Water electrolysis catalyst and water electrolysis device

Abstract

The present invention proposes a water electrolysis catalyst and a water electrolysis device, the water electrolysis catalyst including a catalyst support and a catalyst, the catalyst growing perpendicularly and regularly on the catalyst support, and the catalyst having a nanowire or nanochain microstructure.

Description

[Technical Field]

[0001] The present invention relates to the technical field of hydrogen production by water electrolysis, and more particularly to a water electrolysis catalyst and a water electrolysis device. [Background technology]

[0002] Hydrogen is considered the most promising energy carrier, and its only combustion product is water. Its energy density is more than three times that of gasoline, and it can realize stable and environmentally friendly conversion from electrical energy to chemical energy through electrochemical water splitting.

[0003] However, the low efficiency of hydrogen energy conversion significantly limits the industrialization of hydrogen production by water electrolysis, and catalysts produced by conventional methods have poor stability in industrial electrolyzers. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention proposes a water electrolysis catalyst and a water electrolysis device that can improve catalytic activity, reduce energy consumption, and improve catalyst stability. [Means for solving the problem]

[0005] This invention proposes a water electrolysis catalyst, A microstructure of nanowires or nanochains regularly formed on the catalyst support; and nanoparticles formed by stacking the nanowire or nanochain microstructures. [Effects of the Invention]

[0006] In conclusion, the present invention proposes a water electrolysis catalyst and a water electrolysis device that can enhance the bonding with the catalyst support, thereby improving catalytic activity and efficiency. The water electrolysis efficiency can be improved by quickly diffusing and transporting gases generated by electrolysis. [Brief explanation of the drawings]

[0007] In order to more clearly describe the technical solutions in the embodiments of the present invention, the following briefly describes the drawings necessary for describing the embodiments. Of course, the diagrams described below are only examples, and those skilled in the art can derive other diagrams based on these diagrams without any creative efforts.

[0008] [Figure 1] FIG. 1 is a schematic diagram of the distribution of water electrolysis catalysts in one embodiment of the present invention. [Figure 2] FIG. 2 is an external view of a water electrolysis catalyst according to one embodiment of the present invention. [Figure 3] FIG. 3 is an external view of a water electrolysis catalyst according to another embodiment of the present invention. [Figure 4] FIG. 4 is a SEM image of a water electrolysis catalyst according to one embodiment of the present invention. [Figure 5] FIG. 5 is a SEM image of a water electrolysis catalyst according to another embodiment of the present invention. [Figure 6] FIG. 6 is a schematic diagram of the distribution of the first and second portions of the catalyst in one embodiment of the present invention. [Figure 7] FIG. 7 is a graph comparing the performance of the water electrolysis catalyst obtained in one embodiment of the present invention with that of a conventional alkaline electrode sheet. [Figure 8] FIG. 8 is a graph comparing the electrochemical test results of the water electrolysis catalyst obtained in one embodiment of the present invention with those of a conventional alkaline electrode sheet. [Figure 9] FIG. 9 shows a water electrolysis device according to one embodiment of the present invention. [Figure 10] FIG. 10 shows a water electrolysis device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes the embodiments of the present invention in light of certain specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention through the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details of the present invention can be modified or changed based on different concepts and applications without departing from the spirit of the present invention.

[0010] As shown in Figures 1 to 3, the present invention proposes a water electrolysis catalyst, which includes a catalyst support 10, a catalyst 20, and a gas flow channel 30. The catalyst 20 may, for example, grow vertically and regularly on the catalyst support 10. The gas flow channels 30 may be formed in the catalyst support 10, and the catalyst 20 on the catalyst support 10 may be divided into multiple regions by the gas flow channels 30. The catalyst support 10 is used to support the catalyst 20, which is used to catalyze water electrolysis. The gas flow channels 30 may, for example, be formed on the catalyst support 10 where no catalyst is provided, and a portion of the surface of the catalyst support 10 may be exposed, allowing gas generated during electrolysis to diffuse and transport rapidly, thereby improving electrolysis efficiency.

[0011] As shown in Figures 1 to 3, in one embodiment of the present invention, the surface shape of the catalyst support 10 is, for example, square, circular, or any other shape. The catalyst support 10 is, for example, a porous or diffusion layer of nickel foam, nickel mesh, or carbon cloth, which is used for gas diffusion. In one embodiment of the present invention, the area of ​​the catalyst support 10 is, for example, 0.5 m 2 In another embodiment of the present invention, the area of ​​the catalyst carrier 10 is, for example, 1.0 m 2 In another embodiment of the present invention, the area of ​​the catalyst carrier 10 is, for example, 0.1-5.0 m 2 In other embodiments of the present invention, the catalyst support 10 may have any other suitable shape, for example.

