Carbon monoxide production reaction catalyst, device for producing carbon monoxide, and method for producing carbon monoxide

Abstract

Provided is a carbon monoxide production reaction catalyst which includes a borohydride-containing sheet having a network that is composed of (BH)n (n ≥ 4). Also provided is a device for producing carbon monoxide, which includes a catalyst part that is disposed inside a pipe for circulating formic acid so as to be in contact with formic acid circulated in the pipe, wherein the catalyst part is composed of the carbon monoxide production reaction catalyst.

Description

Carbon monoxide generation reaction catalyst, carbon monoxide production apparatus, and carbon monoxide production method

[0001] The present invention relates to a carbon monoxide production reaction catalyst, a carbon monoxide production apparatus, and a carbon monoxide production method. This application claims priority based on Japanese Patent Application No. 2023-185497, filed in Japan on October 30, 2023, the contents of which are incorporated herein by reference.

[0002] Conventionally, known methods for producing high-purity carbon monoxide include a method in which natural gas is steam reformed to generate high-concentration carbon monoxide, which is then separated and purified, and a method in which formic acid is decomposed and dehydrated using sulfuric acid or a solid catalyst, followed by purification (see, for example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2).

[0003] JP 2011-51852 A

[0004] J. M. TRILLO, G. MUNUERA, J. CRIADO, 'Catalytic Decomposition of Formic Acid on Metal Oxides', CATALYSIS REVIEWS, 7(1), 51-86 (1972). Hyun Ju Lee, Dong-Chang Kang, Seung Hee Pyen, Mi Shin, Young-Woong Suh, Haksoo Han, Chae-Ho Shin, 'Production of H2-free CO by decomposition of formic acid over ZrO2 catalysts', Applied Catalysis A: General 531, 13-20 (2017).

[0005] The method described in Patent Document 1 is advantageous in that it can produce carbon monoxide with high selectivity, taking into account the purification process. However, when the dehydration reaction is carried out using sulfuric acid in the method described in Patent Document 1, the water produced in the reaction reduces the sulfuric acid concentration, and therefore a large amount of sulfuric acid is required to maintain the reaction rate. Furthermore, the method described in Patent Document 1 produces wastewater containing sulfuric acid, and therefore is not an industrially preferable method in terms of wastewater treatment.

[0006] The methods of decomposing formic acid using a solid catalyst as disclosed in Non-Patent Document 1 and Non-Patent Document 2 do not have the problem as in the method disclosed in Patent Document 1, but have a problem in that a side reaction of producing hydrogen and carbon dioxide occurs in addition to the reaction of producing carbon monoxide.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a carbon monoxide production reaction catalyst, a carbon monoxide production apparatus, and a carbon monoxide production method that can decompose formic acid in a gas distribution system to efficiently and continuously produce high-purity carbon monoxide.

[0008] The present invention has the following aspects: [1] (BH) ｎ (n≧4). [2] A carbon monoxide production reaction catalyst comprising a boron-containing sheet having a network consisting of (n≧4). [3] A carbon monoxide production device comprising a catalyst section arranged inside a pipe through which formic acid flows so as to come into contact with the formic acid flowing through the pipe, the catalyst section comprising the carbon monoxide production reaction catalyst according to [1]. [4] A carbon monoxide production method comprising the steps of: vaporizing formic acid; and contacting the vaporized formic acid with the carbon monoxide production reaction catalyst according to [1], the temperature of which has been adjusted to 120°C or higher.

[0009] According to the present invention, it is possible to provide a carbon monoxide production reaction catalyst, a carbon monoxide production apparatus, and a carbon monoxide production method that can decompose formic acid in a gas distribution system and efficiently produce high-purity carbon monoxide continuously.

[0010] FIG. 1 is a schematic diagram showing the molecular structure of a boron-containing sheet constituting a carbon monoxide production reaction catalyst according to one embodiment of the present invention. FIG. 2 is a schematic diagram showing a carbon monoxide production apparatus according to one embodiment of the present invention. FIG. 3 is a diagram showing the relationship between the temperature in the pipe and the amount of recovered product in a comparative example. FIG. 4 is a diagram showing the results of infrared spectroscopic analysis of products obtained in synthesis examples. FIG. 5 is a diagram showing the relationship between the temperature in the pipe and the amount of recovered product in example 1. FIG. 6 is a diagram showing the relationship between the temperature of the catalyst section and the amount of recovered carbon monoxide and water in example 2. FIG. 7 is a diagram showing the relationship between the temperature of the catalyst section and the conversion rate in example 2. FIG. 8 is a diagram showing the relationship between the temperature of the catalyst section and the selectivity in example 2. FIG. 9 is a diagram showing the relationship between the temperature of the catalyst section and the amount of recovered carbon monoxide and water in example 3. FIG. 10 is a diagram showing the relationship between the temperature of the catalyst section and the conversion rate in example 3. FIG. 11 is a diagram showing the relationship between the temperature of the catalyst section and the selectivity in example 3. FIG. 12 is a diagram showing the relationship between the temperature of the catalyst section and the amount of recovered carbon monoxide and water in example 4. FIG. 13 is a diagram showing the relationship between the temperature of the catalyst section and the conversion rate in example 4. FIG. 14 is a diagram showing the relationship between the temperature of the catalyst section and the amount of recovered carbon monoxide and water in example 4. 16 is a diagram showing an Arrhenius plot prepared based on the results of Example 3 in Example 6. FIG. 17 is a diagram showing an Arrhenius plot prepared based on the results of Example 4 in Example 7. FIG. 18 is a diagram collectively showing FIGS. 15 to 17.

