the metal oxide carrier to the catalyst for hydrogen combustion reaction is preferably 50:50 to 99:1, and more preferably 75:25 to 99:1.

[0034] The form and size of the catalyst composition according to an embodiment of the present invention are not particularly limited, and it may be a powder or a molded body. If it is a powder, it is preferable to appropriately adjust the particle size and / or surface area, etc. If it is a molded body, it is preferable to appropriately adjust the pore volume, pore diameter, shape, etc. in consideration of the surface area and strength, etc. The shape of the molded body is not particularly limited and may be any of spherical, cylindrical, ring-shaped, wheel-shaped, granular, plate-shaped, etc.

[0035] The catalyst composition according to an embodiment of the present invention can be produced by bringing the catalyst for hydrogen combustion reaction into contact with the metal oxide carrier, and the method is not particularly limited. For example, a method of mixing the metal oxide carrier and the catalyst for hydrogen combustion reaction can be mentioned. The method of obtaining the metal oxide carrier and the catalyst for hydrogen combustion reaction is not particularly limited, and commercially available ones may be used.

[0036] <3. Hydrogen combustion method using a catalyst for hydrogen combustion reaction and a catalyst composition containing the same> The hydrogen combustion method according to an embodiment of the present invention includes a step of disposing the above-mentioned catalyst for hydrogen combustion reaction or the above-mentioned catalyst composition in a container, a step of heating the container to 80°C or higher and lower than 450°C, and a step of supplying hydrogen and oxygen into the container. Thereby, hydrogen can be burned efficiently.

[0037] The container is not particularly limited as long as it can dispose the above-mentioned catalyst for hydrogen combustion reaction or the above-mentioned catalyst composition. As the material, those having heat resistance so as to withstand the heating temperature are preferable, and examples thereof include glass (such as quartz glass) and stainless steel.

[0038] The minimum ignition temperature of hydrogen can be 450 °C in the presence of oxygen. As the catalyst for hydrogen combustion reaction according to the embodiments of the present invention, hydrogen can be combusted at a heating temperature lower than that. Specifically, the heating temperature of the container in which the catalyst for hydrogen combustion reaction is disposed can be less than 450 °C, preferably 400 °C or lower, more preferably 300 °C or lower, and still more preferably 200 °C or lower. Further, by heating the container in which the catalyst for hydrogen combustion reaction is disposed to 80 °C or higher, more hydrogen can be combusted. The heating temperature is preferably 90 °C or higher, more preferably 100 °C or higher.

[0039] The supply amount ratio, supply rate, supply method, etc. of hydrogen and oxygen are not particularly limited. For example, the supply amount ratio of hydrogen amount / oxygen amount is preferably 0.5 to 60 in terms of volume ratio, more preferably 1 to 20, and still more preferably 2 to 10. Thereby, the hydrogen combustion reaction can be promoted. Also, other gases other than hydrogen and oxygen may be mixed and supplied. For example, an inert gas such as nitrogen and / or argon may be mixed. The total amount of hydrogen and oxygen in the mixed gas is not particularly limited, but is preferably 1% by volume or more, more preferably 10% by volume or more, and still more preferably 20% by volume or more. Thereby, the hydrogen combustion reaction can be promoted. Further, as will be described later, by further mixing and supplying carbon dioxide, a 2 methanation reaction can also occur.

[0040] The method for obtaining hydrogen and oxygen is not particularly limited. For example, as hydrogen, in addition to those available on the market, hydrogen obtained from water electrolysis using renewable energy such as sunlight, wind power, and hydropower, oxidation of water using artificial photosynthesis technology, steam reforming of petroleum-based resources, gasification of coal and / or petrocoke, etc. can also be used. From the viewpoint of reducing carbon dioxide emissions, it is preferable to use hydrogen obtained by water electrolysis using renewable energy-derived power or oxidation of water using artificial photosynthesis technology. Thereby, hydrogen and oxygen can be obtained simultaneously and used as raw materials in the hydrogen combustion method according to the embodiments of the present invention.

[0041] <4.CO 2 Catalyst composition for reduction reaction> The catalyst composition according to another embodiment of the present invention is the catalyst composition according to one embodiment of the present invention (i.e., the metal oxide carrier and the catalyst for hydrogen combustion reaction in contact with the metal oxide carrier), and a CO reduction reaction catalyst containing at least one selected from the group consisting of nickel, iron, cobalt, and copper, which is in contact with the metal oxide carrier 2 and a reduction reaction catalyst, and includes. The catalyst composition can be preferably used as a CO reduction reaction catalyst composition. The inventors have found that, with the above catalyst, the heat generated by hydrogen combustion using the catalyst composition according to one embodiment of the present invention can be utilized for the CO reduction reaction, and one or more selected from the group consisting of methane (CH 2 ), methanol (CH 2 OH), formaldehyde (HCHO), and formic acid (HCOOH) can be efficiently generated. Specifically, whether the CO reduction reaction can occur at a lower heating temperature of the container in which the catalyst is disposed, and / or, even if the heating temperature is the same, one or more selected from the group consisting of the CO conversion rate, CH 4 selectivity, CH 3 production rate, CH 2 OH selectivity, CH 2 OH production rate, HCHO selectivity, HCHO production rate, HCOOH selectivity, and HCOOH production rate described below can be improved. 4 4 3 3

