Reaction device and method of producing chemical compound using the same

Abstract

To provide a reaction device for further efficiently producing a useful chemical compound such as hydrogen peroxide.SOLUTION: The reaction device comprises a unit membrane with a porous anode membrane, a porous electrolyte membrane, and a porous cathode membrane laminated therein one after another in this order, the inside of the unit membrane communicating via pores, and the cathode membrane being configured to react a reducible substance and electrons generated in the anode membrane to generate a chemical compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a reaction apparatus and a method for producing a compound using the same. [Background technology]

[0002] Hydrogen peroxide is a useful compound used as a bleaching agent and / or oxidizing agent in the chemical, pulp, pharmaceutical, food, textile, and semiconductor industries. Conventional methods for producing hydrogen peroxide include (i) an autoxidation method using alkylanthraquinones (see Non-Patent Document 1), (ii) an electrolysis method in which oxygen is cathodicly reduced in an alkali metal hydroxide (see Patent Document 1), and (iii) a method in which hydrogen and oxygen are catalytically reacted using a platinum group catalyst suspended or dissolved in an aqueous sulfuric acid or hydrochloric acid solution (see Patent Document 2). Of these, method (i) is primarily used industrially.

[0003] However, these conventional methods for producing hydrogen peroxide, for example, method (i) above, have the following problems (a) to (f): (a) the addition of a large amount of organic solvent is required; (b) numerous by-products and catalyst degradation are generated, necessitating various separation and regeneration processes; (c) electrolytes with different pH levels are required depending on the catalyst material; (d) production must be performed by a batch method rather than a continuous method, necessitating complex production and purification processes and the necessary equipment; (e) an expensive palladium catalyst is required; and (f) increasing the concentration to reduce transportation costs poses safety issues due to the risk of explosion. Thus, method (i) above requires high energy consumption and capital investment, and also poses safety issues, so the development of a cheaper and safer production method is desired. Furthermore, method (ii) above has the problem of requiring a separation process to remove alkali metal hydroxide. Furthermore, method (iii) above requires mixing hydrogen and oxygen in the same reactor, which poses safety issues such as the risk of explosion, making it difficult to use as an industrial production method.

[0004] Meanwhile, in recent years, research has been progressing on the production of various useful compounds under mild conditions using fuel cell systems and electrolysis cell systems. A fuel cell is a system that electrochemically burns fuel completely across an electrolyte membrane and directly converts the free energy change in the reaction process into electrical energy. Specifically, electron-releasing and electron-accepting reactions occur at the anode and cathode, respectively, and the movement of electrons through an external circuit connecting the two electrodes is used as power. From the perspective of material synthesis, such fuel cells can be viewed as chemical reactors, which, in principle, can produce both electricity and useful compounds. An electrolysis cell applies an external voltage between the anode and cathode to drive an oxidation reaction that releases electrons at the anode and a reduction reaction that requires electrons at the cathode. The application of an external voltage enables the production of hydrogen through water electrolysis and useful compounds such as carbon monoxide and formic acid through carbon dioxide electrolysis. When viewed as an energy conversion technology, such electrolytic cells have the advantage of reducing energy storage costs and minimizing storage losses compared to converting electricity generated from renewable energy sources into chemical energy and storing the electricity in batteries.

[0005] Chemical synthesis methods that apply fuel cell systems and electrolytic cell systems have the following advantageous features for industrial production: (1) They can separate active species and form special reaction fields, making selective reactions that are difficult to achieve with conventional catalytic reactions possible. (2) They can easily electrically control the reaction rate and selectivity. (3) They can reduce the risk of explosion because oxidizing substances such as oxygen and reducing substances such as hydrogen are separated by a membrane.

[0006] As examples of applications of fuel cell systems to chemical synthesis, (iv) partial oxidation reactions of ethylene and propylene (see Non-Patent Document 2), (v) hydroxylation reactions of benzene (see Non-Patent Document 3), (vi) oxidative carbonylation reactions of methanol (see Non-Patent Document 4), (vii) a method for producing hydrogen peroxide from hydrogen and oxygen, and (viii) a method for producing hydrogen peroxide using water, methanol, ethanol, or the like in an oxidation reaction at the anode (see Non-Patent Documents 5-6 and Patent Documents 3-7), etc. have been proposed.

[0007] In the method (vii) disclosed in Patent Document 6 and Non-Patent Document 5, Nafion (a registered trademark of DuPont) is used as a diaphragm, and platinum black is used as the catalytic electrode on the anode side of the membrane, and gold mesh or graphite is used on the cathode side. Hydrogen peroxide is produced by blowing hydrogen gas into the anode chamber and oxygen gas into the cathode chamber, which has been introduced with an aqueous hydrochloric acid solution.

[0008] In the method (vii) disclosed in Patent Documents 3 to 5, an apparatus is used in which the anode and cathode are separated into an anode chamber, an intermediate chamber, and a cathode chamber, an electrolyte solution is present in the intermediate chamber, and the electrodes are externally short-circuited by an electron conductor, or the intermediate chamber is separated by a cation exchange membrane. Hydrogen gas is supplied to the anode chamber and oxygen gas is supplied to the cathode chamber, and hydrogen peroxide is generated in the electrolyte solution in the intermediate chamber.

[0009] In the method (viii) disclosed in Patent Document 7 and Non-Patent Document 6, hydrogen peroxide is produced by generating electrons at the anode either through (A) an oxidation reaction at the anode at a potential lower than the electrode potential at which oxygen is reduced to hydrogen peroxide, and / or (B) an oxidation reaction at the anode due to application of an external voltage between the cathode and anode. Since an electrolytic cell system can also be used to carry out an oxygen-producing reaction by oxidation of water, hydrogen peroxide can be produced without requiring expensive fuel. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent No. 4,431,494 [Patent Document 2] U.S. Patent No. 4,009,252 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-236968 [Patent Document 4] Japanese Patent Application Laid-Open No. 2005-076043 [Patent Document 5] Japanese Patent Application Laid-Open No. 2005-281057 [Patent Document 6] Japanese Patent Application Laid-Open No. 2010-215938 [Patent Document 7] Japanese Patent Application Laid-Open No. 2010-242159 [Non-patent literature]

[0011] [Non-Patent Document 1] Catalyst Handbook, Catalysis Society of Japan, 763 pages, 2008 [Non-patent document 2] Catalyst, Ichiro Yamanaka 62(2) 68(2020) Catalysts contributing to highly difficult clean oxidation reactions, Catalytic reactions [Non-patent document 3] Catalyst, Ichiro Yamanaka 46(1) 25(2004) Aiming for phenol synthesis by direct oxidation of benzene [Non-patent document 4] Catalyst, Ichiro Yamanaka 56(2) 127(2014) Electrochemical oxidation carbonylation of alcohols with emphasis on catalytic activity [Non-Patent Document 5] Catalyst, Ichiro Yamanaka 54(7) 428(2012) Direct synthesis of highly concentrated hydrogen peroxide solution using electrocatalysis [Non-patent document 6] Angew.Chem.Int.Ed.Vol.47,Issue 10,1900-1902,2008 Summary of the Invention [Problem to be solved by the invention]

