Reverse-current-resistant electrode for hydrogen production through water electrolysis and preparation method of reverse-current-resistant electrode

Abstract

The invention discloses an anti-reverse current electrode for hydrogen production through water electrolysis, a catalyst coating is arranged on the electrode, the chemical formula of a catalyst is (Ni < 0.8 > Ti < 0.05 > Zr < 0.05 > Mo < x > Sb < 0.1-x >) O, and x is more than 0 and less than 0.1. Ni is used as a main active component, so that high catalytic activity is ensured. High-entropy design is conducted by introducing multiple elements such as Zr, Ti, Mo and Sb, and the chemical stability and mechanical performance of the material are improved through the high-entropy effect. By adjusting the ratio of Mo to Sb, the catalytic activity and reverse current resistance of the electrode are optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by water electrolysis, and particularly relates to an anti-reverse current electrode for hydrogen production by water electrolysis and a preparation method thereof. Background Art

[0002] Global climate change and energy crisis are becoming increasingly severe. Developing clean energy and realizing the transformation of the energy structure have become a global consensus. Hydrogen energy, as a clean, efficient, and renewable secondary energy, is regarded as an important part of the future energy system. Green hydrogen production, that is, using renewable energy (such as wind power, photovoltaic, etc.) to generate electricity and producing hydrogen by electrolyzing water, is the key path to realizing the large-scale production of "green hydrogen". In the actual industrial electrolytic water production process, the hydrogen evolution electrode works under conditions such as high temperature and pressure, and high-concentration alkaline solution for a long time. Therefore, in addition to the performance of the electrode, its stability and service life are the key points we need to consider.

[0003] Most of the existing electrode materials are Raney nickel and nickel-based alloys. As the time of hydrogen production by water electrolysis increases, the electrode activity decays severely. The Raney nickel electrode has poor anti-reverse current ability. During the process of green hydrogen production, it is inevitable that the load changes due to actual situations, and the electrode components are likely to dissolve out, resulting in a decrease in activity. When the electrolytic cell stops running after operation, due to the long-term charge transfer, a potential difference will be generated between the cathode and the anode, the cathode becomes the anode, and the anode becomes the cathode, thus forming a primary battery, and a reverse current opposite to the direction of the working current is generated inside the electrolytic cell. The reverse current will oxidize the Raney nickel electrode at the cathode, generating β-NiOH that does not have hydrogen evolution activity and covering the active catalyst layer, thereby affecting the electrode activity.

[0004] Therefore, an inorganic non-metallic electrode material is needed to replace the existing electrode, and this material requires a lower overpotential, better stability, and stronger anti-reverse current ability to cope with the changing green hydrogen production environment. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects existing in the prior art and provide an anti-reverse current hydrogen evolution catalyst material for hydrogen production by water electrolysis. This material requires a lower overpotential, better stability, and stronger anti-reverse current ability to cope with the changing green hydrogen production environment.

[0006] To achieve the above purpose, the technical solution of the present invention is to design an anti-reverse current hydrogen evolution catalyst for hydrogen production by water electrolysis, which is characterized in that its chemical formula is (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo x Sb 0 .1-x )O, where 0 < x < 0.1.

[0007] Further, the value range of x is 0.01 to 0.09.

[0008] Further, the value range of x is 0.02 to 0.06, such as 0.02, 0.03, 0.04, 0.05, 0.06, and any value within the range composed of any two of the above values.

[0009] Preferably, the chemical formula of the catalyst can be (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.02 Sb 0.08 )O, (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.05 Sb 0.05 )O or (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.06 Sb 0.04 )O.

[0010] Most preferably, the chemical formula of the catalyst is (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.02 Sb 0.08 )O.

[0011] A preparation method of an anti-reverse current hydrogen evolution catalyst for water electrolysis to produce hydrogen, comprising the following preparation steps: S1: Weigh the powder raw materials of NiO, TiO, ZrO, MoO 3 , Sb 2 O 3 according to the stoichiometric ratio; S2: Put the raw material powder into a ball mill and carry out wet ball milling with distilled water and zirconia balls as the medium; S3: Put the ball-milled slurry into a high-speed centrifugal spray dryer for granulation; and conduct primary sieving on the granulated powder (sieve mesh size 80 - 100 meshes); S4: Through plasma spheroidization treatment, further improve the fluidity and uniformity of the powder, and dry it after treatment; S5: Conduct secondary sieving, with the sieve mesh number of 500 - 550 meshes, to ensure uniform powder particle size; S6: Put the sieved powder into a plasma spraying device and spray it onto a nickel mesh to form a catalyst coating. During the plasma spraying process, the high temperature causes the powder to react, and no additional sintering is required.