[0011] The present invention relates to a carbon monoxide production reaction catalyst, a carbon monoxide production apparatus, and a carbon monoxide production method. The present invention relates to a catalyst for a carbon monoxide production reaction, a carbon monoxide production apparatus, and a carbon monoxide production method. The present invention relates to a catalyst for a carbon monoxide production reaction, a carbon monoxide production apparatus, and a carbon monoxide production method. The present invention relates to a catalyst for a carbon monoxide production reaction, a carbon monoxide production apparatus, and a carbon monoxide production method. The present invention relates to a catalyst for a carbon monoxide production reaction, a carbon monoxide production apparatus, and a carbon monoxide production method. The present invention relates to a catalyst for a carbon monoxide production reaction, a carbon monoxide production method ...

[0012] [Carbon monoxide production reaction catalyst] The carbon monoxide production reaction catalyst according to one embodiment of the present invention comprises (BH) ｎ The borohydride-containing sheet has a network consisting of (n≧4).

[0013] Fig. 1 is a schematic diagram showing the molecular structure of the boron-containing sheet constituting the carbon monoxide production reaction catalyst of this embodiment. As shown in Fig. 1, the boron-containing sheet is a sheet having a two-dimensional network formed only from boron atoms (B) and hydrogen atoms (H) in a molar ratio of 1:1.

[0014] As shown in Figure 1, in the boron-containing sheet, boron atoms (B) are arranged in a hexagonal ring like a benzene ring, and are present at the vertices of the hexagon, and the hexagons formed by the boron atoms (B) are connected without gaps to form a mesh-like surface structure (two-dimensional network). As shown in Figure 1, the boron-containing sheet has a site where two adjacent boron atoms (B) are bonded to the same hydrogen atom (H). In the boron-containing sheet, the hexagonal mesh formed by the boron atoms (B) refers to, for example, a honeycomb structure.

[0015] In Fig. 1, the BH bond is a binding site indicated by the symbol β, and the BHB bond is a binding site indicated by the symbol γ. Note that the combination of BH bond and BHB bond does not have to be 1:1 as shown in Fig. 1.

[0016] The boron-containing sheet is a thin-film material having a network of boron atoms (B) and hydrogen atoms (H). The boron-containing sheet contains almost no metal atoms derived from the metal diboride used in the method for producing the boron-containing sheet described below, or any other metal atoms. The two-dimensional boron-containing sheet may have a two-dimensional network of boron atoms (B) and hydrogen atoms (H), or may have a three-dimensional network of boron atoms (B) and hydrogen atoms (H). Specifically, the two-dimensional boron-containing sheet may have a stack structure in which two-dimensional boron atoms overlap, and the boron bonds of the two-dimensional boron atoms may extend in a direction not parallel to the sheet (for example, in the vertical height direction).

[0017] The bond distance d between two adjacent boron atoms (B) shown in FIG. １is 0.170 nm to 0.185 nm. In addition, the bond distance d between two adjacent boron atoms (B) via one hydrogen atom (H) shown in FIG. ２ is 0.170 nm to 0.185 nm. In addition, the bond distance d between adjacent boron atoms (B) and hydrogen atoms (H) shown in FIG. ３ is 0.125 nm to 0.135 nm.

[0018] The thickness of the boron-containing sheet is 0.23 nm to 0.50 nm. It is preferable that the length of the boron-containing sheet in at least one direction is 100 nm or more. If the length of the boron-containing sheet in at least one direction is 100 nm or more, the boron-containing sheet can be effectively used as a catalyst. The size (area) of the boron-containing sheet is not particularly limited, and it can be formed to any size by the manufacturing method of a boron-compound-containing sheet described below.

[0019] The borohydride-containing sheet may be terminated with an oxide. That is, the end of the molecular structure of the borohydride-containing sheet may form an oxide. Examples of oxides that form the end of the molecular structure of the borohydride-containing sheet include boric acid (B(OH) ３ ) and boron oxide (B ２ O ３ The borohydride-containing sheet is terminated with an oxide, thereby forming a more stable molecular structure.