[0012] However, the present invention is not limited to this, and the catalyst support 10 may be a membrane layer of an electrolytic cell, such as a diaphragm, a proton exchange membrane, or an anion exchange membrane. In this case, the catalyst support 10 provided with the catalyst 20 can be a membrane electrode of the electrolytic cell.

[0013] In one embodiment, the catalyst 20 and the gas channels 30 may be formed on only one side of the catalyst support 10, such as the side closer to or farther from the center (membrane layer location) of the electrolytic cell. However, this is not limiting, and in another embodiment, the catalyst 20 and the gas channels 30 may be formed on opposite sides of the catalyst support 10.

[0014] The catalyst 20 of the present invention can be formed on one side or on both sides of the catalyst support 10 (a porous material, a diffusion layer, a membrane layer, a diaphragm, a proton exchange membrane, an anion exchange membrane, or other support).

[0015] 1 to 3, in one embodiment of the present invention, the gas flow channels 30 are distributed on the catalyst support 10 in a rectangular, square, curved, or fixed-point pattern, such as the center of the catalyst support. In one embodiment of the present invention, the gas flow channels 30 are distributed on the catalyst support 10 in a rectangular, i.e., lattice-like pattern, dividing the catalyst 20 supported on the catalyst support 10 into multiple lattice-like regions. The length or width of the lattice-like catalyst supported on the catalyst support 10 is, for example, 1-100 cm, or, for example, 5-30 cm. In one embodiment of the present invention, the width of the gas flow channels 30 is, for example, 0.1-5 cm.

[0016] As shown in Figures 4 and 5, in one embodiment of the present invention, the catalyst 20 is, for example, a nickel alloy, a nickel-iron-based multi-component alloy, or other alloy, and its microstructure includes a regular nanowire or nanochain structure, with the nanowire or nanochain having a diameter of, for example, 0.1-2.0 μm and a length of, for example, 0.1-200 μm. In one embodiment of the present invention, the catalyst 20 contains, for example, the following components by mass: 70%-95% Ni, 4.98%-14.98% Fe, and the remainder being a noble metal or transition metal, which may be at least one of platinum, ruthenium, or molybdenum. In another embodiment of the present invention, the catalyst 20 contains, for example, the following components by mass: 85%-95% Ni, 0.02%-10.2% at least one of platinum, ruthenium, or molybdenum, and 4.98%-14.98% Fe.

[0017] As shown in Figures 4 and 5, in one embodiment of the present invention, the micromorphology of the catalyst 20 may be nanowires or nanochains, with the nanowire diameter being, for example, 0.1-1.2 μm and the nanowire length being, for example, 0.1-100 μm. The nanowire includes a first portion 201 and a second portion 202, with the second portion 202 covering the first portion 201, and the second portion 202 including, for example, a nanolamella structure covering the first portion 201. In one embodiment of the present invention, the first portion 201 is a framework portion, which includes nickel platinum nanowires with a length of 0.1-0.6 μm, which are composed of nanoparticle "stacks," and the second portion 202 includes honeycomb-shaped nanowires with a length of, for example, 0.1-100 μm, which are composed of nickel iron nanosheets built on the framework portion. In one embodiment of the present invention, the nanoparticles have a diameter of, for example, 5 nm-500 nm.

[0018] The nanowires or nanochains of catalyst 20 can also be formed on the support by in situ growth. When forming nanowires or nanochains by in situ growth, metal ions in the original solution are directly reduced on the support (porous layer or membrane layer) to form nanoparticles, and the reduced nanoparticles are then directly and regularly arranged on the support, thereby directly forming the nanowires or nanochains on the support. Furthermore, forming nanowires or nanochains by in situ growth strengthens the bonding force between the nanowires and the support (porous layer or membrane layer), thereby stably forming catalyst 20 on the support (porous layer or membrane layer). Furthermore, nanoparticles with specific dimensions in the present invention can form regularly and vertically arranged nanowires or nanochains, thereby improving the electrolysis efficiency of the catalyst.

[0019] 5 and 6, in one embodiment of the present invention, the main component of the second portion 202 is, for example, a nickel-iron nanosheet structure, and the second portion 202 of the catalyst 20 coats the first portion 201 in, for example, a fish-scale pattern, i.e., the thickness of the second portion 202 on the first portion 201 is non-uniform, and there is partial overlap between the nanosheet structures. In the present invention, the catalyst is made of nanoparticles that form nanowires, and the nanosheets are constructed based on the nanowires, which can enhance the bond with the catalyst support and increase the contact area between the catalyst and water during water electrolysis, thereby improving catalytic activity and efficiency.

