WO2022210925A1 - アンモニアの製造装置における触媒の再生方法 - Google Patents

アンモニアの製造装置における触媒の再生方法 Download PDF

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WO2022210925A1
WO2022210925A1 PCT/JP2022/016148 JP2022016148W WO2022210925A1 WO 2022210925 A1 WO2022210925 A1 WO 2022210925A1 JP 2022016148 W JP2022016148 W JP 2022016148W WO 2022210925 A1 WO2022210925 A1 WO 2022210925A1
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group
catalyst
cathode
oxide
catalyst layer
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French (fr)
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仁昭 西林
和也 荒芝
章一 近藤
紀仁 志賀
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Nissan Chemical Corp
University of Tokyo NUC
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University of Tokyo NUC
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/26—Catalysts comprising hydrides, coordination complexes or organic compounds containing in addition, inorganic metal compounds not provided for in groups B01J31/02 - B01J31/24
    • B01J31/34—Catalysts comprising hydrides, coordination complexes or organic compounds containing in addition, inorganic metal compounds not provided for in groups B01J31/02 - B01J31/24 of chromium, molybdenum or tungsten
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/40—Regeneration or reactivation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J38/00—Regeneration or reactivation of catalysts, in general
    • B01J38/48—Liquid treating or treating in liquid phase, e.g. dissolved or suspended
    • B01J38/50—Liquid treating or treating in liquid phase, e.g. dissolved or suspended using organic liquids
    • B01J38/54—Liquid treating or treating in liquid phase, e.g. dissolved or suspended using organic liquids halogen-containing
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C1/00—Ammonia; Compounds thereof
    • C01C1/02—Preparation, purification or separation of ammonia
    • C01C1/04—Preparation of ammonia by synthesis
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/27—Ammonia
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/091—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
    • C25B11/095—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds at least one of the compounds being organic

Definitions

  • the present invention relates to a method for regenerating a catalyst in a cathode catalyst layer of an ammonia production apparatus.
  • Non-Patent Document 1 In a method for producing ammonia from nitrogen molecules by electrolysis in a low temperature range, there is a reported example of producing ammonia by electrolysis at 90° C. using a platinum electrode as an anode and a cathode in which ruthenium is supported on carbon felt.
  • Non-Patent Document 2 There is a reported example of producing ammonia by electrolysis using Sm 1.5 Sr 0.5 CoO 4 or the like as an ammonia generating electrode.
  • Non-Patent Documents 3 samarium (II) iodide as a reducing agent and alcohols or water as a proton source. It has been reported that ammonia was produced using a molybdenum complex supported on polystyrene resin (Non-Patent Document 4).
  • Non-Patent Documents 1 and 2 report on technologies related to the electrolytic synthesis of ammonia, they do not report on measures to be taken when the reaction device that carries out the electrolytic synthesis is inactivated.
  • Non-Patent Documents 3 and 4 report technologies related to ammonia batch reactions, but no research has been conducted on methods for regenerating or recycling catalysts charged in batch reactions.
  • the present invention has been made to solve the above-mentioned problems, and its main object is a method for regenerating a catalyst in a cathode catalyst layer of a manufacturing apparatus for electrosynthesizing ammonia.
  • the present inventors combined a highly oxophilic compound with the molybdenum complex to regenerate the deactivated catalyst in the cathode catalyst layer of a production apparatus for electrosynthesizing ammonia.
  • the present inventors have found that the deactivated molybdenum complex can be regenerated by feeding the oxo complex having a double bond with oxygen from the electrolyte bath of the cathode catalyst layer and performing a deoxygenation reaction, thereby completing the present invention.
  • the present invention based on these findings is, for example, as follows. [1] In the presence of a molybdenum complex and a cathode solid catalyst, electrons from a power source, ions from an ion source, and nitrogen molecules from a means for supplying nitrogen gas are donated in a cathode catalyst layer of a manufacturing apparatus that performs electrolysis.
  • a method for producing ammonia from nitrogen molecules comprising:
  • the molybdenum complex is (A) 2,6-bis(dialkylphosphinomethyl)pyridine as a PNP ligand (provided that the two alkyl groups may be the same or different, and at least one hydrogen atom of the pyridine ring is an alkyl group, an alkoxy group or a molybdenum complex having a halogen atom), (B) N,N-bis(dialkylphosphinomethyl)dihydrobenzimidazolidene as a PCP ligand (provided that the two alkyl groups may be the same or different, and at least one hydrogen atom of the benzene ring is an alkyl group , optionally substituted by an alkoxy group or a halogen atom), a molybdenum complex having (C) a molybdenum complex having a bis(dialkylphosphinoethyl)arylphosphine as a P
  • the molybdenum complex (A) has the following formula (A1), (A2) or (A3) (wherein R 1 and R 2 are each an alkyl group that may be the same or different, X is an iodine atom, a bromine atom or a chlorine atom, and at least one hydrogen atom on the pyridine ring is an alkyl
  • the molybdenum complex (B) is represented by the following formula (B1) or (B2) (wherein R 1 and R 2 are each an alkyl group which may be the same or different, X is an iodine atom, a bromine atom or a chlorine atom, and at least one hydrogen atom on the benzene ring is an alkyl optionally substituted with a group, an alkoxy group or a halogen atom, and at least one of R 3 and R 4 is substituted with a trifluoromethyl group).
  • the molybdenum complex of (C) has the formula (C1) (wherein R 1 and R 2 are alkyl groups that may be the same or different, R 5 is an aryl group, and X is an iodine atom, a bromine atom or a chlorine atom)
  • the molybdenum complex (D) has the formula (D1) or (D2) (Wherein, R 5 and R 6 are aryl groups that may be the same or different, R 7 is an alkyl group, and n is 2 or 3).
  • the deactivated catalyst in the cathode catalyst layer can be reactivated due to oxygen mixed in from the electrolytic solution or nitrogen gas during continuous operation.
  • the ammonia production equipment can be used continuously.
  • FIG. 1 is an explanatory diagram of an ammonia electrolyzer (No. 1);
  • FIG. FIG. 2 is an explanatory diagram of an ammonia electrolyzer (No. 2); It is explanatory drawing of the electrolytic device (3) of ammonia. It is explanatory drawing of the electrolytic device (4) of ammonia.
  • n- is normal, “s-” is secondary, “t-” is tertiary, “o-” is ortho, “m-” is meta, and “p-” is Para, “Me” for a methyl group, “t-Bu” for a t-butyl group, “Ph” for a phenyl group, “S” for a sulfur atom, “O” for an oxygen atom, “Si” represents a silicon atom, and "thf” and “THF” represent tetrahydrofuran.
  • C a -C b alkyl group is a monovalent alkyl group produced by losing one hydrogen atom from a linear, branched or cyclic aliphatic hydrocarbon having a to b carbon atoms.
  • n-octyl group represents a group such as methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, cyclobutyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, 1,1-dimethylpropyl group, cyclopentyl group, n-hexyl group, isohexyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, cyclohexyl group, n-heptyl group, 2-methylhexyl group, 3-ethylpentyl group, n-octyl group, 2,2,4-trimethylpentyl group, 2,5-dimethylhex
  • a C a -C b alkoxy group represents a monovalent group in which the above-described alkyl group having a to b carbon atoms is bonded to oxygen, for example, a methoxy group , ethoxy group, n-propoxy group, isopropoxy group, cyclopropoxy group, n-butoxy group, isobutoxy group, s-butoxy group, t-butoxy group, cyclobutoxy group, n-pentoxy group, isopentoxy group, neopentoxy group, t-pentoxy group, 1,1-dimethylpropoxy group, cyclopentoxy group, n-hexythoxy group, isohexyxy group, 3-methylpentoxy group, 2,2-dimethylbutoxy group, 2,3-dimethylbutoxy group, cyclohexy Specific examples include thoxy group, n-heptoxy group, 2-methylhexyoxy group, 3-ethylp
  • halogen atoms in the present specification include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like.
  • Ar 6 aryl group in this specification represents a monovalent group formed by losing one hydrogen atom from an aromatic ring of an aromatic hydrocarbon having 6 carbon atoms, such as a phenyl group, from the 2-position
  • examples thereof include a phenyl group having a substituent at least one of the 6-positions.
  • Substituents on the aromatic ring of Ar 6 aryl include halogen atoms such as fluoro, chloro, bromo and iodo groups, methyl group, trifluoromethyl group, ethyl group, n-propyl group and isopropyl group, Examples include n-butyl, isobutyl, s-butyl and t-butyl groups.
  • Ar 6 aryl groups include a phenyl group, o-fluorophenyl group, m-fluorophenyl group, p-fluorophenyl group, o-trifluoromethylphenyl group, m-trifluoromethylphenyl group, p-trifluorophenyl group, fluoromethylphenyl group, o-chlorophenyl group, m-chlorophenyl group, p-chlorophenyl group, o-bromophenyl group, m-bromophenyl group, p-bromophenyl group, o-tolyl group, m-tolyl group, p- tolyl group, o-ethylphenyl group, m-ethylphenyl group, p-ethylphenyl group, o-(t-butyl)phenyl group, m-(t-butyl)phenyl group, m-
  • the compound having oxygenophilicity can be at least one selected from the group consisting of lanthanide metal halides, organoaluminum compounds and organic boron compounds, and the selected oxygenophilic compound can be used. It is also possible to use a plurality of them in combination.
  • Examples of the oxophilic compound of the present embodiment include lanthanide metal halides, organoaluminum compounds and organoboron compounds, and these compounds can be used by dissolving them in an organic solvent. .
  • Examples of the lanthanide metal halides of the present embodiment include samarium (II) halide, europium (II) halide, ytterbium (II) halide, and tetrahydrofuran-coordinated complexes of the above compounds.
