Electrolyzed water anode catalyst adopting A-bit high-entropy design and preparation method of electrolyzed water anode catalyst

Abstract

The invention discloses an electrolyzed water anode catalyst adopting A-bit high-entropy design and a preparation method of the electrolyzed water anode catalyst, and belongs to the technical field of electrolyzed water catalyst preparation. The chemical formula of the catalyst is (La < 0.25 > Sm < 0.25 > Eu < 0.25 > Ce < 0.25 >) NiO < 3 >. According to the preparation process, La2O3 powder, Sm2O3 powder, Eu2O3 powder, CeO2 powder and Ni2O3 powder are weighed according to the designed stoichiometric ratio, wet ball milling, stirring, granulation, high-temperature sintering, sieving and plasma spraying are adopted, and the prepared catalyst has the advantages of being low in overpotential, good in stability and the like and is expected to be widely applied to anode catalyst materials for preparing hydrogen through water electrolysis.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of electrolyzed water catalysts, and particularly relates to an electrolyzed water anode catalyst with a high-entropy design at the A-site and a preparation method thereof. Background Art

[0002] As a green and sustainable hydrogen production method, the electrolyzed water hydrogen production technology has received extensive attention in recent years. This technology decomposes water into hydrogen and oxygen through electrolysis of water, and its core lies in using electrical energy to drive electrochemical reactions to achieve efficient and clean hydrogen production. Currently, the electrolyzed water hydrogen production technology mainly includes alkaline electrolyzed water hydrogen production technology (ALK), proton exchange membrane electrolyzed water hydrogen production technology (PEM), high-temperature solid oxide electrolyzed water hydrogen production technology (SOEC), and anion exchange membrane electrolyzed water hydrogen production technology (AEM), etc. Each technology has its unique advantages and challenges.

[0003] Among them, the alkaline electrolyzed water hydrogen production technology is the most commercialized one and has been applied in multiple green hydrogen demonstration projects. Its advantages lie in mature technology, relatively low equipment cost, and the ability to use non-precious metal catalysts, making it suitable for large-scale industrial production. However, this technology still has some bottleneck problems, such as a relatively low working current density (usually 0.2 - 0.4 A / cm 2 ), a relatively high energy consumption level (4.5 - 5.5 kWh / Nm 3 H 2 ), and a relatively high hydrogen cost, etc. In addition, the start-up speed of the alkaline electrolytic cell is relatively slow, and its dynamic response ability is poor, making it difficult to adapt to the relatively large fluctuations in renewable energy power input.

[0004] The proton exchange membrane electrolyzed water hydrogen production technology has the advantages of a high working current density (up to 2 A / cm 2 ), relatively low energy consumption (4.0 - 4.5 kWh / Nm 3 H 2 ), high hydrogen purity, etc., and a fast dynamic response speed, making it suitable for coupling with intermittent renewable energy sources such as wind energy and solar energy. However, the core materials of the PEM technology (such as proton exchange membranes and platinum group catalysts) are costly, and the requirements for water quality are extremely high, which limits its large-scale application.

[0005] The high-temperature solid oxide electrolyzed water hydrogen production technology operates at high temperatures (700 - 1000 °C), can utilize thermal energy to reduce electrical energy consumption, and the theoretical energy consumption can be as low as 3.0 kWh / Nm 3 H 2 , and can use non-precious metal catalysts. However, the SOEC technology faces problems such as poor material durability and insufficient stability at the electrode and electrolyte interface at high temperatures, and its commercialization process is relatively slow.

[0006] Anion exchange membrane electrolytic water hydrogen production technology is a newly emerging technical route in recent years. It combines some advantages of ALK and PEM, can use non-noble metal catalysts and has relatively low requirements for water quality. However, the anion exchange membrane of AEM technology is prone to chemical degradation during long-term operation, resulting in performance degradation, and it is still in the laboratory research and development stage.

[0007] In the electrolytic water hydrogen production system, the electricity cost is the main component of the hydrogen production cost, accounting for 40%-60% of the hydrogen price, and even up to 80% in some cases. Therefore, reducing energy consumption and improving electrolysis efficiency are the keys to reducing the cost of hydrogen. At present, one of the core challenges of electrolytic water hydrogen production technology lies in the performance limitations of electrode materials. Traditional electrode materials (such as nickel-based alloys, platinum group metals, etc.) have problems such as high overpotential, insufficient catalytic activity, and poor durability, resulting in difficulty in further improving the electrolysis efficiency. Summary of the Invention

[0008] In view of the above technical problems, the present invention proposes an electrolytic water anode catalyst with high-entropy design at the A site and its preparation method.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] One of the objects of the present invention is to provide an electrolytic water anode catalyst with high-entropy design at the A site, and the chemical formula of the catalyst is (La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 .

