Organic substance cracking catalyst, organic substance cracking method, method for producing compound, and organic substance treatment system

Abstract

This cracking catalyst is used for cracking organic substances (excluding organic fluorine compounds), and has a carrier and a complex. The carrier is constituted from a conductor or a semiconductor. The complex is supported on the carrier. The complex is represented by a formula (1) and is formed from a transition metal and a π electron-containing organic ligand. The cracking catalyst may be used at a temperature below 40ºC. The cracking catalyst may be used in the presence of an oxidizing agent. The carrier may be constituted from a carbon material having a functional group containing hydrogen and / or oxygen.

Description

Decomposition catalyst for organic matter, decomposition method for organic matter, manufacturing method of compound, organic matter treatment system

[0001] The present disclosure relates to a catalyst for decomposing organic matter such as synthetic organic compounds and synthetic polymers, a method for decomposing organic matter using the decomposition catalyst, and an organic matter treatment system. The disclosure also relates to a method for producing at least one compound selected from the group consisting of alcohols, phenols, carboxylic acids, aldehydes, and ketones by decomposing organic matter.

[0002] Among the compounds synthesized by humans, there are many refractory organic compounds that are difficult to decompose due to their high chemical stability, and their treatment requires high energy and highly reactive reagents.Since refractory organic compounds do not decompose even when released into the environment, their retention in nature and in living organisms is a problem.

[0003] In a broad sense, methane, which is known to have a strong greenhouse effect, plant-derived polymers (specifically, lignin, hemicellulose, wood-derived waste oil, etc.), which are incinerated in large quantities every year and are a source of CO2, and synthetic polymers (specifically, polyethylene, etc.), which are a cause of serious environmental pollution in the form of marine plastics, can also be considered to be persistent. Many of these persistent organic substances remain in the environment or are disposed of by landfilling or incineration, thereby causing environmental pollution.

[0004] Chemical decomposition treatments of organic matter are also being carried out. Specifically, decomposition treatments using precious metal catalysts or the Fenton reaction are carried out, in which organic matter is decomposed and rendered harmless under high temperature and high pressure conditions. Furthermore, for example, Patent Document 1 discloses a method for decomposing difficult-to-decompose organic matter using a specific catalyst. According to Patent Document 1, the use of a specific catalyst makes it possible to decompose hydrocarbons, naturally occurring polymers, artificially synthesized polymers, and the like.

[0005] International Publication No. 2019 / 203051

[0006] The Fenton reaction, which is used for decomposition treatment on an industrial scale, uses highly reactive hydroxyl radicals as the reactive species, but the reaction is carried out at high temperatures. In the Fenton reaction, decomposition becomes difficult when the reaction temperature is set to, for example, room temperature, and there are many organic substances that cannot be decomposed efficiently. Furthermore, even in the method described in the aforementioned Patent Document 1, the decomposition reaction is carried out at high temperatures, and heating of the reaction system is required during decomposition of the organic substances. As such, conventional organic substance decomposition methods require thermal energy for the decomposition reaction, and there is room for improvement in terms of energy consumption.

[0007] The present disclosure has been made in consideration of the above circumstances, and aims to provide a decomposition catalyst capable of decomposing organic matter under energetically advantageous conditions (e.g., low temperatures), a method for decomposing organic matter, an organic matter treatment system, and a method for producing compounds as decomposition products.

[0008] Aspects of the present disclosure are as follows [1] to

[10] .

[0009] [1] A decomposition catalyst used for decomposing organic substances (excluding organic fluorine compounds), comprising: a carrier made of a conductor or a semiconductor; and a complex supported on the carrier, wherein the complex is represented by the following formula (1) and is formed of a transition metal and a π-electron-containing organic ligand:

[0010]

[0011] In formula (1), M is a transition metal. 1 ~R 8 are each independently selected from hydrogen, an alkyl group which may be substituted with a substituent, an alkylene group which may be substituted with a substituent, and an aromatic group which may be substituted with a substituent. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 may be bonded to each other to form a single ring which may be substituted with a substituent, or multiple rings which may be substituted with a substituent. 1 and R2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 The ring formed by may be an aromatic ring or a heterocyclic ring. Each X is independently selected from N, CR, or (CR)2. Each R is independently selected from hydrogen, an alkyl group which may be substituted with a substituent, an alkylene group which may be substituted with a substituent, and an aromatic group which may be substituted with a substituent. In addition, one or two of the four Xs may be absent, and the pyrrole rings in formula (1) may be directly bonded to each other via a single bond or a double bond. Het in formula (1) is a hetero element selected from O, N, and S. The bond between Het and M may be a single bond or a double bond.

[0012] [2] The decomposition catalyst according to [1], which is used at a temperature of less than 40° C. [3] The decomposition catalyst according to [1] or [2], which is used in the presence of an oxidizing agent. [4] The decomposition catalyst according to any one of [1] to [3], wherein the support is made of a carbon material having functional groups containing hydrogen and / or oxygen.

[0013] [5] The decomposition catalyst according to [4], wherein the functional group is an electron-withdrawing group. [6] The decomposition catalyst according to any one of [1] to [5], wherein the amount of CO generated when the carbon material is heated from 100°C to 1500°C at a temperature increase rate of 200°C / h by vacuum pyrolysis is 1 mg / g or more. [7] The decomposition catalyst according to any one of [1] to [6], wherein the amount of CO generated when the carbon material is heated from 100°C to 1500°C at a temperature increase rate of 200°C / h by vacuum pyrolysis is 0 or more.

[0014] [8] A method for decomposing organic matter using the decomposition catalyst according to any one of [1] to [7].

[0015] [9] A method for producing a compound, which comprises oxidizing the organic substance by the method according to [8] to produce at least one compound selected from the group consisting of alcohols, phenols, carboxylic acids, aldehydes, and ketones.

[0016]

[10] An organic matter treatment system that decomposes the organic matter using the decomposition catalyst according to any one of [1] to [7].

[0017] The decomposition catalyst, the decomposition method, the production method, and the organic matter treatment system can decompose organic matter at low temperatures, for example, 60°C or lower. In addition, compounds can be produced as decomposition products. In other words, the decomposition catalyst, the decomposition method, the production method, and the organic matter treatment system can decompose organic matter under energetically advantageous conditions (for example, low temperatures).

[0018] FIG. 1A is the chemical structure of a complex in the catalyst of Production Example 2. FIG. 1B is the chemical structure of a complex formed by a transition metal oxo species and a π-electron-containing organic ligand when a transition metal oxo species is formed in the catalyst of Production Example 2. FIG. 2 is a schematic diagram of the carbon materials of Production Examples 1 and 2. FIG. 3 is a schematic diagram showing a structure in which complex molecules in the catalyst of Production Example 2 are stacked on the surface of the carbon material. FIG. 4 is a schematic diagram showing the state of surface functional groups of the carbon materials of Production Examples 1 and 2. FIG. 5 is an explanatory diagram showing the mechanism of the methane oxidative decomposition reaction using the catalyst of Production Example 2. FIG. 6 is the chemical structure of a complex formed by a transition metal oxo species and a π-electron-containing organic ligand when a transition metal oxo species is formed in the catalyst of Production Example 1. FIG. 7 is a graph showing the relationship between the amount of complex supported and the amount of methane decomposition products in Example 2. FIG. 8 is a graph showing the amount of decomposition products by methane oxidative decomposition in Example 3. 1 9 shows the H-NMR spectrum before and after the oxidative decomposition reaction of dioxane in Example 4. 1 10 is a graph showing the results of quantitative analysis of undecomposed dioxane in Example 5. FIG. 11 is a graph showing the results of quantitative analysis of decomposition products after oxidative decomposition of benzene in Example 6. 1 12 is a graph showing the change in benzene conversion over time in Example 6. FIG. 13 is a graph showing the change in benzene conversion 4 hours after the start of the catalytic reaction in Example 6. FIG. 14 is a graph showing the change in benzene conversion over time in Example 7. 115 is a H-NMR spectrum of the decomposition product after oxidative decomposition of dichloromethane in Example 8. 1 16 is a schematic diagram of an organic matter treatment system.

[0019] Hereinafter, embodiments for carrying out the present disclosure will be described. Unless otherwise specified, the numerical ranges "a to b" described in this specification include the lower limit a and the upper limit b. Numerical ranges can be formed by arbitrarily combining these upper and lower limit values, as well as the numerical values ​​listed in the examples. Furthermore, numerical values ​​arbitrarily selected from within the numerical range can be used as the upper and lower limit values.

[0020] The cracking catalyst of the present disclosure includes a complex and a support. The complex is represented by the following formula (1) and is a molecular association formed by a transition metal and a π-electron-containing organic ligand.

[0021]

[0022] In formula (1), M is a transition metal. Het is a hetero element selected from O, N, and S. The bond between Het and M may be a single bond or a double bond. 1 ~R 8 are each independently selected from hydrogen, an alkyl group which may be substituted with a substituent, an alkylene group which may be substituted with a substituent, and an aromatic group which may be substituted with a substituent. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 may be bonded to each other to form a single ring which may be substituted with a substituent, or multiple rings which may be substituted with a substituent. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 The ring formed by R may be an aromatic ring or a heterocyclic ring. 1 ~R8 are each independently preferably hydrogen or an electron-donating group. The electron-donating group is preferably an alkyl group and / or an alkylene group, and the number of carbon atoms therein is preferably 10 or less, more preferably 6 or less, and even more preferably 5 or less. In this case, it is possible to more easily avoid a decrease in the stability of the complex against oxidation reactions. The electron-donating group may also be an alkoxy group. In this case, the number of carbon atoms in the alkoxy group is preferably 10 or less, more preferably 6 or less, and even more preferably 5 or less. R 1 ~R 8 When an alkoxy group is contained in formula (1), a decrease in the stability of the complex against oxidation reactions can be more easily avoided by limiting the number of alkoxy groups to 6 or less, preferably 4 or less, and more preferably 3 or less. Each X is independently selected from N, CR, or (CR) 2. Each R in CR or (CR) 2 is independently selected from hydrogen, an alkyl group which may be substituted with a substituent, an alkylene group which may be substituted with a substituent, and an aromatic group which may be substituted with a substituent. Furthermore, one or two of the four Xs may be absent, and the pyrrole rings in formula (1) may be directly bonded to each other via a single or double bond. Het in formula (1) is a heteroatom selected from O, N, and S. The bond between Het and M may be a single bond or a double bond.