  • a tetrahydrofuran-coordinated complex of samarium (II) iodide and samarium (II) iodide (for example, SmI 2 (thf) 2 ) can be obtained by dissolving SmI 2 in tetrahydrofuran and recrystallizing it. can be done) is more preferable.
  • lanthanide metal halides such as EuCl 2 , EuI 2 , SmI 2 and YbI 2 are available from Sigma-Aldrich Japan.
  • Samarium (II) iodide 0.1 mol/L tetrahydrofuran solution is available from Tokyo Chemical Industry Co., Ltd.
  • organoaluminum compounds include trimethylaluminum, triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride, sodium bis(2-methoxyethoxy)aluminum hydride, and mixtures thereof.
  • organic boron compounds include triethylborane, (R)-5,5-diphenyl-2-methyl-3,4-propano-1,3,2-oxazaborolidine, triisopropyl borate, 2-iso Propoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, bis(hexyleneglycolato)diboron, 4-(4,4,5,5-tetramethyl-1,3,2- dioxaborolan-2-yl)-1H-pyrazole, tert-butyl-N-[4-(4,4,5,5-tetramethyl-1,2,3-dioxaborolan-2-yl)phenyl]carbamate, phenylboron acid, 3-acetylphenylboronic acid, boron trifluoride acetic acid complex, boron trifluoride sulfolane complex, 2-thiophene boronic acid, tris(trimethylsilyl)borate, lithium boron
  • ether compounds include cyclic ether compounds such as tetrahydrofuran (thf), 4-methyltetrahydropyran, tetrahydropyran-4-methanol and 1,4-dioxane, as well as diethyl ether, diisopropyl ether and 1,2-dimethoxyethane. , and chain ether compounds such as cyclopentyl methyl ether.
  • nitrile compounds include acetonitrile and propionitrile.
  • hydrocarbon compounds examples include aromatic hydrocarbon compounds such as toluene and o-xylene, and saturated hydrocarbon compounds such as hexane, heptane and petroleum ether.
  • a preferable solvent in the method for producing ammonia of the present embodiment is tetrahydrofuran.
  • the regeneration of the catalyst in the cathode catalyst layer using the compound having oxygenophilicity according to the present embodiment is carried out in the cathode catalyst layer described below. can be implemented.
  • a dilute sulfuric acid aqueous solution, water, or the like is often used in the electrolyte bath. It is preferable to extract and add a compound having oxygenophilicity. In order to promote the deoxidation reaction of the deactivated catalyst of the cathode catalyst layer, the compound having oxygenophilicity is dissolved in the organic solvent described above. It is more preferable to use
  • the method for producing ammonia according to the present embodiment can be carried out in a production apparatus that performs electrolysis.
  • a production apparatus that performs electrolysis is sometimes referred to as an electrolytic apparatus, and is composed of an electrolytic cell, a nitrogen gas supply means, an ammonia recovery means, and an exhaust gas removal means. Details of the electrolytic apparatus will be described later.
  • the electrolytic cell is composed of an electrode, an electrolyte bath, a nitrogen gas supply port, and an exhaust gas outlet.
  • the anode is the electrode in which the oxidation reaction occurs
  • the cathode is the electrode in which the reduction reaction occurs.
  • the molybdenum complex in the method for producing ammonia of the present embodiment will be described.
  • the molybdenum complex (A) for example, the formula (A1), (A2) or (A3) (wherein R 1 and R 2 are each an alkyl group that may be the same or different, X is an iodine atom, a bromine atom or a chlorine atom, and at least one hydrogen atom on the pyridine ring is an alkyl optionally substituted with a group, an alkoxy group or a halogen atom).
  • the alkyl group, alkoxy group and halogen atom include the same ones as those already exemplified.
  • R 1 and R 2 are preferably bulky alkyl groups such as t-butyl, isopropyl or cyclohexyl.
  • the hydrogen atoms on the pyridine ring are preferably unsubstituted or substituted with a C 1 -C 10 alkyl group, a C 1 -C 8 alkoxy group or a benzyloxy group at the 4-position hydrogen atom.
  • More preferred alkoxy groups include benzyloxy groups in which at least one hydrogen atom on the benzene ring is substituted with a resin, and the resins include chloromethyl resins (e.g., polymer-bound 5-[4-(chloro methyl)phenyl]pentyl]styrene, polymer-bound 4-(benzyloxy)benzyl chloride, polymer-bound 4-methoxybenzhydryl chloride), (chloromethyl)polystyrene, Merrifield resin, JandaJel-Cl (registered trademark), etc. is mentioned. Of these, (chloromethyl)polystyrene, Merrifield resin and JandaJel-Cl® are preferred.
  • chloromethyl resins e.g., polymer-bound 5-[4-(chloro methyl)phenyl]pentyl]styrene, polymer-bound 4-(benzyloxy)benzyl chloride, polymer-bound 4-methoxybenz
  • the molybdenum complex (B) will be described.
  • the molybdenum complex (B) is represented by the following formula (B1) or (B2) (wherein R 1 and R 2 are each a C 1 -C 10 alkyl group which may be the same or different, X is an iodine atom, a bromine atom or a chlorine atom, and the molybdenum complex of (B1) at least one hydrogen atom on the benzene ring of may be substituted with a C 1 -C 10 alkyl group, a C 1 -C 8 alkoxy group or a halogen atom).
  • Examples of the C 1 -C 10 alkyl group, the C 1 -C 8 alkoxy group and the halogen atom include those already exemplified.
  • R 1 and R 2 are preferably bulky alkyl groups such as t-butyl, isopropyl or cyclohexyl.
  • R 3 and R 4 in the molybdenum complex of (B2) each independently represent an electron withdrawing group, and R 3 and R 4 may be electron withdrawing groups, and when R 3 is an electron withdrawing group , R 4 may be a hydrogen atom.
  • An electron-withdrawing group is also called an electron-withdrawing group or an electron-accepting group. It is a theory that focuses on changes in the electron density and bonding state of a substance and tries to interpret it as unified as possible. By effect, it refers to a substituent that attracts electrons from the bonding electron side compared to a hydrogen atom.
  • Examples of the electron-withdrawing group include substituents that have an electron-donating mesomeric effect but that greatly contribute to the electron-withdrawing inductive effect, and substituents that have electron-withdrawing mesomeric and inductive effects.
  • substituents that contribute significantly to the electron-withdrawing properties of the inductive effect include fluorine, chlorine, bromine, iodine, —CH 2 Cl, or —CH ⁇ CHNO 2 .
  • substituents having electron-withdrawing mesomeric and inductive effects include quaternary ammonium groups, trifluoromethyl groups, perfluoroalkyl groups, trichloromethyl groups, and cyano groups with anions as counterions.
  • quaternary ammonium group examples include trialkylammonium groups, such as trimethylammonium group, triethylammonium group, tributyl An ammonium group etc. are mentioned.
  • Counter ions for the nitrogen atoms constituting the quaternary ammonium group include hexafluorophosphate ion, hexachloroantimonate ion, trifluoromethanesulfonate ion, tetrafluoroborate ion, phosphate ion, sulfonate ion, chloride, bromide, iodide, hydroxide and the like.
  • R 3 and R 4 are preferably a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and a trifluoromethyl group, more preferably a chlorine atom and a trifluoromethyl group.
  • the molybdenum complex (C) will be described.
  • the molybdenum complex of (C) for example, the formula (C1) (wherein R 1 and R 2 are C 1 -C 10 alkyl groups which may be the same or different, R 5 is an Ar 6 aryl group, X is an iodine atom, a bromine atom or a chlorine is an atom).
  • R 1 and R 2 are preferably bulky alkyl groups such as t-butyl, isopropyl or cyclohexyl.
  • a phenyl group is preferred as R5 .
  • the molybdenum complex (D) will be described.
  • the formula (D1) or (D2) (wherein R 5 and R 6 are Ar 6 aryl groups, which may be the same or different, R 7 is a C 1 -C 10 alkyl group, and n is 2 or 3); Molybdenum complexes represented by The Ar 6 aryl group and the C 1 -C 10 alkyl group are the same as those already exemplified.
  • R 5 and R 6 are phenyl groups and R 7 is a C 1 -C 4 alkyl group.
  • R 5 and R 6 are phenyl groups and n is 2.
  • the solid catalyst in the method for producing ammonia of the present embodiment is a metal catalyst having a single composition or a mixture of a plurality of metal components such as an alloy catalyst, and a metal oxide of a typical element.
  • metal catalysts and oxides it may be used as a solid catalyst in combination with a catalyst.
  • the solid catalyst may be used as an electron conductor, and the oxide catalyst may be used as a support for the metal catalyst.
  • Examples of solid catalysts in the method for producing ammonia of the present embodiment include metal catalysts such as platinum catalysts, gold catalysts, silver catalysts, ruthenium catalysts, iridium catalysts, rhodium catalysts, palladium catalysts, osmium catalysts, tungsten catalysts, and lead catalysts. , iron catalysts, chromium catalysts, cobalt catalysts, nickel catalysts, manganese catalysts, vanadium catalysts, molybdenum catalysts, gallium catalysts, aluminum catalysts, and alloys thereof.
  • Examples of oxide catalysts include aluminum oxide and zirconium oxide.
  • the solid catalyst used on the cathode side is defined as a cathode solid catalyst
  • preferable cathode solid catalysts are platinum catalyst, gold catalyst, iridium catalyst, palladium catalyst, molybdenum catalyst, zinc oxide, aluminum oxide, molybdenum oxide, and cerium oxide.
  • platinum catalyst gold catalyst, iridium catalyst, palladium catalyst, molybdenum catalyst, zinc oxide, aluminum oxide, molybdenum oxide, and cerium oxide.