[0011] The electrolytic water anode catalyst provided by the present invention has the chemical formula (La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 , and adopts high-entropy design at the A site. The core of high-entropy design is to increase the configurational entropy of the material by doping multiple elements in equal proportion or nearly equal proportion, thereby improving its stability and catalytic performance. In this catalyst, four rare earth elements, La, Sm, Eu, and Ce, and Ni together constitute the A site, forming a high-entropy structure. Rare earth elements have unique electronic structures and rich chemical reactivity, which can significantly improve the activity and stability of the catalyst. In addition, high-entropy design can also optimize the active sites of the catalyst and reduce the overpotential of the oxygen evolution reaction (OER) through lattice distortion and electronic structure regulation.

[0012] Another object of the present invention is to provide a preparation method of an electrolytic water anode catalyst with high-entropy design at the A site, including the following steps:

[0013] 1) Weigh powdered La, Sm, Eu, CeO, and NiO according to the stoichiometric ratio respectively, mix them, and then perform wet ball milling to obtain a powder material. 2 O 3 Sm 2 O 3 Eu 2 O 3 CeO 2 Ni 2 O 3

[0014] 2) Add gum arabic to the powder material, stir it, then granulate it in a high-speed centrifugal spray dryer, perform high-temperature sintering, and sieve it.

[0015] 3) Place the sieved powder material in a plasma spraying device and spray it onto a nickel mesh to obtain an electrolytic water anode catalyst with a high-entropy design at the A site.

[0016] Further, the conditions for the wet ball milling in step 1) are as follows: the rotational speed of the ball mill is 15 - 30 revolutions per minute, the ball milling time is 36 - 48 hours, the ball milling medium is distilled water and zirconia balls, and the mass ratio of zirconia balls, materials, and distilled water is 2∶1∶2.

[0017] The ball milling process helps to break the agglomeration between particles, enabling full mixing of each component. At the same time, as the grinding medium, zirconia balls can further refine the particle size, increase the specific surface area of the material, and thus enhance the catalytic activity. The parameter settings can ensure the uniform mixing and refinement of the material.

[0018] Further, the mass ratio of the distilled water used in the wet ball milling process in step 1) to the gum arabic in step 2) is 10∶1.

[0019] Gum arabic, as a binder, forms particles with a certain particle size distribution through spray drying granulation. Subsequently, high-temperature sintering is carried out to make the particles form a stable crystal structure.

[0020] Further, the conditions for granulation in the high-speed centrifugal spray dryer in step 2) are as follows: the inlet air temperature is 220 - 320 °C, the outlet air temperature is 100 - 150 °C, and the atomization rotational speed is 200 - 300 Hz.

[0021] Spray drying can quickly remove moisture, form uniform particles, and avoid particle agglomeration.

[0022] Further, the conditions for the high-temperature sintering in step 2) are as follows: keep the temperature at 1100 - 1150 °C for 3 - 4 hours.

[0023] High-temperature sintering helps to form a dense crystal structure, improve the mechanical strength and thermal stability of the material.

[0024] Further, the size of the sieve used in the sieving process in step 2) is 120 - 150 mesh.

[0025] Further, the spraying amount of the powder material sprayed onto the nickel mesh in step 3) is 300 g / m 2 .

[0026] Plasma spraying can rapidly melt the powder material at high temperature and uniformly spray it onto the nickel mesh to form a firm coating. The sprayed catalyst has good electrical conductivity and mechanical stability. The setting of the spraying amount is to ensure uniform coating thickness and meet the performance requirements of the electrolytic water anode catalyst.

[0027] The third object of the present invention is to provide an application of an electrolytic water anode catalyst with A-site high-entropy design in the field of electrolytic water hydrogen production.

[0028] The fourth object of the present invention is to provide an application of an electrolytic water anode catalyst with A-site high-entropy design in the field of electrode materials.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] The present invention conducts high-entropy design through the synergistic effect of multiple rare earth elements, optimizes the active sites of the catalyst, and reduces the overpotential of OER. The addition of rare earth elements improves the chemical stability of the catalyst, enabling it to work stably for a long time in the strong oxidation environment of electrolytic water, and by reducing the overpotential, the energy loss during the electrolytic water process is reduced, and the electrolysis efficiency is improved.