[0020] The boron-containing sheet is a substance having a crystalline structure. Furthermore, in the boron-containing sheet, the bonding strength between the boron atoms (B) forming the hexagonal rings and between the boron atoms (B) and the hydrogen atoms (H) is strong. Therefore, even if the boron-containing sheet forms a crystal (aggregate) consisting of multiple layers during production, it can be easily cleaved along the crystal plane, similar to graphite, and separated (recovered) as a single-layer two-dimensional sheet.

[0021] "Method for producing boron compound-containing sheet" The method for producing a boron compound-containing sheet is ２(wherein M is at least one selected from the group consisting of Al, Mg, Ta, Zr, Re, Cr, Ti, and V.) The method comprises a step of mixing a metal diboride having a structure with an ion exchange resin in which metal ions constituting the metal diboride and ion-exchangeable ions are coordinated in a polar organic solvent to obtain a boron-containing sheet precursor (hereinafter referred to as "Step A"), and a step of heat-treating the boron-containing sheet precursor (hereinafter referred to as "Step B").

[0022] "Process A" MB ２ As the metal diboride having the hexagonal ring structure, one having a hexagonal ring structure is used, for example, aluminum diboride (AlB ２ ), magnesium diboride (MgB ２ ), tantalum diboride (TaB ２ ), zirconium diboride (ZrB ２ ), rhenium diboride (ReB ２ ), chromium diboride (CrB ２ ), titanium diboride (TiB ２ ), vanadium diboride (VB ２ Magnesium diboride is preferably used because it can easily undergo ion exchange with an ion exchange resin in a polar organic solvent.

[0023] The ion exchange resin in which ion-exchangeable ions are coordinated with metal ions constituting the metal diboride is not particularly limited, but examples thereof include a styrene polymer having a functional group (hereinafter referred to as "functional group α") in which ion-exchangeable ions are coordinated with metal ions constituting the metal diboride, a divinylbenzene polymer having the functional group α, and a copolymer of styrene having the functional group α and divinylbenzene having the functional group α. Examples of the functional group α include a sulfo group and a carboxyl group. Among these, a sulfo group is preferred because it can easily perform ion exchange with the metal ions constituting the metal diboride in a polar organic solvent.

[0024] The polar organic solvent is not particularly limited, and examples thereof include acetonitrile, N,N-dimethylformamide, alcohol, etc. Among these, acetonitrile is preferred because it does not contain oxygen.

[0025] In step A, the metal diboride and the ion exchange resin are introduced into a polar organic solvent, and the mixed solution containing the polar organic solvent, the metal diboride, and the ion exchange resin is stirred to bring the metal diboride and the ion exchange resin into sufficient contact with each other. This causes ion exchange between the metal ions constituting the metal diboride and the ions of the functional group α of the ion exchange resin, producing a boron compound-containing sheet having a network formed by boron atoms and atoms derived from the functional group α of the ion exchange resin.

[0026] For example, if magnesium diboride is used as the metal diboride and an ion exchange resin having a sulfo group is used as the ion exchange resin, the magnesium ions (Mg ２＋ ) and hydrogen ions (H ＋ ) are substituted with each other to form a boron-containing sheet having a network of boron atoms (B) and hydrogen atoms (H) as described above.

[0027] In step A, it is preferable to gently proceed with the ion exchange reaction between the metal ions constituting the metal diboride and the ions of the functional group α of the ion exchange resin without applying ultrasound or the like to the mixed solution.

[0028] When the mixed solution is stirred, the temperature of the mixed solution is preferably 15° C. to 35° C. The time for stirring the mixed solution is not particularly limited, but is, for example, 700 to 7000 minutes.

[0029] In addition, step A is carried out by adding nitrogen (N ２ The reaction is carried out in an inert atmosphere of an inert gas such as nitrogen (N) or argon (Ar).

[0030] Next, the mixed solution after stirring is filtered. The method for filtering the mixed solution is not particularly limited, and for example, natural filtration, reduced pressure filtration, pressure filtration, centrifugal filtration, etc. are used. In addition, as the filter material, for example, filter paper based on cellulose, membrane filter, filter plate made by compression molding cellulose or glass fiber, etc., etc. are used.

[0031] "Step B" Next, the sheet-shaped borohydride-containing sheet precursor is heat-treated to obtain the borohydride-containing sheet of this embodiment.

[0032] In step B, the temperature at which the sheet-shaped boron-containing sheet precursor is heat-treated is not particularly limited, but is, for example, 150° C. to 450° C. The time for the heat treatment is not particularly limited, but is, for example, 5 minutes to 1200 minutes.

[0033] In addition, step B is carried out under vacuum or nitrogen (N ２ The reaction is carried out in an inert atmosphere of an inert gas such as nitrogen (N) or argon (Ar).

