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CN-122010985-A - Preparation method of chlorine coordination phosphomolybdic acid based two-dimensional copper complex and application of chlorine coordination phosphomolybdic acid based two-dimensional copper complex in electrocatalytic ammonia production

CN122010985ACN 122010985 ACN122010985 ACN 122010985ACN-122010985-A

Abstract

The invention relates to a preparation method of a chlorine coordination phosphomolybdic acid based two-dimensional copper complex and application of the complex in preparing ammonia by electrocatalysis. The complex has a definite chemical formula {[Cu(C 10 H 8 N 6 ) 3 O]Cl[Cu(H 2 O) 7 ](PMo 12 Cl 2 O 40 )]}, which is marked as Cu-PMo 12 Cl 2 -C 10 , and is characterized in that a stable two-dimensional lamellar structure is formed by bridging copper ions with an organic ligand 1, 4-di (4H-1, 2, 4-triazole-4-yl) benzene (the molecular formula is C 10 H 8 N 6 ), so that the technical problems of poor stability and limited catalytic activity in the electrocatalytic application of the traditional multi-acid-based metal-organic complex are solved. The preparation method comprises the steps of taking copper chloride, phosphomolybdic acid, ammonium metavanadate and the organic ligand as raw materials, and synthesizing the organic ligand through one-step hydrothermal reaction. The material is used for electrocatalytic nitrate radical reduction, reaches the maximum ammonia production rate of 18.79: 18.79 mg h –1 mg cat. –1 under the voltage of-1.1V vs. RHE in 0.1M KNO 3 +0.1M K 2 SO 4 neutral electrolyte, and has Faraday efficiency of 80.8%. The invention has simple process and provides a high-performance electrocatalyst for preparing ammonia by nitrate radical reduction.

Inventors

  • WANG XINMING
  • ZHAO NAN
  • LI GANG
  • PANG HAIJUN

Assignees

  • 哈尔滨理工大学

Dates

Publication Date
20260512
Application Date
20260131

Claims (8)

  1. 1. The chlorine coordinated phosphomolybdic acid based two-dimensional copper complex is characterized by having a chemical formula {[Cu(C 10 H 8 N 6 ) 3 O]Cl[Cu(H 2 O) 7 ](PMo 12 Cl 2 O 40 )]},, wherein C 10 H 8 N 6 is 1, 4-di (4H-1, 2, 4-triazole-4-yl) benzene, and the complex has a two-dimensional lamellar structure formed by bridging the dichloro coordinated phosphomolybdic acid anions and copper ions under the organic ligand.
  2. 2. The two-dimensional copper complex based on chlor-co-phosphomolybdic acid according to claim 1, which is characterized in that it belongs to triclinic system and the space group is P The unit cell parameters are a= 10.6479(6)Å,b= 16.8386(10)Å,c= 19.8642(10)Å,α= 89.844(2)°,β= 77.806(2)°,γ= 79.315(2)°,V= 3418.4(3) Å 3 .
  3. 3. A process for preparing a chlorine-coordinated phosphomolybdic acid based two-dimensional copper complex according to claim 1 or 2, characterized in that the process is a hydrothermal process comprising the steps of: Dissolving copper chloride, phosphomolybdic acid, ammonium metavanadate and an organic ligand C 10 H 8 N 6 in water, uniformly stirring, and regulating the pH value of a mixed system to 1.0-2.5; placing the obtained reaction mixture in a closed reactor, and crystallizing for 3-5 days at 160-180 ℃; After the reaction is finished, cooling, washing and drying are carried out to obtain the chlorine coordination phosphomolybdic acid based two-dimensional copper complex.
  4. 4. A method according to claim 3, wherein the molar ratio of copper chloride to phosphomolybdic acid is 6:1.
  5. 5. A method according to claim 3, wherein the molar ratio of copper chloride to ammonium metavanadate is 2:1.
  6. 6. A method according to claim 3, wherein the molar ratio of copper chloride to organic ligand C 10 H 8 N 6 is 4:1.
  7. 7. A method according to claim 3, characterized in that 1 mol/L of hydrochloric acid solution and/or 1 mol/L of sodium hydroxide solution are used for adjusting the pH.
  8. 8. The application of the chlorine coordination phosphomolybdic acid based two-dimensional copper complex prepared by the preparation method of claims 1-7 is characterized in that the chlorine coordination phosphomolybdic acid based two-dimensional copper complex is used as an electrode material and applied to the electrocatalytic nitrate radical reduction ammonia synthesis reaction at normal temperature and pressure.