[0031] The present invention provides a high-performance electrolytic water anode catalyst through A-site high-entropy design in combination with the advantages of the perovskite structure. Its preparation method includes steps such as wet ball milling, spray drying, high-temperature sintering, and plasma spraying, ensuring high homogeneity, high catalytic activity, and high stability of the material. This catalyst has broad application prospects in the fields of electrolytic water hydrogen production and electrode materials, and can effectively solve problems such as high energy consumption, high cost, and insufficient catalytic activity in the preparation of existing catalysts.

[0032] The preparation process of the present invention has the characteristics of simple process, short production cycle, low production cost, and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0034] Figure 1 It is the SEM image of the electrolytic water anode catalyst with A-site high-entropy design prepared in Example 1;

[0035] Figure 2 Instantaneous cell voltage diagram of the anodic catalyst for electrolytic water with high-entropy design at the A-site and the cathode photo-net nickel mesh prepared in Example 1;

[0036] Figure 3 For the anodic catalyst for electrolytic water with high-entropy design at the A-site and the cathode photo-net nickel mesh prepared in Example 1 at 6000 A / m 2 Ageing diagram of the cell voltage under the test. Detailed implementation manners

[0037] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention.

[0038] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0039] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0040] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the present invention specification, which are obvious to those skilled in the art. Other implementation manners obtained from the present invention specification are also obvious to those skilled in the art. The present invention specification and examples are only exemplary.

[0041] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0042] The embodiment of the present invention provides a preparation method of an anodic catalyst for electrolytic water with high-entropy design at the A-site, including the following steps:

[0043] 1) Weigh powdered La respectively according to the stoichiometric ratio 2O 3 、Sm 2 O 3 、Eu 2 O 3 、CeO 2 and Ni 2 O 3 , and then wet ball milling is performed after mixing to obtain a powder material;

[0044] 2) Adding gum arabic to the powder material, stirring, placing in a high-speed centrifugal spray dryer for granulation, sintering at high temperature, and sieving;

[0045] 3) The sieved powder material is placed in a plasma spraying device and sprayed onto a nickel mesh to obtain an A-site high entropy designed water electrolysis anode catalyst.

[0046] In some feasible embodiments, the conditions for wet ball milling in step 1) are: the ball mill speed is 15-30 rpm (such as 20 rpm, 25 rpm or 28 rpm), the ball milling time is 36-48 hours (such as 48 hours), the ball milling medium is distilled water and zirconia balls, and the mass ratio of zirconia balls, material and distilled water is 2:1:2.

[0047] In some feasible embodiments, the mass ratio of the distilled water used in the wet ball milling process in step 1) to the gum arabic in step 2) is 10:1.

[0048] In some feasible embodiments, the conditions for granulation in the high-speed centrifugal spray dryer in step 2) are: inlet air temperature is 220-320°C, outlet air temperature is 100-150°C, and atomization speed is 200-300Hz. As a typical but non-limiting example, in the following preferred embodiments of the present invention, the effect is verified by taking the inlet air temperature of 260°C, the outlet air temperature of 110°C, and the atomization speed of 250Hz as an example.

[0049] In some feasible embodiments, the high temperature sintering condition in step 2) is: keeping at 1100-1150°C for 3-4 hours. As a typical but non-limiting example, in the following preferred embodiments of the present invention, the calcination temperature can be selected from 1100°C, 1120°C or 1150°C, and the calcination time can be selected from 3 hours, 3.5 hours or 4 hours.

[0050] In some feasible embodiments, the size of the sieve used in the screening process in step 2) is 120-150 meshes. As a typical but non-limiting example, in the following preferred embodiments of the present invention, the size of the sieve can be selected to be 120 meshes or 150 meshes.

[0051] In some feasible embodiments, the spraying amount of the powder material sprayed onto the nickel mesh in step 3) is 300 g / m 2 .

[0052] The chemical formula of the electrolytic water anode catalyst with high-entropy design at the A-site prepared by the above preparation method is (La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 . Through the equal-proportion doping of multiple rare earth elements (La, Sm, Eu, Ce) and Ni in the present invention, the configurational entropy of the material is increased, thereby enhancing its stability and catalytic performance. The addition of rare earth elements optimizes the active sites of the catalyst, reduces the overpotential of the oxygen evolution reaction (OER), and simultaneously improves the chemical stability of the catalyst in a strong oxidation environment.

[0053] The electrolytic water anode catalyst with high-entropy design at the A-site is applicable to the field of electrolytic water hydrogen production, and performs particularly well in alkaline electrolytic water. In addition, this catalyst can also be used as a high-performance electrode material in other electrochemical fields, such as fuel cells and metal-air batteries.