  • samarium oxide more preferably platinum catalyst, gold catalyst, zinc oxide, aluminum oxide, cerium oxide and samarium oxide, still more preferably platinum catalyst, gold catalyst, aluminum oxide, molybdenum oxide, and samarium oxide.
  • the catalyst carrier in the cathode catalyst layer 103 of this embodiment may be responsible for at least one of electronic conduction and ion conduction, and is not particularly limited as long as it supports the catalyst of this embodiment.
  • Ion-conducting substances include at least one of protons and hydroxonium ions, or hydroxide ions.
  • catalyst carriers include carbon black, carbon nanotubes, carbon materials, metal meshes, metal foams, metal oxides, multiple oxides, polymer electrolytes, and ionic liquids. may be used in combination. Further, when the catalyst carrier is used in the electrode, it not only plays the role of supporting the catalyst, but also participates as a catalyst or co-catalyst in the reaction occurring at the electrode.
  • Examples of carbon black as a catalyst carrier in the cathode catalyst layer 103 of the present embodiment include Ketjen black, Ketjen black EC, channel black, oil furnace black, vulcan, furnace black, thermal black, acetylene black, and lamp black. , graphitized black, oxide black, etc., and acetylene black, Ketjenblack, and Ketjenblack EC are preferred, and Ketjenblack and Ketjenblack EC are more preferred because of their good conductivity.
  • One type of carbon black may be used alone, or two or more types may be used in combination. Carbon black may be surface-treated.
  • carbon nanotubes for example, vapor growth, catalytic vapor growth, catalytic chemical vapor deposition, chemical vapor deposition, super multiplication, catalytic carbon deposition, arc discharge, laser evaporation, etc.
  • the resulting single-walled nanotubes and multi-walled carbon nanotubes can be exemplified, and these can take any form such as a needle-like, coil-like, or tube-like form.
  • the carbon nanotube tube it has a cylindrical shape by winding one sheet of graphite with a carbon hexagonal network surface, and it is a multi-wall carbon nanotube wound in three or more layers (multi-wall carbon nanotube), one of graphite.
  • Single-walled carbon nanotube single-walled carbon nanotube: SWNT
  • double-walled carbon nanotube double-walled carbon nanotube
  • VGCF vapor-grown carbon fiber
  • TC series such as TC-2010, TC-2020, TC-3210L, TC-1210LN (manufactured by Toda Kogyo Co., Ltd.), spur growth method CNT (National Research and Development Agency New Energy and Industrial Technology Development Organization ), eDIPS-CNT (manufactured by the New Energy and Industrial Technology Development Organization), SWNT series (manufactured by Meijo Nano Carbon Co., Ltd.: product name), VGCF such as VGCF, VGCF-H, and VGCF-X ( Registered trademark) series (manufactured by Showa Denko Co., Ltd.: registered trademark), FloTube series (manufactured by CNano Technology: trade name), AMC (manufactured by Ube Industries, Ltd.: trade name), NANOCYL NC7000 series (manufactured by Nanocyl SA: Baytubes (manufactured by Bayer: trade name), GRAPHISTRENGTH (manufactured by Arke
  • Examples of the carbon material as the catalyst carrier in the cathode catalyst layer 103 of the present embodiment include activated carbon obtained by carbonizing and activating materials containing various carbon atoms, coke, natural graphite, artificial graphite, graphitized carbon, and the like. be done.
  • the metal mesh as the catalyst carrier in the cathode catalyst layer 103 of the present embodiment includes metal meshes of nickel, titanium, zirconium, etc., and metal meshes of zirconium are preferable.
  • Examples of the metal foam as the catalyst carrier in the cathode catalyst layer 103 of the present embodiment include metal foams such as aluminum, magnesium, titanium, zirconium, zinc, iron, tin, lead, and alloys containing these. , a metal foam of zirconium is preferred.
  • Metal oxides as catalyst carriers in the cathode catalyst layer 103 of the present embodiment include, for example, aluminum oxide, zirconium oxide, titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, oxide Copper, zinc oxide, niobium pentoxide, molybdenum oxide, ruthenium oxide, rhodium oxide, silver oxide, tantalum oxide, tungsten oxide, osmium oxide, iridium oxide, indium oxide, cerium oxide, samarium oxide, platinum oxide, gold oxide, magnesium oxide or silica and the like, preferably aluminum oxide, iron oxide, copper oxide, zinc oxide, molybdenum oxide, tungsten oxide, cerium oxide, samarium oxide and silica; aluminum oxide, zinc oxide, molybdenum oxide, cerium oxide, samarium oxide and Silica is more preferred.
  • Examples of the composite oxide as the catalyst carrier in the cathode catalyst layer 103 of the present embodiment include silica-alumina, silica-magnesia, etc. Silica-alumina is preferred.
  • Examples of the polymer electrolyte as the catalyst carrier in the cathode catalyst layer 103 of this embodiment include fluorine-based polymer electrolytes, hydrocarbon-based polymer electrolytes, anion-conducting electrolytes, and the like.
  • fluorine-based polymer electrolytes include fluorine-based sulfonic acid polymers such as DuPont's Nafion (registered trademark), Solvay's Aquivion (registered trademark), AGC's Flemion (registered trademark), and partially fluorine-based carbonization.
  • Examples include hydrogen-based sulfonic acid polymers.
  • Hydrocarbon polymer electrolytes include, for example, sulfonated polyetherketone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polysulfide, and sulfonated polyphenylene.
  • anion-conducting electrolyte Fumion (registered trademark) FAA-3-SOLUT-10 manufactured by Fumasep, A3ver.
  • AS-4 (A3ver.2 and AS-4 are described in, for example, the magazine "Hydrogen Energy System", Vo1.35, No.2, 2010, page 9.), and the electrolyte membrane described later
  • a cation exchange membrane hereinafter also referred to as a cation exchange membrane
  • Nafion registered trademark
  • Aquivion registered trademark
  • an anion exchange membrane hereinafter also referred to as an anion exchange membrane
  • Examples of the ionic liquid as a catalyst carrier in the cathode catalyst layer 103 of this embodiment include imidazolium salts, pyridinium salts, ammonium salts, phosphonium salts, pyrrolidinium salts, piperidinium salts, sulfonium salts, and the like.
  • Specific examples of imidazolium salts include formula (IL1): Those represented by are mentioned.
  • R 1a to R 5a may be the same or different, and may each be a hydrogen atom, a C 1 to C 10 alkyl group, an allyl group, or a vinyl group.
  • anion X a- in formula (IL1) include fluorine ion, chloride ion, bromide ion, iodine ion, tetrafluoroborate, trifluoro(trifluoromethyl)borate, dimethylphosphate ion, diethyl Phosphate ion, hexafluorophosphate, tris(pentafluoroethyl)trifluorophosphate, trifluoroacetate, methylsulfate, ethylsulfate, trifluoromethanesulfonate, bis(trifluoromethanesulfonyl)imide, hydrogen sulfate ion, etc. mentioned.
  • cations in formula (IL1) include 1-allyl-3-methylimidazolium ion, 3-ethyl-1-vinylimidazolium ion, 1-methylimidazolium ion, and 1-ethylimidazolium ion.
  • pyridinium salts include formula (IL2): Those represented by are mentioned.
  • R 1b to R 6b may be the same or different, and each includes a hydrogen atom, a hydroxymethyl group, or a C 1 to C 6 alkyl group.
  • examples of the anion X a — in formula (IL2) include the same ones as in formula (IL1).
  • cations in formula (IL2) include, for example, 1-butyl-3-methylpyridinium ion, 1-butyl-4-methylpyridinium ion, 1-butyl-pyridinium ion, 1-ethyl-3-methylpyridinium ion. and salts of pyridinium ions such as 1-ethylpyridinium ion, 1-ethyl-3-(hydroxymethyl)pyridinium ion, and X a- in the formula (IL1).
  • ammonium salts include formula (IL3): Those represented by are mentioned.
  • R 1c to R 4c may be the same or different and are each a hydrogen atom, a methoxyethyl group, a phenylethyl group, a methoxypropyl group, a cyclohexyl group, or a C 1 -C 8 alkyl group. groups. Further, examples of the anion X a- in formula (IL3) include the same ones as in formula (IL1).
  • cations in formula (IL3) include, for example, triethylpentylammonium ion, diethyl(methyl)propylammonium ion, methyltri-n-octylammonium ion, trimethylpropylammonium ion, cyclohexyltrimethylammonium ion, diethyl(2- methoxyethyl)-methylammonium ion, ethyl(2-methoxyethyl)-dimethylammonium ion, ethyl(3-methoxypropyl)dimethyl-ammonium ion, ethyl(dimethyl)(2-phenylethyl)-ammonium ion, tetramethylammonium ion , tetraethylammonium ion, triethylpentylammonium ion, tetra-n-butylammonium
  • phosphonium salts include formula (IL4): Those represented by are mentioned.
  • R 1d to R 4d may be the same or different, and each includes a hydrogen atom, a methoxyethyl group, or a C 1 to C 10 alkyl group.
  • X a- which is an anion in formula (IL4), includes the same ones as in formula (IL1).
  • cations in formula (IL4) include tributylmethylphosphonium ion, tetrabutylphosphonium ion, trihexyl(tetradecyl)phosphonium ion, trihexyl(ethyl)phosphonium ion, tributyl(2-methoxyethyl)-phosphonium ion, and the like. and a salt of X a- in the above formula (IL1).
  • pyrrolidinium salts include formula (IL5): Those represented by are mentioned.
  • R 1e to R 2e may be the same or different, and each includes a hydrogen atom, an allyl group, a methoxyethyl group, or a C 1 to C 8 alkyl group. Further, examples of the anion X a- in formula (IL5) include the same ones as in formula (IL1).