[0012] Further, in step S2, the ball milling conditions are a rotation speed of 600 - 1500 revolutions per hour, a time of 24 - 48 hours, and a weight ratio of balls: raw material: water of 1 - 3:1:1; Preferably, the weight ratio of balls: raw material: water is 2:1:1; Further, in step S2, gum arabic solution is also added, where the weight ratio of water: gum arabic solution is 8 - 12:1. By adding gum arabic solution and a dispersant, the mixing uniformity can be improved.

[0013] Preferably, the weight ratio of water: gum arabic solution is 10:1.

[0014] Further, in step S3, the granulation conditions are an inlet temperature of 250 - 300 °C, an outlet air temperature of 100 - 150 °C, an atomization rotation speed of 250 - 300 Hz, and a feeding rotation speed of 8 - 15 Hz; the mesh number of the primary sieving is 80 - 100 meshes.

[0015] Further, in step S4, in the plasma spheroidization treatment, the power ≥ 40 kw, the frequency is 0 - 10 MHz, and the vacuum degree is 0.1*10 -2 ~5*10 -2 Pa; Preferably, in the plasma spheroidization treatment, the power is 45 kw, the frequency is 8 MHz, and the vacuum degree is 5*10 -2 Pa; In step S4, the drying conditions are a temperature of 100 - 120 °C and a time of 10 - 12 hours.

[0016] Further, in step S5, the mesh number of the sieve is 500 - 550 meshes.

[0017] Further, in step S6, in the plasma spraying, the power of the plasma power supply is 10 - 100 kw.

[0018] Preferably, in step S6, in the plasma spraying, the power of the plasma power supply is 75 kw.

[0019] The advantages and beneficial effects of the present invention are as follows: (1) Using Ni as the main active component to ensure high catalytic activity. Introducing multiple elements such as Zr, Ti, Mo, and Sb for high-entropy design, and using the high-entropy effect to improve the chemical stability and mechanical properties of the material. By adjusting the ratio of Mo and Sb, the catalytic activity and anti-reverse current ability of the electrode are optimized.

[0020] (2) Through high-entropy design, the catalytic activity and stability of the electrode are significantly improved. At a current density of 3000 A / m 2 the average cell voltage is less than 1.63 V, which is suitable for low current density scenarios. At 9000 A / m2 At a current density, the average cell voltage is less than 1.85 V, which is suitable for high current density scenarios.

[0021] (3) Inorganic non-metallic materials have excellent chemical stability and mechanical strength, and can withstand long-term operation at high temperatures, high alkali concentrations, and high current densities. They have strong resistance to reverse current and can adapt to frequent start-stop and reverse current shocks in the green hydrogen production scenario.

[0022] (4) The preparation process is simple, without high-temperature sintering, reducing energy consumption and production costs. The raw materials are widely sourced and inexpensive, suitable for large-scale industrial production. Specific embodiments

[0023] The following combines examples to further describe the specific embodiments of the present invention. The following examples are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention. (I) Example Example 1:

[0024] A hydrogen evolution catalyst with reverse current resistance for water electrolysis hydrogen production, whose chemical formula is: (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.02 Sb 0.08 )O, and its preparation steps: S1: Weigh the powder raw materials of NiO, TiO, ZrO, MoO 3 , and Sb 2 O 3 according to the stoichiometric ratio; S2: Put the raw material powder into a ball mill and perform wet ball milling with distilled water and zirconia balls as the medium; the ball milling conditions are a rotation speed of 1200 revolutions per hour, a time of 32 hours, and a weight ratio of ball: raw material: water of 2:1:1; add gum arabic solution, where the weight ratio of water: gum arabic solution is 10:1; S3: Put the ball-milled slurry into a high-speed centrifugal spray dryer for granulation; and perform primary sieving on the granulated powder; among them, the granulation conditions are an inlet temperature of 280 °C, an outlet air temperature of 120 °C, an atomization rotation speed of 280 Hz, and a feeding rotation speed of 10 Hz; the mesh number of the primary sieving is 100 meshes; S4: Perform plasma spheroidization treatment and then dry it; among them, the process parameters of the plasma spheroidization treatment are: power of 45 kw, frequency of 8 MHz, and vacuum degree of 5*10 -2 Pa; the drying conditions are a temperature of 120 °C and a time of 10 hours; S5: Perform secondary sieving, and the mesh number is 500 meshes; S6: Put the sieved powder into a plasma spraying device and spray it onto a nickel mesh to form a catalyst coating; among them, the plasma power of the plasma spraying device is 75 kw. Example 2:

[0025] The difference from Example 1 is only that: the chemical formula of the catalyst is (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.05 Sb 0.05 )O. Example 3:

[0026] The difference from Example 1 is only that: the chemical formula of the catalyst is (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.06 Sb 0.04 )O.