[0012] However, the methods (vii) and (viii) disclosed in Non-Patent Documents 5 and 6 have the advantages of (1) to (3) above, but have problems such as a low concentration of hydrogen peroxide obtained and a plateau in the production of hydrogen peroxide over time. Also, the method (vii) disclosed in Patent Documents 3 to 5 improves the rate of hydrogen peroxide production, but is not necessarily satisfactory in terms of the accumulated concentration of hydrogen peroxide, and also has problems such as the inevitable inclusion of electrolytes in the obtained hydrogen peroxide. Furthermore, fuel cell systems require the consumption of expensive hydrogen as fuel. In electrolytic cell systems that produce hydrogen peroxide by applying an external voltage between a cathode and an anode, the above-mentioned (vii) disclosed in Patent Documents 3 to 5 has a problem in that the presence of an electrolyte solution in the intermediate chamber increases the cell resistance and results in a large consumption of electrical energy.

[0013] In the chemical industry, there is a constant demand for the development of reaction methods and catalysts for more efficiently producing useful compounds using electricity generated from renewable energy sources, in addition to these methods for producing hydrogen peroxide.

[0014] The problem to be solved by the present invention is to provide a reactor for more efficiently producing useful compounds such as hydrogen peroxide by utilizing communication (crossover) between the anode side and the cathode side in a diaphragm that separates materials on the anode side and the cathode side. Another problem to be solved by the present invention is to provide a method for more efficiently producing useful compounds such as hydrogen peroxide using the above-mentioned reaction apparatus. [Means for solving the problem]

[0015] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by providing a reactor comprising a unit membrane in which a porous anode membrane, a porous electrolyte membrane, and a porous cathode membrane are laminated in this order, with the unit membranes being communicated with each other via pores; this reactor utilizes crossover of the reducible substance from the anode side to the cathode side, supplies the gaseous reducible substance to a reduction catalyst on the cathode, and recovers the generated useful compounds such as hydrogen peroxide in a liquid solvent supplied to the cathode side, thereby completing the present invention.

[0016] That is, the present invention has the following aspects. [1] A reactor having a unit membrane in which a porous anode membrane, a porous electrolyte membrane, and a porous cathode membrane are stacked in this order, The unit membranes are interconnected through pores, The cathode membrane is a reactor configured to react a reducible substance with electrons produced by the anode membrane to produce a compound. [2] The reaction device according to [1], wherein the anode membrane generates the electrons through a reaction represented by the following formula (I): 2H2O→O2+4H + +4e - (I) [3] The reaction apparatus according to [1], wherein the compound is at least one of hydrogen peroxide, formic acid, methanol, acetic acid, ethanol, and urea. [4] The reaction device according to [1], wherein the cathode membrane generates at least one of hydrogen peroxide, formic acid, methanol, acetic acid, ethanol, and urea as the compound by at least one reaction of the following formulas (II) to (VII): O2+2H + +2e - →H2O2 (II) CO2+2H + +2e - →HCO2H (III) CO2+6H + +6e - →CH3OH+H2O (IV) 2CO2+8H + +8e - →CH3CO2H+2H2O (V) 2CO2+8H + +8e - →CH3CH2OH+H2O (VI) CO2+2NO3 - +18H + +16e - →CO(NH2)2+7H2O (VII) [5] The reactor according to [1], wherein the anode membrane is a catalytic electrode comprising a porous conductive support and an anode active material. [6] The reactor according to [1], wherein the cathode membrane is a catalytic electrode comprising a porous conductive support and a cathode active material. [7] The reaction device according to [5], wherein the anode active material is an electrode that utilizes electrical energy or light energy to promote the reaction of formula (I). [8] The cathode membrane is a catalyst electrode comprising a porous conductive support and a cathode active material; The reaction device according to [4], wherein the cathode active material is an electrode that utilizes electrical energy or light energy to promote at least one reaction among the reactions represented by formulas (II) to (VII). [9] The reaction device according to [1], wherein the porous electrolyte membrane is an ion conductor that does not have electronic conductivity and has a porous structure that does not prevent gas permeation.

[10] The reaction apparatus according to [1], further comprising a supply pipe for supplying a liquid into the unit membrane and a recovery pipe for recovering the compound solution.

[11] A method for producing a compound, using the reaction apparatus according to any one of [1] to

[10] .

[12] A method for producing the compound according to

[11] , which is a continuous method.

[13] A method for producing the compound according to

[11] , comprising supplying a liquid into the unit membrane and recovering a solution of the compound. [Effects of the Invention]

[0017] According to the present invention, a porous electrolyte membrane that allows gas crossover from the anode side to the cathode side is utilized to supply a reducible substance to a reduction catalyst, thereby providing a reactor for more efficiently producing useful compounds such as hydrogen peroxide. Furthermore, according to the present invention, it is possible to provide a method for more efficiently producing useful compounds such as hydrogen peroxide using the reaction apparatus and either electricity (electrical energy) generated from renewable energy or light energy. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing an example of a reaction apparatus of the present invention. [Figure 2A] FIG. 2 is a schematic diagram showing another example of the reaction apparatus of the present invention. [Figure 2B] FIG. 2 is a schematic diagram showing another example of the reaction apparatus of the present invention. [Figure 3] FIG. 2 is a schematic diagram showing another example of the reaction apparatus of the present invention. [Figure 4] 1 is a graph showing the applied voltage when hydrogen peroxide is produced at a constant current of −1.0 mAcm −2 in Example 1. [Figure 5] 1 is a graph showing the current efficiency of hydrogen peroxide production in Example 1. [Figure 6] 1 is a graph showing the applied voltage when hydrogen peroxide is produced at a constant current of −40 mAcm −2 in Example 2. [Figure 7] 1 is a graph showing the concentration of aqueous hydrogen peroxide solutions produced in Example 2. [Figure 8] 1 is a graph showing the current efficiency of hydrogen peroxide production in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below. Note that the present invention is not limited to the following embodiments, and can be practiced in various modifications within the scope of the invention.