[0023] The phrase "optionally substituted with a substituent" will be explained below. For example, in the case of an alkyl group, "optionally substituted with a substituent" means an alkyl group in which one or more hydrogen atoms of the alkyl group are substituted with a substituent, or an alkyl group having no particular substituent.

[0024] Examples of the substituent include alkyl groups, alkenyl groups, alkynyl groups, aromatic groups, heterocyclic groups, halogen, OH, SH, CN, SCN, OCN, nitro groups, alkoxy groups, unsaturated alkoxy groups, amino groups, alkylamino groups, dialkylamino groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, acyloxy groups, aryloxycarbonyl groups, acylamino groups, alkoxycarbonylamino groups, aryloxycarbonylamino groups, sulfonylamino groups, sulfamoyl groups, carbamoyl groups, alkylthio groups, arylthio groups, sulfonyl groups, sulfinyl groups, ureido groups, phosphoric acid amide groups, sulfo groups, carboxy groups, hydroxamic acid groups, sulfino groups, hydrazino groups, imino groups, and silyl groups. These substituents may be further substituted. Furthermore, when there are two or more substituents, these substituents may be the same or different from each other.

[0025] From the viewpoints of versatility and cost, the transition metal M is preferably at least one selected from the group consisting of Mn, Fe, Co, Ni, Cu, Ru, Rh, Cr, V, Mo, Re, and Os. Furthermore, from the viewpoint of improving the decomposition performance of PFAS, the transition metal M is more preferably at least one selected from the group consisting of Mn, Fe, Co, Ni, Cu, and Cr.

[0026] The π-electron-containing organic ligand is an organic ligand having a conjugated structure with a π-electron plane and a heteroatom capable of coordinating to a transition metal. The π-electron plane interacts primarily with the conductive material or semiconductor on which the complex is supported, thereby shifting the energy of the complex formed by the transition metal oxo species and the π-electron-containing organic ligand, i.e., the transition metal complex oxo species. This is thought to result in a decrease or shift in the SOMO energy level of the transition metal complex oxo species.

[0027] The complex of formula (1) may be purchased commercially, or may be prepared by the method described in J. Metz, O. Schneider, M. Hanack, Inorg. Chem. 23 (1984) 1065-1071, L. A. Bottomley, J.-N. Gorce, V. L. Goedken, C. Ercolani, Inorg. Chem. 24 (1985) 3733-3737, A. B. Sorokin, E. V. Kudrik, D. Bouchu, Chem. Commun. (2008) 2562-2564, Y. Yamada, T. It may be synthesized based on the contents of literature such as K. Sugiura, K. Morita, H. Ariga-Miwa, K. Tanaka, Inorganica Chimica Acta, 489 (2019) 160-163.

[0028] The complex is supported on a support. The support is composed of a conductor (specifically, a conductive material) or a semiconductor. As the support, it is preferable to use a substance that can impart electronic perturbation to a complex formed from a transition metal oxo species and a π-electron-containing organic ligand and that may be able to appropriately control the SOMO energy level of the complex. The support may be in the form of a powder, plate, or sheet. Examples of conductors include carbon materials such as conductive carbon, and metals. As the semiconductor, a planar semiconductor formed on a substrate is preferable, and it may also be an n-type semiconductor or a p-type semiconductor.

[0029] When conductive carbon is used as a support, the π-π stacking of the π-electron plane of the carbon and the π-electron-containing organic ligand of the complex creates stabilization energy, and electronic perturbation by the π-electrons of the conductive carbon lowers or raises the energy level of the SOMO of the complex formed by the transition metal oxo species and the π-electron-containing organic ligand.

[0030] For electronic interactions such as more stable π-π stacking that occur between the π-electron plane of the conductive carbon and the π-electrons of the π-electron-containing organic ligand of the complex, conductive carbon with a large conjugated plane area is preferred. As conductive carbon, plate-like carbon such as flake graphite or highly oriented pyrolytic graphite is preferred. Furthermore, conductive carbon having a cleavage plane where the layered structure of graphite is exfoliated is preferred.

[0031] The support is preferably a carbon material such as conductive carbon, and more preferably the carbon material has a functional group. In this case, the catalytic activity of the decomposition catalyst is improved, and the decomposition performance for organic substances is improved. Examples of the functional group include a functional group containing at least one element selected from the group consisting of hydrogen, oxygen, nitrogen, boron, and phosphorus. From the viewpoint of improving the catalytic activity, the functional group preferably contains hydrogen and / or oxygen. Examples of such functional groups include hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, carbonyl groups, carboxy groups, aldehyde groups, ketone groups, and hydroxy groups. In addition, graphene doped with at least one element selected from the group consisting of boron, nitrogen, and phosphorus can also be used as the carbon material.

[0032] The reason why the cracking reaction proceeds with the cracking catalyst of the present disclosure is presumed to be as follows. Representative examples of the complex represented by formula (1) include the compounds represented by FIGS. 1A and 1B. In the cracking catalyst of the present disclosure, a complex having a two-story molecular structure as exemplified in FIGS. 1A and 1B is stacked on the surface of a carbon material as exemplified in FIG. 2. More specifically, the cyclic planes of the cyclic compound constituting the complex (e.g., two parallel planes including each phthalocyanine ring in FIGS. 1A and 1B) are supported parallel to the surface of the carbon material (see FIG. 3). In a cracking catalyst with such a structure, charge transfer occurs from the complex molecules to the carbon material, which is thought to promote electron transfer from the organic substance to be decomposed. Furthermore, for example, in the cracking reaction of hydrocarbons with the cracking catalyst, proton transfer occurs along with electron transfer, resulting in the cleavage of C—H bonds. In the decomposition catalyst of the present disclosure, the complex has a two-story molecular structure. However, the aforementioned electron transfer (charge transfer) occurs primarily in the first floor, which is closer to the carbon material, and the oxygen atoms bonded to the metal elements in the second floor are largely unaffected by the charge transfer. As a result, proton transfer (specifically, proton abstraction) can occur in the oxygen atoms in the second floor, which are not affected by the charge transfer. In other words, the first floor of the complex is electron-deficient, which favors electron abstraction from the organic matter being decomposed, while the second floor is not electron-deficient, thereby maintaining its proton abstraction ability. This is thought to enable the decomposition catalyst of the present disclosure to promote the oxidative decomposition of organic matter.

[0033] To further explain the mechanism of the decomposition reaction, Figure 5 illustrates the oxidative decomposition reaction of methane. As shown in Figure 5, the complex of the decomposition catalyst has a two-story molecular structure, and the complex is stacked on the surface of the carbon material. This causes a slight charge transfer from the complex molecule to the graphite surface, resulting in the formation of electron-rich and electron-deficient regions within each molecule. Because electron transfer (charge transfer) occurs primarily in the first-story region closer to the carbon material, oxygen atoms bonded to metal elements in the second-story region are largely unaffected by the charge transfer. Proton transfer (specifically, proton abstraction) from the target organic substance (specifically, methane) occurs via oxygen atoms in the second-story region, which are unaffected by the charge transfer. Meanwhile, the first-story region of the complex is electron-deficient, favoring electron abstraction from the target organic substance, while the second-story region is not electron-deficient and therefore maintains its proton abstraction ability. This is presumably why the decomposition catalyst of the present disclosure enables the promotion of oxidative decomposition of organic substances.

[0034] The reason why the presence of functional groups in carbon materials improves catalytic activity (specifically, oxidative decomposition activity for organic substances) is thought to be as follows: Lattice defects exist in carbon materials (see Figure 4). When carbon materials have functional groups, it is thought that many of the functional groups are present around the lattice defects. In the decomposition catalyst, high catalytic activity is achieved by the interaction of complex molecules with lattice defects. This is thought to be because the presence of functional groups makes the area around the lattice defects electron-deficient, facilitating electron transfer from the complex to the carbon material, and the aforementioned electron transfer (charge transfer) occurs more significantly. Therefore, from the perspective of improving catalytic activity, it is preferable for carbon materials to have functional groups, and it is more preferable for the functional groups to be electron-withdrawing groups. The electron-withdrawing groups are functional groups containing oxygen atoms and may further contain hydrogen atoms. Examples of electron-withdrawing groups include carboxyl groups, hydroxyl groups, ketone groups, aldehyde groups, and carbonyl groups.

[0035] From the viewpoint of further improving the catalytic activity described above, the amount of CO generated when a carbon material is heated from 100°C to 1500°C at a heating rate of 200°C / h by vacuum pyrolysis is preferably 1 mg / g or more, more preferably 3 mg / g or more, even more preferably 5 mg / g or more, even more preferably 8 mg / g or more, even more preferably 10 mg / g or more, still even more preferably 12 mg / g or more, particularly preferably 15 mg / g or more, particularly preferably 20 mg / g or more, and most preferably 25 mg / g or more. From the same viewpoint, the amount of CO generated when a carbon material is heated from 100°C to 1500°C at a heating rate of 200°C / h by vacuum pyrolysis may be 0, but is preferably 1 mg / g or more, more preferably 2 mg / g or more, and even more preferably 3 mg / g or more. In order to prevent the inherent properties of carbon materials such as carbon black from being impaired, the amount of CO generated when a carbon material is heated from 100°C to 1500°C at a heating rate of 200°C / h by vacuum pyrolysis is typically 150 mg / g or less, preferably 100 mg / g or less, more preferably 70 mg / g or less, and even more preferably 40 mg / g or less. From a similar perspective, the amount of CO generated when a carbon material is heated from 100°C to 1500°C at a heating rate of 200°C / h by vacuum pyrolysis is typically 150 mg / g or less, preferably 100 mg / g or less, more preferably 50 mg / g or less, and even more preferably 30 mg / g or less. The amounts of CO and CO generated from carbon materials are measured by vacuum pyrolysis. In vacuum pyrolysis, the carbon material to be measured is heated in a vacuum, and the amount of gas derived from functional groups generated by heating can be quantified.