[0042] CO 2 The reduction reaction catalyst (composition) can contain methane in its reaction product, so it can also be referred to as a catalyst (composition) for the methanation reaction. Methane is the main component of natural gas and is widely used as a clean fuel. CO 2 2 ​​​​​By synthesizing methane, a sustainable energy supply that does not rely on fossil fuels becomes possible, contributing to energy security and sustainable development. CO 2 Since the catalyst (composition) for the reduction reaction may contain methanol in its reaction product, it may also be referred to as a catalyst (composition) for the methanol synthesis reaction. Methanol is used not only as a fuel but also as a raw material for various chemical products. By synthesizing methanol from CO 2 it is possible to reduce the consumption of fossil fuels and realize a more environmentally friendly chemical process. In particular, methanol synthesis using renewable energy is expected to be used as a carbon-neutral fuel and can greatly contribute to reducing CO 2 emissions in fields such as aviation and shipping. CO 2 Since the catalyst (composition) for the reduction reaction may contain formaldehyde in its reaction product, it may also be referred to as a catalyst (composition) for the formaldehyde synthesis reaction. CO 2 Since the catalyst (composition) for the reduction reaction may contain formic acid in its reaction product, it may also be referred to as a catalyst (composition) for the formic acid synthesis reaction. Formaldehyde and formic acid are important intermediates in the chemical industry and the manufacture of pharmaceuticals. Formaldehyde is indispensable for the production of resins and plastics and is also widely used as an antibacterial agent. Formic acid is used as a preservative, a cleaning agent, or a fuel for fuel cells by utilizing its acidity. Synthesizing these compounds from CO 2 not only reduces the environmental impact but also promotes the efficient use of resources and contributes to the realization of a sustainable chemical industry.

[0043] CO 2 The catalyst for the reduction reaction contains at least one selected from the group consisting of nickel, iron, cobalt, and copper. CO 2 The content of at least one selected from the group consisting of nickel, iron, cobalt, and copper in the catalyst for the reduction reaction is not particularly limited and may be, for example, 1% by mass or more. The content is preferably 10% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more in order. CO 2The catalyst for the reduction reaction preferably consists of at least one selected from the group consisting of nickel, iron, cobalt, and copper and inevitable impurities. Also, CO 2 For the catalyst for the reduction reaction to promote the CO 2 methanation reaction, it is preferable to contain nickel. By using nickel, higher hydrogen adsorption performance and catalytic activity can be obtained, and it is also possible to constitute a more inexpensive catalyst. Also, CO 2 For the catalyst for the reduction reaction to promote any one or more of the methanol synthesis reaction, formaldehyde synthesis reaction, and formic acid synthesis reaction, it is preferable to contain copper.

[0044] CO 2 The form and size of the catalyst for the reduction reaction are not particularly limited. For example, CO 2 the catalyst for the reduction reaction may be in powder form. If it is in powder form, it is preferable to appropriately adjust the particle size and / or surface area, etc.

[0045] In the catalyst composition according to another embodiment of the present invention, the total content of the metal oxide carrier, the catalyst for the hydrogen combustion reaction, and CO 2 the catalyst for the reduction reaction is not particularly limited, and can be, for example, 1% by mass or more, and preferably 10% by mass or more, 30% by mass or more, 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more in order. The catalyst composition according to another embodiment of the present invention preferably consists of a metal oxide carrier, a catalyst for the hydrogen combustion reaction, CO 2 the catalyst for the reduction reaction, and inevitable impurities.

[0046] In the catalyst composition according to another embodiment of the present invention, the mass ratio of the content of the metal oxide carrier to the total content of the catalyst for the hydrogen combustion reaction and CO 2 the catalyst for the reduction reaction is not particularly limited. For example, the mass ratio of the metal oxide carrier: the total of the catalyst for the hydrogen combustion reaction and CO 2 the catalyst for the reduction reaction can be 1:99 to 99:1. To cause the CO 2 reduction reaction more efficiently at a lower cost, it is preferable to increase the ratio of the metal oxide carrier. For example, the metal oxide carrier: the total of the catalyst for the hydrogen combustion reaction and CO2 The mass ratio of the total of the catalysts for the reduction reaction is preferably 50:50 to 99:1, and more preferably 75:25 to 99:1.

[0047] In the catalyst composition according to another embodiment of the present invention, the catalyst for the hydrogen combustion reaction and CO 2 The mass ratio of the catalyst for the reduction reaction is not particularly limited. For example, the catalyst for the hydrogen combustion reaction: CO 2 The mass ratio of the catalyst for the reduction reaction can be 1:99 to 99:1. Utilizing the heat generated by hydrogen combustion, CO 2 In order to efficiently cause the reduction reaction, the catalyst for the hydrogen combustion reaction: CO 2 The mass ratio of the catalyst for the reduction reaction is preferably 25:75 to 75:25.

[0048] The form and size of the catalyst composition according to another embodiment of the present invention are not particularly limited, and it may be a powder or a molded body. If it is a powder, it is preferable to appropriately adjust the particle size and / or surface area, etc. If it is a molded body, it is preferable to appropriately adjust the pore volume, pore diameter, shape, etc. in consideration of the surface area and strength, etc. The shape of the molded body is not particularly limited and may be any of spherical, cylindrical, ring-shaped, wheel-shaped, granular, plate-shaped, etc.

[0049] <5.CO 2 Manufacturing method of the catalyst composition for the reduction reaction The above catalyst composition according to another embodiment of the present invention can be produced by bringing the catalyst for the hydrogen combustion reaction and the catalyst for the CO reduction reaction into contact with a metal oxide support, and the method is not particularly limited. For example, methods such as mixing a metal oxide support, a catalyst for the hydrogen combustion reaction, and a catalyst for the CO 2 reduction reaction can be mentioned. The method of obtaining the metal oxide support, the catalyst for the hydrogen combustion reaction, and the catalyst for the CO 2 reduction reaction is not particularly limited, and for example, commercially available ones may be used. 2 The method of obtaining the catalyst for the methanation reaction is not particularly limited, and for example, commercially available ones may be used.

