Alkaline water electrolysis hydrogen production self-supporting anode and preparation method and application thereof

Abstract

The invention relates to the technical field of water electrolysis, in particular to an alkaline water electrolysis hydrogen production self-supporting anode and a preparation method and application thereof. The preparation method of the alkaline electrolytic water hydrogen production self-supporting anode comprises the following steps that (1) a porous nickel material is bonded to the surface of an S pole of a permanent magnet through a conductive adhesive, the S pole bonded with the porous nickel material and an N pole of another permanent magnet are both inserted into an electromagnetic plating solution to serve as electrodes, and the two electrodes are electrified for electromagnetic plating, forming a deposition layer on the surface of the porous nickel material; the electromagnetic plating solution contains Fe < 3 + > ions and Ta < 5 + > ions; and 2) carrying out microwave heating treatment on the porous nickel material with the deposition layer formed on the surface to obtain the porous nickel material. The prepared alkaline water electrolysis hydrogen production self-supporting anode is high in operation stability under large current.

Description

Technical Field

[0001] The present invention relates to the technical field of water electrolysis, and in particular to a self-supporting anode for producing hydrogen by alkaline water electrolysis, and a preparation method and application thereof. Background Art

[0002] With the extensive use of fossil energy, environmental pollution problems are becoming increasingly serious, and clean energy is receiving more and more attention. Traditional clean energy such as solar energy and wind energy have the advantages of large total amount and the limitation of low energy density, while hydrogen energy is a form of energy with less restrictions on use. There are many types of hydrogen production technologies at present, among which water electrolysis is a relatively ideal and environmentally friendly hydrogen production method.

[0003] At present, the four mainstream water electrolysis hydrogen production technologies include: alkaline water electrolysis hydrogen production technology, proton exchange membrane water electrolysis hydrogen production technology, anion exchange membrane water electrolysis hydrogen production technology and high-temperature solid oxide water electrolysis hydrogen production technology. Among them, alkaline water electrolysis hydrogen production technology is the most mature and has the highest economic benefits, so it is widely used. For the alkaline water electrolysis reaction, during the electrolysis of water, the oxygen evolution reaction (OER) at the anode is limited by factors such as high overpotential and relatively slow kinetics. Therefore, reasonable electrode design is particularly important in improving the efficiency of water decomposition.

[0004] Most water electrolysis hydrogen production catalysts use polymer adhesives to connect them to electrodes. This method not only covers up the active sites of the catalyst, but also reduces its conductivity. Moreover, it is easy to fall off after long-term use, which cannot meet the needs of practical applications. In comparison, self-supporting electrodes do not require additional binders, conductive agents, and current collectors, and can be used directly as electrodes. They have high active sites, good mechanical properties, higher specific capacity and energy density, and have obvious advantages. However, most of the current self-supporting electrodes cannot be used stably for a long time, especially when they cannot operate stably for a long time at higher currents. Summary of the invention

[0005] The invention provides a self-supporting anode for producing hydrogen by alkaline water electrolysis and a preparation method and application thereof, so as to solve the problem of poor stability of the self-supporting electrode in the prior art.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing a self-supporting anode for producing hydrogen by alkaline water electrolysis comprises the following steps:

[0008] 1) The porous nickel material is bonded to the S pole surface of the permanent magnet by using a conductive adhesive, the S pole bonded with the porous nickel material and the N pole of another permanent magnet are inserted into an electromagnetic plating solution as electrodes, and electromagnetic plating is performed on the two electrodes to form a deposition layer on the surface of the porous nickel material; the electromagnetic plating solution contains Fe3+ Ions and Ta 5+ ion;

[0009] 2) The porous nickel material with a deposition layer formed on the surface is subjected to microwave heating treatment to obtain a self-supporting anode for producing hydrogen by alkaline water electrolysis.

[0010] Preferably, in step 1), the porous nickel material is subjected to plasma cleaning pretreatment before use; the frequency of the plasma cleaning pretreatment is 200kHz-400kHz, and the power is 100W-1000W.

[0011] Preferably, the cleaning pretreatment is performed by a plasma cleaning machine; the gas flow rate of the plasma cleaning machine is 0.1 m 3 / h-20m 3 / h; gas pressure is 1bar-10bar; vacuum degree of plasma cleaning machine is 10-10 4 Torr; cleaning time is 5-10min.

[0012] Preferably, in step 1), the porous nickel material is nickel foam or nickel mesh.

[0013] Further preferably, the pore size of the nickel foam is 50-300 μm, the nickel foam is a nickel foam sheet with a thickness of 0.5-2 mm, the mesh number of the nickel mesh is 60-300 meshes, and the diameter of the nickel wire of the nickel mesh is 100-300 μm.

[0014] Preferably, in step 1), Fe 3+ The concentration of the ions is 0.3-0.6 mol / L. Furthermore, the iron salt used in the preparation of the electromagnetic plating solution is one or more of ferric chloride, ferric nitrate and ferric sulfate.