[0034] Examples of methods for analyzing the product obtained by the above-mentioned method for producing a boron compound-containing sheet include X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and energy dispersive X-ray spectroscopy (EDS) and electron energy loss spectroscopy (EELS) performed within a transmission electron microscope.

[0035] In X-ray photoelectron spectroscopy (XPS), for example, an X-ray photoelectron spectrometer (trade name: JPS9010TR) manufactured by JEOL is used to irradiate the surface of the product with X-rays and measure the energy of the photoelectrons generated, thereby analyzing the constituent elements and their electronic states of the product. If, in this analysis, almost no photoelectron energy originating from the metal elements constituting the raw material metal diboride is detected, and only photoelectron energy originating from boron and elements derived from the functional group α of the ion exchange resin is detected, it can be said that the product is composed only of boron and elements derived from the functional group α of the ion exchange resin. If, in X-ray photoelectron spectroscopy analysis, almost no photoelectron energy originating from the metal elements constituting the raw material metal diboride is detected, and only photoelectron energy originating from boron and hydrogen is detected, it can be said that the product is composed only of boron and hydrogen.

[0036] In observations using a transmission electron microscope (TEM), for example, a transmission electron microscope (product name: JEM-2100F TEM / STEM) manufactured by JEOL Ltd. is used to observe the product and analyze its shape (appearance), etc. If a film-like (sheet-like) substance is observed in this analysis, the product can be said to be a two-dimensional sheet-like substance. By performing energy dispersive X-ray analysis (EDS) in the transmission electron microscope, the presence or absence of metal elements in the TEM-observed portion of the product can be observed. In this analysis, if almost no X-ray energy originating from the metal elements constituting the raw material metal diboride is detected and no peak of the metal element (e.g., Mg) appears, it can be said that the metal element is not present. Furthermore, by performing electron energy loss spectroscopy (EELS) in the transmission electron microscope, the constituent elements in the TEM-observed portion of the product can be observed. In this analysis, if only X-ray energy derived from boron and elements derived from the functional group α of the ion exchange resin is detected, it can be said that the product is composed only of boron and elements derived from the functional group α of the ion exchange resin.

[0037] According to the carbon monoxide production reaction catalyst of this embodiment, (BH) ｎBecause the device contains a two-dimensional boron hydride-containing sheet having a two-dimensional network consisting of (n≧4), it can decompose formic acid in a gas flow system and efficiently produce high-purity carbon monoxide continuously.

[0038] [Carbon monoxide production apparatus] Fig. 2 is a schematic diagram showing a carbon monoxide production apparatus according to one embodiment of the present invention. As shown in Fig. 2, the carbon monoxide production apparatus 10 of this embodiment includes a catalyst section 50. The carbon monoxide production apparatus 10 of this embodiment may include a reaction section 20, a supply section 30, and a vaporization section 40. The reaction section 20 has a pipe 21 and a heating section (hereinafter referred to as the "first heating section") 22. The carbon monoxide production apparatus 10 of this embodiment may include a second heating section 60 and an analysis section 70.

[0039] The reaction section 20 has a pipe 21 through which formic acid decomposed by the carbon monoxide production apparatus 10 of this embodiment flows. A catalyst section 50 for decomposing formic acid is disposed inside the pipe 21. The first heating section 22 is disposed so as to surround the outer periphery of the pipe 21 and heats the pipe 21 and the catalyst section 50 to a predetermined temperature. An example of the pipe 21 is a quartz tube. An example of the first heating section 22 is an electric wire heater.

[0040] The supply unit 30 supplies formic acid to the pipe 21. Specifically, the supply unit 30 supplies formic acid to the pipe 21 via the vaporization unit 40. The supply unit 30 has a syringe 31 and a flow rate control unit 32. The flow rate control unit 32 controls the flow rate of the formic acid discharged from the syringe 31 to a predetermined value. The supply unit 30 and the vaporization unit 40 are connected via a pipe 81.

[0041] The vaporizing unit 40 vaporizes the formic acid supplied from the supply unit 30 and supplies the vaporized formic acid to the pipe 21. The vaporizing unit 40 may be, for example, an evaporator.

[0042] The catalyst unit 50 is disposed inside the pipe 21 so as to come into contact with the formic acid flowing through the pipe 21. Examples of a mode in which the catalyst unit 50 is disposed so as to come into contact with the formic acid flowing through the pipe 21 include a mode in which the catalyst unit 50 is attached to the inner surface of the pipe 21 and a mode in which a porous catalyst unit 50 is disposed inside the pipe 21. The catalyst unit 50 is configured from the carbon monoxide production reaction catalyst of the above-described embodiment. The amount of catalyst unit 50 provided inside the pipe 21 is adjusted appropriately depending on the inner diameter of the pipe 21 and the flow rate of vaporized formic acid flowing through the pipe 21. For example, the catalyst unit 50 is disposed evenly inside the pipe 21 so that the formic acid flowing through the pipe 21 comes into contact with the catalyst unit 50 as evenly as possible (for example, so that no formic acid flows through the pipe 21 without coming into contact with the catalyst unit 50).