[0050] A preferred method for producing the catalyst composition according to another embodiment of the present invention is to contact the metal oxide support with at least one oxide selected from the group consisting of nickel, iron, cobalt, and copper, and containing CO 2 A step of heating and reducing the catalyst oxide for the reduction reaction containing at least one selected from the group consisting of nickel, iron, cobalt, and copper in a hydrogen-containing gas atmosphere at 100 to 650 ° C., and after the step of reducing, mixing the metal oxide support and the catalyst for the hydrogen combustion reaction. This can further improve the activity of the catalyst for the CO 2 reduction reaction in the catalyst composition.

[0051] The CO in contact with the metal oxide support 2 The catalyst oxide for the reduction reaction can be prepared, for example, by dissolving (or dispersing) a metal oxide support and a compound containing at least one selected from the group consisting of nickel, iron, cobalt, and copper in a solvent (or dispersion medium) and then heating. The heating temperature and heating time can be appropriately set depending on the compound type and the solvent type (or dispersion medium type). The heating temperature may be, for example, 50 to 600 ° C. Further, the heating may be in one step or in multiple steps. For example, after heating at a relatively low temperature of 50 to 200 ° C. to remove the solvent (or dispersion medium), it may be heated at a relatively high temperature of 80 to 600 ° C. Thereby, while more surely removing the solvent (or dispersion medium), the influence on the crystal structure of the catalyst due to a rapid temperature rise can be reduced. As the compound type containing at least one selected from the group consisting of nickel, iron, cobalt, and copper, for example, not only inorganic salts such as nitrates, carbonates, sulfates, and chlorides, but also organic salts such as acetates are preferably used. More preferably, nitrates, carbonates or acetates, in which impurities contained after firing are less likely to cause catalyst poisoning, or sulfates that are easy to perform waste liquid treatment in the manufacturing process, etc. are mentioned.

[0052] The hydrogen content of the hydrogen-containing gas is not particularly limited, and can be, for example, 5% by volume or more. The hydrogen-containing gas may contain other gases in addition to hydrogen, and examples include inert gases such as nitrogen and argon.

[0053] The temperature during reduction is preferably 100 to 650°C, and the reduction time can be, for example, 30 minutes to 24 hours, but is not limited thereto, and can be appropriately set according to the reduction situation (that is, the precipitation situation of at least one metal selected from the group consisting of nickel, iron, cobalt, and copper).

[0054] After the above reduction, the above CO in contact with the metal oxide carrier 2 A catalyst for the reduction reaction is obtained. Then, by mixing with a catalyst for the hydrogen combustion reaction, a catalyst composition according to another embodiment of the present invention is obtained. Since the catalyst for the hydrogen combustion reaction is easily decomposed, it is preferably mixed after the above reduction.

[0055] <6.CO 2 <Method for producing methane using a catalyst composition for reduction reaction> The method for producing methane according to an embodiment of the present invention is The catalyst composition according to another embodiment of the present invention (that is, the above metal oxide carrier, the above catalyst for the hydrogen combustion reaction in contact with the metal oxide carrier, and the above CO in contact with the metal oxide carrier 2 A catalyst composition including a catalyst for the reduction reaction) is placed in a container, the container is heated to 80°C or higher and 350°C or lower, and hydrogen, oxygen, and carbon dioxide are supplied into the container. Thereby, the CO 2 Methanation reaction can be efficiently caused to produce methane. Specifically, whether the methanation reaction of CO can occur at a lower heating temperature of the container in which the catalyst is disposed, and / or even if the heating temperature is the same, the CO 2 Conversion rate, CH 2 Selectivity and CH 4 Any one or more selected from the group consisting of production rate can be improved. 4

[0056] The container is not particularly limited as long as the above catalyst composition can be placed therein. When the catalyst composition is in powder form, a fluidized bed type or a moving bed type, etc. are preferred. When the catalyst composition is in the form of a molded body, a fixed bed type or a moving bed type, etc. are preferably used. As the material, those having heat resistance so as to withstand the heating temperature are preferred, and examples thereof include glass (quartz) and stainless steel.

[0057] The heating temperature of the container in which the catalyst composition is placed is set to 80 to 350 °C. By setting the heating temperature to 80 °C or higher, the catalytic activity when carbon dioxide and hydrogen undergo a methanation reaction can be improved. The heating temperature of the container in which the catalyst composition is placed is preferably 90 °C or higher, more preferably 100 °C or higher. On the other hand, by setting the heating temperature of the container in which the catalyst composition is placed to 350 °C or lower, the heat generation of the catalyst can be appropriately suppressed, the local temperature rise of the catalyst can be suppressed, and the decrease in activity due to metal aggregation (sintering), etc. can be suppressed. Also, by setting the heating temperature of the container in which the catalyst composition is placed to 350 °C or lower, the decrease in CO 2 conversion rate and methane selectivity, as well as the by-production of CO can be suppressed. However, the yield of methane will decrease, and energy will be required for subsequent gas separation, etc. The heating temperature of the container in which the catalyst composition is placed is preferably 300 °C or lower, more preferably 250 °C or lower, and even more preferably 200 °C or lower.

[0058] The supply ratio, supply rate, supply method, etc. of carbon dioxide, hydrogen and oxygen are not particularly limited. Regarding the supply ratio, for example, the amount of hydrogen / (total amount of carbon dioxide and oxygen) can be 0.5 to 10 in volume ratio, preferably 1 to 8, and more preferably 1.5 to 5. Thereby, the hydrogen combustion reaction and CO 2 methanation reaction can be promoted. The supply ratio of carbon dioxide and oxygen is for the hydrogen combustion reaction catalyst and CO 2It can be appropriately set according to the mass ratio of the catalyst for the reduction reaction. Further, other gases other than carbon dioxide, hydrogen, and oxygen may be mixed and supplied, for example, an inert gas such as nitrogen and / or argon may be mixed. The total amount of carbon dioxide, hydrogen, and oxygen in the mixed gas is not particularly limited, but it is preferably 1% by volume or more, more preferably 10% by volume or more, still more preferably 20% by volume or more, and even more preferably 30% by volume or more. Thereby, the hydrogen combustion reaction and CO 2 The methanation reaction can be promoted. The pressure in the container is not particularly limited, and for example, normal pressure may be used, or it may be in the range of 0.01 to 100 MPa.