  • cations in formula (IL5) include, for example, 1-allyl-1-methylpyrrolidinium ion, 1-(2-methoxyethyl)-1-methylpyrrolidinium ion, 1-butyl-1-methylpyrroli Pyrrolidinium ion such as dinium ion, 1-methyl-1-propylpyrrolidinium ion, 1-octyl-1-methylpyrrolidinium ion, 1-hexyl-1-methylpyrrolidinium ion and X a- in formula (IL1) and salt.
  • piperidinium salts include formula (IL6): Those represented by are mentioned.
  • R 1f to R 2f may be the same or different, and each includes a hydrogen atom or a C 1 to C 6 alkyl group. Further, examples of the anion X a- in formula (IL6) include the same ones as in formula (IL1).
  • cations in formula (IL6) include piperidinium ions such as 1-butyl-1-methylpiperidinium ion and 1-methyl-1-propylpiperidinium ion and X a in formula (IL1). - and salts.
  • sulfonium salts include formula (IL7): Those represented by are mentioned.
  • R 1g to R 3g may be the same or different, and each includes a hydrogen atom or a C 1 to C 4 alkyl group. Further, examples of the anion X a- in formula (IL7) include the same as those in formula (IL1).
  • cations in formula (IL7) include salts of sulfonium ions such as triethylsulfonium ion and trisulfonium ion with X a- in formula (IL1).
  • ionic liquid 1-allyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3- Methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium iodide , 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorotrifluorophosphate, 1-butyl-3-methylimidazolium trifluoro(trifluoromethyl)borate, 1-butyl-2,3-dimethylimidazolium lithium trifluoromethanesulfonate, 1-butyl-3-methylimid
  • the catalyst carrier of the present embodiment carbon black, Ketjenblack, Ketjenblack EC, Nafion (registered trademark), aluminum oxide, zinc oxide, molybdenum oxide, cerium oxide, samarium oxide, silica, silica-alumina , 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide, 1-butyl-3-methylimidazolium tris(pentafluoroethyl) Trifluorotrifluorophosphate is preferred.
  • One of these catalyst carriers may be used alone, or two or more may be used in combination.
  • carbon black and aluminum oxide in combination, carbon black and zinc oxide in combination, carbon black and molybdenum oxide, carbon black and cerium oxide, carbon black and samarium oxide, carbon black and silica, Ketjenblack EC and aluminum oxide, Ketjenblack EC and zinc oxide Ketjenblack EC and molybdenum oxide, Ketjenblack EC and cerium oxide, Ketjenblack EC and samarium oxide, and Ketjenblack EC and silica are preferable.
  • the electron conductor in the cathode catalyst layer 103 of the present embodiment is not particularly limited as long as it conducts electrons, and may serve as a catalyst carrier.
  • examples thereof include carbon black, carbon nanotubes, carbon materials, metal meshes, metal foams, and the like, and may be used singly or in combination of two or more.
  • Carbon black, carbon nanotubes, carbon materials, metal Specific examples of the mesh and metal foam are the same as those described in the description of the catalyst carrier herein.
  • the electronic conductor of the present embodiment carbon black, Ketjenblack, Ketjenblack EC, nickel metal mesh, titanium metal mesh and metal foam are used because of their high specific surface area and excellent electronic conductivity.
  • IFPC40 and IFPC40-II manufactured by Ishifuku Metal Industry Co., Ltd., TEC10E40E, TEC10E50E, TEC10E60TPM, TEC10E70TPM, TEC10V30E, TEC10V40E, TEC10V50E manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., Johnson Matthey Fuels. ⁇ HiSPEC4000 manufactured by Japan Co., Ltd., etc. can be mentioned.
  • the electrolyte in the cathode catalyst layer 103 of the embodiment is not particularly limited as long as it is responsible for ion conduction, and examples thereof include cation-exchange electrolytes and anion-exchange electrolytes.
  • cation exchange type electrolytes include fluorine-based polymer electrolytes and hydrocarbon-based polymer electrolytes.
  • fluorine-based polymer electrolytes include fluorine-based sulfonic acid polymers such as DuPont's Nafion (registered trademark), Solvay's Aquivion (registered trademark), AGC's Flemion (registered trademark), and partially fluorine-based carbonization. Examples include hydrogen-based sulfonic acid polymers.
  • Hydrocarbon polymer electrolytes include, for example, sulfonated polyetherketone, sulfonated polyethersulfone, sulfonated polyetherethersulfone, sulfonated polysulfide, and sulfonated polyphenylene.
  • anion-exchange electrolytes include FuMA-Tech's Fumion (registered trademark) FAA-3-SOLUT-10 and Tokuyama's A3ver. 2, AS-4 (A3ver.2 and AS-4 are described, for example, in the magazine "Hydrogen Energy System", Vol. 1.35, No. 2, 2010, page 9).
  • electrolyte in the cathode catalyst layer 103 of the present embodiment when a cation exchange membrane is used as the electrolyte membrane to be described later, an electrolyte that conducts at least one of protons and hydroxonium ions is preferable. trademark) and Aquivion® are preferred.
  • an anion exchange membrane is used as the electrolyte membrane to be described later, it is preferable to conduct hydroxide ions, and FAA-3-SOLUT-10 and AS-4 are preferable.
  • the gas diffusion layer in the cathode catalyst layer 103 of this embodiment is not particularly limited as long as it is responsible for electron conduction, gas diffusion, and electrolyte diffusion. Examples thereof include carbon paper, carbon felt, carbon cloth, and the like.
  • Examples of carbon paper include Toray's TGP-H-060, TGP-H-090, TGP-H-120, TGP-H-060H, TGP-H-090H, TGP-H-120H, Electrochem's EC-TP1-030T, EC-TP1-060T, EC-TP1-090T, EC-TP1-120T, SIGRACET 22BB, 28BC, 36BB, 39BB and the like.
  • Examples of the carbon cloth include EC-CC1-060, EC-CC1-060T, and EC-CCC-060 manufactured by Electrochem Corporation, Torayca (registered trademark) cloth manufactured by Toray Industries, Inc., and CO6142, CO6151B, CO6343, CO6343B, and CO6347B. , CO6644B, CO1302, CO1303, CO5642, CO7354, CO7359B, CK6244C, CK6273C, CK6261C and the like.
  • Examples of carbon felt include H1410 and H2415 manufactured by Freudenberg.
  • TGP-H-060, TGP-H-090, TGP-H-060H, TGP-H-090H, and EC-TP1-060T are preferable for the gas diffusion layer in the cathode catalyst layer 103 of this embodiment.
  • the ion sources arranged in the electrolytic device include, for example, the electrolyte membrane 102 arranged beside the cathode catalyst layer 103, the electrolytic solution derived from the electrolyte membrane, and the
  • the electrolytic solution is a solution containing an electrolyte, and is not particularly limited as long as it can supply ions, which are raw materials for producing ammonia, to the catalyst layer.
  • the ion source is preferably capable of supplying at least one of protons and hydroxonium ions when the environment of the catalyst layer is acidic, and can supply hydroxide ions when the environment of the catalyst layer is alkaline. These ion sources may be used singly or in combination of two or more.
  • solutions in the electrolytic solution in the method for producing ammonia of the present embodiment include water, ionic liquids, methanol, isopropyl alcohol, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, Diethylamine, hexamethylphosphonic acid triamide, acetic acid, acetonitrile, methylene chloride, trifluoroethanol, nitromethane, sulfolane, pyridine, tetrahydrofuran, dimethoxyethane, propylene carbonate, etc., water and ionic liquids are preferred.
  • Examples of the ionic liquid as a solution in the electrolytic solution in the ammonia production method of the present embodiment include imidazolium salts, pyridinium salts, ammonium salts, phosphonium salts, pyrrolidinium salts, piperidinium salts, sulfonium salts, and the like. mentioned.
  • an acid or a base to the ionic liquid as a solution in the electrolytic solution in the ammonia production method of the present embodiment, and when using a cation exchange membrane as the electrolyte membrane described later, an acid can be added.
  • an acid can be added.
  • a base specifically sodium hydroxide, potassium hydroxide etc.
  • Preferred ionic liquids to be added with acid or base are 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazolium tris(pentafluoroethyl)trifluorotrifluorophosphate.
  • Examples of the electrolyte contained in the electrolytic solution in the method for producing ammonia of the present embodiment include protons, hydronium ions, lithium ions, sodium ions, potassium ions, imidazolium ions, pyridinium ions, ammonium ions, phosphonium ions, pylori cations such as dinium ion, piperidinium ion, or sulfonium ion, or cations in which a plurality of such cations are combined; ) borate, dimethyl phosphate ion, diethyl phosphate ion, hexafluorophosphate, tris(pentafluoroethyl)trifluorophosphate, trifluoroacetate, methylsulfate, trifluoromethanesulfonate, bis(trifluoromethanesulfonyl)imide, Anions such as perchlorate ions, hydrogensulfate ions, sulfate
  • imidazolium ions, pyridinium ions, ammonium ions, phosphonium ions, pyrrolidinium ions, piperidinium ions and sulfonium ions as electrolytes contained in the electrolytic solution in the method for producing ammonia of the present embodiment are represented by the above formula (IL1) to (IL7) include cations described in formulas (IL7).
  • the cation that is the electrolyte contained in the electrolytic solution in the method for producing ammonia of the present embodiment is preferably proton, hydronium ion, imidazolium ion, pyrrolidinium ion, and the anion that is the electrolyte is hydroxide ion, peroxide Chlorate ion, hydrogen sulfate ion and sulfate ion are preferred.