[0036] When determining a preferred range of the amount of CO generated when a carbon material is heated from 100°C to 1500°C at a heating rate of 200°C / h by vacuum pyrolysis, the above-mentioned upper and lower limits of the amount of CO can be combined arbitrarily. The preferred range of the amount of CO can be, for example, 1 mg / g to 150 mg / g, 3 mg / g to 150 mg / g, 5 mg / g to 100 mg / g, 8 mg / g to 100 mg / g, 10 mg / g to 70 mg / g, 12 mg / g to 70 mg / g, 15 mg / g to 40 mg / g, 20 mg / g to 40 mg / g, or 25 mg / g to 40 mg / g.

[0037] In determining a preferred range of the amount of CO generated when a carbon material is heated from 100°C to 1500°C at a temperature increase rate of 200°C / h by vacuum pyrolysis, the above-mentioned upper and lower limits of the amount of CO can be combined arbitrarily. The preferred range of the amount of CO can be, for example, 0 mg / g or more and 150 mg / g or less, 1 mg / g or more and 150 mg / g or less, 2 mg / g or more and 100 mg / g or less, 3 mg / g or more and 50 mg / g or less, or 3 mg / g or more and 30 mg / g or less.

[0038] Carbon materials such as carbon black are produced by methods such as the furnace method, contact method, thermal method, acetylene method, lamp black method, etc. The type and amount of functional groups in the carbon material can be adjusted by adjusting the production method and heating conditions during production.

[0039] The specific surface area of ​​the carbon material is preferably small. If the specific surface area is large, the adsorption of the organic fluorine compound becomes significant and decomposition does not occur sufficiently. The specific surface area of ​​the carbon material is 10 to 600 m 2 / g, and 10 to 500m 2 / g, and more preferably 10 to 400m 2 / g, and more preferably 5 to 300m 2 It is particularly preferred that the SiO2 content is 1 / g.

[0040] The density of the carbon material is 1.5 to 2.3 g / cm 3 is preferably 1.7 to 2.26 g / cm 3More preferably, it is 2 to 2.25 g / cm 3 More preferably, it is 2.1 to 2.25 g / cm 3 It is even more preferable that the density is 2.2 to 2.25 g / cm 3 It is particularly preferable that the bulk density of the carbon material is 20 to 700 kg / m 3 is preferably 50 to 600 kg / m 3 More preferably, it is 100 to 500 kg / m 3 More preferably, it is 200 to 400 kg / m 3 It is even more preferable that the 3 It is particularly preferred that:

[0041] Specific examples of suitable carbon materials under trade names include VULCAN (registered trademark) XC-72R (manufactured by CABOT Corporation), Mitsubishi (registered trademark) Carbon Black #3230B, Mitsubishi Carbon Black #3050B, Mitsubishi Carbon Black #3250B (all manufactured by Mitsubishi Chemical Corporation), KEC, KEC-DJ600 (all manufactured by Ketjenblack International), acetylene black (manufactured by Denki Kagaku Kogyo Kabushiki Kaisha), Conductex (registered trademark)-975, Conductex-SC (all manufactured by Columbian Chemicals).

[0042] When a metal is used as a support, it is considered that free electrons of the metal interact with π electrons of the π electron-containing organic ligand of the complex, and the resulting stabilization energy can appropriately control the SOMO energy level of the complex formed by the transition metal oxo species and the π electron-containing organic ligand.

[0043] In consideration of the electronic interaction between the complex and the support, a metal ligand having a wide π-plane can be used as the π-electron-containing organic ligand. Specifically, a π-electron-containing organic ligand having a salen skeleton, a porphyrin skeleton, an azaporphyrin skeleton, a porphycene skeleton, a corrphycene skeleton, a hemiporphycene skeleton, a corrole skeleton, a phthalocyanine skeleton, a naphthalocyanine skeleton, a bipyridine skeleton, a phenanthroline skeleton, a dipyrromethene skeleton, or an aromatic ring-containing dithiolene skeleton is preferred.

[0044] The decomposition catalyst is preferably used in the presence of an oxidizing agent. By allowing the oxidizing agent to act on the decomposition catalyst complex, oxygen is bonded to the transition metal, forming a complex formed of a transition metal oxo species and a π-electron-containing organic ligand. That is, the complex formed of the transition metal oxo species and the π-electron-containing organic ligand is generated in situ within the decomposition reaction system of the organic matter, and the transition metal oxo species effectively contributes to the oxidative decomposition of the organic matter.

[0045] Examples of the oxidizing agent include peroxides, halogen acids or salts thereof, perhalogen acids or salts thereof, and ozone. One type of oxidizing agent may be used, or two or more types may be used in combination.

[0046] Examples of peroxides include peracids or their salts, non-peracid organic peroxides, and non-peracid inorganic peroxides. Examples of peracids include percarboxylic acids, persulfuric acids, percarbonic acids, perphosphoric acids, and hypoperhalogen acids. Examples of percarboxylic acids include peracetic acid, perbenzoic acid, and metachloroperbenzoic acid. Examples of hypoperhalogen acids include hypoperchloric acid, hypoperbromic acid, and hypoperiodic acid. Examples of non-peracid organic peroxides include tert-butyl hydroperoxide, cumene hydroperoxide, di-tert-butyl peroxide, dimethyldioxirane, acetone peroxide, methyl ethyl ketone peroxide, and hexamethylene triperoxide diamine. Examples of non-peracid inorganic peroxides include hydrogen peroxide, lithium peroxide, sodium peroxide, and potassium peroxide.

[0047] Examples of halogen acids include chloric acid, bromic acid, and iodic acid. Examples of perhalogen acids include perchloric acid, perbromic acid, and periodic acid.

[0048] Examples of salts of peracids, salts of halogen acids, and salts of perhalogen acids include salts of alkali metals such as lithium, sodium, and potassium, salts of alkaline earth metals such as magnesium, calcium, and barium, other metal salts, and ammonium salts.

[0049] In view of ease of handling, cost, ease of progress of the decomposition reaction, and the purpose of the present disclosure of decomposing organic matter, inorganic oxidizing agents are preferred, and hydrogen peroxide is particularly preferred. The amount of oxidizing agent used may be determined appropriately depending on the amount of organic matter to be decomposed. The larger the amount of oxidizing agent used, the faster the decomposition reaction rate.

[0050] The decomposition catalyst of the present disclosure is used for decomposing organic matter. The organic matter to be decomposed is not particularly limited, but organic fluorine compounds are not included in the organic matter to be decomposed. Note that organic fluorine compounds are organic compounds that contain at least one fluoro group (—F) in their molecular structure.

[0051] Examples of materials to be decomposed include waste materials containing organic matter in general, such as waste wood generated during wood processing or forest harvesting, grass clippings, driftwood removed for river maintenance, and disaster waste. Harmful substances (organic matter) under the Soil Countermeasures Act are also included in the materials to be decomposed. Other examples of materials to be decomposed include sludge containing organic matter, synthetic polymers such as waste rubber and waste tires, natural polymers such as carbohydrates, and fats and oils such as waste oil. Further examples of materials to be decomposed include industrial waste such as waste paper generated from the manufacture of pulp, paper, and paper products, waste fiber generated from the textile industry, discarded food, and discarded printed circuit boards. Substances regulated by the Toxic Substances Control Act (TSCA) are also included in the materials to be decomposed. Specific examples of substances to be decomposed by the decomposition catalyst include decabromodiphenyl ether, decabromodiphenyl oxide, tris(isopropylphenyl)phosphate, tris(isopropylphenyl)phosphate, 2,4,6-tri-tert-butylphenol, pentachlorothiophenol, 2,3,4,5,6-pentachlorobenzenethiol, hexachlorobutadiene, hexachlorobuta-1,3-diene, and hexachlorobutadiene. Other examples of substances to be decomposed by the decomposition catalyst include benzidine dyes, bisphenol A, hexabromocyclododecane (HBCD), methylene diphenyl diisocyanate (MDI), nonylphenol, nonylphenol ethoxylate, PBDEs (specifically, polybrominated diphenyl ethers such as pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether), phthalic acids, short-chain chlorinated paraffins, and toluene diisocyanate (TDI).

[0052] Hydrocarbons are also included in the organic matter to be decomposed. The hydrocarbons may be low-molecular-weight or high-molecular-weight hydrocarbons. Examples of hydrocarbons include lower alkanes such as methane, ethane, propane, and butane contained in natural gas; lower alkenes such as ethylene, propene, and butene; and lower alkynes such as acetylene, propyne, and butyne, as well as linear hydrocarbons, cyclic hydrocarbons, and aromatic hydrocarbons contained in petroleum. Furthermore, hydrocarbons may be halides in which at least a portion of the hydrogen atoms is substituted with a halogen group other than a fluoro group. Specific examples of halides include chloroethylene, carbon tetrachloride, 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-dichloroethylene, 1,3-dichloropropene, dichloromethane, tetrachloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, and trichloroethylene. As described above, natural carbon resources such as natural gas and petroleum can be used as the decomposition target. Furthermore, since the above-mentioned low-molecular-weight organic compounds can be produced using cracking catalysts, cracking catalysts can contribute to the efficient use of natural carbon resources. In the cracking of organic matter such as hydrocarbons, the hydrocarbons can be oxidized to produce alcohols and the like. In this specification, the term "cracking" also refers to the oxidation of hydrocarbons such as methane and ethane, and aromatic compounds such as benzene, to convert them into other organic compounds.

[0053] From the viewpoint of industrial utility, examples of organic matter to be decomposed include wood-based materials containing cellulose, lignin, lignocellulose, hemicellulose, etc., and chemically stable, difficult-to-decompose organic matter, such as synthetic polymers such as polyethylene, polyethylene terephthalate, polyvinyl chloride, etc. Furthermore, since polyethylene terephthalate contains a benzenecarboxylic acid skeleton, it is expected that benzenecarboxylic acids such as terephthalic acid will be obtained as decomposition products.