[0059] The method for obtaining hydrogen, oxygen, and carbon dioxide is not particularly limited. For example, as hydrogen, in addition to those available on the market, hydrogen obtained from water electrolysis using renewable energy such as sunlight, wind power, and hydropower, oxidation of water using artificial photosynthesis technology, steam reforming of petroleum-based resources, gasification of coal and / or petcoke, etc. can also be used. From the viewpoint of reducing carbon dioxide emissions, it is preferable to use hydrogen obtained by water electrolysis using renewable energy-derived electricity or oxidation of water using artificial photosynthesis technology. Thereby, hydrogen and oxygen can be obtained simultaneously and used as raw materials in the methane production method according to the embodiment of the present invention. As carbon dioxide, carbon dioxide separated and recovered by chemical absorption method, physical adsorption method, separation membrane method, etc. from blast furnace gas, hot blast stove exhaust gas, heating furnace exhaust gas, power plant exhaust gas, etc. in a steelworks can be used.

[0060] <7.CO 2 Method for producing methanol using a catalyst composition for reduction reaction> The methane production method according to the embodiment of the present invention is The catalyst composition according to another embodiment of the present invention (that is, the above metal oxide carrier, the catalyst for hydrogen combustion reaction in contact with the above metal oxide carrier, and the CO in contact with the above metal oxide carrier 2A step of disposing a catalyst composition containing a catalyst for reduction reaction in a container, a step of heating the container to 80°C or higher and 350°C or lower so that the pressure in the container becomes 0.1 to 20 MPa, and a step of supplying hydrogen, oxygen, and carbon dioxide into the container. Thereby, a methanol synthesis reaction can be efficiently caused to produce methanol. Specifically, can a methanol synthesis reaction occur at a lower heating temperature of the container in which the catalyst is disposed, and / or even if the heating temperature is the same, CO 2 conversion rate, CH 3 OH selectivity, and CH 3 One or more selected from the group consisting of OH production rate can be improved.

[0061] Regarding the container, the heating temperature of the container in which the catalyst composition is disposed, the supply ratio, supply rate, supply method, etc. of carbon dioxide, hydrogen, and oxygen, and the method of obtaining hydrogen, oxygen, and carbon dioxide, refer to <6.CO 2 The method for producing methane using the catalyst composition for reduction reaction> is the same. Regarding the pressure in the container, it is necessary to set it to 0.1 to 20 MPa. Thereby, the methanol synthesis reaction can be promoted.

[0062] <8.CO 2 The method for producing formaldehyde using the catalyst composition for reduction reaction> The method for producing methane according to an embodiment of the present invention The catalyst composition according to another embodiment of the present invention (that is, the above metal oxide carrier, the catalyst for hydrogen combustion reaction in contact with the metal oxide carrier, and the CO in contact with the metal oxide carrier 2 A step of disposing a catalyst composition containing a catalyst for reduction reaction in a container, a step of heating the container to 80°C or higher and 350°C or lower, and a step of supplying hydrogen, oxygen, and carbon dioxide into the container so that the pressure in the container becomes 0.1 to 10 MPa. As a result, the formaldehyde synthesis reaction can be efficiently caused to produce formaldehyde. Specifically, can the formaldehyde synthesis reaction occur at a lower heating temperature of the container in which the catalyst is disposed, and / or even if the heating temperature is the same, can any one or more selected from the group consisting of CO 2 conversion rate, HCHO selectivity, and HCHO production rate be improved?

[0063] Regarding the container, the heating temperature of the container in which the catalyst composition is disposed, the supply ratio, supply rate, supply method, etc. of carbon dioxide, hydrogen, and oxygen, and the method of obtaining hydrogen, oxygen, and carbon dioxide, refer to <6.CO 2 Production method of methane using a catalyst composition for reduction reaction>. The pressure inside the container needs to be 0.1 to 10 MPa. Thereby, the formaldehyde synthesis reaction can be promoted.

[0064] <9.CO 2 Production method of formic acid using a catalyst composition for reduction reaction The methane production method according to an embodiment of the present invention The catalyst composition according to another embodiment of the present invention (that is, the above metal oxide carrier, the catalyst for hydrogen combustion reaction in contact with the metal oxide carrier, and the CO 2 catalyst for reduction reaction in contact with the metal oxide carrier, including the catalyst composition) is disposed in a container, the container is heated to 80°C or higher and 350°C or lower, and hydrogen, oxygen, and carbon dioxide are supplied into the container so that the pressure inside the container becomes 0.1 to 10 MPa. As a result, the formic acid synthesis reaction can be efficiently caused to produce formic acid. Specifically, can the formic acid synthesis reaction occur at a lower heating temperature of the container in which the catalyst is disposed, and / or even if the heating temperature is the same, can any one or more selected from the group consisting of CO 2 conversion rate, HCOOH selectivity, and HCOOH production rate be improved?

[0065] Regarding the container, the heating temperature of the container in which the catalyst composition is disposed, the supply ratio, supply rate, and supply method of carbon dioxide, hydrogen, and oxygen, and the method of obtaining hydrogen, oxygen, and carbon dioxide, refer to <6.CO 2 The method for producing methane using a catalyst composition for reduction reaction> is the same. Regarding the pressure inside the container, it is necessary to set it to 0.1 to 10 MPa. This can promote the formic acid synthesis reaction.