[0054] In the present invention, the "room temperature" refers to 20 - 30 °C unless otherwise specified.

[0055] All raw materials used in the present invention are obtained by purchasing in the market.

[0056] The technical solution of the present invention is further described below through examples.

[0057] Example 1

[0058] A preparation method of an electrolytic water anode catalyst with high-entropy design at the A-site includes the following steps:

[0059] 1) According to the chemical formula and stoichiometric ratio of the high-entropy designed (La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 , weigh powdery La 2 O 3 , Sm 2 O 3 , Eu 2 O 3 , CeO 2 and Ni 2 O 3 , after mixing the powders, put them into a ball mill for wet ball milling. Ball mill for 48 hours at a ball mill rotation speed of 25 revolutions per minute according to the mass ratio of zirconia balls, mixed powders and distilled water of 2∶1∶2 to obtain a powder material;

[0060] 2) Add the powder material into a blender, then add gum arabic (the mass ratio of gum arabic to the distilled water used in step 1) wet ball milling is 1:10), stir for 30 minutes, and put the obtained mixed slurry into a high-speed centrifugal spray dryer (parameters: inlet air temperature is 260 °C, outlet air temperature is 110 °C, atomization rotation speed is 250 Hz) for drying. The obtained ceramic powder is placed in a muffle furnace for calcination (heating rate is 6 °C / min, heating from room temperature to 1100 °C, and holding at this temperature for 3 h), and the calcined powder is sieved through a 120-mesh sieve;

[0061] 3) Place the sieved powder material in a plasma spraying device and spray it onto a nickel mesh, with the powder feeding amount being 300 g / m 2 , thus obtaining the electrolytic water anode catalyst with high-entropy design at the A site.

[0062] Example 2

[0063] A preparation method of an electrolytic water anode catalyst with high-entropy design at the A site, comprising the following steps:

[0064] 1) Weigh powdery La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 according to the chemical formula and stoichiometric ratio of the high-entropy design, and weigh powdery La 2 O 3 , Sm 2 O 3 , Eu 2 O 3 , CeO 2 and Ni 2 O 3 . After mixing the powders, put them into a ball mill for wet ball milling. Ball mill for 48 hours under the condition that the mass ratio of zirconia balls, mixed powders and distilled water is 2:1:2 and the ball mill rotation speed is 20 revolutions per minute to obtain a powder material;

[0065] 2) Add the powder material into a blender, then add gum arabic (the mass ratio of gum arabic to the distilled water used in step 1) wet ball milling is 1:10), stir for 30 minutes, and put the obtained mixed slurry into a high-speed centrifugal spray dryer (parameters: inlet air temperature is 260 °C, outlet air temperature is 110 °C, atomization rotation speed is 250 Hz) for drying. The obtained ceramic powder is placed in a muffle furnace for calcination (heating rate is 6 °C / min, heating from room temperature to 1120 °C, and holding at this temperature for 3.5 h), and the calcined powder is sieved through a 120-mesh sieve;

[0066] 3) Place the sieved powder material in a plasma spraying equipment and spray it onto a nickel mesh, with a powder feeding amount of 300 g / m 2 , thus obtaining the electrolytic water anode catalyst with high-entropy design at the A-site.

[0067] Example 3

[0068] A preparation method of an electrolytic water anode catalyst with high-entropy design at the A-site includes the following steps:

[0069] 1) Weigh powdery La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 according to the chemical formula and stoichiometric ratio, and weigh powdery La 2 O 3 , Sm 2 O 3 , Eu 2 O 3 , CeO 2 and Ni 2 O 3 . After mixing the powders, put them into a ball mill for wet ball milling. Ball mill for 48 hours at a ball mill rotation speed of 28 revolutions per minute according to the mass ratio of zirconia balls, mixed powders and distilled water being 2:1:2 to obtain a powder material;

[0070] 2) Add the powder material into a blender, then add gum arabic (the mass ratio of gum arabic to the distilled water used in step 1 for wet ball milling is 1:10), stir for 30 minutes, put the obtained mixed slurry into a high-speed centrifugal spray dryer (parameters: inlet air temperature is 260 °C, outlet air temperature is 110 °C, atomization rotation speed is 250 Hz) for drying, place the obtained ceramic powder in a muffle furnace for calcination (heating rate is 6 °C / min, heat up from room temperature to 1150 °C, keep warm at this temperature for 4 h), and sieve the calcined powder through a 150-mesh sieve;

[0071] 3) Place the sieved powder material in a plasma spraying equipment and spray it onto a light-net nickel mesh, with a powder feeding amount of 300 g / m 2 , thus obtaining the electrolytic water anode catalyst with high-entropy design at the A-site.