[0020] <Reaction device> The reactor of the present invention is a reactor comprising a unit membrane in which a porous anode membrane, a porous electrolyte membrane, and a porous cathode membrane are stacked in this order, the unit membranes being interconnected via pores, and a reducible substance permeates the porous electrolyte membrane and is supplied to the porous cathode membrane. The porous cathode membrane is a reactor in which, in the presence of a reduction catalyst, electrons produced in the anode membrane react with the reducible substance to produce a compound. Each of the multiple porous membranes has pores that communicate with adjacent porous membranes and do not prevent gas permeation. Furthermore, the reactor may be configured so that the reaction product is recovered using a liquid solvent supplied to the cathode membrane.

[0021] The present invention will be described in detail below using a method for producing hydrogen peroxide as an example. The present invention is not limited to the method for producing hydrogen peroxide, but can also be applied to other chemical synthesis reactions in which an oxidation reaction proceeds at the anode by applying an external voltage between the cathode and anode. As an example of the reactor of the present invention, a schematic diagram of the reactor used in the examples and the reactor used to produce hydrogen peroxide from water and oxygen using electric power according to the production method of the present invention is shown in FIG. 1.

[0022] The reactor 1 shown in Figure 1 has a unit membrane 2 that integrates an anode membrane 3, a porous electrolyte membrane 4, and a porous cathode membrane 5. The unit membrane 2 is made entirely of porous materials, and its interior is connected so that a liquid or gas can be introduced from the cathode membrane 5 to the anode membrane 3. A liquid or electrolyte solution is introduced from the outside of the cathode membrane 5. It is preferable to supply a gas from the anode membrane 3 side to the cathode membrane 5 side. As shown in FIG. 2A, the reaction device 9 of the present invention may be configured such that two tubes are connected to the outside of the cathode membrane 5, a liquid or electrolyte solution is supplied from one tube (hereinafter also referred to as the supply tube) 6a into the inside of the unit membrane 2, and hydrogen peroxide solution is recovered from the outside of the unit membrane 2 through the other tube (hereinafter also referred to as the recovery tube) 6b. The liquid solvent for recovering the reaction product may be water or an organic solvent such as alcohol. The liquid solvent is not limited to a high-purity solvent, and may be a mixture or solution, and may contain ions such as acid, alkali, or electrolyte salt. The supply tube 6a and recovery tube 6b are not limited to the cathode membrane 5 side as long as they are connected to the unit membrane 2 and communicate with the inside of the unit membrane 2. 2B, the reactor 10 of the present invention may have a cathode chamber 8 provided outside the cathode membrane 5. The cathode chamber 8 is configured so that a liquid or an electrolyte solution is introduced therein and at least a part of the outside of the cathode membrane 5 comes into contact with the liquid. The liquid or electrolyte solution is also used to recover the product, hydrogen peroxide, as a solution, and a portion of it is introduced from the cathode membrane 5 through the porous electrolyte membrane 4 to the anode membrane 3. Here, the amount of liquid introduced to the anode membrane 3 is preferably 0.1 to 5 mass % of the total mass of the liquid supplied to the unit membrane 2. The outside of the anode membrane 3 may be configured so that at least a portion is exposed to the gas phase. A current-collecting conductor (e.g., gold-plated copper, resin-impregnated carbon) (not shown) is attached to the outer surfaces of the anode membrane 3 and the cathode membrane 5, and a lead wire 7, which is an electron conductor, is provided on the outer surface of the conductor, and the anode membrane 3 and the cathode membrane 5 are connected to each other by the lead wire 7. If current can be collected efficiently, a current-collecting conductor may not be provided. If desired, a power supply may be provided between the anode membrane 3 and the cathode membrane 5 to apply a voltage to promote the reaction. If desired, the anode film 3 and the cathode film 5 can be irradiated with light to form a light energy-driven reaction device.

[0023] <Anode film> The anode membrane used in the present invention is preferably a catalytic electrode containing a porous conductive support and an anode active material.

[0024] The conductive support is not particularly limited, but examples thereof include nonwoven fabric made of metal fibers, porous sintered bodies of metal particles, and porous conductive carbon materials, such as carbon paper and carbon cloth.

[0025] In the present invention, an oxidation reaction that releases electrons occurs in the anode membrane. In the case of a water oxidation reaction, the reaction represented by the following formula (I) may occur. In a basic condition, an oxidation reaction of hydroxide ions may occur. 2H2O→O2+4H + +4e - (I) The anode membrane contains an anode active material to drive the oxidation reaction. The anode active material for promoting the reaction of formula (I) may be any known catalyst for converting water into protons, oxygen, and electrons. It may also be any known catalyst for converting hydroxide ions into oxygen and electrons. For example, metals selected from Groups 7 to 10 of the periodic table, their metal compounds, and conductive carbon materials can be used. Examples of metals or metal compounds include ruthenium, iridium, nickel, manganese, iron, platinum, and palladium, as well as metal compounds containing these metals. Ruthenium oxide and iridium oxide are particularly preferred. Examples of conductive carbon materials include activated carbon, carbon fiber, graphene, carbon whiskers, carbon nanotubes, and carbon black. A catalyst electrode in which an anode active material is attached to a porous conductive support may also be used. Examples of conductive supports include titanium mesh, sintered titanium fiber, carbon paper, and carbon cloth.

[0026] In the present invention, it is sufficient that an oxidation reaction that releases electrons occurs in the anode film, and the anode film may be a film having a conductive support, making it an electric energy-driven reactor, or may be a photoanode film that functions as a semiconductor electrode, making it a light energy-driven reactor. Solar energy may be used as the light energy. Examples of the photoanode film for promoting the oxidation reaction of the above formula (I) include oxides such as titanium oxide, strontium titanate, tungsten oxide, bismuth vanadate, and iron oxide, as well as oxynitrides and oxysulfides, which are attached to a porous conductive support.

[0027] <Porous electrolyte membrane> The porous electrolyte membrane of the present invention is preferably an ion conductor without electronic conductivity. Furthermore, the porous electrolyte membrane of the present invention preferably has gas diffusivity. Examples of porous electrolyte membranes include protonic acid membranes in which a support is impregnated with an acidic electrolyte such as heteropolyacid, phosphoric acid, hydrochloric acid, sulfuric acid, and hydrochloric acid; acidic solid electrolyte membranes such as silica alumina, H-type zeolite, zirconium phosphate, and heteropolyacid; porous supports supporting cation exchange polymers such as polystyrene-sulfonic acid and fluorocarbon polymer-sulfonic acid; anion exchange membranes in which a support is impregnated with a basic electrolyte such as an alkaline anionic substance; porous supports supporting an anion exchange polymer with alkali-stable cations; and basic solid electrolytes containing alkaline components. The support is not particularly limited, but examples include cellulose filters, polytetrafluoroethylene filters, and nonwoven fabrics made of glass fibers or chemical fibers. In the present invention, a porous electrolyte membrane is preferably used in which a membrane filter made of a cellulose mixed ester is used as the support and an ion exchange polymer such as fluororesin-based Nafion (registered trademark of DuPont) is drop-cast onto the support. Ion-conductive nanofibers produced by electrospinning, proton exchange membranes or anion exchange membranes with fine pores, etc. may also be used. The porous electrolyte membrane may be subjected to hydrophilic and hydrophobic treatments as necessary.