Example

[0066] Hereinafter, embodiments of the present invention will be described more specifically with reference to examples. The embodiments of the present invention are not limited by the following examples, and can be appropriately modified and implemented within the scope that can conform to the foregoing and following gists, and all of them are included in the technical scope of the embodiments of the present invention.

[0067] [Example 1] Example 1 shows the hydrogen combustion promotion effect of the catalyst for hydrogen combustion reaction according to the embodiment of the present invention.

[0068] As the catalyst for hydrogen combustion reaction, 100 mg of Ag 2 CO 3 (manufactured by Kanto Chemical) was placed in a container (quartz tube, inner diameter 6 mm, outer diameter 8 mm). The heating temperature of the container was set to 150°C. The container was provided with a gas inlet and an outlet, and a mixed gas with a volume ratio of Ar:H 2 :O 2 =118:40:5.6 (oxygen concentration 3.4% by volume) was adjusted so that the total flow rate was 163.6 ml / min, supplied into the container from the gas inlet, and held for 30 minutes or more (Test No. 1-1). Also, the oxygen concentration was changed to 2.0% by volume (Test No. 1-2) and 1.0% by volume (Test No. 1-3), and held in the same manner. After each holding, the catalyst temperature was measured with a thermocouple. The results are shown in Table 1.

[0069]

Table 1

[0070] The test results in Table 1 reveal the following. In Test Nos. 1-1 to 1-3, the catalyst temperature rose by at least 20°C above the heating temperature of the container, which is believed to be due to heat generation from the hydrogen combustion reaction. In other words, in Test Nos. 1-1 to 1-3, the hydrogen combustion reaction occurred at less than 450°C, which is the minimum ignition temperature in the presence of oxygen. In Tests No. 1-1 and 1-2, the volume ratio of hydrogen to oxygen satisfied the preferable requirement of 1 to 20, and therefore the hydrogen combustion reaction was promoted, and the catalyst temperature rose by at least 50°C relative to the heating temperature of the container. In addition, in Test No. 1-1, the volume ratio of hydrogen to oxygen satisfied the more favorable requirement of 2 to 10, so the hydrogen combustion reaction was promoted and the catalyst temperature rose by at least 100°C relative to the heating temperature of the container.

[0071] [Example 2] Example 2 illustrates the hydrogen combustion promoting effect of a catalyst composition according to one embodiment of the present invention.

[0072] α-Al as a metal oxide support 2 O 3 (High Purity Chemical Laboratory) powder, α-Al 2 O 3 : Ag per 100 parts by mass 2 CO 3 (manufactured by Kanto Chemical): 11 parts by mass were mixed in a mortar to obtain a catalyst composition containing a catalyst for hydrogen combustion reactions in contact with a metal oxide support. 100 mg of the above catalyst composition was placed in a container (quartz tube, inner diameter 6 mm, outer diameter 8 mm). The heating temperature of the container was set to 150° C. The container was provided with a gas inlet and outlet, and the volume ratio of Ar:H 2 :O 2 The flow rate of the mixed gas with a ratio of 118:40:5.6 (oxygen concentration 3.4% by volume) was adjusted to a total of 163.6 ml / min, and the gas was supplied from the gas inlet into the container and held for 30 minutes or more (Test No. 2-1). The oxygen concentration was also changed to 2.0% by volume (Test No. 2-2) and 1.0% by volume (Test No. 2-3), and the catalyst temperature was measured after the holding period. The results are shown in Table 2.

[0073]

Table 2

[0074] The following can be understood from the test results in Table 2. In Tests No. 2-1 to 2-3, the catalyst temperature increased by at least 30°C or more with respect to the heating temperature of the container, and it is considered that heat was generated by the hydrogen combustion reaction. That is, in Tests No. 2-1 to 2-3, the hydrogen combustion reaction could occur at a temperature lower than 450°C, which is the lowest ignition temperature in the presence of oxygen. In Tests No. 2-1 and 2-2, since the hydrogen amount / oxygen amount satisfied the preferable requirement of 1 to 20 in terms of volume ratio, the hydrogen combustion reaction was promoted, and the catalyst temperature increased by at least 60°C or more with respect to the heating temperature of the container. In addition, in Test No. 2-1, since the hydrogen amount / oxygen amount satisfied the more preferable requirement of 2 to 10 in terms of volume ratio, the hydrogen combustion reaction was further promoted, and the catalyst temperature increased by at least 120°C or more with respect to the heating temperature of the container. When comparing Test No. 1-1 and Test No. 2-1, although the oxygen concentration remained the same, the catalyst temperature of Test No. 2-1 was higher. Similarly, the catalyst temperature of Test No. 2-2 was higher than that of Test No. 1-2, and the catalyst temperature of Test No. 2-3 was higher than that of Test No. 1-3. These are considered to be due to the far-infrared radiation characteristics of the metal oxide carriers in Tests No. 2-1 to 2-3.

[0075] [Example 3] Example 3 shows the CO 2 methanation reaction promoting effect of the catalyst composition according to another embodiment of the present invention.