[0027] Comparative Example 1: The difference from Example 1 is only that: the chemical formula of the catalyst is (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo 0.1 )O.

[0028] Comparative Example 2: The difference from Example 1 is only that: the chemical formula of the catalyst is (Ni 0 .8 Ti 0.05 Zr 0 .05 Sb 0.1 )O.

[0029] Comparative Example 3: The difference from Example 1 is only that: the secondary sieving step S5 is missing. (II) Performance Test

[0030] Test method: After assembling a 1000-square electrolytic water hydrogen production system, apply 2V direct current for electrolysis work. As the electrolysis process proceeds, control the working temperature to gradually rise and stabilize at 95 °C. When the given current densities are 12000 A / m 2 , 9000 A / m 2 , 6000 A / m 2 , 3000 A / m 2 respectively, measure its average cell voltage and energy consumption.

[0031] The performance test results of the examples and comparative examples are as follows:

[0032] The present invention uses Ni as the main active component to ensure high catalytic activity. A variety of elements such as Zr, Ti, Mo, and Sb are introduced for high-entropy design, and the high-entropy effect is utilized to improve the chemical stability and mechanical properties of the material. By adjusting the ratio of Mo and Sb, the catalytic activity and anti-reverse current ability of the electrode are optimized.

[0033] Through high-entropy design, the present invention significantly improves the catalytic activity and stability of the electrode. At a current density of 3000 A / m 2 , the average cell voltage is less than 1.63 V, which is suitable for low current density scenarios. At a current density of 9000 A / m 2 , the average cell voltage is less than 1.85 V, which is suitable for high current density scenarios.

[0034] The catalyst prepared by the present invention has excellent chemical stability and mechanical strength, and can withstand long-term operation at high temperature, high alkali concentration and high current density. It has strong anti-reverse current ability and can adapt to the frequent start-stop and reverse current impact in the green hydrogen production scenario.

[0035] In addition, the preparation process is simple, without high-temperature sintering, reducing energy consumption and production costs. The raw materials are widely sourced and inexpensive, suitable for large-scale industrial production.

[0036] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A reverse current resistant electrode for producing hydrogen by water electrolysis, characterized in that: The electrode is provided with a catalyst coating, and the chemical formula of the catalyst is (Ni 0 .8 Ti 0.05 Zr 0 .05 Mo x Sb 0 .1-x )O, where 0<x<0.

1.

2. The reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 1, characterized in that: The numerical range of x is 0.01~0.

09.

3. The reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 2, characterized in that: The numerical range of x is 0.02~0.

06.

4. A method for preparing a reverse current resistant electrode for hydrogen production by water electrolysis as claimed in any one of claims 1 to 3, characterized in that: The method comprises the following preparation steps: S1: Weigh NiO, TiO, ZrO, MoO3, Sb2O3 powder raw materials according to the stoichiometric ratio; S2: placing the raw material powder into a ball mill and performing wet ball milling using distilled water and zirconia balls as media; S3: placing the ball-milled slurry into a high-speed centrifugal spray dryer for granulation; and performing a primary sieving on the granulated powder; S4: plasma spheroidization treatment, followed by drying; S5: secondary screening; S6: The sieved powder is placed in a plasma spraying device and sprayed onto the nickel mesh to form a catalyst coating.

5. The method for preparing a reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 4, characterized in that: In step S2, the ball milling conditions are a rotation speed of 600 to 1500 rpm, a time of 24 to 48 hours, and a weight ratio of ball: raw material: water of 1 to 3:1:

1.

6. The method for preparing a reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 4, characterized in that: In step S2, gum arabic solution is also added, wherein the weight ratio of water to gum arabic solution is 8-12:

1.

7. The method for preparing a reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 4, characterized in that: In step S3, the granulation conditions are as follows: inlet temperature 250-300°C, outlet air temperature 100-150°C, atomization speed 250-300Hz, and feeding speed 8-15Hz; the mesh size of the initial screening is 80-100 meshes.

8. The method for preparing a reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 4, characterized in that: In step S4, during the plasma spheroidization treatment, the power is ≥40 kW, the frequency is 0-10 MHz, and the vacuum degree is 0.1*10 -2 ~5*10 - 2 Pa; In step S4, the drying conditions are a temperature of 100-120° C. and a time of 10-12 hours.

9. The method for preparing a reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 4, characterized in that: In step S5, the mesh size of the sieve is 500-550 meshes.

10. The method for preparing a reverse current resistant electrode for producing hydrogen by water electrolysis according to claim 4, characterized in that: In step S6, during plasma spraying, the power of the plasma power supply is 10-100 kW.

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