[0043] The second heating unit 60 is connected to the analysis unit 70 via a pipe 82. The second heating unit 60 is disposed so as to surround the outer periphery of the end 21a of the pipe 21 on the downstream side in the direction of gas flow, and the end 82a of the pipe 82 connected to the end 21a on the upstream side in the direction of gas flow. The second heating unit 60 heats the end 21a of the pipe 21 and the end 82a of the pipe 82, thereby adjusting the temperature of the gas (product) leaving the reaction unit 20 (pipe 21) to a temperature suitable for analysis in the analysis unit 70. An example of the second heating unit 60 is a ribbon heater.

[0044] The analysis unit 70 analyzes the components of the gas that has left the reaction unit 20 (pipe 21). The analysis unit 70 may be, for example, a gas chromatograph.

[0045] A switching valve 90 having two or more ports may be provided in the pipe 82. An example of the switching valve 90 is a two-position six-port switching valve. The switching valve 90 performs automatic switching for sample concentration, column selection, and sample cleanup.

[0046] A carbon monoxide production method using the carbon monoxide production apparatus 10 of this embodiment will be described. Formic acid is supplied from the syringe 31 of the supply unit 30 to the vaporization unit 40 via the pipe 81. The flow rate of the formic acid discharged from the syringe 31 is controlled to a predetermined value by the flow rate control unit 32. The formic acid supplied from the syringe 31 is vaporized in the vaporization unit 40. The formic acid vaporized in the vaporization unit 40 is supplied into the pipe 21 of the reaction unit 20. The formic acid supplied into the pipe 21 comes into contact with the catalyst unit 50, which has been heated to a predetermined temperature by the first heating unit 22. The formic acid then decomposes to produce carbon monoxide and water (carbon monoxide and water are collectively referred to as the "product"). The product discharged from the pipe 21 flows into the analysis unit 70 via the pipe 82. The product that has flowed into the analysis unit 70 is analyzed for its components in the analysis unit 70. It is not necessary for all of the product coming out of the pipe 21 to flow into the analysis section 70, but the outlet may be switched by the switching valve 90 and the product may be collected in a collection section (not shown).

[0047] According to the carbon monoxide manufacturing apparatus 10 of this embodiment, the catalyst section 50 made of the carbon monoxide production reaction catalyst of the above-described embodiment is arranged inside the pipe 21 so as to come into contact with formic acid flowing through the pipe 21, so that the vaporized formic acid can be decomposed while flowing, thereby efficiently producing high-purity carbon monoxide continuously.

[0048] [Method for Producing Carbon Monoxide] The method for producing carbon monoxide of this embodiment includes a step of vaporizing formic acid (hereinafter referred to as the "first step"), and a step of bringing the vaporized formic acid into contact with the carbon monoxide production reaction catalyst of the above-described embodiment, which has been adjusted to a temperature of 120°C or higher (hereinafter referred to as the "second step").

[0049] In the first step, the method for vaporizing formic acid is not particularly limited, and formic acid may be heated to a boiling point (100.75°C) or higher under normal pressure, or formic acid may be heated under reduced pressure.

[0050] In the second step, the formic acid vaporized in the first step is brought into contact with the carbon monoxide production reaction catalyst of the above embodiment, which has been adjusted to a temperature of 120° C. or higher. When the vaporized formic acid is brought into contact with the carbon monoxide production reaction catalyst, the contact is carried out in a state in which the vaporized formic acid is allowed to flow.

[0051] When vaporized formic acid is brought into contact with the carbon monoxide production reaction catalyst, the molar flow rate of the vaporized formic acid is preferably 0.1 μL / min to 3.0 μL / min, more preferably 0.1 μL / min to 2.0 μL / min, when, for example, about 200 mg of the carbon monoxide production reaction catalyst is used. If the molar flow rate of the vaporized formic acid is equal to or greater than the lower limit, the amount of carbon monoxide produced per unit time increases. If the molar flow rate of the vaporized formic acid is equal to or less than the upper limit, the proportion of formic acid that passes through unreacted decreases.

[0052] When the mass of the catalyst portion (mass of the carbon monoxide production reaction catalyst) is W (g) and the molar flow rate of formic acid is F (mol / h), W / F, which is defined as the contact time indicating the degree of load on the catalyst, is preferably 3 g·h / mol or more and 16 g·h / mol or less. When W / F is equal to or more than the lower limit, the proportion of formic acid that passes through unreacted decreases. When W / F is equal to or less than the upper limit, the amount of carbon monoxide produced per unit time increases.