[0054] Examples of phenol derivatives include phenol, compounds in which the benzene ring of phenol is substituted with a substituent such as a hydroxyl group, a methoxy group, a CHO group, or a carboxyl group, salts thereof, and dimers thereof. Examples of quinone derivatives include orthobenzoquinone, parabenzoquinone, compounds in which the quinone skeleton is substituted with the above-mentioned substituents, and salts thereof. Examples of benzenecarboxylic acids include benzoic acid, terephthalic acid, compounds in which the benzene ring is substituted with the above-mentioned substituents, and salts thereof.

[0055] Preferred organic substances to be decomposed are hydrocarbons such as methane, aromatic compounds such as benzene, and cyclic ethers such as dioxane. Examples include linear or branched aliphatic hydrocarbons having six or fewer carbon atoms, chlorides in which at least a portion of the hydrogen atoms in these aliphatic hydrocarbons have been substituted with Cl, benzene and aromatic compounds in which at least a portion of the hydrogen atoms in benzene have been substituted with Cl, and cyclic ethers having five or fewer carbon atoms and containing one or more ether bonds. In these cases, the excellent effects of the decomposition catalyst are prominently exhibited, allowing organic substances to be decomposed at low temperatures, for example, below 40°C.

[0056] The decomposition catalyst can produce, for example, low-molecular-weight organic compounds as decomposition products. Specifically, carboxylic acids such as formic acid, acetic acid, and benzenecarboxylic acids (e.g., terephthalic acid); alcohols such as methanol and ethanol; aldehydes such as formaldehyde and acetaldehyde; ketones such as ketones, quinones, and quinone derivatives; and phenols such as phenol and phenol derivatives can be produced. As the decomposition of organic matter progresses, the decomposition products are converted, for example, sequentially into lower alcohols, lower aldehydes, and lower carboxylic acids. By appropriately setting the reaction conditions of the decomposition catalyst and the organic matter to be decomposed, desired low-molecular-weight organic compounds can be produced. It is even possible to decompose organic matter down to carbon dioxide. Furthermore, the low-molecular-weight organic compounds obtained as decomposition products, such as formic acid, acetic acid, methanol, ethanol, formaldehyde, acetaldehyde, phenol derivatives, quinone derivatives, and benzenecarboxylic acids, can be used as raw materials for chemical products.

[0057] The decomposition catalyst is obtained by supporting a complex formed of a transition metal and a π-electron-containing organic ligand on a support made of a carbon material. Decomposition using the decomposition catalyst is preferably carried out via a step of reacting an oxidizing agent with the decomposition catalyst to convert the transition metal into a transition metal oxo species. By going through the above-mentioned step, the transition metal of the complex reacts with the oxidizing agent on the decomposition catalyst having the complex fixed on the surface of the support to form a transition metal oxo species, and the transition metal oxo species can be prevented from oxidizing the π-electron-containing organic ligand or the support.

[0058] The following mechanisms 1 and 2 are thought to occur during decomposition using a decomposition catalyst. Mechanism 1: Due to electronic interaction between the transition metal complex oxo species and the support, the electronic state of the transition metal complex oxo species changes, resulting in improved reactivity of the transition metal complex oxo species with organic substances. Mechanism 2: Due to electronic interaction between the support and the complex formed from the transition metal and the π-electron-containing organic ligand, the electronic state of the complex changes, resulting in an increased reaction rate for the complex to convert to the transition metal complex oxo species, and therefore an increased concentration of the oxo species in the reaction system, improving the decomposition reaction rate of the organic substances.

[0059] The decomposition method of the present disclosure is preferably carried out in a solvent such as water that is difficult to decompose with transition metal oxo species. Because the catalyst of the present disclosure significantly increases the rate of the oxidation reaction, when an organic solvent is used, there is a risk that the organic solvent itself will be oxidatively decomposed. Furthermore, when organic matter is decomposed in an aqueous solution using the decomposition catalyst, decomposition becomes possible at a low temperature, for example, 60°C or less. Furthermore, in this case, the organic matter can be decomposed without using any special equipment such as a light irradiation device.

[0060] The decomposition catalyst enables oxidative decomposition at temperatures as low as below 40°C, for example, when attempting to decompose hydrocarbons, aromatic compounds, and cyclic ethers. Therefore, the effect of being able to decompose organic matter under energetically favorable conditions is more pronounced. While it is generally known in the field of catalytic chemistry that catalysts are advantageously used under high-temperature conditions, the present inventors have discovered that the decomposition catalyst of the present disclosure can decompose organic matter even at temperatures as low as below 40°C, and can even decompose chemically very stable organic matter such as methane at low temperatures. Furthermore, decomposition using the decomposition catalyst can produce useful organic compounds such as alcohols such as methanol, carboxylic acids such as formic acid, and formaldehyde. From the viewpoint of further enhancing the effect of being able to decompose the organic matter under energetically favorable conditions, the decomposition catalyst is preferably used at temperatures below 40°C, more preferably at 30°C or below, and even more preferably at room temperature or below (e.g., room temperature 25°C or below). The decomposition catalyst can decompose organic matter even at such low temperatures. For example, the bond dissociation energy of the CH-H bond in hydrocarbons is 105 kcal / mol, which is particularly high among the many C-H bonds in hydrocarbons. However, the cracking catalyst of the present disclosure makes it possible to crack the CH-H bond even at low temperatures, for example, at or below 25°C, and thus to crack hydrocarbons in a short period of time.

[0061] The time for the decomposition reaction may be appropriately determined by, for example, monitoring the progress of the decomposition reaction. Alternatively, the reaction apparatus may be combined with an analyzer to perform the decomposition reaction while measuring the concentration of decomposition products (hereinafter also referred to as "decomposition products") in the reaction solution in situ. The decomposition is preferably performed under stirring.

[0062] The decomposition using the decomposition catalyst is preferably carried out in the presence of an acid. The presence of an acid increases the rate of the oxidation reaction. The amount of acid used can be determined appropriately depending on the amounts of catalyst and oxidizing agent, the amount of organic matter to be decomposed, and the reaction rate.

[0063] The acid may be any acid used in general chemical reactions. Specific examples of the acid include hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, sulfuric acid, nitric acid, phosphoric acid, and perchloric acid. When the oxidizing agent or a decomposition product of the oxidizing agent functions as an acid, the oxidizing agent or a decomposition product of the oxidizing agent may be used as the acid.

[0064] Next, an organic matter treatment system using a decomposition catalyst (hereinafter referred to as a "treatment system") will be described. Note that the treatment system will be described with reference to Fig. 16, but the configuration of the treatment system of the present disclosure is not limited to that shown in the schematic diagram of Fig. 16, and the configuration can be changed as appropriate as long as the intended purpose is not impaired.

[0065] 16, the decomposition catalyst and decomposition method described above can be applied to construct an organic matter treatment system 1. The organic matter treatment system 1 includes, for example, a reaction tank 2, a treatment target material supply device 3, and a catalyst supply device 4.

[0066] The reaction tank 2 includes, for example, a tank body 20, an agitator 21, and an optional temperature control device 22. The tank body 20 can accommodate a decomposition catalyst, organic matter, or a treatment target containing organic matter. Decomposition of the organic matter is carried out within the tank body 20. The capacity of the tank body 20 is not particularly limited and is adjusted appropriately depending on the treatment amount. The agitator 21 is a device capable of agitating the contents of the tank body 20 and is composed of, for example, a screw, a motor, etc. The temperature control device 22 is a device that controls the temperature within the tank body 20 and may include, for example, a heating device, a thermometer, a cooling device, etc. As described above, the oxidative decomposition reaction of organic matter by the decomposition catalyst proceeds even at relatively low temperatures, such as room temperature. Therefore, the treatment system 1 can decompose organic matter in the treatment target even if it does not include a heating device.

[0067] The treatment target material supply device 3 is a device that supplies the treatment target material to the reaction tank 2 (specifically, the tank body 20). The treatment target material is, for example, organic matter or organic-containing material. The organic-containing material is an aqueous solution or mixture containing organic matter. More specifically, examples of organic-containing material include industrial wastewater, domestic wastewater, sewage, seawater, river water, well water, soil, etc. When the organic-containing material is used, the organic matter in the material can be decomposed. If the organic matter places a burden on the environment, the organic-containing material will be purified by decomposition.

[0068] The catalyst supply device 4 is a device that supplies the above-mentioned decomposition catalyst to the reaction tank 2 (specifically, the tank body 20). The decomposition catalyst is supplied from the catalyst supply device 4 to the reaction tank 2 in a state where it is dissolved or suspended in a liquid such as water.

[0069] The treatment system 1 may further include an oxidizing agent supplying device 5 and an acid supplying device 6. The oxidizing agent supplying device 5 is a device that supplies the above-mentioned oxidizing agent to the reaction tank 2. The acid supplying device 6 is a device that supplies the above-mentioned acid to the reaction tank 2.

[0070] The processing system 1 may further include a control device 7. The control device 7 receives signals of detection parameters from each device constituting the processing system 1 and transmits signals to control the operating parameters of each device. In Fig. 16, examples of signals are illustrated by dashed lines. Examples of detection parameters include the concentration of the material to be processed, the concentration of decomposition products, and the temperature in the reaction tank 20. Examples of operating parameters include the amount of material supplied from each supply device to the reaction tank 20, the screw rotation speed of the agitator 21, and the temperature.

[0071] Organic matter can be decomposed using the organic matter treatment system 1. As one aspect of the organic matter treatment system, a wastewater treatment system for decomposing organic matter present or dissolved in industrial wastewater, domestic wastewater, sewage, etc. can also be provided.

[0072] Although not shown in the drawings, it is also possible to construct an organic matter treatment system equipped with a column packed with the decomposition catalyst of the present disclosure. The oxidizing agent and acid may be packed in the column or may be supplied separately to the column. The treatment system may also be equipped with spraying devices that spray the decomposition catalyst, oxidizing agent, and acid onto the treatment target, such as soil or wastewater containing organic matter. In this case, the organic matter in the treatment target can be decomposed by spraying the decomposition catalyst or the like onto the treatment target.