[0076] As the metal oxide carrier, α-Al 2 O 3 (manufactured by High Purity Chemical Research Institute) powder was used as α-Al 2 O 3It was added to and mixed with an aqueous nickel nitrate solution so that it was 90% by mass and Ni was 10% by mass. Next, the solvent of the mixture was removed using an evaporator at 70 °C for about 1 hour. Next, the above mixture was placed in a heat treatment furnace, held at 100 °C for 10 hours, and then further heated at 500 °C for 5 hours. Thereafter, it was cooled to room temperature and taken out of the heat treatment furnace. Next, a reduction step was performed by holding it at 500 °C for 1 hour in a heat treatment furnace filled with a hydrogen atmosphere (hydrogen concentration: 26.8% by volume). Thereafter, it was cooled to room temperature, and the mixture (Ni in contact with α-Al 2 O 3 ): For 100% by mass, Ag 2 CO 3 (manufactured by Kanto Chemical): They were mixed in a mortar so that it was 11% by mass. 100 mg of the above catalyst composition was placed in a container (quartz tube, inner diameter 6 mm, outer diameter 8 mm). The heating temperature of the container was set as described later. The container was provided with a gas inlet and an outlet, and a mixed gas with a volume ratio of Ar:H 2 :CO 2 :O 2 = 118:40:10:5.6 was adjusted to a total flow rate of 163.6 ml / min and supplied into the container from the gas inlet and held for 30 minutes or more (Test No. 3-1). Quadrupole mass spectrometers (manufactured by Pfeiffer Vacuum, GSD301) were placed at the gas inlet and outlet of the container to analyze the composition and component amounts of the gas components.

[0077] As shown in Table 3, for Test No. 3-1, the catalyst for hydrogen combustion reaction was changed to CH 3 COOAg (manufactured by Kanto Chemical) and tested (Test No. 3-2). Also, for Test No. 3-1, the catalyst for hydrogen combustion reaction was changed to a mixture of Ag 2 CO 3 (manufactured by Kanto Chemical) and CH 3 COOAg (manufactured by Kanto Chemical) mixed so that the mass ratio was 1:1 and tested (Test No. 3-3). Also, for comparison, the catalyst for hydrogen combustion reaction was Rb that does not satisfy the requirements of the embodiment of the present invention 2 CO3 (Test No. 3-4), Cs 2 CO 3 (Test No. 3-5) and Ag 2 SO 4 (Test No. 3-6) and tested. Further, for comparison, it was changed to a sample without the catalyst for hydrogen combustion reaction and tested (Test No. 3-7). In Test No. 3-7, the heating temperature of the container was gradually increased from 150 °C to 250 °C at a rate of 3.3 °C / min, and the heating temperature of the container when methane (CH 4 ) was generated was investigated. The heating temperature of the containers in Test Nos. 3-1 to 3-3 was set to be equal to or lower than the temperature when methane was generated in Test No. 3-7 and at a temperature at which methane was detected at the gas outlet. The heating temperature of the containers in Test Nos. 3-4 to 3-6 was made the same as that in Test No. 3-1. The results are shown in Table 3. The CO 2 conversion rate, CH 4 selectivity, and CH 4 production rate were calculated as follows. CO 2 Conversion rate (%) = (CO volume concentration at gas inlet - CO volume concentration at gas outlet) / CO concentration at gas inlet × 100 2 2 2 CH 4 Selectivity (%) = (CH volume concentration at gas outlet) / (CH volume concentration at gas outlet + CO volume concentration at gas outlet) × 100 4 4 CH 4 Production rate (mol / (g·h)) = (CH volume amount at gas outlet) / (22.4 × reaction time × weight of Ni catalyst for methanation reaction) 4 2

[0078]

Table 3

[0079] ​​​​​​​The following can be understood from the test results in Table 3. Test Nos. 3-1 to 3-3 contain a catalyst for hydrogen combustion reaction that satisfies the requirements of the embodiment of the present invention. Compared with Test No. 3-7 that does not contain a catalyst for hydrogen combustion reaction, methane was generated at a temperature 20°C or more lower in the heating temperature of the container. Test Nos. 3-4 to 3-6 do not contain a catalyst for hydrogen combustion reaction that satisfies the requirements of the embodiment of the present invention, and methane was not generated at the same heating temperature of the container as in Test No. 3-1.

[0080] [Example 4] Example 4 shows the CO 2 methanation reaction promoting effect when the metal oxide carrier is changed to ZrO 2 .

[0081] The test was conducted in the same manner as in Test No. 3-1 except that the metal oxide carrier was made into a powder of ZrO 2 (manufactured by Kojundo Chemical Laboratory Co., Ltd.) (Test No. 4-1).

[0082] As shown in Table 4, for Test No. 4-1, the catalyst for hydrogen combustion reaction was changed to CH 3 COOAg (manufactured by Kanto Chemical Co., Inc.) and the test was conducted (Test No. 4-2). Also, for comparison, the test was conducted by changing to a sample without mixing the catalyst for hydrogen combustion reaction (Test Nos. 4-3, 4-4). In Test No. 4-3, the heating temperature of the container was set to 150°C. The heating temperature of the container in Test No. 4-4 was set to 130°C, which is 20°C lower than the heating temperature of the container in Test No. 4-3. In Test Nos. 4-1 and 4-2, the heating temperature of the container was set to the same temperature as in Test No. 4-4. The results are shown in Table 4.

[0083]

Table 4

[0084] The following can be understood from the test results in Table 4. Test Nos. 4-1 and 4-2 contain a catalyst for hydrogen combustion reaction that meets the requirements of the embodiments of the present invention. Compared with Test No. 4-3 that does not contain a catalyst for hydrogen combustion reaction, methane was generated at a temperature 20°C lower in the heating temperature of the container.

[0085] [Example 5] Example 5 shows the effect of promoting the CO 2 methanation reaction when the metal oxide support is changed to TiO 2 .

[0086] The test was conducted in the same manner as Test Nos. 3-1 and 4-1 except that the metal oxide support was made into a powder of TiO 2 (rutile type, manufactured by High Purity Chemical Research Institute) (Test No. 5-1).