  • Catholyte electrolyte 106 used in cathode electrolyte tank 105 of the present embodiment is preferably water, aqueous sulfuric acid solution, 1-butyl-3-methyl Imidazolium bis(trifluoromethanesulfonyl) imides may be mentioned, and one kind may be used alone or two or more kinds may be used in combination.
  • an anion exchange membrane is used as the electrolyte membrane to be described later, specific examples include water, an aqueous sodium hydroxide solution, and an aqueous potassium hydroxide solution.
  • Preferred examples of the anode electrolyte 116 used in the anode electrolyte tank 115 of the present embodiment include water and an aqueous solution of sulfuric acid when a cation exchange membrane is used as the electrolyte membrane described later.
  • a cation exchange membrane is used as the electrolyte membrane described later.
  • water, an aqueous sodium hydroxide solution, and an aqueous potassium hydroxide solution can be mentioned.
  • Examples of the electrolyte membrane 102 in the method for producing ammonia of the present embodiment include polymer electrolyte membranes and reinforcing membranes.
  • a bipolar membrane and a mosaic charged membrane can be mentioned as composite charged membranes having a structure of a cation exchange membrane and an anion exchange membrane in one membrane.
  • electrolyte membranes include Nafion membrane (registered trademark) from DuPont, Aquivion membrane (registered trademark) from Solvay, Flemion membrane (registered trademark) from AGC, Aciplex (registered trademark) from Asahi Kasei, Dow Dow membrane (registered trademark) of the company, sulfonated polyether ketone polymer membrane, sulfonated polyether sulfone polymer membrane, sulfonated polyether ether sulfone polymer membrane, sulfonated polysulfide polymer membrane, sulfonated polyphenylene polymer membrane, poly as reinforcement Gore select membrane (registered trademark) of Gore Japan LLC impregnated with perfluorosulfonic acid polymer using tetrafluoroethylene (PTFE) porous material, membrane reinforced with PTFE woven fabric, polyethylene (PE) porous material and polypropylene ( PP) Membrane
  • PTFE te
  • Nafion membrane registered trademark
  • Aquivion membrane registered trademark
  • Gore Select membrane from Gore Japan LLC.
  • FAP-450 membrane of Fumasep membrane (registered trademark) of FuMA-Tech, FAA-3 membrane, ASVN membrane of Selemion membrane (registered trademark) of AGC, and AHO films are preferred.
  • the electrolyte membrane 102 in the ammonia production method of the present embodiment is more preferably Nafion membrane (registered trademark) and Aquivion membrane (registered trademark) of cation exchange membranes.
  • the reaction temperature in the ammonia production method of the present embodiment is not limited as long as the reaction proceeds, but is preferably -40°C to 120°C, more preferably -20°C to 80°C, and -5°C to 50°C. Even more preferred.
  • the reaction atmosphere in the ammonia production method of the present embodiment is usually carried out in a normal pressure atmosphere, but it can also be carried out in a pressurized atmosphere, and the outline is the ammonia production method and production apparatus described later. Explanation will be given with an electrolysis apparatus.
  • the reaction time in the method for producing ammonia of the present embodiment is not particularly limited, but usually it may be set in the range of several tens of minutes to several tens of hours, and it is possible to carry out the reaction continuously. It is also possible to stop the reaction in the middle. For example, after performing the reaction for several hours, it is possible to temporarily stop the reaction and then perform the reaction again.
  • FIG. 1 shows an ammonia electrolyzer (Part 1) 100 of Example 1 for producing ammonia
  • FIG. 2 shows an ammonia electrolyzer (Part 2) 200 of Example 2 for producing ammonia
  • An ammonia electrolysis apparatus (part 3) 300 of Example 3 for producing ammonia and an ammonia electrolysis apparatus (part 4) 400 of Example 4 for producing ammonia are shown in FIG. 4, respectively.
  • An ammonia electrolysis apparatus (part 1) 100 of the present embodiment includes a cathode 108 and an anode 118, and a membrane electrode assembly 131 in which a cathode catalyst layer 103 and an anode catalyst layer 113 are integrated via an electrolyte membrane 102.
  • Ammonia production equipment A cathode catalyst layer 103 is bonded to one side of the electrolyte membrane 102, and a cathode current collector 104 is arranged on the outside thereof, and an anode catalyst layer 113 is bonded to the other side of the electrolyte membrane 102, and the outside thereof.
  • the anode current collector 114 is arranged in the .
  • the cathode catalyst layer 103 comprises a molybdenum complex and a cathode solid catalyst
  • the anode catalyst layer 113 comprises an anode solid catalyst.
  • the manufacturing apparatus includes a cathode electrolyte bath 105 for a catholyte electrolyte 106 in liquid contact with a cathode 108 of a membrane electrode assembly 131, and an anode electrolyte for an anode electrolyte 116 in liquid contact with an anode 118 of a membrane electrode assembly 131.
  • a power source (power supply device 101) that supplies electrons to the cathode 108, an ion source that supplies ions to the cathode 108, and means for supplying nitrogen gas to the cathode electrolyte 106 and the cathode 108.
  • the source of ions is electrolyte membrane 102 , catholyte 106 , anolyte 116 , both electrolyte membrane 102 and catholyte 106 , or both electrolyte membrane 102 and anolyte 116 .
  • it is an ammonia production apparatus for producing ammonia from nitrogen molecules by electrolysis.
  • the means for supplying nitrogen gas is means for supplying nitrogen gas from a nitrogen cylinder 122 through a pipe 121 via a nitrogen cylinder regulator 123 and a nitrogen gas mass flow controller 124 .
  • Ammonia generated at the cathode 108 can be collected in the cathode electrolyte bath 105 of the cathode electrolyte 106 and the diluted sulfuric acid aqueous solution bath 125 for collecting ammonia.
  • the by-produced hydrogen and unreacted nitrogen pass through a pipe 121, a diluted sulfuric acid aqueous solution tank 125 for collecting ammonia, and are discharged to the outside through a draft device 126.
  • the ammonia electrolyzer (part 2) 200 of the present embodiment is an ammonia production apparatus that includes a cathode 108 composed of a cathode catalyst layer 103 and a cathode current collector 104 and a metal plate electrode 117 as an anode.
  • the cathode catalyst layer 103 comprises a molybdenum complex and a cathode solid catalyst and is the gas diffusion electrode 133 .
  • the manufacturing apparatus includes an anode electrolyte bath 115 for an anode electrolyte 116 in liquid contact with the cathode catalyst layer 103, a power supply (power supply device 101) that supplies electrons to the cathode 108, and an ion source that supplies ions to the cathode 108.
  • the gas diffusion layer of the cathode catalyst layer 103 is preferably carbon paper made of polytetrafluoroethylene (hereinafter also referred to as "PTFE") and treated with a fluorocarbon resin for water repellency.
  • PTFE polytetrafluoroethylene
  • TGP-H-060H, TGP-H-090H, TGP-H-120H, EC-TP1-030T, EC-TP1-060T, EC-TP1-090T or EC-TP1-120T are preferred.
  • the source of ions is the anolyte 116 . Furthermore, it is an ammonia production apparatus for producing ammonia from nitrogen molecules by electrolysis.
  • the means for supplying nitrogen gas is means for supplying nitrogen gas from a nitrogen cylinder 122 through a pipe 121 via a nitrogen cylinder regulator 123 and a nitrogen gas mass flow controller 124 .
  • Ammonia produced at the cathode 108 can be collected in the anode electrolyte tank 115 of the anode electrolyte 116 and the diluted sulfuric acid aqueous solution tank 125 for collecting ammonia.
  • the by-produced hydrogen and unreacted nitrogen pass through a pipe 121, a diluted sulfuric acid aqueous solution tank 125 for collecting ammonia, and are discharged to the outside through a draft device 126.
  • the ammonia electrolysis apparatus (3) 300 of the present embodiment includes a cathode 108 and an anode 118, and a membrane electrode assembly 131 in which the cathode catalyst layer 103 and the anode catalyst layer 113 are integrated via the electrolyte membrane 102.
  • Ammonia production equipment A cathode catalyst layer 103 is bonded to one side of the electrolyte membrane 102, and a cathode current collector 104 is arranged on the outside thereof, and an anode catalyst layer 113 is bonded to the other side of the electrolyte membrane 102, and the outside thereof.
  • the anode current collector 114 is arranged in the .
  • the cathode catalyst layer 103 comprises a molybdenum complex and a cathode solid catalyst
  • the anode catalyst layer 113 comprises an anode solid catalyst.
  • the manufacturing apparatus includes an anode electrolyte bath 115 of an anode electrolyte 116 that is in liquid contact with an anode 118 of a membrane electrode assembly 131, a power source (power supply device 101) that supplies electrons to the cathode 108, and ions to the cathode 108.
  • a supply ion source and means for supplying nitrogen gas to the catholyte 106 and the cathode 108 are provided.
  • the ion source is the electrolyte membrane 102 , the anolyte 116 , or both the electrolyte membrane 102 and the anolyte 116 . Furthermore, it is an ammonia production apparatus for producing ammonia from nitrogen molecules by electrolysis.
  • the means for supplying nitrogen gas is means for supplying nitrogen gas from a nitrogen cylinder 122 through a pipe 121 via a nitrogen cylinder regulator 123 and a nitrogen gas mass flow controller 124 .
  • Ammonia generated at the cathode 108 can be collected in a dilute sulfuric acid aqueous solution tank 125 for collecting ammonia.
  • the by-produced hydrogen and unreacted nitrogen pass through a pipe 121, a diluted sulfuric acid aqueous solution tank 125 for collecting ammonia, and are discharged to the outside through a draft device 126.