[0015] Preferably, in step 1), Ta in the electromagnetic plating solution 5+ The concentration of the ions is 0.3-0.6 mol / L. Furthermore, the tantalum salt used in the preparation of the electromagnetic plating solution is tantalum chloride.

[0016] Preferably, in step 1), Fe 3+ Ions and Ta 5+ The molar ratio of the ions is 1:1.

[0017] Preferably, in step 1), the current of electromagnetic plating is 100-200 mA cm -2 of constant current.

[0018] Preferably, in step 1), the electromagnetic plating time is 10-20 minutes.

[0019] Preferably, in step 2), the microwave heating treatment time is 10-20 min.

[0020] A self-supporting anode for producing hydrogen by alkaline water electrolysis, prepared by the preparation method as described above.

[0021] An application of the above-mentioned alkaline water electrolysis hydrogen production self-supporting anode in water electrolysis.

[0022] The technical solution of the present invention has the following advantages and beneficial effects:

[0023] The conductive substrate of the present invention is made of porous nickel material (nickel mesh or nickel foam). On the one hand, nickel mesh, nickel foam and other products are relatively mature, and the mesh size and thickness of the nickel mesh and the pore size and thickness of the nickel foam can be well controlled; on the other hand, the porous substrate can provide more metal binding sites during the ion etching process.

[0024] The plasma high-energy plasma cleaning adopted by the present invention increases the specific surface area of ​​the porous conductive substrate surface, and forms an active layer on the surface of the material, so that the material has excellent adhesion properties, so that it can be well combined with the catalyst later. The present invention applies an external voltage to the electrode for reduction reaction, and at the same time, adds two magnets to introduce an external magnetic field, so that the charged particles are in an accelerated state in the magnetic field so as to be more firmly combined with the surface of the nickel metal carrier, and the dual effect of electromagnetics can improve the catalyst binding degree and also make the electrons arranged in a directional manner, so that the electrode has excellent oxygen precipitation catalytic performance and long-term stability under high current density, which meets the industrial demand for high current stability of water electrolysis anode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a SEM image of the self-supporting anode of Example 1 of the present invention;

[0026] Figure 2 is a SEM image of the self-supporting anode of Example 2 of the present invention;

[0027] Figure 3 1 is the LSV curve of the self-supporting anode of Example 1 and Example 2 of the present invention;

[0028] Figure 4 These are stability test curves of the self-supporting anodes of Examples 1 and 2 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1

[0031] The method for preparing the self-supporting anode for hydrogen production by alkaline water electrolysis of this embodiment comprises the following steps:

[0032] 1) Take a nickel foam sheet with a pore size of 110um and a thickness of 1.7mm, and cut it into a rectangular nickel foam sheet of 1*2cm. Put the cut nickel foam sheet into a plasma cleaning instrument for cleaning, and use plasma technology to perform surface treatment on the nickel foam sheet. Under the bombardment of high-speed electric field plasma, the specific surface area of ​​the material structure surface is increased, and an active layer is formed on the material surface. Specifically, the parameters of the plasma cleaning instrument are: frequency is 300kHz, power is 500W, gas flow is 100m 3 / h, gas pressure is 5 bar, vacuum degree is 102 Torr, and cleaning time is 10 min.

[0033] 2) 300mmol / L Fe(NO 3 ) 3 Solution, 300mmol / L TaCl 5 The solutions were mixed in a volume ratio of 1:1, and magnetically stirred for 10 min to obtain a mixed solution, which was used as an electromagnetic plating solution;

[0034] Prepare two permanent magnets of 4*4*2cm in size, cover the S side of the permanent magnet with double-sided conductive adhesive, stick the nickel foam material treated in step 1) on its surface, pass voltage on both ends, close the two magnets together to generate current, insert the closed magnets into the electromagnetic plating solution, and carry out electromagnetic plating for 10 minutes. While the cathode is reduced, the NS level of the magnet can simultaneously attract anions and cations in the electromagnetic plating solution, and the S pole can adsorb iron tantalum ions.

[0035] 3) The material after electromagnetic plating in step 2) is taken out, dried and transferred to a microwave oven for rotary heating. The microwave oven is set to high heat and the heating time is 10 minutes to finally obtain a FeTaOx / Ni self-supporting electrode.

[0036] Example 2

[0037] The difference between this embodiment and embodiment 1 is that the nickel foam sheet is replaced by a nickel mesh, the mesh number of the nickel mesh is 300 meshes, and the diameter of the nickel wire is 100 μm. The other parts are the same as those in embodiment 1.

[0038] Example 3

[0039] The method for preparing the self-supporting anode for hydrogen production by alkaline water electrolysis of this embodiment comprises the following steps:

[0040] 1) Take a nickel foam sheet with a pore size of 110um and a thickness of 1.7mm, and cut it into a rectangular nickel foam sheet of 1*2cm. Put the cut nickel foam sheet into a plasma cleaning instrument for cleaning, and use plasma technology to perform surface treatment on the nickel foam sheet. Under the bombardment of high-speed electric field plasma, the specific surface area of ​​the material structure surface is increased, and an active layer is formed on the material surface. Specifically, the parameters of the plasma cleaning instrument are: frequency is 300kHz, power is 500W, gas flow is 100m 3 / h, gas pressure is 5 bar, vacuum degree is 102 Torr, and cleaning time is 10 min.