[0087] As shown in Table 5, for Test No. 5-1, the catalyst for hydrogen combustion reaction was changed to CH 3 COOAg (manufactured by Kanto Chemical) and tested (Test No. 5-2). Also, for comparison, it was changed to one without a mixed catalyst for hydrogen combustion reaction and tested (Test Nos. 5-3, 5-4). In Test No. 5-3, the heating temperature of the container was set to 120°C. The heating temperature of the container in Test No. 5-4 was set to 110°C, which is 10°C lower than the heating temperature of the container in Test No. 5-3. In Test No. 5-1, the heating temperature of the container was the same as that in Test No. 5-3, and in Test No. 5-2, the heating temperature of the container was set to the same temperature as that in Test No. 5-4. The results are shown in Table 5.

[0088]

Table 5

[0089] The following can be understood from the test results in Table 5. Test No. 5-1 contains a catalyst for hydrogen combustion reaction that meets the requirements of the embodiments of the present invention. Compared with Test No. 5-3 that does not contain a catalyst for hydrogen combustion reaction, the heating temperature of the container was the same, but the CO 2Conversion rate, CH 4 Selectivity and CH 4 The production rate was improved. Test No. 5-2 contains a catalyst for hydrogen combustion reaction that satisfies the requirements of the embodiment of the present invention. Compared with Test No. 5-3 that does not contain a catalyst for hydrogen combustion reaction, methane was produced at a temperature 10 °C lower than the heating temperature of the container.

[0090] [Example 6] Example 6 shows the CO methanation reaction promoting effect of the catalyst composition according to another embodiment of the present invention. 2

[0091] As the metal oxide carrier, α-Al 2 O 3 (manufactured by High Purity Chemical Research Institute) powder was added to an aqueous nickel nitrate solution and mixed. Next, the solvent of the mixture was removed using an evaporator at 80 °C for about 1 hour. Next, the above mixture was placed in a heat treatment furnace, held at 100 °C for 10 hours, and then further heated at 500 °C for 5 hours. Then, it was cooled to room temperature and taken out of the heat treatment furnace. Next, a reduction process was performed by holding at 500 °C for 1 hour in a heat treatment furnace filled with a hydrogen atmosphere (hydrogen concentration: 26.8% by volume). Then, it was cooled to room temperature, and the mixture (Ni in contact with α-Al 2 O 3 ) was mixed with Ag 2 CO 3 (manufactured by Kanto Chemical) in a mortar. The amounts of each compound were adjusted for catalyst preparation so that the metal molar ratio was Ag:Ni:Al = 4.38:8.42:87.2. 100 mg of the above catalyst composition was placed in a container (quartz tube, inner diameter 6 mm, outer diameter 8 mm). The heating temperature of the container was set as described later. The container was provided with a gas inlet and outlet, and a mixed gas with a volume ratio of Ar:H 2 :CO 2 :O 2 = 54:36:8:2 was adjusted to a total flow rate of 900 ml / min, and the heating temperature of the container was gradually increased from 50 °C to 400 °C at 4.0 °C / min to produce methane (CH 4 ​) When it was generated, the heating temperature of the container was investigated (Test No. 6-1). A quadrupole mass spectrometer (manufactured by Pfeiffer Vacuum, GSD301) was placed at the gas inlet and outlet of the container to analyze the composition and component amounts of the gas components.

[0092] As shown in Table 6, for Test No. 6-1, the catalyst for hydrogen combustion reaction was changed to CH 3 COOAg (manufactured by Kanto Chemical) and tested (Test No. 6-2). Also, for Test No. 6-1, the catalyst for hydrogen combustion reaction was changed to Ag 2 O (manufactured by Kanto Chemical) and tested (Test No. 6-3). Also, for comparison, it was changed to one without a mixed catalyst for hydrogen combustion reaction and tested (Test No. 6-4). The results are shown in Table 6. Note that the CO 2 conversion rate, CH 4 selectivity, CH 4 production rate, and catalyst temperature were extracted as representative values when the heating temperature of the container was 200°C.

[0093]

Table 6

[0094] From the test results in Table 6, the following can be understood. Tests No. 6-1 to 6-3 contain a catalyst for hydrogen combustion reaction that satisfies the requirements of the embodiment of the present invention, and compared with Test No. 6-4 without a catalyst for hydrogen combustion reaction, the heating temperature of the container decreased. Also, the CO 2 conversion rate and CH 4 production rate were found to be larger values and the catalyst activity was improved when a hydrogen combustion catalyst was added compared to when it was not added. It is considered that the highly active hydrogen generated by the hydrogen combustion catalyst directly contributed to the CO 2 methanation reaction and improved the catalyst activity.

[0095] [Example 7] Example 7 relates to another embodiment of the present invention, and the methanol (CH3 The promoting effects on the reactions of OH), formaldehyde (HCHO), and formic acid (HCOOH) are shown.