[0073] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to these specific examples.

[0074] (Production Example 1) A solution of tetra tert-butylphthalocyanine iron complex μ-nitrogen-bridged dimer (11.7 mg, 10.1 μmol) dissolved in 10 mL of CHCl was mixed with a solution of 1.27 g of a carbon material (specifically, Cabot Corporation's "Vulcan XC-72R") suspended in 60 mL of CHCl, and the mixture was sonicated for 30 minutes. The CHCl was then removed using an evaporator. The resulting black powder was dried under reduced pressure at 1 mmHg and 60°C for 12 hours to produce 1.27 g of the cracking catalyst of Production Example 1. Figure 2 shows a schematic diagram of the carbon material, and Figure 4 shows a schematic diagram of the functional groups on the surface of the carbon material. As shown in Figure 2, the carbon material is a layered material composed of multiple layers. It is presumed that the carbon material contains functional groups, as shown in Figure 4, which form defects, and that the complex molecules are embedded in these defects. The catalyst of Production Example 1 has a structure in which a tetra-tert-butylphthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (Vulcan XC-72R).

[0075] The tetra tert-butylphthalocyanine iron complex μ-nitrogen-bridged dimer in the catalyst of Production Example 1 is represented by the formula (1), where M is Fe and R 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8are bonded to each other to form a benzene ring substituted with a tert-butyl group, all X's are N, Het's are N, and one of the bonds between Het and M is a single bond and the other is a double bond.

[0076] (Preparation Example 2) A μ-nitrogen-bridged phthalocyanine iron complex dimer was synthesized by mixing a phthalocyanine iron complex and NaN3 in 1-chloronaphthalene as a solvent and reacting for 2 hours at 280°C. CHCl3 was added to the reaction solution to precipitate the μ-nitrogen-bridged phthalocyanine iron complex dimer. The precipitate was filtered, washed with CHCl3, ethanol, and water, and then dried to isolate the μ-nitrogen-bridged phthalocyanine iron complex dimer. The isolated μ-nitrogen-bridged phthalocyanine iron complex dimer was dissolved in pyridine, and insoluble matter was removed by filtration. To the solution, iodine was added and stirred at room temperature (specifically, 25°C) for 18 hours to form a salt of the cation in which pyridine was coordinated to the μ-nitrogen-bridged phthalocyanine iron complex dimer and iodide ion. The solvent was removed to isolate the salt. The salt was then dissolved in pyridine, and the insoluble matter was removed by filtration. To the solution, acetonitrile and water were added to precipitate a purple precipitate. The purple precipitate was collected by filtration, washed with water, and then dried. The resulting solid was dissolved in pyridine, and insoluble matter was removed by filtration. Diethyl ether was gradually added to the filtrate to obtain a salt of a cation in which pyridine was coordinated to a phthalocyanine iron complex μ-nitrogen-bridged dimer and iodide ions (hereinafter, sometimes referred to as the salt of Production Example 2) as bluish purple crystals. The structure of the salt of Production Example 2 is 1 H-NMR, 13 This was supported by the results of C-NMR and MALDI-TOF MS.

[0077] A solution of the salt from Preparation Example 2 (7.3 mg, 5.2 μmol) dissolved in 4 mL of pyridine was mixed with a solution of 968 mg of carbon material (specifically, Cabot Corporation's "Vulcan XC-72R") suspended in 20 mL of pyridine and sonicated for 30 minutes. This mixture was sonicated for 1 hour and then stirred at 80°C for 22 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. At this point, the color of the solution was significantly lighter than before mixing, confirming efficient adsorption. A PTFE filter (1.0 μm) from Advantec was used as the membrane filter. The resulting solid was washed twice with 30 mL of pyridine and twice with 50 mL of CHCl, and then dried for 2 hours at 1 mmHg and 80°C. 3 mL of 3.3 M sulfuric acid and 30 mL of water were added to the dried solid, and sonicated for 1 hour. The solid was recovered by membrane filtration and then washed four times with 50 mL of water, confirming that the washing solution had become neutral. 3 mL of 3.3 M sulfuric acid and 30 mL of water were added to the obtained solid again, and the mixture was subjected to ultrasonic treatment for 1 hour and then stirred at room temperature for 14 hours. The solid was recovered by membrane filtration and then washed four times with 50 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80°C for 10 hours and then allowed to reach a constant weight at room temperature, thereby producing the cracking catalyst of Production Example 2. The yield of the catalyst of Production Example 2 was 915 mg.

[0078] The catalyst of Production Example 2 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (Vulcan XC-72R) (see FIG. 3). A schematic diagram of the catalyst of Production Example 2 is shown in FIG. 3. The layered structure of the carbon material is omitted in FIG. 3. Although not shown, the catalyst of Production Example 1 has the same structure as that of Production Example 2, except for the different complex.

[0079] The phthalocyanine iron complex μ-nitrogen-bridged dimer in the catalyst of Production Example 2 is a compound represented by the formula (1), in which M is Fe and R 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8are bonded to each other to form a benzene ring, all X's are N, Het's are N, and one of the bonds between Het and M is a single bond and the other is a double bond.

[0080] (Production Example 3) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (11.3 mg, 8.1 μmol) dissolved in 6 mL of pyridine was mixed with a solution of 1.52 g of a carbon material (specifically, "Mitsubishi Carbon Black #3230B" manufactured by Mitsubishi Chemical Corporation) suspended in 30 mL of pyridine, and the mixture was sonicated for 30 minutes. This mixture was sonicated for 1 hour and then stirred at 80°C for 17 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was much lighter than before mixing, confirming that adsorption had occurred efficiently. The resulting solid was washed twice with 30 mL of pyridine and twice with 50 mL of CHCl, then dried at 1 mmHg and 80°C for 2 hours. 5 mL of 3.3 M sulfuric acid and 50 mL of water were added to the dried solid, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and washed four times with 50 mL of water, confirming that the washing solution was neutral. 5 mL of 3.3 M sulfuric acid and 50 mL of water were added to the resulting solid again, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 17 hours. The solid was recovered by membrane filtration and washed four times with 50 mL of water, confirming that the washing solution was neutral. The resulting black powder was dried under reduced pressure at 1 mmHg and 80°C for 17 hours, and then allowed to reach a constant weight at room temperature to produce the cracking catalyst of Production Example 3. The yield of the catalyst of Production Example 3 was 1.48 g.

[0081] The catalyst of Production Example 3 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (Mitsubishi Carbon Black #3230B).

[0082] (Production Example 4) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (16.3 mg, 11.6 μmol) dissolved in 10 mL of pyridine was mixed with a solution of 2.17 g of graphite (specifically, "Graphite Powder" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) suspended in 32 mL of pyridine, followed by 30 minutes of ultrasonic treatment. This mixture was ultrasonicated for 1 hour and then stirred at 80°C for 24 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was significantly lighter than before mixing, confirming efficient adsorption. The resulting solid was washed twice with 3 mL of pyridine and twice with 50 mL of CHCl, and then dried for 1 hour at 1 mmHg and 80°C. To the dried solid, 6 mL of trifluoroacetic acid and 60 mL of water were added, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and then washed four times with 100 mL of water, confirming that the washing solution had become neutral. 6 mL of trifluoroacetic acid and 100 mL of water were added again to the obtained solid, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 19.5 hours. The solid was filtered off by membrane filtration and then washed four times with 50 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80°C for 1 hour, and then allowed to reach a constant weight at room temperature, thereby producing the decomposition catalyst of Production Example 4. The yield of the catalyst of Production Example 4 was 2.12 g.

[0083] The catalyst of Production Example 4 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (graphite).

[0084] (Production Example 5) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (7.3 mg, 5.2 μmol) dissolved in 4 mL of pyridine was mixed with a solution of 968 mg of a carbon material (specifically, Cabot Corporation's "Black Pearls 2000") suspended in 40 mL of pyridine, and the mixture was sonicated for 30 minutes. This mixture was sonicated for 1 hour and then stirred at 80°C for 21 hours. The resulting suspension was filtered through a membrane filter to separate the solid and the solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was significantly lighter than before mixing, confirming efficient adsorption. The resulting solid was washed twice with 30 mL of pyridine and twice with 50 mL of CHCl, and then dried for 1 hour at 1 mmHg and 80°C. 5 mL of 3.3 M sulfuric acid and 50 mL of water were added to the dried solid, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and then washed four times with 50 mL of water, confirming that the washing solution had become neutral. 5 mL of 3.3 M sulfuric acid and 50 mL of water were added again to the obtained solid, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 25 hours. The solid was filtered off by membrane filtration and then washed four times with 50 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80°C for 21 hours, and then allowed to reach a constant weight at room temperature, thereby producing the cracking catalyst of Production Example 5. The yield of the catalyst of Production Example 5 was 924 mg.

[0085] The catalyst of Production Example 5 has a structure in which a μ-nitrogen-bridged phthalocyanine iron complex dimer is supported on a carbon material (Black Pearls 2000).

[0086] (Production Example 6) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (7.3 mg, 5.2 μmol) dissolved in 4 mL of pyridine was mixed with a solution of 970 mg of Ketjen Black (KEC-DJ600 manufactured by Ketjen Black International) as a carbon material suspended in 42 mL of pyridine, and the mixture was sonicated for 30 minutes. After sonicating this mixture for 1 hour, 20 mL of pyridine was added and the mixture was stirred at 80°C for 20 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was significantly lighter than before mixing, confirming efficient adsorption. The resulting solid was washed twice with 20 mL of pyridine and twice with 50 mL of CHCl, and then dried for 2 hours at 1 mmHg and 80°C. To the dried solid, 3 mL of trifluoroacetic acid and 30 mL of water were added, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and then washed four times with 50 mL of water, confirming that the washing solution had become neutral. 3 mL of trifluoroacetic acid and 50 mL of water were added again to the obtained solid, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 15.5 hours. The solid was filtered off by membrane filtration and then washed twice with 100 mL of water and three times with 200 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80 °C for 19 hours, and then allowed to reach a constant weight at room temperature, thereby producing the decomposition catalyst of Production Example 6. The yield of the catalyst of Production Example 6 was 963 mg.