[0072] Figure 1 is the SEM image of the electrolytic water anode catalyst with high-entropy design at the A-site prepared in Example 1. It can be seen from Figure 1 that the bonding force of this ceramic electrode is very good and there is no peeling phenomenon.

[0073] The sprayed optical nickel mesh and the unsprayed optical nickel mesh were used as comparison materials for effect comparison. The concentration of the tested KOH lye was 30%, the test pressure was 1.2 MPa, and the temperature of the tested lye was 70 °C.

[0074] Figure 2 It is the instantaneous cell voltage diagram of the electrolytic water anode catalyst with high-entropy design at the A site and the cathode optical nickel mesh prepared in Example 1. From Figure 2 it can be seen that, compared with the unsprayed anode optical nickel mesh + cathode optical nickel mesh and the sprayed anode (La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO 3 + cathode optical nickel mesh, the average cell voltage is reduced by 0.1 V.

[0075] The durability test was carried out on the electrolytic water anode catalyst with high-entropy design at the A site prepared in Example 1. The concentration of the tested KOH lye was 30%, the test pressure was 1.2 MPa, and the temperature of the tested lye was 70 °C.

[0076] Figure 3 It is the aging diagram of the cell voltage of the electrolytic water anode catalyst with high-entropy design at the A site and the cathode optical nickel mesh prepared in Example 1 under the test of 6000 A / m 2 . From Figure 3 it can be seen that after Example 1 was tested at 6000 A / m 2 for 2100 h, the cell voltage did not change significantly, indicating that the electrolytic water anode catalyst with high-entropy design at the A site prepared in Example 1 of the present invention has good stability.

[0077] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A water electrolysis anode catalyst with high entropy design at the A position, characterized in that: The chemical formula of the catalyst is (La 0.25 Sm 0.25 Eu 0.25 Ce 0.25 )NiO3.

2. A method for preparing the anode catalyst for water electrolysis with high entropy design at the A position as claimed in claim 1, characterized in that: The following steps are involved: 1) Weigh powdered La2O3, Sm2O3, Eu2O3, CeO2 and Ni2O3 respectively according to the stoichiometric ratio, mix them and perform wet ball milling to obtain a powder material; 2) Adding gum arabic to the powder material, stirring, placing in a high-speed centrifugal spray dryer for granulation, sintering at high temperature, and sieving; 3) The sieved powder material is placed in a plasma spraying device and sprayed onto a nickel mesh to obtain an A-site high entropy designed water electrolysis anode catalyst.

3. The method for preparing the anode catalyst for electrolysis of water according to claim 2, wherein: The conditions for wet ball milling in step 1) are: the ball mill speed is 15-30 rpm, the ball milling time is 36-48 hours, the ball milling media are distilled water and zirconia balls, and the mass ratio of zirconia balls, material and distilled water is 2:1:

2.

4. The method for preparing the anode catalyst for electrolysis of water according to claim 2, wherein: The mass ratio of the distilled water used in the wet ball milling process in step 1) to the gum arabic in step 2) is 10:

1.

5. The method for preparing the anode catalyst for electrolysis of water with high entropy design at the A position according to claim 2, characterized in that: The conditions for granulation in the high-speed centrifugal spray dryer in step 2) are: inlet air temperature is 220-320°C, outlet air temperature is 100-150°C, and atomization speed is 200-300Hz.

6. The method for preparing the anode catalyst for electrolysis of water with high entropy design at the A position according to claim 2, characterized in that: The high temperature sintering conditions in step 2) are: keeping the temperature at 1100-1150° C. for 3-4 hours.

7. The method for preparing the anode catalyst for electrolysis of water with high entropy design at the A position according to claim 2, characterized in that: The size of the sieve used in the screening process in step 2) is 120-150 mesh.

8. The method for preparing the anode catalyst for electrolysis of water with high entropy design at the A position according to claim 2, characterized in that: The amount of powder material sprayed onto the nickel mesh in step 3) is 300 g / m 2 .

9. An application of the water electrolysis anode catalyst with high entropy design at the A site as claimed in claim 1 in the field of hydrogen production by water electrolysis.

10. Use of the water electrolysis anode catalyst with high entropy design at the A site as claimed in claim 1 in the field of electrode materials.

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