[0053] When vaporized formic acid is brought into contact with the carbon monoxide production reaction catalyst, the pressure of the vaporized formic acid is preferably about atmospheric pressure.

[0054] According to the method for producing carbon monoxide of this embodiment, vaporized formic acid is brought into contact with the carbon monoxide production reaction catalyst of the above-described embodiment, which has been adjusted to a temperature of 120°C or higher. Therefore, the vaporized formic acid is decomposed in a flowing state, and high-purity carbon monoxide can be efficiently and continuously produced.

[0055] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0056] Comparative Example The following experiment was conducted in the carbon monoxide production apparatus shown in FIG. 2 without providing a catalyst section. Formic acid vaporized by an evaporator was supplied to the piping of the reaction section, and the temperature inside the piping was adjusted to 120°C to 300°C. The components of the product leaving the piping and the amount of the product recovered from the piping were analyzed by gas chromatography. The molar flow rate of the formic acid supplied to the piping was 2 μL / min. The relationship between the temperature inside the piping and the amount of the product recovered (moles per cc) is shown in FIG. 3. The results shown in FIG. 3 show that carbon monoxide, carbon dioxide, and water were produced. It was also found that the amounts of carbon monoxide, carbon dioxide, and water recovered increased as the temperature inside the piping increased.

[0057] [Synthesis Example] Magnesium diboride (purity: 99%, manufactured by Rare Metallic Co., Ltd.) was added to acetonitrile, and 30 mL of an ion exchange resin having a sulfo group (Amberlite (registered trademark) IR120B, manufactured by Organo Corporation) was added by volume. The mixture was stirred with a glass rod to prepare a mixed solution of magnesium diboride and ion exchange resin. The amount of magnesium diboride added to acetonitrile was 5 mg / mL. At this time, 1.5 times the amount of ion exchange resin was added as the ion exchange capacity. After stirring this mixed solution at 25°C for 72 hours, the mixed solution was filtered through a membrane filter with a pore size of 0.2 μm, and the filtrate was collected. Thereafter, the mixture was dried under reduced pressure for 30 minutes using a 70°C oil bath under a nitrogen atmosphere to obtain a product.

[0058] "Infrared Spectroscopic Analysis" The obtained product was analyzed using an infrared spectroscopic analyzer (trade name: FTIR ALPHA II, manufactured by Bruker). The results are shown in Figure 4. From the results shown in Figure 4, －１ There is an absorption peak corresponding to the B-H stretching vibration at 1350 cm －１ It was shown that a vibration absorption peak due to B-H-B species appeared in the vicinity, confirming that a borohydride-containing sheet had been obtained.

[0059] Example 1 In the carbon monoxide production apparatus shown in FIG. 2 , formic acid vaporized by an evaporator was supplied to the piping of the reaction section, and the vaporized formic acid was decomposed by contacting it with a catalyst section (catalyst section temperature) consisting of a carbon monoxide production reaction catalyst including a two-dimensional borohydride-containing sheet disposed within the piping. The temperature (catalyst section temperature) when the vaporized formic acid was contacted with the catalyst section was adjusted to 120°C to 300°C using the first heating section of the reaction section. The components of the product leaving the piping and the amount of product recovered from the piping were analyzed by gas chromatography. The molar flow rate of the formic acid supplied to the piping was 2 μL / min. The relationship between the temperature when the vaporized formic acid was contacted with the catalyst section and the amount of product recovered (moles per cc) is shown in FIG. 5 . The results shown in FIG. 5 indicate that contacting the vaporized formic acid with the catalyst section produced only carbon monoxide and water, and no carbon dioxide. It was also found that the amount of carbon monoxide and water recovered increased as the temperature of the catalyst section increased. In Example 1, the recovered amounts of carbon monoxide and water were about 100 times greater than those in the comparative example, demonstrating that the efficiency of decomposing formic acid into carbon monoxide and water was excellent.