[0028] <Cathode film> The cathode membrane used in the present invention is preferably a catalytic electrode comprising a porous conductive support and a cathode active material. Examples of the porous conductive support include those similar to those described above for the anode membrane. The cathode may have, for example, a multilayer structure having a catalyst layer and a porous conductive support, in which the catalyst layer has a cathode active material, or may have a single-layer structure in which the cathode active material as a catalyst is supported on a porous conductive support.

[0029] The cathode active material may be any known catalyst that promotes the reduction reaction of oxygen, carbon dioxide, or the like. A reduction reaction refers to both a reaction in which a substance combines with hydrogen and a reaction in which electrons are gained. For example, in the production of hydrogen peroxide, an oxygen reduction reaction is used, in which oxygen is reduced by two electrons to produce hydrogen peroxide. The reduction of carbon dioxide (CO2) produces chemical substances such as carbon monoxide (CO), formic acid (HCOOH), methanol (CH3OH), methane (CH4), acetic acid (CH3COOH), ethanol (C2H5OH), ethane (C2H6), ethylene (C2H4), and urea (CO(NH2)2). In the present invention, the cathode membrane may undergo one of the following reactions: an oxygen reduction reaction represented by the following formula (II) or a carbon dioxide reduction reaction represented by formulas (III) to (VII). For convenience, the reaction formulas are given under acidic conditions, but the same reaction involving hydroxide ions may also occur. O2+2H + +2e - →H2O2 (II) CO2+2H + +2e - →HCO2H (III) CO2+6H + +6e - →CH3OH+H2O (IV) 2CO2+8H + +8e -→CH3CO2H+2H2O (V) 2CO2+8H + +8e - →CH3CH2OH+H2O (VI) CO2+2NO3 - +18H + +16e - →CO(NH2)2+7H2O···(VII)

[0030] In the case of formula (II), i.e., when oxygen is supplied to the reduction catalyst of the cathode membrane to produce hydrogen peroxide, it is desirable to use a catalyst that can reduce the overvoltage of such a reaction. Examples of reduction catalysts include metals selected from Groups 4 to 15 of the periodic table or their metal compounds, conductive carbon materials, carbon materials with oxidized surfaces, and carbon materials with metal atoms or molecules fixed to the surface.

[0031] The catalyst is preferably a mixture of a metal complex coordinated with a nitrogen-containing organic compound and a conductive carbon material, which has been heat-treated. Examples of conductive carbon materials include activated carbon, carbon fiber, graphene, carbon whiskers, carbon black, carbon nanotubes, and acetylene black. The heat treatment can be carried out in oxygen, air, or an inert gas, but is preferably carried out in an inert gas such as nitrogen, helium, or argon. The heat treatment temperature is preferably 100 to 1000°C, more preferably 400 to 1000°C, and even more preferably 500 to 900°C.

[0032] Examples of methods for mixing the metal complex and the conductive carbon material include a method of uniformly physically mixing the metal complex and the particulate conductive carbon material, or a method of dissolving or dispersing the metal complex and the particulate conductive carbon material in a solvent, then distilling off the solvent and impregnating the conductive carbon material with the resulting material. Examples of solvents that can be used in the above mixing methods include dimethylformamide, quinoline, acetone, dichloromethane, ethanol, and water. The metal complex (hereinafter sometimes simply referred to as "metal complex") is preferably a metal amine, a metal pyridine, a metal phenanthroline, or a metal porphyrin, and more preferably a metal porphyrin. These metal complexes may be used alone or in combination of two or more.

[0033] The metal porphyrins used as catalysts can be compounds having a porphyrin-based macrocyclic ligand and a metal coordinated at the center of the porphyrin ring. The porphyrin ring can be bonded to various substituents, such as a phenyl group or a phenyl group substituted with various substituents such as a methyl group, a carboxy group, a bromo group, a fluoro group, a hydroxy group, an amino group, or a sulfo group, or can be unsubstituted. The porphyrin ring is preferably tetraphenylporphyrin. These metal porphyrins can be used alone or as a mixture of two or more. The metal atom forming the metal complex can be manganese, nickel, tin, zinc, cobalt, copper, cadmium, iron, or vanadium, with cobalt being preferred. These metal atoms can be used alone or as a mixture of two or more.

[0034] Examples of methods for supporting the catalyst on the support include a method in which a solvent containing the catalyst is dropped and dried to support the catalyst, a method in which the support is impregnated with a solvent containing the catalyst and dried to support the catalyst, and a method in which a solvent containing the catalyst is sprayed onto the support and dried to support the catalyst, etc. A reduction catalyst membrane may be supported on the surface of the porous electrolyte membrane.

[0035] In the cases of formulas (III) to (VII), i.e., when carbon dioxide is supplied to the cathode membrane and reduced to produce formic acid, methanol, acetic acid, ethanol, or urea, it is desirable to use a catalyst capable of reducing carbon dioxide to produce a carbon compound. It is also desirable to use a catalyst capable of further reducing the carbon compound produced thereby to produce a carbon compound, if necessary. These catalysts are capable of reducing the overvoltage of such reactions, increasing the selectivity of the desired product, and exhibiting sufficient durability. Examples of catalysts include metals, metal oxides, and hydroxides selected from Groups 4 to 15 of the periodic table, as well as alloys, intermetallic compounds, and composite metal oxides containing at least one of these metals. Nitrides, sulfides, selenides, and the like can also be used. Catalysts containing copper, silver, gold, zinc, cadmium, indium, tin, lead, bismuth, and the like are preferred.

[0036] The reduction catalyst can also be used by immobilizing it on a porous conductive support. Supports are not particularly limited, but examples include titanium mesh, sintered titanium fibers, and porous conductive carbon materials. Porous conductive carbon materials include carbon paper and carbon cloth. The reduction catalyst and the conductive support may be subjected to hydrophilic and hydrophobic treatments as needed. The reduction catalyst itself can also be made porous before use.

[0037] Examples of methods for supporting a catalyst on a support include a method in which a solvent containing the catalyst is dropped onto a support and then dried to support the catalyst, a method in which a solvent containing the catalyst is impregnated into a support and then dried to support the catalyst, and a method in which a solvent containing the catalyst is sprayed onto a support and then dried to support the catalyst, etc. The catalyst may also be immobilized on a conductive support by methods such as electrolytic deposition, vacuum deposition, and sputtering.