[0087] The catalyst of Production Example 6 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (Ketjen black).

[0088] (Production Example 7) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (15.2 mg, 10.9 μmol) dissolved in 14 mL of pyridine was mixed with a solution of 2.028 g of a carbon material (specifically, "acetylene black" manufactured by Denki Kagaku Kogyo Co., Ltd.) suspended in 80 mL of pyridine, and the mixture was sonicated for 30 minutes. This mixture was sonicated for 1 hour and then stirred at 80°C for 22 hours. The resulting suspension was filtered through a membrane filter to separate the solid and the solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was significantly lighter than before mixing, confirming efficient adsorption. The resulting solid was washed twice with 40 mL of pyridine and three times with 100 mL of CHCl, and then dried for 2 hours at 1 mmHg and 80°C. To the dried solid, 6 mL of trifluoroacetic acid and 60 mL of water were added, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and then washed three times with 200 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80 ° C for 2 hours, and then 5 mL of trifluoroacetic acid and 80 mL of water were added to the obtained solid again, ultrasonic treatment was performed for 1 hour, and stirring was performed at room temperature for 21.5 hours. The solid was filtered off by membrane filtration and then washed three times with 200 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80 ° C for 15 hours, and then the weight was constant at room temperature, thereby producing the decomposition catalyst of Production Example 7. The yield of the catalyst of Production Example 7 was 1.96 g.

[0089] The catalyst of Production Example 7 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (acetylene black).

[0090] (Production Example 8) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (6.4 mg, 4.5 μmol) dissolved in 5 mL of pyridine was mixed with a solution of 850 mg of boron-doped graphene (specifically, "Boron-doped graphene" manufactured by Sigma-Aldrich) as a carbon material suspended in 25 mL of pyridine, and the mixture was sonicated for 30 minutes. This mixture was sonicated for 1 hour and then stirred at 80°C for 21.5 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was much lighter than before mixing, confirming that adsorption had occurred efficiently. The resulting solid was washed twice with 20 mL of pyridine and three times with 20 mL of CHCl, and then dried at 1 mmHg and 80°C for 2.5 hours. 5 mL of trifluoroacetic acid and 50 mL of water were added to the dried solid, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and washed four times with 50 mL of water, confirming that the washing solution had become neutral. 5 mL of trifluoroacetic acid and 50 mL of water were added again to the resulting solid, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 16.5 hours. The solid was filtered off by membrane filtration and washed four times with 50 mL of water, confirming that the washing solution had become neutral. The resulting black powder was dried under reduced pressure at 1 mmHg and 80°C for 9 hours, and then allowed to reach a constant weight at room temperature, producing the decomposition catalyst of Production Example 8. The yield of the catalyst of Production Example 8 was 794 mg.

[0091] The catalyst of Production Example 8 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (B-doped graphene).

[0092] (Production Example 9) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (6.3 mg, 4.5 μmol) dissolved in 5 mL of pyridine was mixed with a solution of 850 mg of phosphorus-doped graphene (specifically, "Phosphorus-doped graphene" manufactured by Sigma-Aldrich) as a carbon material suspended in 25 mL of pyridine, and the mixture was sonicated for 30 minutes. This mixture was sonicated for 1 hour and then stirred at 80°C for 19 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was much lighter than before mixing, confirming that adsorption had occurred efficiently. The resulting solid was washed twice with 20 mL of pyridine and three times with 50 mL of CHCl, and then dried at 1 mmHg and 80°C for 3.5 hours. 5 mL of trifluoroacetic acid and 50 mL of water were added to the dried solid, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and washed four times with 50 mL of water, confirming that the washing solution had become neutral. 5 mL of trifluoroacetic acid and 50 mL of water were added again to the resulting solid, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 14 hours. The solid was filtered off by membrane filtration and washed four times with 50 mL of water, confirming that the washing solution had become neutral. The resulting black powder was dried under reduced pressure at 1 mmHg and 80°C for 8 hours, and then allowed to reach a constant weight at room temperature, producing the decomposition catalyst of Production Example 9. The yield of the catalyst of Production Example 9 was 831 mg.

[0093] The catalyst of Production Example 9 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (P-doped graphene).

[0094] (Production Example 10) First, the salt of Production Example 2 was produced in the same manner as in Production Example 2. Next, a solution of the salt of Production Example 2 (16.3 mg, 11.64 μmol) dissolved in 10 mL of pyridine was mixed with a solution of 2.17 g of graphite (specifically, "Graphite Powder" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) suspended in 32 mL of pyridine, followed by 60 minutes of ultrasonic treatment. This mixture was ultrasonicated for 1 hour and then stirred at 80°C for 24 hours. The resulting suspension was filtered through a membrane filter to separate the solid and solution. Note that a PTFE filter (1.0 μm) manufactured by Advantec was used as the membrane filter. At this time, the color of the solution was significantly lighter than before mixing, confirming efficient adsorption. The resulting solid was washed twice with 3 mL of pyridine and twice with 50 mL of CHCl, and then dried for 1 hour at 1 mmHg and 80°C. To the dried solid, 6 mL of trifluoroacetic acid and 60 mL of water were added, and ultrasonic treatment was performed for 1 hour. The solid was recovered by membrane filtration and then washed four times with 100 mL of water, confirming that the washing solution had become neutral. 6 mL of trifluoroacetic acid and 100 mL of water were added again to the obtained solid, and ultrasonic treatment was performed for 1 hour, followed by stirring at room temperature for 19.5 hours. The solid was filtered off by membrane filtration and then washed four times with 5100 mL of water, confirming that the washing solution had become neutral. The obtained black powder was dried under reduced pressure at 1 mmHg and 80 ° C for 13 hours, and then allowed to reach a constant weight at room temperature, thereby producing the decomposition catalyst of Production Example 10. The yield of the catalyst of Production Example 10 was 2.12 g.

[0095] The catalyst of Production Example 10 is a catalyst in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on a carbon material (graphite).

[0096] Comparative Production Example 1 A cracking catalyst of Comparative Production Example 1 was produced in the same manner as in Production Example 1, except that silica gel (Merck Silica Gel 60 (0.040-0.063 mm)) was used instead of the carbon material. The catalyst of Comparative Production Example 1 has a structure in which a tetra-tert-butylphthalocyanine iron complex μ-nitrogen-bridged dimer is supported on silica gel, which is neither a conductor nor a semiconductor, nor a carbon material.

[0097] Comparative Production Example 2 A cracking catalyst of Comparative Production Example 2 was produced in the same manner as in Production Example 2, except that silica gel (Merck Silica Gel 60 (0.040-0.063 mm)) was used instead of the conductive carbon. The catalyst of Comparative Production Example 2 has a structure in which a phthalocyanine iron complex μ-nitrogen-bridged dimer is supported on silica gel, which is neither a conductive material nor a semiconductor.

[0098] (Evaluation Example 1) In this example, a catalase test was performed. Specifically, 30% by mass of hydrogen peroxide solution was added to the decomposition catalyst of Production Example 1 in a glass container, and the presence or absence of foaming was observed. As a result, intense foaming was observed. In other words, when the decomposition catalyst of Production Example 1 was used, gas generation was confirmed. On the other hand, 30% by mass of hydrogen peroxide solution was added to the decomposition catalyst of Comparative Production Example 1 in a glass container. However, almost no foaming was observed. As a reference experiment, 30% by mass of hydrogen peroxide solution was added to conductive carbon black (Vulcan XC-72R) in a glass container. However, almost no foaming was observed.

[0099] From the results of Evaluation Example 1, it is believed that transition metal oxo species were formed in the catalyst of Production Example 1, and that the transition metal oxo species decomposed hydrogen peroxide to generate oxygen. The activity of the catalyst of Production Example 1 supported on a conductive carbon material, or the activity of the transition metal oxo species formed from the catalyst of Production Example 1, can be said to be extremely high. The chemical structure of the complex formed by the transition metal oxo species and the π-electron-containing organic ligand when the transition metal oxo species was formed in the catalyst of Production Example 1 is shown in Figure 5. The catalysts of Production Examples 2 to 10 use a complex similar to that of Production Example 1, and a carbon material is used as the support, just like Production Example 1. Therefore, it is presumed that the catalysts of Production Examples 2 to 10 also exhibit the same catalase reaction as Production Example 1.

[0100] (Evaluation Example 2) In this example, the amounts of CO and CO generated from various carbon materials were measured by vacuum pyrolysis. Table 1 shows the amounts of gas generated when the carbon materials were heated from 100°C to 1500°C at a temperature increase rate of 200°C / h by vacuum pyrolysis.

[0101]

[0102] As can be seen from Table 1, some carbon materials have functional groups containing H or O. Such carbon materials are thought to have functional groups such as hydrogen, hydrocarbon groups, carbonyl groups, carboxyl groups, ketone groups, and aldehyde groups. Table 1 also lists graphite, which is known to contain no functional groups. Catalysts formed from complexes and supports were prepared using each of the carbon materials in Table 1 as a support, and the activity of each catalyst in the methane oxidation reaction described below was compared. It was confirmed that the activity increases sequentially from the top to the bottom of the carbon materials in Table 1. In other words, the catalytic activity was lowest when graphite was used as a support, and highest when conductive carbon was used. Therefore, it can be said that using a carbon material having functional groups as a support for a decomposition catalyst improves the catalytic activity for the oxidative decomposition of organic matter.

[0103] Example 1: Decomposition of methane in aqueous solution In this example, the influence of the type of carrier on the oxidative decomposition of methane is examined. In this example, the oxidative decomposition reaction of methane is carried out at a temperature of 25°C (room temperature).