[0060] Example 2 In the carbon monoxide production apparatus shown in FIG. 2 , formic acid vaporized by an evaporator was supplied to the piping of the reaction section, and the vaporized formic acid was decomposed by contacting it with a catalyst section (catalyst section temperature) consisting of a carbon monoxide production reaction catalyst including a two-dimensional borohydride-containing sheet disposed within the piping. The temperature (catalyst section temperature) when the vaporized formic acid was contacted with the catalyst section was adjusted to 120°C to 300°C using the first heating section of the reaction section. The components of the product leaving the piping and the recovered amount of the product leaving the piping were analyzed by gas chromatography. The molar flow rate of the formic acid supplied to the piping was 0.5 μL / min. Here, when the mass of the catalyst section (mass of the carbon monoxide production reaction catalyst) is W (g) and the molar flow rate of formic acid is F (mol / h), W / F, defined as the contact time representing the degree of load on the catalyst, was 15.2. In Example 2, the relationship between temperature and conversion rate and the relationship between temperature and selectivity were investigated by varying the temperature of the catalyst section. The results are shown in Figures 6 to 8. Figure 6 is a graph showing the relationship between the temperature of the catalyst section and the amount of recovered carbon monoxide and water, and the relationship between the temperature of the catalyst section and the amount of formic acid reduced. Figure 7 is a graph showing the relationship between the temperature of the catalyst section and the conversion rate. In Figure 7, FA consumption is the amount of recovered carbon monoxide and water calculated from the amount of formic acid consumed. FA consumption is calculated using the following formula: (1 - (molar flow rate of formic acid detected at the outlet side of the piping)) / molar flow rate of formic acid detected at the inlet side of the piping × 100). Figure 8 is a graph showing the relationship between the temperature of the catalyst section and the selectivity. The selectivity (%) is defined by the following formula (1): molar flow rate of carbon monoxide / molar flow rate of detected product × 100 (1). The conversion rate (%) is defined by the following formula (2). Molar flow rate of carbon monoxide detected at the outlet side of the pipe / Molar flow rate of formic acid detected at the inlet side of the pipe × 100 (2) From the results shown in Figure 7, it was confirmed that the conversion rate increased as the temperature of the catalyst section was changed. Furthermore, carbon monoxide and water were obtained at all temperatures. Because water was released as vapor, carbon monoxide and water could be obtained continuously, unlike when reacting in sulfuric acid. From the results shown in Figure 8, it was confirmed that the selectivity was 100% at all temperatures, and that only carbon monoxide was obtained in 100% yield at all temperatures.This indicates that no carbon dioxide is generated, which is a problem in the decomposition reaction of formic acid.

[0061] Example 3 In the carbon monoxide production apparatus shown in Figure 2, formic acid vaporized by an evaporator was supplied to the piping of the reaction section, and the vaporized formic acid was decomposed by contacting it with a catalyst section consisting of a carbon monoxide production reaction catalyst including a two-dimensional borohydride-containing sheet disposed within the piping. The temperature (catalyst section temperature) when the vaporized formic acid was contacted with the catalyst section was adjusted to 120°C to 300°C using the first heating section of the reaction section. The components of the product leaving the piping and the amount of product recovered were analyzed by gas chromatography. The molar flow rate of the formic acid supplied to the piping was 1.0 μL / min. The W / F ratio was 7.6. In Example 3, the relationship between temperature and conversion rate and the relationship between temperature and selectivity were investigated when the temperature of the catalyst section was changed. The results are shown in Figures 9 to 11. Figure 9 shows the relationship between the catalyst section temperature and the amount of recovered carbon monoxide and water, as well as the relationship between the catalyst section temperature and the amount of formic acid lost. FIG. 10 shows the relationship between the temperature of the catalyst section and the conversion rate. FIG. 11 shows the relationship between the temperature of the catalyst section and the selectivity. From the results shown in FIG. 10, it was confirmed that the conversion rate increased as the temperature increased when the temperature of the catalyst section was changed. Furthermore, carbon monoxide and water were obtained at all temperatures. Because water was released as vapor, carbon monoxide and water could be obtained continuously, unlike when reacting in sulfuric acid. From the results shown in FIG. 11, it was confirmed that the selectivity was 100% at all temperatures, and that only carbon monoxide was obtained in 100% yield at all temperatures. This indicates that no carbon dioxide, which is a problem in the decomposition reaction of formic acid, was generated.

[0062] Example 4 In the carbon monoxide production apparatus shown in Figure 2, formic acid vaporized by an evaporator was supplied to the piping of the reaction section, and the vaporized formic acid was decomposed by contacting it with a catalyst section consisting of a carbon monoxide production reaction catalyst including a two-dimensional borohydride-containing sheet disposed within the piping. The temperature (catalyst section temperature) when the vaporized formic acid was contacted with the catalyst section was adjusted to 120°C to 300°C using the first heating section of the reaction section. The components of the product leaving the piping and the recovered amount of the product leaving the piping were analyzed by gas chromatography. The molar flow rate of the formic acid supplied to the piping was 2.0 μL / min. The W / F ratio was 3.8. In Example 4, the relationship between temperature and conversion rate and the relationship between temperature and selectivity were investigated when the temperature of the catalyst section was changed. The results are shown in Figures 12 to 14. Figure 12 shows the relationship between the catalyst section temperature and the recovered amounts of carbon monoxide and water, as well as the relationship between the catalyst section temperature and the amount of formic acid lost. FIG. 13 shows the relationship between the temperature of the catalyst section and the conversion rate. FIG. 14 shows the relationship between the temperature of the catalyst section and the selectivity. From the results shown in FIG. 13, it was confirmed that the conversion rate increased as the temperature increased when the temperature of the catalyst section was changed. Furthermore, carbon monoxide and water were obtained at all temperatures. Because water was released as vapor, carbon monoxide and water could be obtained continuously, unlike when reacting in sulfuric acid. From the results shown in FIG. 14, it was confirmed that the selectivity was 100% at all temperatures, and that only carbon monoxide was obtained in 100% yield at all temperatures. This indicates that no carbon dioxide, which is a problem in the decomposition reaction of formic acid, was generated.

