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CN-122013228-A - Electrolytic water catalyst and preparation method and application thereof

CN122013228ACN 122013228 ACN122013228 ACN 122013228ACN-122013228-A

Abstract

The invention discloses an electrolyzed water catalyst and a preparation method and application thereof. The electrolytic water catalyst comprises a substrate made of foam nickel and a nickel oxide-containing nano-sheet array perpendicular to the surface of the substrate. The catalyst provided by the invention has a special nano-sheet array structure, shows excellent oxygen evolution performance, and has the advantages of simple preparation method, mild condition, easily available raw materials, low requirements on equipment and suitability for large-scale production.

Inventors

  • ZHAO QINGRUI
  • FENG YINGJIE
  • FU XIAOYUE
  • FENG JING
  • ZHOU YUE
  • LI WEI

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (11)

  1. 1. An electrolytic water catalyst comprises a substrate made of foam nickel and a nickel oxide-containing nano-sheet array vertical to the surface of the substrate.
  2. 2. The electrolyzed water catalyst of claim 1, wherein: the nanoplatelets have a thickness of from 5 to 30nm, preferably from 8 to 20nm, more preferably from 10 to 16nm, and/or, The thickness of the substrate is 0.2 to 6mm, preferably 0.5 to 3mm, more preferably 0.5 to 2mm.
  3. 3. A process for preparing an electrolyzed water catalyst, preferably for use in the process of any of claims 1-2, comprising the step of reacting a nickel foam with a nitrate solution.
  4. 4. A method of preparation as claimed in claim 3, wherein: The nickel foam is in the form of a sheet having a thickness of 0.2-6mm, preferably 0.5-3mm, more preferably 0.5-2mm, and/or the nickel foam has a porosity of 60-95%, preferably 80-95%, more preferably 80-90%.
  5. 5. A method of preparation as claimed in claim 3, wherein: The nitrate is selected from at least one of the nitrates of alkali metals, preferably at least one of potassium nitrate and sodium nitrate, and/or, The nitrate solution is nitrate aqueous solution, preferably, the concentration of the nitrate aqueous solution is 0.1-5g/L, preferably 0.3-2.5g/L, more preferably 0.5-1.5g/L.
  6. 6. A method of preparation as claimed in claim 3, wherein: the volume ratio of the foam nickel to the nitrate solution is 1 (50-150), preferably 1 (70-90).
  7. 7. A method of preparation as claimed in claim 3, wherein: The reaction conditions include a reaction temperature of 80 to 150 ℃, preferably 90 to 120 ℃, and/or a reaction time of 6 to 15 hours, preferably 8 to 12 hours.
  8. 8. The method of any one of claims 3-7, wherein: The nickel foam further comprises a first cleaning step prior to reacting with the nitrate solution, preferably, The first cleaning includes a step of washing the nickel foam with an organic solvent and an inorganic acid solution in this order, more preferably, The organic solvent is at least one selected from organic solvents with carbon number less than or equal to 5, preferably at least one selected from ethanol and acetone, and/or, The mineral acid solution is selected from aqueous solution of at least one of sulfuric acid, hydrochloric acid and nitric acid, preferably the mineral acid solution has a H + concentration of not more than 3M, more preferably 0.5-2M, and/or, The first cleaning is performed under ultrasonic conditions, preferably in the organic solvent and the inorganic acid solution for 5 to 60 minutes, preferably 10 to 40 minutes, respectively and independently.
  9. 9. The method of any one of claims 3-7, wherein: after the reaction of the nickel foam with the nitrate solution is completed, a second cleaning step is further included, preferably, The second cleaning comprises a step of rinsing with water and/or an organic solvent, and/or, After the second cleaning, a drying step is included, and further preferably, The drying conditions include a drying temperature of 20-60 ℃ and/or a drying time of 4-12h.
  10. 10. A method for producing hydrogen by electrolyzing water, which takes the electrolyzed water catalyst as defined in any one of claims 1-2 or the electrolyzed water catalyst obtained by the preparation method as defined in any one of claims 3-9 as an oxygen evolution electrode catalyst for producing hydrogen by electrolyzing water to produce hydrogen by electrolyzing water.
  11. 11. Use of an electrolyzed water catalyst according to any of claims 1-2 or a process according to any of claims 3-9 or a process according to claim 10 in the field of hydrogen production by electrolysis of water.