[0104] First, a mixed solution was prepared by mixing the catalyst of Production Example 2, 30% by mass aqueous hydrogen peroxide, trifluoroacetic acid, and 3 mL of water. In the mixed solution, the concentration of the phthalocyanine iron complex μ-nitrogen-bridged dimer was 19 μmol / L, the concentration of hydrogen peroxide was 189 mmol / L, and the concentration of trifluoroacetic acid was 51 mmol / L. Methane gas was introduced at 1.0 MPa pressure for 8 hours into the mixed solution under stirring at a temperature of 25°C, to carry out an oxidative decomposition reaction of methane. As a result, methanol, formaldehyde, and formic acid were observed as reaction products. In other words, the oxidative decomposition reaction of methane is thought to proceed according to the following formula (A). Furthermore, the same oxidative decomposition reaction of methane as in this example was carried out, except that the catalysts of Production Examples 3 to 9 were used instead of the catalyst of Production Example 2. Next, the reaction products produced by the oxidative decomposition of methane in this example were analyzed by gas chromatography-mass spectrometry (GC-MS). These results are shown in Table 2. CH4→CH3OH→HCHO→HCOOH→CO2, CO...(A)

[0105] The total catalyst turnover number (i.e., TTN) in Table 2 was calculated as follows. First, as a reference experiment, measurements were made when nitrogen gas was introduced at 1.0 MPa into a mixed solution at a temperature of 25°C under stirring conditions. In other words, an experiment was conducted in which nitrogen gas was introduced instead of methane gas. Next, the substances in the aqueous solution after the reference experiment were examined by gas chromatography mass spectrometry (GC-MS analysis). Furthermore, in order to define the number of times the catalyst has substantially oxidized methane, TTN was calculated based on the following formulas (I) and (II). In formula (I), C cat is the catalyst concentration, and C CH3OH is the methanol concentration, and C HCHO is the formaldehyde concentration, and C HCOOH is the formic acid concentration. TTN(CH4) means the total catalyst turnover number when methane is introduced, and TTN(N2) means the total catalyst turnover number when nitrogen is introduced.

[0106]

[0107]

[0108] Furthermore, an index (i.e., MCN) indicating how many times the C—H bond of methane was cleaved by the catalyst was calculated based on the following formulas (III) and (IV). cat is the catalyst concentration, C CH3OH is the methanol concentration, and C HCHO is the formaldehyde concentration, and C HCOOH is the formic acid concentration. MCN(CH4) means the aforementioned indicator when methane is introduced, and MCN(N2) means the aforementioned indicator when nitrogen is introduced.

[0109]

[0110]

[0111] The values ​​in parentheses in Table 2 indicate standard deviations, which were calculated from measurements taken three times.

[0112]

[0113] As can be seen from Table 2, the cracking catalysts of Production Examples 2 to 9 are capable of oxidatively decomposing hydrocarbons such as methane even at room temperature, although there are differences in the cracking products and production amounts. Furthermore, changing the carbon material that can be used as a support results in differences in the total catalyst turnover number. This is thought to be due to the charge state of the carbon material. Since the total catalyst turnover number tends to be higher when a carbon material with functional groups is used compared to the total catalyst turnover number when graphite without functional groups is used, it is preferable to use a carbon material with functional groups. Furthermore, from the perspective of further improving the total catalyst turnover number, it is more preferable to use a carbon material with functional groups containing oxygen and / or hydrogen. Furthermore, as mentioned above, a higher amount of functional groups is thought to be advantageous.

[0114] (Example 2: Decomposition of methane) In this example, the amount of decomposition product in the oxidative decomposition of methane was investigated when the amount of complex supported on the support was changed. Specifically, decomposition catalysts were first produced in the same manner as in Production Example 2, except that the amount of complex supported was changed. That is, in this example, Vulcan XC-72R was used as the support, and a μ-nitrogen-bridged phthalocyanine iron complex dimer was used as the complex. Next, the same oxidative decomposition reaction of methane as in Example 1 was carried out using each decomposition catalyst. The results are shown in Figure 7.

[0115] As can be seen from Figure 7, increasing the amount of complex molecules supported per gram of carbon material (i.e., the supported amount, unit: μmol / g) increases the amount of decomposition products (unit: μmol) in the oxidative decomposition reaction to a certain extent, but the increase in the amount of decomposition products eventually stops and plateaus. This suggests that defects in the carbon material having functional groups affect the activity of the complex molecules. In other words, there is a limit to the amount of complex molecules that can interact with defects, and it is presumed that if the amount of complex molecules supported on the support exceeds this limit, the activity of the complex molecules will no longer improve. Furthermore, considering the results of other examples, it is believed that as a support, not only electrical conductivity but also having many defects in the carbon material is advantageous for improving catalytic activity, and for this purpose, a large amount of functional groups is advantageous.

[0116] (Example 3: Decomposition of methane) In this example, decomposition products resulting from the oxidative decomposition reaction of methane at room temperature were examined by NMR analysis. First, the same oxidative decomposition reaction of methane as in Example 1 was carried out using the catalyst of Production Example 2, except that the methane introduction time was set to 2 hours. Next, the supernatant of the suspension after the reaction was separated by centrifugation, and 1 The resulting solution was subjected to H-NMR analysis. Trimethylsilylpropanoic acid (TSP) was used as an external standard for the analysis. The results are shown in Figure 8. For comparison, the results of the Fenton reaction are also shown in Figure 8.

[0117] 8, while the Fenton reaction produces aldehydes, the catalyst of Production Example 2 produces methanol, formic acid, and a hemiacetal (CHO-CHOH) formed by the reaction of methanol with formaldehyde. Therefore, it can be seen that the cracking catalyst of the present disclosure can oxidatively decompose hydrocarbons such as methane to produce useful compounds such as alcohols, carboxylic acids, and hemiacetals.

[0118] (Example 4: Decomposition of Dioxane) In this example, 1,4-dioxane is used as the organic substance to be decomposed. In this example, 1,4-dioxane is oxidatively decomposed at room temperature, and the decomposition products are examined by NMR analysis. First, a mixed solution was prepared by mixing 10 mg (35 μM) of the catalyst from Production Example 2, 1.5 mL of a 10 mM 1,4-dioxane heavy water solution (1,4-dioxane / DO), 50 μL (374 mM) of 35% by mass hydrogen peroxide solution, and 10 μL of 1 / 1 sulfuric acid. Note that 1 / 1 sulfuric acid refers to an aqueous solution in which sulfuric acid and water are mixed at a volume ratio of 1:1. Next, the mixed solution was reacted at a temperature of 25°C for 24 hours while stirring to carry out an oxidative decomposition reaction. The catalyst was removed by filtration from the liquid before and after the reaction. Then, each liquid was 1 The result is shown in Figure 9.

[0119] 9, a peak derived from 1,4-dioxane was detected in the liquid before the decomposition reaction, whereas a peak derived from 1,4-dioxane was not detected in the liquid after the decomposition reaction, but a peak derived from formic acid was detected. This means that 1,4-dioxane can be decomposed at room temperature (specifically, 25°C) using the catalyst of Production Example 2, and formic acid can be produced as a decomposition product.

[0120] The concentration of 1,4-dioxane in the liquid after the reaction is 1 The concentration was below the detection limit of H-NMR analysis (specifically, 0.1 μg / L), far below the environmental standard value for groundwater of 50 μg / L or less. Therefore, it is believed that the decomposition catalyst of the present disclosure can be used to purify contaminated groundwater. As such, this example demonstrates that the decomposition catalyst of the present disclosure can sufficiently oxidize and decompose ethers such as cyclic ethers at low temperatures, such as room temperature.

[0121] Example 5: Decomposition of Dioxane In this example, quantitative analysis of undecomposed 1,4-dioxane remaining after oxidative decomposition of 1,4-dioxane was performed. First, a mixed solution was prepared by mixing 301 mg (16 μM) of the catalyst from Production Example 2, 100 mL of 10 mM 1,4-dioxane-containing waste liquid (specifically, a groundwater monitoring sample from a certain location in Osaka Prefecture), 3.0 mL (335 mM) of 35% by mass hydrogen peroxide solution, and 1.0 mL of 1 / 1 sulfuric acid. Next, the mixed solution was reacted at a temperature of 25°C for 24 hours while stirring to perform an oxidative decomposition reaction. The catalyst was removed from the liquid after the reaction by filtration. Then, quantitative analysis of undecomposed dioxane contained in the liquid was performed.

[0122] For comparison, the same procedure was carried out using only the carrier of the catalyst (i.e., "Vulcan XC-72R" manufactured by Cabot Corporation) instead of the catalyst of Production Example 2. Furthermore, for reference, a quantitative analysis of a 1,4-dioxane-containing waste liquid (i.e., the undiluted liquid) was carried out. The results of this example are shown in Figure 10.

[0123] 10 , after the oxidative decomposition reaction using the catalyst of Production Example 2, the concentration of undecomposed dioxane was reduced to below the detection limit (specifically, less than 0.005 mg / L). On the other hand, a decrease in dioxane concentration was also observed when the comparative carrier was used, but it can be seen that the dioxane concentration was significantly reduced by using the catalyst of Production Example 2. Examples 4 and 5 show that the decomposition catalyst of the present disclosure can sufficiently oxidatively decompose ethers at low temperatures around room temperature.

[0124] Example 6: Decomposition of Benzene In this example, benzene is used as the organic substance to be decomposed, and the benzene is oxidatively decomposed using the graphite-supported catalyst of Production Example 10. In this example, benzene is oxidized at room temperature, and the resulting product is examined by NMR analysis. First, an excess amount of hydrogen peroxide and trifluoroacetic acid was added to an acetonitrile solution containing the decomposition catalyst of Production Example 10 and an excess amount of benzene, and the mixture was mixed. Next, an oxidative decomposition reaction was carried out by reacting the mixture at a temperature of 25°C for 10 hours while stirring. After the reaction, the mixture was diluted with deuterated DMSO, and the diluted solution was 1 The result is shown in Figure 11.

[0125] As can be seen from FIG. 11 , the NMR spectrum after the reaction using the catalyst of Production Example 10 showed a significant amount of peaks derived from phenol and a small amount of peaks derived from p-benzoquinone. Therefore, this example demonstrates that the cracking catalyst of the present disclosure can also be applied to the oxidation and hydroxylation of aromatic compounds such as benzene. A peak was observed near 8.12 ppm in the NMR spectrum, which is the peak of formic acid produced by the oxidation of the solvent acetonitrile. Thus, the cracking catalyst of the present disclosure can decompose benzene at temperatures as low as room temperature. While graphite was used as the support in this example, considering the results of Example 1, it is presumed that the benzene decomposition activity would be further improved by using a carbon material having functional groups.