[0038] In the present invention, if the conductivity of the active material in the anode and cathode films is insufficient, the conductive carbon material may be incorporated into the anode and cathode films not as a catalyst but for the purpose of increasing conductivity. For example, when the electrode active material (anode active material and cathode active material) is used in combination with a conductive carbon material added for the purpose of increasing conductivity, it is preferable to uniformly mix the electrode active material with particulate conductive carbon material or to use particles in which the electrode active material is supported on particulate conductive carbon material, since this results in anode and cathode films with a uniform composition and excellent electronic conductivity. Examples of conductive carbon materials that can be used include those described above. When the electrode active material is used in combination with a conductive carbon material as an electrode, the mass ratio (metal equivalent) of the electrode active material to the total mass of both materials is preferably 0.001 to 50 mass%, more preferably 0.01 to 30 mass%, and even more preferably 0.1 to 10 mass%.

[0039] As will be shown in the examples below, when hydrogen peroxide is produced from water and oxygen using the reactor of the present invention, a titanium fiber sintered body supporting a mixed oxide of iridium oxide and tantalum oxide is preferably used as the anode membrane. Commonly available electrode active materials and electrodes used in water electrolysis cells may also be used. The cathode membrane is preferably an electrode component prepared by impregnating and supporting a cobalt porphyrin on a conductive carbon material and heat-treating the material in an inert gas.

[0040] In the anode membrane, the porous electrolyte membrane, and the cathode membrane, a water repellent may be mixed in addition to the above-mentioned main components. Examples of the water repellent include polytetrafluoroethylene (PTFE), tetrafluoroethylene oligomer (TFEO), and graphite fluoride (CF). n), and fluororesin-based ion exchange polymers. In the present invention, the water repellent promotes gas permeation of reducible substances such as oxygen or carbon dioxide through the unit membrane and prevents excess water from permeating the porous electrolyte membrane, thereby improving the efficiency of the electrochemical reaction. The water repellent also functions as a binder for catalyst particles, and can be used to fix them to a porous conductive support. The catalyst particles and the binder can also be physically mixed and molded into a sheet for use. When used as a binder, the amount used is preferably 1 to 250 mass % and more preferably 5 to 50 mass % relative to the mass of the support used.

[0041] In the present invention, the anode membrane, electrolyte membrane, and cathode membrane are pressure-bonded together to form a unit membrane in the form of a sheet, which is then placed in the reactor of the present invention. The anode membrane, electrolyte membrane, and cathode membrane can each be formed by a method generally employed in fuel cells and electrolysis cells, such as a coating method or a drop-casting method.

[0042] The thickness of the anode film is preferably 0.001 to 2.0 mm, more preferably 0.01 to 1.0 mm, and even more preferably 0.1 to 0.5 mm. The thickness of the porous electrolyte membrane is preferably 0.001 to 2.0 mm, more preferably 0.01 to 1.0 mm, and even more preferably 0.1 to 0.5 mm. The thickness of the cathode membrane is preferably 0.001 to 2.0 mm, more preferably 0.01 to 1.0 mm, and even more preferably 0.1 to 0.5 mm. The thickness of the unit membrane is preferably 0.003 to 6.0 mm, more preferably 0.03 to 3.0 mm, and even more preferably 0.3 to 1.5 mm.

[0043] As shown in Fig. 2B, the reaction apparatus of the present invention may be provided with a cathode chamber 8 outside the cathode membrane 5, and a liquid or an electrolyte solution may be circulated through the cathode chamber 8. In this case, the liquid or electrolyte solution may be introduced into the cathode chamber 8 in a state where it is mixed with a gas.

[0044] In the present invention, pure water or ion-exchanged water is used as the liquid present in the cathode chamber. Acidic, neutral, or alkaline weak or strong electrolyte aqueous solutions are used as the electrolyte solution. Examples of these electrolyte aqueous solutions include aqueous solutions of NaOH, KOH, NaNO3, KNO3, NaHCO3, and KHCO3, as well as tap water and industrial water. Water or electrolyte aqueous solutions may be used alone or as a mixture of two or more. Non-aqueous solvents such as alcohol, formic acid, acetic acid, and acetonitrile, or mixtures thereof, may also be used as the solvent for the electrolyte solution. When the reaction apparatus of the present invention is used as a water treatment apparatus, the water present in the cathode chamber may be sewage such as domestic wastewater or industrial wastewater, or seawater.

[0045] The reducible substance (hereinafter also referred to as oxidizing substance) used in the present invention is not particularly limited as long as it is a compound capable of accepting electrons, and examples thereof include oxygen-containing compounds such as air, oxygen, carbon oxides, and nitrogen oxides. Preferably, gases such as air, oxygen, and carbon dioxide are used. The reducible substance does not necessarily have to be pure, and may be used as a mixture with an inert gas such as nitrogen, helium, or argon. When the reducible substance is oxygen, it may be oxygen obtained by supplying water to the anode and causing a reaction, or it may be oxygen supplied from an external source. When the reducible substance is carbon dioxide, it may be carbon dioxide supplied from an external source. The reducible substance may be supplied from an external source by bringing the anode membrane side into contact with the reducible substance, or by connecting a pump or tube to the outside of the anode membrane.

[0046] In the present invention, various conditions (e.g., water flow rate, voltage, etc.) that change with the scale of the reactor can be appropriately selected according to the scale of the reactor. For example, when water is supplied to the cathode chamber, the water flow rate can be appropriately selected according to the scale of the reactor, and is preferably 0.05 to 100,000 mL / min, more preferably 0.1 to 1,000 mL / min.

[0047] In the present invention, the current flowing between the anode film and the cathode film is preferably 0.1 to 1000 mAcm. -2 , more preferably 1.0 to 100 mAcm -2 It can be said that: In the present invention, the reaction can be accelerated by applying a voltage between the anode film and the cathode film. When a voltage is applied, the voltage can be preferably 0.1 to 5 V, more preferably 0.2 to 1 V. In the case of a light energy-driven type, the reaction can be initiated and electricity can be generated without applying a voltage, but a voltage may be applied to accelerate the reaction. The reaction temperature is preferably selected from the range of 0 to 80°C, more preferably 5 to 30°C. The reaction time may be appropriately selected by determining the actual target values ​​of the selectivity and yield of the reaction product, and is not particularly limited, but is preferably several minutes to several hours.

[0048] The reaction can be carried out continuously by continuously introducing water or an aqueous electrolyte solution into the cathode chamber while continuously withdrawing the reaction mixture formed in the cathode chamber. For example, as shown in FIG. 2B, an outlet for new liquid containing the product may be provided in the cathode chamber 8, and water or an aqueous electrolyte solution may be continuously introduced into the cathode chamber 8. The reaction product can be separated from the reaction mixture in the reactor by conventional means, such as distillation or extraction, to the desired purity.