Description

Electrolytic water catalyst and preparation method and application thereof Technical Field The invention relates to the technical field of hydrogen production by water electrolysis, in particular to an electrolytic water catalyst and a preparation method and application thereof. Background Fossil energy shortage and environmental pollution problems are significant challenges facing current humans, and hydrogen energy is considered one of the most potential clean energy sources in future energy structures. The traditional hydrogen production method needs to consume huge conventional energy, so that the hydrogen production cost is greatly improved, and the development, popularization and application of hydrogen energy are greatly limited. Electrolytic water hydrogen production is considered an effective way of renewable energy conversion and storage. The anion exchange membrane electrolyzed water has the advantages of high current density and quick response, can adopt low-concentration alkaline solution or water as electrolyte, has the multiple advantages of low cost, high efficiency and the like, and becomes a water electrolysis technology which is paid attention to in the future. Noble metal-based catalysts such as Ru, pt and Ir are widely considered to be the most effective electrocatalysts, but their large-scale application is hindered by their high cost and scarcity. Non-noble metals, particularly transition metal compounds, such as Co-based, ni-based, fe-based materials, are widely used for oxygen evolution catalysts due to their good stability in alkaline media. Therefore, development of a non-noble metal catalyst with high activity is necessary for development in this field. Disclosure of Invention In order to solve the problems in the prior art, the invention provides an electrolyzed water catalyst, and a preparation method and application thereof. The invention can obviously increase the active site of the catalyst by utilizing the strategy of ultra-thinning and heterogeneous composition, enhance the internal activity of the catalyst and promote the electron transmission rate, thereby improving the performance of the water electrolysis catalyst. One of the purposes of the invention is to provide an electrolytic water catalyst which comprises a substrate made of foam nickel and a nickel oxide-containing nano-sheet array vertical to the surface of the substrate. Namely, the electrolyzed water catalyst is an ultrathin nano-sheet array catalyst with a NiO heterostructure supported on foam nickel. The catalyst takes foam nickel as a substrate, a NiO nano-sheet array grows in situ perpendicular to the surface of a Ni substrate, and the substrate is assembled into a Ni/NiO heterostructure, which can be simply called as a Ni/NiO composite material, a Ni/NiO material or a Ni/NiO. The NiO nano-sheet array prepared by the invention has high bonding degree with the Ni matrix and excellent electrocatalytic performance. The oxygen evolution capability of the oxygen evolution electrode catalyst prepared when the thickness of the slice layer of the Ni/NiO nano-slice array is ultrathin is better. In a preferred embodiment of the present invention, The nanoplatelets have a thickness of from 5 to 30nm, such as 5nm、6nm、7nm、8nm、9nm、10nm、11nm、12nm、13nm、14nm、15nm、16nm、17nm、18nm、19nm、20nm、21nm、22nm、23nm、23nm、25nm、26nm、27nm、28nm、29nm、30nm or an intermediate value between any two, etc., preferably from 8 to 20nm, more preferably from 10 to 16nm, and/or, The thickness of the substrate is 0.2 to 6mm, for example 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm or an intermediate value between any two values, etc., preferably 0.5 to 3mm, more preferably 0.5 to 2mm. The thickness of the raw material foam nickel has little change before and after the reaction and is neglected. In a preferred embodiment of the present invention, In the electrolytic water catalyst, the molar ratio of nickel to nickel oxide is (1-10): 1, preferably (1.5-5): 1, from the surface to a depth of 1 μm. It is a second object of the present invention to provide a method for preparing the electrolytic water catalyst according to one of the objects of the present invention, comprising the step of reacting foamed nickel with a nitrate solution. This process causes the NiO to be supported thereon during formation. In a preferred embodiment of the present invention, The nickel foam is sheet-like having a thickness of 0.2 to 6mm, for example 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm or an intermediate value between any two values, etc., preferably 0.5 to 3mm, more preferably 0.5 to 2mm, and/or the nickel foam has a porosity of 60 to 95%, preferably 80 to 95%, more preferably 80 to 90%. In a preferred embodiment of the present invention, The nitrate is selected from at least one of the nitrates of alkali metals, preferably at least one of potassium nitrate and sodium nitrate, and/or, The nitrate solu