[0126] To evaluate catalytic activity, the benzene conversion number (i.e., BCN) was calculated from the catalyst concentration of Production Example 10 and the phenol and p-benzoquinone concentrations calculated based on the NMR spectrum. BCN is an index of the conversion rate when benzene is oxidatively decomposed into phenol and benzoquinone by the catalyst, and is calculated using formula (V). In formula (V), [cat.] is the catalyst concentration, [PhOH] is the phenol concentration, and [p-Quinone] is the p-benzoquinone concentration. The results are shown in Figures 12 and 13. Figure 12 shows the change in BCN over time, and Figure 13 shows the BCN 4 hours after the start of the reaction. For comparison with the catalyst of Production Example 10, Figure 13 also shows the results of a benzene oxidative decomposition reaction similar to this example using the catalyst of Comparative Production Example 2.

[0127]

[0128] As can be seen from Figure 12, BCN increases over time but gradually saturates. The reason for this saturation of BCN is thought to be the consumption of hydrogen peroxide during the catalytic reaction. Furthermore, because the catalytic activity did not decrease even when the radical scavenger 5-dimethyl-1-pyrroline-N-oxide (DMPO) was added during the catalytic reaction, the intermediate in the catalytic reaction is thought to be a high-valent iron-oxo species, as in the oxidative decomposition of methane.

[0129] 13 , the catalyst of Comparative Production Example 2, in which the complex was supported on silica, exhibited almost no catalytic activity at room temperature (25° C.), whereas the catalyst of Production Example 10, in which the complex was supported on a conductor (specifically, a conductive carbon material), exhibited high catalytic activity. This demonstrates that a conductor such as a carbon material significantly improves the catalytic activity of the complex. This example demonstrates that the decomposition catalyst of the present disclosure can sufficiently oxidatively decompose aromatic compounds such as benzene at low temperatures.

[0130] Example 7: Decomposition of Benzene In this example, benzene is used as the organic substance to be decomposed, as in Example 6, and the benzene is oxidatively decomposed. In this example, the benzene is oxidized at a temperature of 60°C, and the product is examined by NMR analysis. Specifically, the same operation as in Example 6 was performed, except that the temperature of the oxidative decomposition reaction was changed to 60°C. 1 The results of the H-NMR analysis are shown in FIG.

[0131] 14 and FIG. 12 of Example 6, it can be seen that benzene is oxidatively decomposed by the catalyst of Production Example 10 even when the temperature is changed, but the type and amount of decomposition products can be changed by changing the temperature. Thus, Examples 6 and 7 show that aromatic compounds such as benzene can be oxidatively decomposed by the decomposition catalyst of the present disclosure.

[0132] Example 8: Decomposition of dichloromethane In this example, dichloromethane is used as the organic substance to be decomposed, and the dichloromethane is oxidized and decomposed. In this example, dichloromethane is oxidized at room temperature, and the product is examined by NMR analysis.

[0133] First, 20 mg (100 μM) of the catalyst of Production Example 2, 10 μL of dichloromethane, 1.0 mL of water, 10 μL of 1 / 1 sulfuric acid, and 50 μL (541 mM) of 35% by mass hydrogen peroxide solution were mixed to prepare a mixed solution. Next, the mixed solution was reacted at a temperature of 25°C for 4 hours while stirring to carry out an oxidative decomposition reaction. The liquid after the reaction was filtered to remove the catalyst. Thereafter, the liquid after the reaction was diluted 2-fold with heavy water (DO), and the diluted liquid was 1 The product was subjected to H-NMR analysis, and trimethylsilylpropanoic acid (TSP) was used as an external standard for the analysis.

[0134] For comparison with the catalyst of Production Example 2, the same operation as in this example was carried out without using a catalyst. Furthermore, an oxidative decomposition reaction was carried out by the Fenton reaction using iron (II) sulfate instead of the catalyst of Production Example 2. Specifically, the same operation as in this example was carried out except that the Fenton reaction was carried out. The results of this example are shown in Figure 15.

[0135] As can be seen from Figure 15, when no catalyst was used or in the Fenton reaction, a peak derived from the decomposition target, dichloromethane, was detected, but no peak derived from the decomposition product was detected. The peak near 2.12 ppm is presumed to be derived from acetone used to clean the equipment.

[0136] In contrast, when the catalyst of Production Example 2 was used, a peak derived from formic acid was detected. The formic acid concentration calculated from the peak height is thought to be approximately 1.2 mM at most. Furthermore, while 6.5 mM of dichloromethane was detected in the Fenton reaction, 5.0 mM of dichloromethane was detected when the catalyst of Production Example 2 was used. Therefore, it can be seen that the catalyst of Production Example 2 oxidized and decomposed dichloromethane, producing formic acid as a product.

[0137] Reference Example 1: Decomposition of Ethane In this example, ethane was used as the organic substance to be decomposed. Specifically, the catalyst of Production Example 1 was used, and an oxidative decomposition reaction of ethane was carried out at a temperature of 60°C in the same manner as in the Examples. Analysis in this Reference Example was carried out by gas chromatography mass spectrometry (GC-MS analysis). As a result, it was confirmed that ethane was decomposed to produce ethanol, acetaldehyde, and acetic acid. Furthermore, when the catalyst of Production Example 2 was used instead of the catalyst of Production Example 1, similar results to those of this example were obtained.

[0138] Reference Example 2: Decomposition of Lignin In this example, lignin was used as the organic substance to be decomposed. Specifically, the catalyst of Production Example 1 was used, and the oxidative decomposition reaction of lignin was carried out at a temperature of 60°C in the same manner as in the Examples. As a result, it was confirmed that lignin was decomposed and methanol, acetic acid, and formic acid were produced. Furthermore, when the catalyst of Production Example 2 was used instead of the catalyst of Production Example 1, similar results to this example were obtained.

[0139] Reference Example 3: Decomposition of polyethylene In this example, polyethylene is used as the organic substance to be decomposed. Specifically, using the catalyst of Production Example 1, an oxidative decomposition reaction of polyethylene was carried out at a temperature of 60°C in the same manner as in the Examples. As a result, it was confirmed that polyethylene was decomposed and acetaldehyde, acetic acid, and formic acid were produced.

[0140] Reference Example 4: Decomposition of glucose In this example, glucose is used as the organic substance to be decomposed. Specifically, using the catalyst of Production Example 1, an oxidative decomposition reaction of glucose was carried out at a temperature of 60°C in the same manner as in the Examples. As a result, it was confirmed that glucose was decomposed and formic acid was produced.

[0141] Reference Example 5: Decomposition of cellulose In this example, cellulose is used as the organic substance to be decomposed. Specifically, using the catalyst of Production Example 1, an oxidative decomposition reaction of cellulose was carried out at a temperature of 60°C in the same manner as in the Examples. As a result, it was confirmed that cellulose was decomposed and acetaldehyde and formic acid were produced.

[0142] As described above, the decomposition catalyst of the present disclosure can decompose various organic substances. Furthermore, the decomposition catalyst enables decomposition of organic substances even at low temperatures, allowing decomposition of organic substances under energetically advantageous conditions. Furthermore, no special equipment such as a light irradiation device is required for decomposition. Furthermore, useful compounds such as alcohols, phenols, carboxylic acids, aldehydes, ketones, and hemiacetals can be produced by decomposing organic substances. The present disclosure is not limited to the above examples and can be applied to various embodiments within the scope of the present disclosure.

Claims

A decomposition catalyst used for decomposing organic substances (excluding organic fluorine compounds), a carrier made of a conductor or semiconductor; a complex supported on the carrier, The decomposition catalyst, wherein the complex is represented by the following formula (1) and is formed from a transition metal and a π-electron-containing organic ligand: (In formula (1), M is a transition metal. R 1 ~R 8 are each independently selected from hydrogen, an alkyl group which may be substituted with a substituent, an alkylene group which may be substituted with a substituent, and an aromatic group which may be substituted with a substituent. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 may be bonded to each other to form a single ring which may be substituted with a substituent, or multiple rings which may be substituted with a substituent. 1 and R 2 , R 3 and R 4 , R 5 and R 6 , R 7 and R 8 The ring formed by may be an aromatic ring or a heterocyclic ring. Each X is independently selected from N, CR, or (CR)2. Each R is independently selected from hydrogen, an alkyl group which may be substituted with a substituent, an alkylene group which may be substituted with a substituent, and an aromatic group which may be substituted with a substituent. In addition, one or two of the four Xs may be absent, and the pyrrole rings in formula (1) may be directly bonded to each other via a single bond or a double bond. Het in formula (1) is a hetero element selected from O, N, and S. The bond between Het and M may be a single bond or a double bond.

10. The cracking catalyst of claim 1 used at a temperature below 40°C. 　 The cracking catalyst of claim 2 used in the presence of an oxidizing agent.

2. The decomposition catalyst according to claim 1, wherein the support is made of a carbon material having functional groups containing hydrogen and / or oxygen. 　 The cracking catalyst according to claim 4, wherein the functional group is an electron-withdrawing group.

5. The decomposition catalyst according to claim 4, wherein the amount of CO generated when the carbon material is heated from 100°C to 1500°C at a temperature increase rate of 200°C / h by vacuum pyrolysis is 1 mg / g or more.

7. The decomposition catalyst according to claim 6, wherein the amount of CO2 generated when the carbon material is heated from 100°C to 1500°C at a temperature increase rate of 200°C / h by vacuum pyrolysis is 0 or more. 　 A method for decomposing organic matter using the decomposition catalyst according to any one of claims 1 to 7. 　 A method for producing a compound, comprising decomposing the organic matter by the method according to claim 8 to produce at least one compound selected from the group consisting of alcohols, phenols, carboxylic acids, aldehydes, and ketones. 　 An organic matter treatment system, which decomposes the organic matter using the decomposition catalyst according to any one of claims 1 to 7.

Images