[0063] [Example 5] Based on the results of Example 2, an Arrhenius plot shown in Fig. 15 was created in the catalyst temperature range of 140°C to 200°C, where the conversion rate is not too high. In Fig. 15, the vertical axis represents the reciprocal of absolute temperature, and the horizontal axis represents the reciprocal of time. In addition, in Figure 15, the curve shows the logarithm of k calculated using actual measured values ​​(average values ​​of conversion (conversion rate) at each temperature in Figure 7 (average of conversion rates calculated from the amount of change in carbon and conversion rates calculated from the amount of formic acid consumed): k = {flow rate (unit: mol / s) x (conversion rate ÷ 100) / (amount of catalytic two-dimensional borohydride-containing sheet (unit: mol))}, and the straight line shows an approximation of the distribution of actual measured values. The activation energy (Ea) for producing carbon monoxide by decomposing formic acid was calculated by multiplying the slope of the tangent to the curve shown in Figure 15 by the gas constant R, and was found to be 73.5 kJ / mol (17.6 kcal / mol).

[0064] Example 6 Based on the results of Example 3, an Arrhenius plot shown in Fig. 16 was created for the catalyst temperature range of 140°C to 200°C, where the conversion rate is not too high. In Fig. 16, the vertical axis represents the reciprocal of absolute temperature, and the horizontal axis represents the reciprocal of time. In addition, in Figure 16, the curve shows the logarithm of k calculated using actual measured values ​​(average values ​​of conversion (conversion rate) at each temperature in Figure 10 (average of conversion rates calculated from the amount of change in carbon and conversion rates calculated from the amount of formic acid consumed): k = {flow rate (unit: mol / s) x (conversion rate ÷ 100) / (amount of catalytic two-dimensional borohydride-containing sheet (unit: mol))}, and the straight line shows an approximation of the distribution of actual measured values. By multiplying the slope of the tangent to the curve shown in Figure 16 by the gas constant R, the activation energy (Ea) for producing carbon monoxide by decomposing formic acid was calculated to be 62.8 kJ / mol (15 kcal / mol).

[0065] [Example 7] Based on the results of Example 4, an Arrhenius plot shown in Fig. 17 was created for the catalyst temperature range of 140°C to 200°C, where the conversion rate is not too high. In Fig. 17, the vertical axis represents the reciprocal of absolute temperature, and the horizontal axis represents the reciprocal of time. In addition, in Figure 17, the curve shows the logarithm of k calculated using the actual measured values ​​(average values ​​of conversion (conversion rate) at each temperature in Figure 13 (average of conversion rates calculated from the amount of change in carbon and conversion rates calculated from the amount of formic acid consumed): k = {flow rate (unit: mol / s) x (conversion rate ÷ 100) / (amount of catalytic two-dimensional borohydride-containing sheet (unit: mol))}, and the straight line shows an approximation of the distribution of the actual measured values. By multiplying the slope of the tangent to the curve shown in Figure 17 by the gas constant R, the activation energy (Ea) for producing carbon monoxide by decomposing formic acid was calculated to be 68.1 kJ / mol (16.3 kcal / mol).

[0066] 15 to 17 are shown together in Figure 18. The results shown in Figure 18 reveal that the activation energy for producing carbon monoxide by decomposing formic acid increases as the W / F ratio decreases. In addition, in all Examples, the activation energy was found to be 68±6 kJ / mol (16.2±1.4 kcal / mol).

[0067] REFERENCE SIGNS LIST 10 Carbon monoxide production apparatus 20 Reaction section 21 Pipe 22 Heating section (first heating section) 30 Supply section 31 Syringe 32 Flow rate control section 40 Vaporization section 50 Catalyst section 60 Second heating section 70 Analysis section 81, 82 Pipe

Claims

1. (BH) ｎ A carbon monoxide production reaction catalyst comprising a borohydride-containing sheet having a network consisting of (n≧4).

2. A carbon monoxide manufacturing apparatus comprising a catalyst section disposed inside a pipe through which formic acid flows so as to come into contact with the formic acid flowing through the pipe, the catalyst section comprising the carbon monoxide production reaction catalyst according to claim 1.

3. A method for producing carbon monoxide, comprising the steps of: vaporizing formic acid; and contacting the vaporized formic acid with the carbon monoxide production reaction catalyst according to claim 1, the temperature of which has been adjusted to 120°C or higher.

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