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JP-7854988-B2 - The use of metal-organic structures to generate metal-organic structures and H2.

JP7854988B2JP 7854988 B2JP7854988 B2JP 7854988B2JP-7854988-B2

Inventors

  • ナバロン オルトラ，セルジオ
  • バレス ガルシア，クリスティーナ
  • カブレロ アントニーノ，マリア
  • ガルシア ゴメス，エルメネヒルド
  • セール，クリスチャン
  • ムーチャハム，ジョルジュ
  • チョウ，リン

Assignees

  • コンセホ スペリオール デ インベスティガシオネス シエンティフィカス（セエセイセ）
  • ウニヴェルシダッド ポリテクニカ デ バレンシア
  • パリ サイエンス エ レトレ
  • エコール・シュペリュール・ドゥ・フィシック・エ・ドゥ・シミー・アンデュストリエル・ドゥ・ラ・ヴィル・ドゥ・パリ
  • セントレ ナシオナル デ ラ ルシェルシェ シエンティフィーク
  • エコール ノルマル シュペリウール

Dates

Publication Date
20260507
Application Date
20211005
Priority Date
20201005

Claims (9)

  1. The use of a metal-organic structure characterized by including a unit of formula (I) in its structure: M1 , M2 , and M3 are metal cations selected from a list consisting of Co and Cu, and M1 , M2 , and M3 are equal to each other; X and Z are H ; Y is COO - ; L1 , L2 , L3 , and L4 are groups independently selected from a list consisting of O2- , OH- , and H2O . n1 , n2 , n3 , and n4 are numbers independently selected from 0 and 1. Use of metal-organic structures as catalysts for photocatalytic hydrogen production starting from water.
  2. The use according to claim 1 , wherein L1 , L2 , L3 , and L4 are OH- .
  3. M1 , M2 , and M3 are Cu cations; X and Z are H, The use according to claim 1 or 2 , wherein Y is -CO2- and L1 , L2 , L3 and L4 are OH- or absent .
  4. The proportion of units of formula (I) in the above structure is The use according to any one of claims 1 to 3 , wherein the amount is between 15% and 100% in moles relative to the total amount of ligands.
  5. The aforementioned metal-organic structure is [Zr 6 (μ 3 -O) 4 (μ 3 -OH) 4 (OH) 6 (H 2 O) 6 ]-[Cu 3 (μ 3 -O) (μ-PyC) 3 (H 2 O) 6 ] 2 , [Zr 6 (μ 3 -O) 4 (μ 3 -OH) 4 (OH) 6 (H 2 O) 6 ]-[Co 3 (μ 3 -O) (μ-PyC) 3 (H 2 O) 6 ] 2 and [Hf 6 (μ 3 -O) 4 (μ 3 -OH) 4 (OH) 6 (H 2 O) 6 ]-[Cu 3 (μ 3 -O) (μ-PyC) 3 (H 2 O) 6 ] 2 Selected from a list consisting of, The aforementioned PyC represents Py-4- CO2 . The use described in claim 1.
  6. The metal-organic structure contains one or more species contained within its pores that act as co-catalysts that favorably contribute to the H2 photocatalyst generation reaction. The co-catalyst is selected from the following list for use according to any one of claims 1 to 5 : - Nanoparticles of metals selected from platinum , gold, iridium, silver, rhodium, nickel, palladium, and combinations thereof. Nanoparticles of metal oxides selected from cobalt, copper, ruthenium, molybdenum, strontium, zirconium, and combinations thereof. Nanoparticles of metal chalcogenides based on sulfides, selenides, or tellurides combined with molybdenum, cadmium, zinc, lead, indium, copper, tungsten, and combinations thereof, and metal complexes wherein the metal of the metal complex is chromium, manganese, iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, platinum, and iridium, and the organic ligand of the metal complex comprises amine-type, imine-type, or heterocyclic nitrogen atoms , and combinations thereof.
  7. A water-start photocatalytic method for producing hydrogen, comprising bringing a metal-organic structure according to any one of claims 1 to 6 into contact with water in a liquid or vapor state in the presence of sunlight or artificial light.
  8. The aforementioned metal-organic structure is deposited in the form of a thin film with a thickness between 1 micron and 20 microns, A bed of water with a thickness between 0.5 cm and 12 cm is configured to flow over the membrane at a temperature between 4°C and 40°C and a speed between 0.1 ml/hour and 2 ml/hour. The method according to claim 7 , wherein the film is exposed to sunlight or artificial light.
  9. It is characterized by including the following formula: [ Hf 6 (μ 3 -O) 4 (μ 3 -OH) 4 (OH) 6 (H 2 O) 6 ]-[Cu 3 (μ 3 -O) (μ-PyC) 3 (H 2 O) 6 ] 2 ; The aforementioned PyC represents Py-4- CO2 . Metal-organic structures .