[0096] As the metal oxide carrier, α - Al 2 O 3 (manufactured by High - Purity Chemical Research Institute) and ZnO powder (manufactured by Kanto Chemical) were selected. For α - Al 2 O 3 : 6.25% by mass, ZnO: 25% by mass, Cu(NO 3 ) 2 ·3H 2 O (manufactured by Kishida Chemical): 68.75% by mass, they were added to distilled water and mixed. Next, the mixture was heated using an evaporator at 70 °C for about 1 hour to remove water. Next, the above mixture was put into a heat treatment furnace and heated at 500 °C for 5 hours. Then, it was cooled to room temperature and taken out of the heat treatment furnace. Next, after placing about 0.7 g of the above mixture in a container (stainless steel tube, inner diameter 12 mm), a mixed gas of hydrogen and argon (hydrogen flow rate: 100 ml / min, argon: 300 ml / min) was passed through, and the reduction process was carried out by holding at 240 °C for 2 hours. Then, it was cooled to room temperature while flowing argon, and the mixture (Cu in contact with α - Al 2 O 3 and ZnO) was obtained (Test No. 7 - 4). Also, for the mixture (Cu in contact with α - Al 2 O 3 and ZnO): 100% by mass, Ag 2 CO 3 (manufactured by Kanto Chemical): 20% by mass, they were mixed in a mortar (Test No. 7 - 1). Note that, except for changing Ag 2 CO 3 to CH 3 COOAg (manufactured by Kanto Chemical) (Test No. 7 - 2) or Ag 2 O (manufactured by Kanto Chemical) (Test No. 7 - 3), the catalyst composition was obtained in the same manner as in Test No. 7 - 1. 600 mg of the above catalyst composition was placed in a container (stainless steel tube, inner diameter 12 mm). The heating temperature of the container was set to increase from room temperature to 260 °C at a rate of 2 °C per minute. The container was provided with pressure relief valves at the gas inlet and outlet, and H 2 (300 ml / min), CO 2 (100 ml / min), O 2 (15 ml / min) (volume ratio of H 2 :CO 2 :O 2 = 72.4:24:3.6) of the mixed gas was supplied into the container from the gas inlet (Test Nos. 7-1 to 7-4). Quadrupole mass spectrometers (Quadrupol mass spectrometer, manufactured by Pfeiffer Vacuum, GSD301) were placed at the gas inlet and outlet of the container to analyze the composition and amount of gas components.

[0097] The results are described below. In Test No. 7-4 without the catalyst for hydrogen combustion reaction, the heating temperature of the container when methanol (CH 3 OH), formaldehyde (HCHO) and formic acid (HCOOH) were produced was 220 °C. Test No. 7-1 contains the catalyst for hydrogen combustion reaction (Ag 2 CO 3 ) that meets the requirements of the embodiment of the present invention. Compared with Test No. 7-4 without the catalyst for hydrogen combustion reaction, the heating temperature of the container when methanol (CH 3 OH), formaldehyde (HCHO) and formic acid (HCOOH) were produced was as low as 160 °C. Test No. 7-2 contains the catalyst for hydrogen combustion reaction (CH 3 COOAg) that meets the requirements of the embodiment of the present invention. Compared with Test No. 7-4 without the catalyst for hydrogen combustion reaction, the heating temperature of the container when methanol (CH 3 OH), formaldehyde (HCHO) and formic acid (HCOOH) were produced was as low as 190 °C. Test No. 7-3 contains the catalyst for hydrogen combustion reaction (Ag 2O), and compared with Test No. 7-4 which does not contain a catalyst for hydrogen combustion reaction, the heating temperature of the container when methanol (CH 3 OH), formaldehyde (HCHO), and formic acid (HCOOH) were generated was as low as 200 °C.

Claims

1. Silver carbonate (Ag ２ CO ３ ), silver acetate (CH ３ COOAg) and silver oxide (Ag ２ A catalyst for hydrogen combustion reaction comprising at least one selected from the group consisting of:

2. Silver carbonate (Ag ２ CO ３ ) and silver acetate (CH ３ 2. The catalyst for hydrogen combustion reaction according to claim 1, comprising at least one selected from the group consisting of:

3. A metal oxide support; A catalyst composition comprising the catalyst for hydrogen combustion reactions according to claim 1 or 2 in contact with the metal oxide support.

4. CO containing at least one selected from the group consisting of nickel, iron, cobalt and copper, in contact with the metal oxide support. ２ The catalyst composition of claim 3 further comprising a catalyst for a reduction reaction.

5. 4. The catalyst composition of claim 3, wherein the metal oxide support comprises at least one selected from the group consisting of alumina, zirconia, titania and zinc oxide.

6. A step of placing the catalyst for hydrogen combustion reaction according to claim 1 or the catalyst composition according to claim 3 in a container; heating the container to a temperature of 80° C. or more and less than 450° C.; and supplying hydrogen and oxygen into said vessel.

7. placing the catalyst composition of claim 4 in a container; heating the container to a temperature of 80° C. or higher and 350° C. or lower; providing hydrogen, oxygen and carbon dioxide into said vessel; A method for producing methane comprising the steps of:

8. placing the catalyst composition of claim 4 in a container; heating the container to a temperature of 80° C. or higher and 350° C. or lower; supplying hydrogen, oxygen and carbon dioxide into the vessel so that the pressure in the vessel is 0.1 to 20 MPa; A method for producing methanol comprising the steps of:

9. placing the catalyst composition of claim 4 in a container; heating the container to a temperature of 80° C. or higher and 350° C. or lower; supplying hydrogen, oxygen and carbon dioxide into the vessel so that the pressure in the vessel is 0.1 to 10 MPa; A method for producing formaldehyde comprising the steps of:

10. placing the catalyst composition of claim 4 in a container; heating the container to a temperature of 80° C. or higher and 350° C. or lower; supplying hydrogen, oxygen and carbon dioxide into the vessel so that the pressure in the vessel is 0.1 to 10 MPa; A method for producing formic acid comprising the steps of:

11. A method for producing the catalyst composition of claim 4, comprising the steps of: CO containing at least one oxide selected from the group consisting of nickel, iron, cobalt and copper in contact with a metal oxide support. ２ A step of reducing a catalytic oxide for reduction reaction by heating it to 100 to 650° C. in a hydrogen-containing gas atmosphere; After the reduction step, mixing the metal oxide support with the hydrogen combustion reaction catalyst; A method for producing a catalyst composition comprising the steps of:

12. The method for producing a catalyst composition according to claim 11, wherein the metal oxide support comprises at least one selected from the group consisting of alumina, zirconia, titania and zinc oxide.

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