[0049] The size of the reactor is not particularly limited, but for example, the volume of the cathode chamber is about 0.1 cm 3 Approximately 10m from 3 The sizes of the anode membrane, the porous electrolyte membrane, the cathode membrane, and the unit membranes composed of these can also be adjusted accordingly.

[0050] As shown in Fig. 2B, the reactor of the present invention may be provided with a cathode chamber 8 outside the cathode membrane 5. Water or an aqueous electrolyte solution is introduced into the cathode chamber 8 to recover the product hydrogen peroxide as an aqueous solution. A portion of the water is introduced from the cathode membrane 5 through the porous electrolyte membrane 4 to the anode membrane 3.

[0051] As shown in FIG. 3, the reactor of the present invention may be a cylindrical unit membrane with the cathode membrane 5 side on the inside and the anode membrane 3 side on the outside, and may be configured so that water flows through a hollow space in the center of the unit membrane. In addition, the reaction apparatus of the present invention may be a cylindrical unit membrane (not shown) with the cathode membrane 5 side facing outward and the anode membrane 3 side facing inward, as opposed to the configuration shown in Figure 3, and may be configured so that water flows outside the unit membrane.

[0052] <Method of manufacturing the compound> The method for producing the compound of the present invention includes producing the compound using the reaction apparatus of the present invention. When hydrogen peroxide is produced as a compound using oxygen and water as raw materials, if the ion conductor exhibits proton conductivity, the reactions shown in the following formulas (I) and (II) proceed in a unit membrane comprising an anode membrane, a porous electrolyte membrane, and a cathode membrane in this order. 2H2O→O2+4H + +4e - (I) O2+2H + +2e - →H2O2 (II) Explaining with reference to Fig. 1, water, which is a proton donor supplied to the unit membrane 2, releases oxygen, protons, and electrons at the anode membrane 3 (formula (I)), and the oxygen and protons pass through the porous electrolyte membrane 4 and move to the cathode membrane 5, while the electrons move to the cathode membrane 5 via an external circuit. Then, oxygen supplied from the outside or oxygen generated in formula (I) reacts with the protons and electrons to produce hydrogen peroxide, a reaction product (formula (II)).

[0053] Referring to FIG. 2A, water flows into the cathode membrane 5 through the supply pipe 6a. The water flows along the cathode membrane 5 from the supply pipe 6a to the recovery pipe 6b. Because the cathode membrane 5, porous electrolyte membrane 4, and anode membrane 3 are all made of porous materials, water permeates from the cathode membrane 5 to the anode membrane 3. Water, which acts as a proton donor, is supplied to the anode membrane 3 and releases oxygen, protons, and electrons at the electrode (Equation (I)). The oxygen and protons pass through the porous electrolyte membrane 4 to the cathode membrane 5, while the electrons pass through an external circuit to the cathode membrane 5. In the reduction catalyst, the oxygen and protons that have passed through the porous electrolyte membrane 4 react with the electrons supplied from the cathode membrane 5 to produce the reaction product, hydrogen peroxide (Equation (II)). The hydrogen peroxide dissolves in the water that has permeated the cathode membrane 5, forming hydrogen peroxide water. The hydrogen peroxide solution flows out of the cathode membrane 5 and further flows into the recovery pipe 6b along the water flow from the supply pipe 6a toward the recovery pipe 6b. In this way, by flowing water into the reactor, the hydrogen peroxide solution can be continuously recovered.

[0054] Similarly, when formic acid is produced as a compound, the reactions shown in the following formulas (I) and (III) proceed in the unit membrane. When methanol is produced as a compound, the reactions shown in the following formulas (I) and (IV) proceed in the unit membrane. When acetic acid is produced as a compound, the reactions shown in the following formulas (I) and (V) proceed in the unit membrane. When ethanol is produced as a compound, the reactions shown in the following formulas (I) and (VI) proceed in the unit membrane. When urea is produced as a compound, the reactions shown in the following formulas (I) and (VII) proceed in the unit membrane by introducing an aqueous nitric acid solution. 2H2O→O2+4H + +4e - (I) CO2+2H + +2e - →HCO2H (III) CO2+6H + +6e- →CH3OH+H2O (IV) 2CO2+8H + +8e - →CH3CO2H+2H2O (V) 2CO2+12H + +12e - →CH3CH2OH+3H2O (VI) CO2+2NO3 - +18H + +16e - →CO(NH2)2+7H2O (VII) Referring to FIG. 1, water, which is a proton donor supplied to the anode membrane 3, releases protons and electrons on the electrode (formula (I)). The protons pass through the porous electrolyte membrane 4 and move to the cathode membrane 5, while the electrons move to the cathode membrane 5 via an external circuit. Carbon dioxide supplied from the outside then reacts with the electrons and protons to produce reaction products such as formic acid (formulas (III) to (VII)). The reaction products dissolve in the water that has permeated the cathode membrane 5, forming an aqueous solution. The aqueous solution flows out of the cathode membrane 5 and further flows into the recovery pipe 6b along the water flow from the supply pipe 6a toward the recovery pipe 6b. This allows the aqueous solution of the reaction products to be continuously recovered by flowing water through the reactor.

[0055] The reaction conditions for producing hydrogen peroxide may be the same as those described above for the reactor. The reaction conditions for producing formic acid, methanol, acetic acid, ethanol, and urea can be the same as those described for the reactor.

[0056] The reactor of the present invention is a reactor that can produce useful compounds under mild conditions with high selectivity, efficiently, and economically, thereby overcoming the problems associated with conventional catalytic processes. Furthermore, the reactor of the present invention can be used to produce useful compounds under mild conditions with high selectivity, efficiently, and economically. In particular, by using the reactor of the present invention to produce hydrogen peroxide from water and air, it is possible to overcome problems associated with conventional production methods, such as the use of large amounts of organic solvents, the complexity of the production process, the large consumption of electrical energy, the risk of explosion due to the mixing of hydrogen and oxygen, and the low yield of hydrogen peroxide.

[0057] Furthermore, unlike conventional techniques in which an electrolyte solution is present in an intermediate chamber, the reactor of the present invention does not require the anode membrane and cathode membrane to be separated from each other during the reaction. Because the anode membrane and cathode membrane form a unit membrane in close proximity, cell resistance can be reduced, resulting in reduced electrical energy consumption. According to the present invention, as shown in the following examples, hydrogen peroxide can be produced from water with high efficiency by using the reactor of the present invention. Furthermore, the reaction apparatus of the present invention allows gases such as oxygen and carbon dioxide to cross over between the anode and the cathode, thereby shortening the diffusion distance of the gas to the cathode, thereby enabling efficient production of compounds. Furthermore, the reaction apparatus of the present invention allows water to crossover between the anode and the cathode, thereby using water at the anode as a raw material for the reaction product and also using water at the cathode as a solvent for recovering the reaction product, thereby enabling efficient production and recovery of compounds. [Example]

[0058] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Those skilled in the art will be able to implement the present invention by making various modifications in addition to the examples shown below, and such modifications are also encompassed within the scope of the present claims.