Description

Detailed description of the invention This invention describes a metal-organic structure having in its structure a ligand (or connector between metal nodes) formed by three metal centers linked to a pyrazole, and its use for generating H2 under exposure to sunlight. [Latest technological standards] Metal-organic structures (MOFs) are crystalline and porous materials whose structure is formed by nodes containing one or more metal atoms, linked by coordination bonds and Coulomb interactions with rigid organic ligands. These metal nodes of MOFs, composed of M6O4 (OH) 4¹²- units , are known in the art, where M is a tetrapositive metal cation such as Zr⁺⁴ , Ce⁴⁺ , and Hf⁴⁺ , and the organic ligands are trimesic acid and 1,3,5(4-carboxyphenyl)benzene (Liu, Q. et al., Mesoporous Cages in Chemically Robust MOF Created by Large Number of Vertices with Reduced Connectivity. Journal of American Chemical Society). These are tricarboxylic acid aromatic compounds, such as those listed in 2019, 141, 488-496. These components define a porous structure corresponding to a solid exhibiting X-ray diffraction, as shown in Figure 1 accompanying the document. These MOF materials possess various properties derived from their surface area and composition, including their high gas adsorption capacity and catalytic activity. It is known in the art that, directly related to the present invention, some MOF materials exhibit photocatalytic activity when irradiated with photons of wavelengths corresponding to the UV-visible or near-infrared region, which can accelerate chemical reactions. A specific case of using MOFs as a photocatalyst concerns the case where the irradiation source is natural sunlight reaching the Earth's surface. The spectrum of solar radiation on the Earth's surface corresponds to a photon distribution having wavelengths in the UV region above 380 nm, in addition to photons in the visible region between 400 nm and 800 nm, which contribute about 48% of the solar energy, and the remaining low-energy photons in the near-infrared region, in addition to wavelengths in the UV region above 380 nm, which contribute about 4% of the total energy. Of the photocatalytic reactions described for MOF-type metal-organic materials, those particularly relevant to the present invention are the production of H2 by irradiating these materials in contact with water, either in the liquid or vapor phase. A rare and exceptional case is the photocatalytic production of H2 using distilled water, fresh water, or seawater, in which amounts of H2 and O2 are simultaneously produced depending on the composition of the water. This type of process is known in the current state of the art as photocatalytic water splitting, and the evidence described shows that water acts simultaneously as both an electron donor and an electron acceptor compound. The reaction occurring in photocatalytic water splitting is represented by the following equation, which also includes the enthalpy change of the process. In light of non-fossil fuel-based renewable energy, the above reaction could be useful as a way to convert sunlight as a primary energy source into chemical energy, specifically into H₂ , which can be used as an energy vector in fuel cells or combustion systems. Furthermore, H₂ can function as a chemical reagent in hydrogenation or reduction reactions. Nevertheless, despite the potential for photocatalytic generation of H₂O starting from H₂O , MOF materials have been described that, at the current level of technology, are very inadequate and still insufficient in efficiency for use in any industrial process (A. Dhakshinamoorthy, Z. Li, H. Garcia., Catalysis and photocatalysis by metal organic frameworks, Chem. Soc. Rev. 2018, 47, 8134-8172). Furthermore, the described MOF-type photocatalysts require precious metals, and especially platinum, to enhance their photocatalytic performance in H₂ generation. Since platinum is an expensive metal, including it in MOF materials significantly increases the cost of the materials, reducing the economic appeal of the process. Moreover, the photocatalytic activity of the MOF materials described to date drops considerably to less than 50% of its efficiency when irradiation is carried out exclusively with visible light and not with ultraviolet light, making solar radiation of these materials highly inefficient. Considering the latest technological advancements, the development of MOF materials as photocatalysts for the efficient generation of H2 , which do not require the presence of noble metals in their composition and whose photocatalytic response is primarily due to irradiation in the visible or near-infrared region of the electromagnetic spectrum, is considered important. [Description of the Invention] The inventors have demonstrated that an MOF material containing a unit formed by a trimetallic center linked to a pyrazole (represented by the following formula (I)) has photocatalytic activity for decomposing water into H