  • the ammonia electrolysis apparatus (part 4) 400 of the present embodiment includes a cathode 108 comprising a cathode membrane electrode assembly 132 in which a cathode catalyst layer 103 is joined to one side of an electrolyte membrane 102, and a cathode current collector 104, and This is an ammonia production apparatus having a metal plate electrode 117 as an anode.
  • Cathode catalyst layer 103 comprises a molybdenum complex and a cathode solid catalyst.
  • the manufacturing apparatus includes an anode electrolyte bath 115 of an anode electrolyte 116 in liquid contact with the electrolyte membrane 102 of the cathode membrane electrode assembly 132, a power supply (power supply device 101) for supplying electrons to the cathode 108, and An ion source for supplying ions and means for supplying nitrogen gas to the cathode 108 are provided.
  • the ion source is the electrolyte membrane 102 , the anolyte 116 , or both the electrolyte membrane 102 and the anolyte 116 .
  • it is an ammonia production apparatus for producing ammonia from nitrogen molecules by electrolysis.
  • the means for supplying nitrogen gas is means for supplying nitrogen gas from a nitrogen cylinder 122 through a pipe 121 via a nitrogen cylinder regulator 123 and a nitrogen gas mass flow controller 124 .
  • Ammonia generated at the cathode 108 can be collected in a dilute sulfuric acid aqueous solution tank 125 for collecting ammonia.
  • the by-produced hydrogen and unreacted nitrogen pass through a pipe 121, a diluted sulfuric acid aqueous solution tank 125 for collecting ammonia, and are discharged to the outside through a draft device 126.
  • the cathode current collector 104 and the anode current collector 114 in the electrolytic device of the present embodiment are, for example, carbon, metal, oxide, an alloy containing two or more kinds of metals, an oxide containing two or more kinds of metals, Examples include stainless steel, indium tin oxide, and indium zinc oxide.
  • metals include titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, rhodium, silver, tantalum, tungsten, osmium, iridium, indium, platinum, and gold.
  • oxides include titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, niobium pentoxide, molybdenum oxide, ruthenium oxide, rhodium oxide, and silver oxide. , tantalum oxide, tungsten oxide, osmium oxide, iridium oxide, indium oxide, platinum oxide, and gold oxide.
  • the shape of the current collector in the electrolysis device of the present embodiment is not particularly limited as long as it is a shape through which the gas or the electrolytic solution can pass. Examples include cloth, nonwoven fabric, expanded material, porous material, and foamed material. In order to prevent corrosion during manufacturing by electrolysis, it is possible to use a current collector plated with gold or the like.
  • Nitrogen gas can be supplied from the nitrogen cylinder 122 by controlling the flow rate using the nitrogen cylinder regulator 123 and the nitrogen gas mass flow controller 124 .
  • a method of bubbling nitrogen gas into the electrolyte in the cathode electrolyte bath 105 in FIG. 1 and the electrolyte in the anode electrolyte bath 115 in FIG. 2 is also possible. It is also possible to supply nitrogen gas directly to the cathode catalyst layer 103 through the holes in the conductor 104 .
  • the electrolytic reaction for producing ammonia in the cathode catalyst layer 103 in the electrolytic device of this embodiment will be described.
  • the molybdenum complex and the cathode solid catalyst of the present embodiment form a reaction in which ammonia is produced from electrons supplied from the power supply device 101, nitrogen gas supplied to the cathode 108, and ions supplied to the cathode 108.
  • reaction formula is “N 2 +6e ⁇ +6H + ⁇ 2NH 3 ” when the above ions are protons, and “N 2 +6e ⁇ +6H 3 O + ⁇ 2NH 3 +6H 2 O", and in the case of hydroxide ions, it can be formally described as "N 2 +6e ⁇ +6H 2 O ⁇ 2NH 3 +6OH ⁇ ".
  • This by-produced hydrogen can take the form of being dissociated on the molybdenum complex, the cathode solid catalyst, or the catalyst support. and that adsorbed hydrogen dissociates into protons and hydrides on zinc oxide, which is a metal oxide. Therefore, in the method for producing ammonia of the present embodiment, at least one selected from the group consisting of activated hydrogen atoms, protons, and hydrides in the molybdenum complex, cathode solid catalyst, or catalyst support reacts to produce ammonia. It is speculated that it is a chemical species that promotes
  • Ammonia produced at the cathode 108 can be sent to the dilute sulfuric acid aqueous solution tank 125 for collecting ammonia together with by-produced hydrogen and unreacted nitrogen. It is also possible to collect in the electrolytic solution used.
  • the electrolyte used in the cathode electrolyte bath 105 is preferably water or an aqueous solution of dilute sulfuric acid from the viewpoint of recovery and reuse. It is possible to raise it.
  • the mixed gas composed of ammonia produced in the cathode catalyst layer 103, by-produced hydrogen, and unreacted nitrogen in the electrolysis apparatus of the present embodiment is selected from ammonia by using water or a diluted sulfuric acid aqueous solution. Since the mixed gas of by-produced hydrogen and nitrogen can be taken out at the same time, hydrogen, which is useful as an energy carrier, can also be obtained in this embodiment. For safety, by-produced hydrogen can also be discharged to the outside through the draft device 126 .
  • the electrolytic reaction in the anode catalyst layer 113 or the metal plate electrode 117 in the electrolytic device of this embodiment will be described.
  • Oxygen, electrons and protons are generated from water or hydroxide ions by the catalyst of the anode 118.
  • the reaction formula is "2H 2 O ⁇ O 2 +4e ⁇ +4H + " or "4OH ⁇ ⁇ O 2 +2e ⁇ +2H 2 O”.
  • the produced protons or water pass through the electrolyte membrane 102 or the electrolytic solution and move to the cathode 108 , and the electrons pass through the anode current collector 114 or the metal plate electrode 117 and move to the power supply device 101 .
  • the generated oxygen can be partially dissolved in the water in the anode electrolyte bath 115 and released to the atmosphere.
  • the anode catalyst layer 113 in the electrolytic device of this embodiment includes a catalyst carrier, an electrolyte and a gas diffusion layer in addition to the solid catalyst.
  • the anode catalyst layer 113 including the anode solid catalyst, catalyst carrier, electron conductor, electrolyte, and gas diffusion layer may be referred to as the gas diffusion electrode 133 .
  • the solid catalyst in the anode catalyst layer 113 of the electrolytic device of this embodiment includes the same ones as those described in the solid catalyst and cathode solid catalyst in the method for producing ammonia of this embodiment.
  • a solid catalyst used on the anode side is defined as an anode solid catalyst, and preferred anode solid catalysts are iridium (IV) oxide catalyst, platinum catalyst, gold catalyst, silver catalyst, ruthenium catalyst, iridium catalyst, rhodium catalyst, palladium catalyst, osmium catalyst.
  • Catalysts include iridium (IV) oxide catalysts and platinum catalysts.
  • the catalyst carrier in the anode catalyst layer 113 of the present embodiment may conduct electrons, and is not particularly limited as long as it supports the catalyst of the present embodiment.
  • Examples of the catalyst carrier include the same ones as those described for the catalyst carrier in the cathode catalyst layer 103 in the method for producing ammonia of the present embodiment.
  • Preferred catalyst carriers in the anode catalyst layer 113 of the present embodiment include carbon black, for example, channel black, furnace black, thermal black, acetylene black, ketjen black, ketjen black EC.
  • materials include activated carbon obtained by carbonizing and activating materials containing various carbon atoms, coke, natural graphite, artificial graphite, graphitized carbon, and the like.
  • Metal meshes include metal meshes such as nickel or titanium.
  • metal foams include metal foams such as aluminum, magnesium, titanium, zinc, iron, tin, lead, and alloys containing these.
  • metal oxides include aluminum oxide, oxide Zirconium, titanium oxide, vanadium oxide, chromium oxide, manganese oxide, iron oxide, cobalt oxide, nickel oxide, copper oxide, zinc oxide, niobium pentoxide, molybdenum oxide, ruthenium oxide, rhodium oxide, silver oxide, tantalum oxide, tungsten oxide , osmium oxide, iridium oxide, indium oxide, platinum oxide, gold oxide, magnesium oxide, silica, etc.
  • composite oxides include silica-alumina, silica-magnesia, and the like.
  • carbon black, Ketjenblack, Ketjenblack EC, nickel metal mesh, titanium metal mesh and metal foam are more preferable in terms of high specific surface area and excellent electronic conductivity, and more durable. Titanium metal mesh and metal foam are even more preferred due to their superior properties.
  • the electron conductor in the anode catalyst layer 113 of the present embodiment is not particularly limited as long as it conducts electrons, and may serve as a catalyst carrier.
  • the same materials as those described for the electron conductor in the catalyst layer 103 can be used.
  • the electronic conductor of the present embodiment carbon black, Ketjenblack, Ketjenblack EC, nickel metal mesh, titanium metal mesh and metal foam are used because of their high specific surface area and excellent electronic conductivity.
  • IFPC40 and IFPC40-II manufactured by Ishifuku Metal Industry Co., Ltd., TEC10E40E, TEC10E50E, TEC10E60TPM, TEC10E70TPM, TEC10V30E, TEC10V40E, TEC10V50E manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., Johnson Matthey Fuels. ⁇ HiSPEC4000 manufactured by Japan Co., Ltd., etc. can be mentioned.
  • the electrolyte in the anode catalyst layer 113 of this embodiment is not particularly limited as long as it is responsible for ion conduction.
  • the same as those described in the electrolyte in the cathode catalyst layer 103 of the present embodiment can be used.
  • the electrolyte in the anode catalyst layer 113 of the present embodiment when a cation exchange membrane is used as the electrolyte membrane described later, one that conducts at least one of protons and hydroxonium ions is preferable. trademark) and Aquivion® are preferred.