[0059] [Example 1] In Example 1, hydrogen peroxide was produced from water using the reactor shown in FIG. 2A. The reactor included a unit membrane 2 that integrated an anode membrane 3, a porous electrolyte membrane 4, and a cathode membrane 5. Two tubes were connected to the outside of the cathode membrane 5, with water supplied from one tube to the inside of the unit membrane 2 and hydrogen peroxide solution collected from the other tube to the outside of the unit membrane 2. A stainless steel plate (not shown) was laminated on the outside of the anode membrane, and a tube was connected to the stainless steel plate, allowing oxygen to be supplied from the outside to the inside of the unit membrane 2. Gold-plated copper plates were placed on the anode membrane 3 and the cathode membrane 5 for current collection, and lead wires 7 connected the anode and cathode via an electrochemical measurement device.

[0060] The method for producing the unit membrane 2 in which the anode membrane 3, the porous electrolyte membrane 4, and the cathode membrane 5 are integrated is as follows.

[0061] The anode membrane 3 was prepared as follows. A titanium fiber sintered compact (Nikko Techno Co., Ltd., equivalent fiber diameter: 20 μm, thickness: 0.10 mm, porosity: 66.7%) was used as the porous support. First, hexachloroiridium (Fujifilm Wako Pure Chemical Corporation) was dissolved in 2-propanol (Fujifilm Wako Pure Chemical Corporation) to prepare a 0.2 M iridium solution. Next, 0.06 g of tantalum chloride (Kojundo Chemical Laboratory Co., Ltd.) was weighed out, and 3.0 mL of 2-propanol and 0.80 mL of 35% hydrochloric acid were added and stirred. A liquid aliquot was taken from the iridium solution so that the iridium concentration was 0.07 mmol, and a liquid aliquot was taken from the tantalum chloride solution so that the tantalum concentration was 0.03 mmol. To this mixed solution, 50 mg of PEG20000 (Fujifilm Wako Pure Chemical Corporation) was added and ultrasonically stirred. A 40 μL aliquot of the PEG20000-dissolved mixed solution was drop-cast onto a titanium fiber sintered compact and then heated and dried at 80°C for 3 minutes in a dryer. This drop-casting procedure was repeated three times. The compact was then baked at 350°C for 1 hour in a baking oven (heating rate: approximately 11°C / min). After natural cooling, 80 μL of a 5 wt% Nafion dispersion (Fujifilm Wako Pure Chemical Corporation) was drop-cast onto the compact and then baked at 80°C for 30 minutes.

[0062] The porous electrolyte membrane 4 was prepared by using a cellulose mixed ester membrane filter (Merck Millipore, thickness 0.14 mm, porosity 84%, pore size 8 μm) as a porous support, cutting it into a 3 cm square, immersing it in 800 μL of 5 wt% Nafion dispersion (Fujifilm Wako Pure Chemical Industries, Ltd.), and drying it at 80°C for 8 minutes.

[0063] The cathode film 5 was prepared by the following procedure. First, 0.024 g of cobalt tetraphenylporphyrin (Tokyo Chemical Industry, purity 85.6%) was weighed out and added to N,N-dimethylformamide (Fujifilm Wako Pure Chemical Industries, Ltd.) to make a 10 mL solution. This solution was then ultrasonically stirred for 10 minutes to prepare a cobalt tetraphenylporphyrin solution. Next, 0.20 g of Ketjen Black ECP600JD (Lion Specialty Chemicals Co., Ltd.) was weighed out and 3.5 mL of the cobalt tetraphenylporphyrin solution was added dropwise to impregnate the Ketjen Black. The solvent was evaporated by heating to 85 °C using a hot stirrer, and the mixture was then dried in a dryer at 80 °C to support the cobalt tetraphenylporphyrin. The cobalt loading amount was 0.3 wt%. After drying for 1 hour, the powder was ground in an agate mortar and then dried again in a dryer at 80 °C overnight. After grinding again in an agate mortar, the mixture was placed in a quartz glass container and sieved at a flow rate of 100 mL min -1 The mixture was heated to 500°C (heating rate: 8°C / min) under a nitrogen flow and then heat-treated for 2 hours. The powder obtained after natural cooling under a nitrogen flow was used as a catalyst for generating hydrogen peroxide. 7 mg of the prepared catalyst was weighed out, 5.0 mL of 2-propanol and 43 μL of 5 wt% Nafion dispersion were added, and the mixture was thoroughly stirred using an ultrasonic cleaner and ultrasonic homogenizer to prepare catalyst ink. The catalyst ink obtained after ultrasonic stirring was dissolved in water to obtain a catalyst with a density of 0.03 mg cm. -2 The porous electrolyte membrane was spray-coated with the catalyst layer to form a 2 cm square membrane. This was then air-dried overnight to obtain a catalyst layer. This catalyst layer was combined with a porous conductive support to form cathode membrane 5. The porous conductive support was made from carbon paper Sigracet GDL39AA (SGL Carbon Japan Co., Ltd., thickness 0.28 mm, porosity 80%) cut into 2 cm squares, and vacuum plasma treatment was performed on both the front and back sides for 5 minutes each to increase hydrophilicity.

[0064] The unit membrane, consisting of the anode membrane 3, porous electrolyte membrane 4, and cathode membrane 5 obtained above stacked in that order, was installed in an electrolysis cell. A titanium current collector plate equipped with a gas flow path for supplying oxygen was installed on the outside of the anode membrane. A carbon current collector plate equipped with a solution flow path for supplying water was installed on the outside of the cathode membrane. The outside of the current collector plate was sandwiched between a pair of stainless steel support plates and further tightened with bolts. The bolts were tightened with a torque of 2.0 N m.