Description

Preparation method of chlorine coordination phosphomolybdic acid based two-dimensional copper complex and application of chlorine coordination phosphomolybdic acid based two-dimensional copper complex in electrocatalytic ammonia production Technical Field The invention relates to the technical field of electrocatalytic nitrate reduction synthesis ammonia catalyst materials, in particular to a preparation method of a chlorine coordination phosphomolybdic acid-based two-dimensional copper complex and an electrocatalytic ammonia preparation application, and belongs to the technical field of functional inorganic-organic hybrid materials and electrocatalytic energy conversion intersection. Background The Haber-Bosch process (Haber-Bosch) has been the dominant technology for industrial synthesis of ammonia since the beginning of the 20 th century. The process can realize large-scale stable production of ammonia, but needs to operate under high-temperature and high-pressure (generally 300-500 ℃ and 150-300 atm ℃) conditions, so that the energy consumption per unit ammonia yield is extremely high, and about 1.8 tons of carbon dioxide emission is accompanied by 1 ton of ammonia produced, thereby seriously aggravating energy crisis and environmental pressure. As an electrochemical process which can be carried out at normal temperature and normal pressure, the electrocatalytic nitrate reduction ammonia (e-NO 3 RR) has the advantages of mild reaction conditions, high energy utilization efficiency, good environmental compatibility and the like, and is considered to be a green synthesis path which is expected to replace the traditional Haber-Bosch process. However, the conventional e-NO 3 RR system still faces a plurality of key challenges in practical application, such as insufficient catalytic activity, higher adsorption and activation energy barrier of nitrate, limited ammonia generation selectivity, easiness in generating side reaction to generate nitrogen, nitrite and other products, poor catalyst stability, easiness in agglomeration and loss of active centers, and excessively rapid attenuation of ammonia production rate, thereby severely restricting the industrialized application of the catalyst. The structure and composition of the electrocatalyst are the core factors for determining the reaction efficiency of the e-NO 3 RR, and the development of a catalytic material with high activity, high selectivity, high stability and low cost is a research hotspot in the field. Polyoxometalates (POMs) are a group of polynuclear metal oxygen cluster compounds based on transition metal elements of high oxidation state such as tungsten, molybdenum, vanadium, etc. The compound has reversible oxidation-reduction characteristics and a highly controllable composition structure, and shows excellent functional diversity, so that the compound has wide application prospects in the fields of catalytic chemistry, energy conversion technology, functional material development, biological medicine and the like. Wherein, keggin type polyacid [ PMo 12O40]3- (abbreviated as { PMo 12 }) is tightly connected with twelve MoO 6 octahedrons by a central PO 4 tetrahedron through sharing oxygen atoms, forming a highly symmetrical cage-like structure. The electron density is high, the oxidation-reduction potential is adjustable, and the method is an ideal primitive for constructing the functional hybrid material. In the prior art, polyacid-based catalytic materials are prepared by simple composite metal ions or organic ligands, and have the problems of poor structural order, insufficient exposure of active centers, poor stability and the like. Particularly in the aspect of polyacid molecule modification, the research of halogen atom coordination modification is less, and no report of constructing a two-dimensional ordered structure by coordination modification of { PMo 12 } polyacid by chlorine atoms and molybdenum sites and then cooperation of the polyacid with copper ions and organic ligands is yet seen. The two-dimensional structure can maximize the exposure of active sites and accelerate the electron transmission, the chlorine coordination modification can regulate and control the electronic structure and the catalytic activity of polyacid, the introduction of copper ions and specific organic ligands can stabilize the structure and optimize the reaction selectivity, and the synergistic effect of the three is expected to break through the performance bottleneck of the existing polyacid-based catalyst. Based on the method, the chlorine coordination phosphomolybdic acid based two-dimensional copper-organic complex is designed and prepared, and a new strategy is provided for the development of the high-efficiency e-NO 3 RR catalyst. Disclosure of Invention 1. Object of the invention Aiming at the defects of insufficient activity, limited selectivity and poor stability of the conventional multi-acid-based electrocatalyst in the electrocatalytic nitrat