  • an anion exchange membrane is used as the electrolyte membrane to be described later, it is preferable to conduct hydroxide ions, and FAA-3-SOLUT-10 and AS-4 are preferable.
  • the gas diffusion layer in the anode catalyst layer 113 of this embodiment is not particularly limited as long as it is responsible for electron conduction, gas diffusion, and electrolyte diffusion.
  • the same materials as those described in the gas diffusion layer in the cathode catalyst layer 103 of the present embodiment can be mentioned, and carbon paper is preferable.
  • Specific examples include TGP-H-060 and TGP-H- 090, TGP-H-120, TGP-H-060H, TGP-H-090H, TGP-H-120H, Electrochem EC-TP1-030T, EC-TP1-060T, EC-TP1-090T, EC- TP1-120T, SIGRACET 22BB, 28BC, 36BB, 39BB and the like.
  • TGP-H-060, TGP-H-090, TGP-H-060H, TGP-H-090H and EC-TP1-060T are preferable for the gas diffusion layer.
  • the metal of the metal plate electrode 117 of the present embodiment include stainless steel, indium tin oxide, indium zinc oxide, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, Niobium, molybdenum, ruthenium, rhodium, silver, tantalum, tungsten, osmium, iridium, indium, platinum, gold metals and alloys thereof.
  • platinum is preferred.
  • the shape of the metal plate electrode 117 includes, for example, a linear shape, a bar shape, a plate shape, a foil shape, a mesh shape, a woven fabric, a nonwoven fabric, an expanded body, a porous body, a foamed body, and the like, and preferably a mesh shape and a porous body. body.
  • An onium compound can also be used in the cathode catalyst layer in the method for producing ammonia of the present embodiment.
  • the onium compound is supported by at least one selected from the group consisting of a molybdenum complex, a cathode solid catalyst, and a catalyst carrier, which are materials constituting the cathode catalyst layer. Those having these forms are also described as immobilized onium bodies in this specification.
  • a preferred form of the immobilized onium body in the ammonia production method of the present embodiment is a form supported on a cathode solid catalyst.
  • the immobilized onium body in the ammonia production method of the present embodiment will be described.
  • the method of supporting the immobilized onium body includes at least one supporting method selected from the group consisting of supporting by physical adsorption, supporting by electrostatic interaction, and supporting by chemical bonding. Well, two or more supporting methods may be used.
  • Supporting of the immobilized onium body by physical adsorption in the method for producing ammonia of the present embodiment includes the fact that the onium compound is adsorbed on the surface of the catalyst support, the electrolyte, etc. via weak intermolecular force.
  • Support by electrostatic interaction of the immobilized onium body in the method for producing ammonia of the present embodiment is support by intermolecular interaction.
  • the immobilized onium body is supported by chemical bonds, such as covalent bonds, ionic bonds, coordinate bonds, metallic bonds, hydrogen bonds, and charge transfer bonds, depending on the bonding mechanism.
  • chemical bonds such as covalent bonds, ionic bonds, coordinate bonds, metallic bonds, hydrogen bonds, and charge transfer bonds, depending on the bonding mechanism.
  • Hydrogen bonding is a compound containing a hydrogen bound to an atom of a highly electronegative element, in which the hydrogen atom (while remaining bound to that atom) also exhibits an affinity for other highly electronegative atoms. is.
  • a hydrogen bond between an H atom bonded to an atom X and another atom Y with one or more lone electron pairs is represented as “X—H ... Y”. It is known that hydrogen compounds represented by
  • the immobilized onium body in the ammonia production method of the present embodiment will be described.
  • the immobilized onium body in which the onium compound is supported on the material constituting the cathode catalyst layer is represented by formulas (Z1) to (Z4), for example.
  • Z is the surface of the material constituting the cathode catalyst layer, and depending on the type of the material, the surface may be a hydrogen atom, a metal atom, or a hydroxyl group.
  • a carboxyl group a carbonyl group, a formyl group, a sulfonic acid group, an oxysulfonic acid group, a carboxylic anhydride structure, a chromene structure, a lactone structure, an ester structure and an ether structure.
  • L is a divalent group, oxygen atom (-O-), sulfur atom (-S-), "-(CH 2 ) m - (m represents an integer of 1 to 20)", “- (OCH 2 CH 2 ) n — (n represents an integer of 1 to 150.)”, formulas (L1) to formulas (L18), or divalent groups such as formula (L19), or these divalent represents a divalent group in which two or more groups are bonded, R Si and R N are each independently a C 1 -C 4 alkyl group; T is selected from the group consisting of the ionic liquids described in the above formulas (IL1) to (IL7), and formally, one hydrogen atom in the structure carrying the cation of the ionic liquid is divalent is substituted with L which is a group, and the position where one hydrogen atom is formally substituted with L can be selected from one hydrogen atom in the structure carrying the cation of the ionic liquid, X b- is an anion that compensates the charge
  • the anion of X b- may change depending on the environment when the immobilized onium body, gas diffusion electrode, and membrane electrode assembly are produced, and when ammonia is produced in this embodiment. ion, chloride ion, bromide ion, iodine ion, tetrafluoroborate, trifluoro(trifluoromethyl)borate, dimethyl phosphate ion, diethyl phosphate ion, hexafluorophosphate, tris(pentafluoroethyl)trifluorophosphate, trifluoroacetate, methylsulfate, ethylsulfate, methanesulfonate, trifluoromethanesulfonate, bis(trifluoromethanesulfonyl)imide, hydrogensulfate ion, sulfate ion, etc.
  • ammonia of the present embodiment is preferably an anion derived from the electrolytic solution, such as
  • Preferred structures of the immobilized onium body in the ammonia production method of the present embodiment include an imidazolium salt structure and a pyridinium salt structure.
  • the cathode catalyst layer 103 (shown in FIGS. 1 to 4) for producing ammonia of the present embodiment is a material constituting the cathode catalyst layer, which is a molybdenum complex, An onium compound supported by at least one selected from the group consisting of a cathode solid catalyst and a catalyst carrier, a molybdenum complex, a cathode solid catalyst, a catalyst carrier, an electron conductor, an electrolyte, and a gas diffusion layer.
  • the cathode catalyst layer 103 may be referred to as a gas diffusion electrode 133 in this specification.
  • a cathode catalyst layer 103 for producing ammonia was produced as follows.
  • the catalyst ink A used for the cathode 108 is an ink for applying the cathode solid catalyst of the present embodiment to the cathode catalyst layer 103 .
  • Carbon black-supported platinum catalyst (manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., platinum content: 46.6% by weight, product name "TEC10E50E") as a solid catalyst, 2-propanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and Nafion dispersion as an electrolyte
  • a catalyst ink A was prepared using a solution (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd., product name “5% Nafion dispersion solution DE520 CS type”).
  • Carbon-supported platinum catalyst, Nafion dispersion solution and 2-propanol are added in this order to a glass vial bottle, and the resulting dispersion solution is oscillated using an ultrasonic cleaner ASU-6 manufactured by AS ONE.
  • a catalyst ink A was prepared by setting the power to "High” and irradiating ultrasonic waves for 30 minutes.
  • catalyst ink A ⁇ Preparation conditions for catalyst ink A> Specifically, carbon-supported platinum catalyst (100.0 mg, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd., platinum content: 46.5% by weight, product name "TEC10E50E”), Nafion dispersion solution (0.705 g, manufactured by Wako Pure Chemical Industries, Ltd. , product name "5% Nafion dispersion solution DE520 CS type", 35.3 mg as Nafion solid content) and 2-propanol (2.5 mL, manufactured by Wako Pure Chemical Industries, Ltd.), catalyst ink A was prepared.
  • the ratio of Nafion (hereinafter also referred to as "ionomer”) in the above catalyst ink will be explained.
  • the ionomer ratio (% by weight) calculated from the following formula was adjusted to 26% by weight.
  • Proportion of ionomer (% by weight) [solid content of ionomer (weight) / ⁇ carbon-supported platinum catalyst (weight) + solid content of ionomer (weight) ⁇ ] ⁇ 100
  • this catalyst ink A is applied to fixed carbon paper (manufactured by Toray Industries, Inc., product name “TGP-H-060H”) at a room temperature of 20 to 25° C., and is applied on a hot plate set at 80° C. Water and alcohols, which are solvent components in the catalyst ink, were dried. The coating amount was adjusted so that the amount of platinum per 1 cm 2 was 1.0 mg.
  • a gas diffusion electrode 133 GDE
  • the gas diffusion electrode 133 is a gas diffusion electrode 133 in which a platinum catalyst (7.3 mg), which is a solid catalyst, is a square of 2.7 ⁇ 2.7 cm 2 , which is called “GDE-Cathode -1P”.
  • catalyst ink B was prepared by applying the complex of the present embodiment to the cathode catalyst layer 103 .
  • Molybdenum complex represented by formula (A1-1) (Of 5.8 mg, the number of moles per molybdenum is 4.2 ⁇ mol by ICP emission spectroscopy)) was dissolved in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (1.0 mL). The resulting solution was used as catalyst ink B.
  • the molybdenum complex represented by formula (A1-1) was synthesized by the method described in Non-Patent Document Chem. Lett. 2019, Vol. 48, pages 693-695.
  • a catalyst ink C1 for applying the complex of the present embodiment to the cathode catalyst layer 103 was prepared.
  • Compounds represented by formulas (1) and (2) were reacted in tetrahydrofuran to prepare onium compounds represented by formula (FO1), formula (FO1a), etc., and used as catalyst ink C1.