[0065] The reaction was carried out using the above reactor as follows: A 1.0 mL min solution was applied to the cathode membrane 5 under normal pressure. -1 Pure water was supplied to the anode membrane 3 at a flow rate of 50 mL min -1 Humidified oxygen gas was supplied at a flow rate of 1 mAcm, and the current density was measured using an electrochemical measurement device (Hokuto Denko, HZ-ProS4). -2 The reaction was carried out at room temperature (around 25°C) under controlled conditions. The aqueous solution discharged from the electrolytic cell was sampled every 30 minutes, and the reaction was carried out for a total of 120 minutes. The concentration of the hydrogen peroxide produced was quantified using potentiometric titration with a KMnO4 aqueous solution. As a result, the production of hydrogen peroxide was confirmed in the water recovered from the cathode membrane 5. During this time, the voltage applied externally between the anode film 3 and the cathode film 5 was measured using an electrochemical measurement device. Based on the amount of electricity that flowed, the current efficiency for hydrogen peroxide production was calculated using the following formula. Current efficiency (%) = Amount of hydrogen peroxide produced (mol) x 2 x 96485 (C / mol) x 100 / Amount of electricity passed (C) The quantity of electricity (C) in the formula is the current value (A) multiplied by the time (s). The current value is expressed as the current density (mAcm -2 ) to electrode area (cm 2 ) is the value obtained by multiplying

[0066] The current efficiency of the obtained hydrogen peroxide solution was 94% at 30 minutes, 95% at 60 minutes, 94% at 90 minutes, and 96% at 120 minutes after the start of measurement. The concentration of the obtained hydrogen peroxide solution was 40-41 ppm. As shown in Figure 4, no significant change in voltage was observed over time. In other words, it was found that hydrogen peroxide solution can be produced for a long period of time while maintaining a low cell voltage. As shown in Figure 5, it was found that aqueous hydrogen peroxide could be produced with a high current efficiency of up to 96% even 120 minutes after the start of the reaction. This indicates that there is no deterioration over time in the reaction selectivity of the catalyst, and that hydrogen peroxide can be produced continuously while maintaining low electrical energy consumption.

[0067] [Example 2] The heat treatment temperature under nitrogen flow was changed to 750°C (heating rate 12°C / min), and the catalyst density was set to 0.1 mg cm -2 A cathode membrane was produced in the same manner as in Example 1, except that the current density was changed to -40 mAcm. A reactor was produced in the same manner as in Example 1, and a current density of -40 mAcm was changed to -40 mAcm. -2 The cathode membrane was supplied with pure water at normal pressure at 0.10 mL min -1 , 0.50 mL min -1 , 1.0 mL min -1 , 5.0 mL min -1 , and 10 mL min -1 The reaction was carried out in the same manner as in Example 1, except that the respective flow rates were changed to As shown in Figure 6, no change in cell voltage was observed over time when the water flow rate was changed. This means that the resistance of the unit membrane remained at 1.1 Ω, and the overpotential of the catalytic reaction also showed almost no change. As shown in Figure 7, the lower the water flow rate, the higher the concentration of hydrogen peroxide in the recovered hydrogen peroxide solution. -1 The hydrogen peroxide concentration in the following cases appears to be higher, but this is because the content of water as a solvent is lower. In other words, it was found that hydrogen peroxide solution of the desired concentration can be produced by adjusting the water flow rate. As shown in Figure 8, it was found that the reaction could be carried out with high current efficiency regardless of whether the water flow rate was low or high. -1Although the current efficiency appears to be low in the case of , this is because the recovery of hydrogen peroxide does not proceed fast enough when the water flow rate is low, resulting in decomposition of hydrogen peroxide. However, even when the water flow rate is low, the current efficiency was found to be higher than that of the conventional technology. In addition, when the water flow rate is 0.50 mL min -1 It was found that the current efficiency of hydrogen peroxide can be increased by making the value larger than 1 / 2. From the above, it was found that no increase in resistance was observed due to differences in water flow rate, and that by changing the flow rate, it was possible to produce hydrogen peroxide water of the desired concentration while maintaining high current efficiency. [Industrial Applicability]

[0068] The reactor of the present invention and the method for producing a compound using the reactor of the present invention can easily and efficiently produce hydrogen peroxide from chemicals, particularly water, and can therefore be used to produce useful compounds in the chemical industry, particularly hydrogen peroxide from water. [Explanation of symbols]

[0069] 1, 9, 10, 11 Reactor 2 unit membrane 3. Anode film 4 Porous electrolyte membrane 5. Cathode membrane 6a Supply pipe 6b Collection pipe 7 Lead Wires 8 Cathode Chamber

Claims

1. A reactor comprising a unit membrane in which a porous anode membrane, a porous electrolyte membrane, and a porous cathode membrane are stacked in this order, The unit membranes are interconnected through pores, The cathode membrane is a reactor configured to react a reducible substance with electrons produced by the anode membrane to produce a compound.

2. The reactor of claim 1 , wherein the anode membrane generates the electrons according to the reaction of formula (I): 2H ２ O→O ２ +4H ＋ +4e － ・・・(@)

3. 10. The reactor of claim 1, wherein the compound is at least one of hydrogen peroxide, formic acid, methanol, acetic acid, ethanol, and urea.

4. 2. The reaction device according to claim 1, wherein the cathode membrane generates at least one of hydrogen peroxide, formic acid, methanol, acetic acid, ethanol, and urea as the compound by at least one reaction of the following formulas (II) to (VII): Oh ２ +2H ＋ +2e － →H ２ Oh ２ ・・・(II) CO ２ +2H ＋ +2e － →HCO ２ H ・・・(---) CO ２ +6H ＋ +6e － →CH ３ OH+H ２ O ・・・(IV) 2.2 ２ +8H ＋ +8e － →CH ３ CO ２ H+2H ２ O ・・・(V) 2CO ２ +8H ＋ +8e － →CH ３ CH ２ OH+H ２ O ・・・(VI) CO ２ +2NO ３ － +18H ＋ +16e － →[(EX ２ ) ２ +7H ２ O ・・・(O-I)

5. 10. The reactor of claim 1, wherein the anode membrane is a catalytic electrode comprising a porous conductive support and an anode active material.

6. 10. The reactor of claim 1, wherein the cathode membrane is a catalytic electrode comprising a porous conductive support and a cathode active material.

7. 6. The reactor according to claim 5, wherein the anode active material is an electrode that utilizes electrical energy or light energy to promote the reaction of formula (I).

8. The cathode membrane is a catalytic electrode comprising a porous conductive support and a cathode active material.

5. The reactor according to claim 4, wherein the cathode active material is an electrode that utilizes electrical energy or light energy to promote at least one reaction of formulas (II) to (VII).

9. 2. The reactor according to claim 1, wherein the porous electrolyte membrane is an ion conductor that does not have electronic conductivity and has a porous structure that does not prevent gas permeation.

10. 2. The reaction apparatus according to claim 1, further comprising a supply pipe for supplying a liquid into the unit membrane, and a recovery pipe for recovering the compound solution.

11. A method for producing a compound, using the reaction apparatus according to any one of claims 1 to 10.

12. 12. A process for producing the compound of claim 11, which is continuous.

13. 12. A method for producing the compound according to claim 11, comprising supplying a liquid into the unit membrane and recovering the solution of the compound.

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