Ammonia production method and ammonia production apparatus

Patent metadata

Field	Value
Publication number	US-2024328014-A1
Application number	US-202218285352-A
Country	US
Kind code	A1
Filing date	Mar 30, 2022
Priority date	Mar 30, 2021
Publication date	Oct 3, 2024
Grant date	—

Abstract

An ammonia production method is a method that produces ammonia from nitrogen molecules by donating electrons from a power supply, protons from a proton source, and the nitrogen molecules from means for supplying a nitrogen gas in presence of a complex, a solid catalyst, and a reaction field forming material in a cathode by a production apparatus for performing electrolysis. In the complex, the solid catalyst, and the reaction field forming material, for example, a molybdenum complex expressed by Formula (A1-1) is used as the complex.A platinum catalyst is used as the solid catalyst, and a rare earth metal-carbon-based binder is used as the reaction field forming material.

First claim

1 . An ammonia production method that produces ammonia from nitrogen molecules by donating electrons from a power supply, protons from a proton source, and the nitrogen molecules from means for supplying a nitrogen gas in presence of a complex, a solid catalyst, and a reaction field forming material in a cathode by a production apparatus for performing electrolysis, wherein
the complex is:
(A) a molybdenum complex having 2,6-bis(dialkylphosphinomethyl) pyridine (where two alkyl groups may be identical or different, and at least one hydrogen atom on a pyridine ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom) as a PNP ligand;
(B) a molybdenum complex having N,N-bis(dialkylphosphinomethyl) dihydrobenzimidazolidene (where two alkyl groups may be identical or different, and at least one hydrogen atom on a benzene ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom) as a PCP ligand;
(C) a molybdenum complex having bis(dialkylphosphinoethyl) arylphosphine (where two alkyl groups may be identical or different) as a PPP ligand; or
(D) a molybdenum complex expressed as trans-Mo(N 2 ) 2 (R 5 R 6 R 7 P) 4 (where R 5 and R 6 are aryl groups that may be identical or different, R 7 is an alkyl group, and two R 7 groups may be connected with one another to form an alkylene chain),
the solid catalyst is a metal catalyst or an oxide catalyst, the reaction field forming material is a rare earth metal-carbon-based binder, and the proton source is an electrolyte membrane, an electrolytic solution, or both of the electrolyte membrane and the electrolytic solution.

2 . The ammonia production method according to claim 1 , wherein
the molybdenum complex (A) is a molybdenum complex expressed by the following Formula (A1), (A2), or (A3):

(In the formula, R 1 and R 2 are alkyl groups that may be identical or different, X is an iodine atom, a bromine atom, or a chlorine atom, and at least one hydrogen atom on a pyridine ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom).

3 . The ammonia production method according to claim 1 , wherein
the molybdenum complex (B) is a molybdenum complex expressed by the following Formula (B1) or (B2):

(In the formula, R 1 and R 2 are alkyl groups that may be identical or different, X is an iodine atom, a bromine atom, or a chlorine atom, at least one hydrogen atom on a benzene ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom, and at least one of R 3 and R 4 is substituted with a trifluoromethyl group).

4 . The ammonia production method according to claim 1 , wherein
the molybdenum complex (C) is a molybdenum complex expressed by Formula (C 1 ):

(In the formula, R 1 and R 2 are alkyl groups that may be identical or different, R 5 is an aryl group, and X is an iodine atom, a bromine atom, or a chlorine atom).

5 . The ammonia production method according to claim 1 , wherein
the molybdenum complex (D) is a molybdenum complex expressed by Formula (D1) or (D2):

(In the formula, R 5 and R 6 are aryl groups that may be identical or different, R 7 is an alkyl group, and n is 2 or 3).

6 . The ammonia production method according to claim 1 , wherein
the solid catalyst is a platinum catalyst or a palladium catalyst.

7 . A membrane electrode assembly in which an electrolyte membrane is sandwiched between a cathode catalyst layer and an anode catalyst layer to assemble together, wherein
the cathode catalyst layer contains a complex, a cathode solid catalyst, and a reaction field forming material, the anode catalyst layer contains an anode solid catalyst, the complex is:
(A) a molybdenum complex having 2,6-bis(dialkylphosphinomethyl) pyridine (where two alkyl groups may be identical or different, and at least one hydrogen atom on a pyridine ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom) as a PNP ligand;
(B) a molybdenum complex having N,N-bis(dialkylphosphinomethyl) dihydrobenzimidazolidene (where two alkyl groups may be identical or different, and at least one hydrogen atom on a benzene ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom) as a PCP ligand;
(C) a molybdenum complex having bis(dialkylphosphinoethyl) arylphosphine (where two alkyl groups may be identical or different) as a PPP ligand; or
(D) a molybdenum complex expressed as trans-Mo(N 2 ) 2 (R 5 R 6 R 7 P) 4 (where R 5 and R 6 are aryl groups that may be identical or different, R 7 is an alkyl group, and two R 7 groups may be connected with one another to form an alkylene chain),
the cathode solid catalyst and the anode solid catalyst are metal catalysts or oxide catalysts, and the reaction field forming material is a rare earth metal-carbon-based binder.

8 . The membrane electrode assembly according to claim 7 , wherein
the molybdenum complex (A) is a molybdenum complex expressed by the following Formula (A1), (A2), or (A3):

(In the formula, R 1 and R 2 are alkyl groups that may be identical or different, X is an iodine atom, a bromine atom, or a chlorine atom, and at least one hydrogen atom on a pyridine ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom).

9 . The membrane electrode assembly according to claim 7 , wherein
the molybdenum complex (B) is a molybdenum complex expressed by the following Formula (B1) or (B2):

(In the formula, R 1 and R 2 are alkyl groups that may be identical or different, X is an iodine atom, a bromine atom, or a chlorine atom, at least one hydrogen atom on a benzene ring may be substituted with an alkyl group, an alkoxy group, or a halogen atom, and at least one of R 3 and R 4 is substituted with a trifluoromethyl group).

10 . The membrane electrode assembly according to claim 7 , wherein
the molybdenum complex (C) is a molybdenum complex expressed by Formula (C1):

(In the formula, R 1 and R 2 are alkyl groups that may be identical or different, R 5 is an aryl group, and X is an iodine atom, a bromine atom, or a chlorine atom).

11 . The membrane electrode assembly according to claim 7 , wherein
the molybdenum complex (D) is a molybdenum complex expressed by Formula (D1) or (D2):

(In the formula, R 5 and R 6 are aryl groups that may be identical or different, R 7 is an alkyl group, and n is 2 or 3).

12 . The membrane electrode assembly according to claim 7 , wherein
the cathode solid catalyst is a platinum catalyst or a palladium catalyst.

13 . An ammonia production apparatus comprising
the membrane electrode assembly according to claim 7 that includes the cathode catalyst layer, the electrolyte membrane, and the anode catalyst layer, wherein in a cathode, the cathode catalyst layer is ass

Assignees

• Univ Tokyo
• Nissan Chemical Corp

Inventors

• Nishibayashi Yoshiaki
• Arashiba Kazuya
• Ashida Yuya
• Kondo Shoichi
• Kikuchi Takamasa
• Shiga Norihito

Classifications

• C25B11/075

  consisting of a single catalytic element or catalytic compound · CPC title

• C07F11/005

  compounds without a metal-carbon linkage · CPC title

• C25B11/032

  Gas diffusion electrodes · CPC title

• C25B11/095 Primary

  at least one of the compounds being organic · CPC title

• C25B11/052

  Electrodes comprising one or more electrocatalytic coatings on a substrate · CPC title