  • the compound represented by the formula (1) 100 mg, 0.55 mmol
  • the compound represented by the formula (2) 290 mg, 1.10 mmol
  • tetrahydrofuran 200 ⁇ L
  • the gas diffusion electrode 133 which is the cathode catalyst layer 103, is composed of a platinum catalyst (7.3 mg) as a solid catalyst, an onium compound (10 ⁇ L) represented by the formula (FO1), the formula (FO1a), or the like, and A gas diffusion electrode 133, which is a square of 2.7 ⁇ 2.7 cm 2 coated with a molybdenum complex represented by formula (A1-1) (0.058 mg, 0.042 ⁇ mol per molybdenum), which is It was called "GDE-Cathode-1".
  • the anode catalyst layer 113 was produced as follows.
  • the ink for applying the anode solid catalyst of the present embodiment to the anode catalyst layer 113 is the same as the catalyst ink A described above, and the gas diffusion electrode 133 in the anode catalyst layer 113 is the above "GDE-Cathode-1P". was produced in the same manner as the production of , and this was designated as "GDE-1".
  • a membrane electrode assembly (hereinafter also referred to as "MEA") consisting of the electrolyte membrane 102, the cathode catalyst layer 103 and the anode catalyst layer 113 was produced as follows.
  • MEA membrane electrode assembly
  • Nafion 212 membrane registered trademark manufactured by DuPont (film thickness: 50 ⁇ m, 5 cm x 4 cm) was used.
  • the "GDE-Cathode-1" of the gas diffusion electrode 133 which is the cathode catalyst layer, is arranged on one side of the ion exchange membrane, and the "GDE-1" of the gas diffusion electrode 133, which is the anode catalyst layer, is arranged on the other side of the ion exchange membrane.
  • the membrane electrode assembly "MEA-1" was produced by thermocompression bonding under the conditions of a temperature of 132° C., a load of 5.4 kN, and a bonding time of 240 seconds.
  • a stainless steel current collector having 25 circular holes with a diameter of 2.5 mm was provided together with a Teflon (registered trademark) sheet frame as a gasket for electrolysis. It was attached to the liquid bath, and the electrolytic device (part 1) 100 described in FIG. 1 was assembled.
  • the acid component and water required for forming the siloxane bond are supplied from the acid group (for example, sulfonic acid group) and water contained in the electrolyte membrane.
  • (a) to (c) show examples in which an onium compound is supported in this structure.
  • (a) is a case where the onium compound is supported by a covalent bond
  • (b) is a case where the onium compound is supported by hydrogen bonds formed at the portion where the siloxane bond is interrupted
  • (c) assumes the case where the onium compound is supported by hydrogen bonding via water molecules, It is believed that the reaction site for ammonia production was provided by allowing the onium compound to remain at the active site of the reaction.
  • a cathode membrane electrode assembly 132 consisting of the electrolyte membrane 102 and the cathode catalyst layer 103 was produced as follows.
  • the ion exchange membrane used for the electrolyte membrane Nafion 212 membrane (registered trademark) manufactured by DuPont (film thickness: 50 ⁇ m, 5 cm x 4 cm) was used.
  • the "GDE-Cathode-1" of the gas diffusion electrode 133 is placed on one side of the ion exchange membrane, and the cathode membrane is bonded by thermocompression under the conditions of a temperature of 132° C., a load of 5.4 kN, and a bonding time of 240 seconds.
  • a stainless steel current collector having 25 circular holes with a diameter of 2.5 mm was attached to the surface of "MEA-2" which was not on the side of the electrolyte membrane.
  • a platinum mesh electrode was used as the metal plate electrode 117 for the anode.
  • An ammonia electrolysis apparatus (part 4) 400 shown in FIG. 4 and equipped with the two electrodes was assembled.
  • Cathode electrolyte bath 105 0.02 mol/L sulfuric acid aqueous solution (6 mL)
  • Anode electrolyte tank 115 0.02 mol/L sulfuric acid aqueous solution (6 mL)
  • Dilute sulfuric acid aqueous solution tank 125 for collecting ammonia 0.02 mol/L sulfuric acid aqueous solution (10 mL)
  • Measurement conditions Constant potential measurement was performed at -2.3V.
  • Ammonia was quantified using a Thermo Scientific Dionex ion chromatography (IC) system, Dionex Integrion from Thermo.
  • IC Dionex ion chromatography
  • the amount of ammonia in the sulfuric acid aqueous solution in the dilute sulfuric acid aqueous solution tank 125 for collecting ammonia and in the sulfuric acid aqueous solution in the cathode electrolyte tank 105 was quantified to determine the amount of ammonia produced.
  • the amount of ammonia produced per complex in the cathode catalyst layer was defined as the number of rotations of the catalyst, and was calculated using the following formula.
  • Catalyst rotation speed (mol/mol) [ammonia production amount ( ⁇ mol)/moles of molybdenum in cathode catalyst layer ( ⁇ mol)] (mol/mol)
  • the ammonia production amount was 0.97 ⁇ mol
  • the catalyst turnover number was 23.0 mol/mol
  • the reaction time was 2 to 3 hours.
  • the regeneration of the catalyst was confirmed from the improvement of 4.5 times as compared with the catalyst turnover rate of 5.1 mol/mol per hour.
  • the molybdenum complex represented by, for example, formula (A1-1) incorporated in the catalyst layer of the electrolytic device can be regenerated.
  • the cathode catalyst is regenerated, the oxo complex represented by the formula (A1-1-O) is regenerated to the nitride complex represented by the formula (A1-1-N), and the catalyst cycle It is speculated that the efficiency of ammonia production was recovered by returning to . Furthermore, this is the first case where the molybdenum complex supported on the electrode catalyst could be regenerated without disassembling the electrolytic device.
  • the present invention can also be used to regenerate a molybdenum catalyst that has become an oxo complex under the influence of water and oxygen mixed in from the production environment when producing a cathode catalyst layer.
  • An ammonia electrolysis device (Part 1) was produced in the same manner as in Test Example 1 except that the catalyst ink C1 was not used for the cathode catalyst layer 103, and production by electrolysis of ammonia was performed in the same manner as in Test Example 1. Carried out. Specifically, the catalyst ink B (10 ⁇ L) was applied to the “GDE-Cathode-1P” of the gas diffusion electrode 133 to prepare the cathode catalyst layer 103 . Specifically, the gas diffusion electrode 133, which is the cathode catalyst layer 103, is composed of a platinum catalyst (7.3 mg) which is a solid catalyst and a molybdenum complex (0.058 mg, 0.042 ⁇ mol) represented by the formula (A1-1).
  • Regeneration of the cathode catalyst is carried out by removing the electrolyte from the cathode electrolyte tank 105 while maintaining the cathode electrolyte tank 105 in a nitrogen gas atmosphere after the production of ammonia for a reaction time of up to 3 hours, and generating samarium (II) iodide.
  • the amount of ammonia produced was 0.14 ⁇ mol, and the catalyst turnover rate was 3.3 mol/mol, which was three times higher than the catalyst turnover rate of 1.0 mol/mol per hour when the reaction time was 2 to 3 hours. From this, regeneration of the catalyst was confirmed.
  • the present invention enables continuous use of an ammonia production apparatus, and is a technique useful for an ammonia production method.
  • Ammonia Electrolyzer (Part 1) 101 power supply device 102 electrolyte membrane 103 cathode catalyst layer (catalyst layer for producing ammonia) 104 cathode current collector 105 cathode electrolyte bath 106 cathode electrolyte 108 cathode (cathode catalyst layer and cathode current collector) 113 anode catalyst layer 114 anode current collector 115 anode electrolyte tank 116 anode electrolyte 117 metal plate electrode 118 anode (anode catalyst layer and anode current collector, or metal plate electrode) 121 Piping 122 Nitrogen cylinder 123 Nitrogen cylinder regulator 124 Nitrogen gas mass flow controller 125 Dilute sulfuric acid aqueous solution tank for collecting ammonia 126 Draft device 131 Membrane electrode assembly 132 Cathode membrane electrode assembly 133 Gas diffusion electrode (GDE) 141 Electrolysis cell 200 Ammonia electrolysis device (Part 2) 300 Ammonia Electrolyzer (Part 3) 400 Ammonia

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WO2023222862A1 (fr) * 2022-05-19 2023-11-23 Centre National De La Recherche Scientifique Procédé de production d'azote ammoniacal

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JP2010195703A (ja) * 2009-02-24 2010-09-09 Toyota Motor Corp 新規モリブデン錯体
JP2013159568A (ja) * 2012-02-02 2013-08-19 Toyota Motor Corp 二核モリブデン錯体及びその合成方法、並びにアンモニア合成方法
WO2019168093A1 (ja) * 2018-03-01 2019-09-06 国立大学法人東京大学 アンモニアの製造方法、モリブデン錯体及びベンゾイミダゾール化合物
WO2021045206A1 (ja) * 2019-09-05 2021-03-11 国立大学法人東京大学 アンモニアの製造方法及び製造装置

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Publication number Priority date Publication date Assignee Title
JP2010195703A (ja) * 2009-02-24 2010-09-09 Toyota Motor Corp 新規モリブデン錯体
JP2013159568A (ja) * 2012-02-02 2013-08-19 Toyota Motor Corp 二核モリブデン錯体及びその合成方法、並びにアンモニア合成方法
WO2019168093A1 (ja) * 2018-03-01 2019-09-06 国立大学法人東京大学 アンモニアの製造方法、モリブデン錯体及びベンゾイミダゾール化合物
WO2021045206A1 (ja) * 2019-09-05 2021-03-11 国立大学法人東京大学 アンモニアの製造方法及び製造装置

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023222862A1 (fr) * 2022-05-19 2023-11-23 Centre National De La Recherche Scientifique Procédé de production d'azote ammoniacal
FR3135733A1 (fr) * 2022-05-19 2023-11-24 Centre National De La Recherche Scientifique Procédé de production d’azote ammoniacal

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