[0041] 2) 600mmol / L Fe(NO 3 ) 3 Solution, 600mmol / L TaCl 5 The solutions were mixed in a volume ratio of 1:1, and magnetically stirred for 10 min to obtain a mixed solution, which was used as an electromagnetic plating solution;

[0042] Prepare two permanent magnets of 4*4*2cm in size, cover the S side of the permanent magnet with double-sided conductive adhesive, stick the nickel foam material treated in step 1) on its surface, pass voltage on both ends, close the two magnets together to generate current, insert the closed magnets into the electromagnetic plating solution, and carry out electromagnetic plating for 20 minutes. While the cathode is reduced, the NS level of the magnet can simultaneously attract anions and cations in the electromagnetic plating solution, and the S pole can adsorb iron and tantalum ions.

[0043] 3) The material after electromagnetic plating in step 2) is taken out, dried and transferred to a microwave oven for rotary heating. The microwave oven is set to high heat and the heating time is 20 minutes to finally obtain a FeTaOx / Ni self-supporting electrode.

[0044] Comparative Example

[0045] The pure nickel foam sheet in Example 1 and the pure nickel mesh in Example 2 were used as electrode comparison examples.

[0046] Experimental example

[0047] (1) Morphology test

[0048] The self-supporting electrodes prepared in Example 1 and Example 2 were tested by SEM respectively. The results are as follows: Figure 1 and Figure 2 shown.

[0049] Depend on Figure 1 and Figure 2 It can be seen that the electrode catalyst presents a nanowire (tube) structure, and a nanowhisker-like structure also grows on the nanowire.

[0050] (2) OER performance test

[0051] The self-supporting electrodes obtained in Example 1 (Case 1) and Example 2 (Case 2) were used as anodes to test the OER performance. The results are as follows: Figure 3 shown.

[0052] from Figure 3 From the LSV curves in Figure 1, it can be seen that the self-supporting materials of Example 1 and Example 2 have a maximum current of 700 mA / cm 2 The excellent performance of current density is far ahead of pure nickel mesh and pure nickel foam in electrochemical performance. In addition, the LSV of the electrode of the present invention does not fluctuate under a large current environment, indicating that it has excellent stability under a large current environment.

[0053] Further, the stability test results of the self-supporting electrodes prepared in Example 1 (Case 1) and Example 2 (Case 2) are as follows: Figure 4 shown.

[0054] from Figure 4 It can be clearly seen that the self-supporting materials of Example 1 and Example 2 are 2 Under certain conditions, it can remain stable for more than 2500 hours without any degradation, which greatly meets the current industrial demand for the stability of oxygen evolution materials by water electrolysis.

[0055] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis, characterized in that: The steps include: 1) The porous nickel material is bonded to the S pole surface of the permanent magnet by using a conductive adhesive, the S pole bonded with the porous nickel material and the N pole of another permanent magnet are inserted into an electromagnetic plating solution as electrodes, and electromagnetic plating is performed on the two electrodes to form a deposition layer on the surface of the porous nickel material; the electromagnetic plating solution contains Fe 3+ Ions and Ta 5+ ion; 2) The porous nickel material with a deposition layer formed on the surface is subjected to microwave heating treatment to obtain a self-supporting anode for producing hydrogen by alkaline water electrolysis.

2. The method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis according to claim 1, characterized in that: In step 1), the porous nickel material is subjected to plasma cleaning pretreatment before use; the frequency of the plasma cleaning pretreatment is 200kHz-400kHz, and the power is 100W-1000W.

3. The method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis according to claim 1, characterized in that: In step 1), the porous nickel material is nickel foam or nickel mesh.

4. The method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis according to claim 1, characterized in that: In step 1), Fe 3+ The concentration of ions is 0.3-0.6 mol / L.

5. The method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis according to claim 4, characterized in that: In step 1), Ta in the electromagnetic plating solution 5+ The concentration of ions is 0.3-0.6 mol / L.

6. The method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis according to claim 5, characterized in that: In step 1), Fe 3+ Ions and Ta 5+ The molar ratio of the ions is 1:

1.

7. The method for preparing a self-supporting anode for hydrogen production by alkaline water electrolysis according to claim 1, characterized in that: In step 1), the current of electromagnetic plating is 100-200mAcm -2 of constant current.

8. The method for preparing a self-supporting anode for producing hydrogen by alkaline water electrolysis according to claim 1, characterized in that: In step 2), the microwave heating treatment time is 10-20 minutes.

9. A self-supporting anode for producing hydrogen by alkaline water electrolysis, prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the self-supporting anode for producing hydrogen by alkaline water electrolysis as claimed in claim 9 in water electrolysis.

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