[0020] It should be noted that the second portion 202 covering at least a part of the first portion 201 may have other shapes, such as a particulate shape or an irregular shape.

[0021] In one embodiment, the catalyst 20 may be an anode catalyst. In this case, the catalyst 20 may include a first portion 201 and a second portion 202. The first portion 201 may be a nanowire or nanochain composed of nanoparticles, and the second portion 202 may be a nanosheet-like structure covering the nanowire or nanochain of the first portion 201. The main components of the first portion 201 and the second portion 202 may be different. For example, the main component of the first portion 201 is nickel (e.g., containing the following components by mass percentage: 85% to 99.8% Ni, the remainder may be a noble metal or a transition metal), and the main components of the second portion 202 are nickel and iron (e.g., containing the following components by mass percentage: 85% to 95% Ni, 4.98% to 14.98% Fe, the remainder may be a noble metal or a transition metal). When the catalyst 20 is disposed in an electrolytic cell, the catalyst 20 as an anode catalyst may include a first portion 201 and a second portion 202, and the main components of the first portion 201 and the second portion 202 may be different. In this case, the catalyst 20 as a cathode catalyst may include only the nanowires or nanochains of the first portion 201.

[0022] However, without being limited thereto, in one embodiment, the catalyst 20 serving as the anode catalyst and the cathode catalyst may include only the nanowires or nanochains of the first portion 201, and may not cover the second portion 202. In this case, the main components of the catalyst 20 serving as the anode catalyst and the cathode catalyst may be the same (for example, containing the following components by mass percentage: 70%-95% Ni, 4.98%-29.98% Fe, and the remainder may be a noble metal or a transition metal) or may be different.

[0023] 4 to 5, the scanning electron microscope images shown in Figures 4 and 5 were obtained by observing the water electrolysis catalyst in one specific embodiment of the present invention using a scanning electron microscope (SEM). As can be seen from Figure 4, the micromorphology of the catalyst in this embodiment of the present invention can have a nanowire or nanochain structure that can grow substantially perpendicular to the substrate material (catalyst support), and the nanowire or nanochain structure is made up of "stacking" nanoparticles, with the nanowire diameter being, for example, 0.1-0.6 μm and the nanowire length being 0.1 μm to 100 μm. As can be seen from FIG. 5, in one embodiment of the present invention, the microstructure of the catalyst 20 is, for example, platinum-nickel-iron nanowires grown perpendicular to the catalyst support, with a diameter of 0.1-1.2 μm, and the platinum-nickel-iron nanowires comprising a first portion and a second portion, the first portion being a framework portion comprising nanowires or nanochains formed by "stacking" nanoparticles of 0.1-0.6 μm, and the second portion being nanosheets constructed based on the framework portion, e.g., honeycomb- or fish-scale-shaped nanowires, with a length of, for example, 0.1 μm-100 μm.

[0024] As shown in Figure 7, an alkaline electrolytic cell (Example 1) was constructed by combining the water electrocatalyst of one embodiment of the present invention with a diaphragm and an electrode plate, and an operational test was conducted to compare the performance of the water electrocatalyst manufactured in this example with that of a conventional alkaline electrode sheet, which has, for example, a "nickel mesh + Raney nickel plating" structure. As can be seen from Figure 7, an electrochemical test was used to compare the performance of the water electrocatalyst manufactured in this example with that of a conventional alkaline electrode sheet, and it was found that the current density of the water electrocatalyst manufactured in this example was up to 11,000 A / m at 2.0 V. 2 This is clearly superior to conventional alkaline sheets.

[0025] As shown in Figure 8, the electrochemical activity of the water electrocatalyst prepared in one embodiment of the present invention (Example 1) was compared with that of a conventional alkaline electrode sheet, which has a structure such as "nickel mesh + Raney nickel plating." The electrochemical activity of the water electrocatalyst prepared in this embodiment was significantly superior to that of the conventional alkaline electrode sheet, with the oxygen evolution overpotential (η10) of the water electrocatalyst prepared in this embodiment being 231 mV, while that of the Raney nickel was 302 mV.

[0026] 7 and 8 are applied to alkaline electrolyzers, but are not limited thereto, and the water electrolysis catalyst of the present invention can also be applied to electrolyzers with other catalytic electrodes, such as proton exchange membrane (PEM) electrolyzers, anion exchange membrane (AEM) electrolyzers, solid oxide electrolytic capacitors (SOEC) electrolyzers, or other electrolyzers using catalytic electrodes. In this case, a water electrolysis device (e.g., a hydrogen production electrolyzer) or system using the catalyst of the present invention can include a membrane cell 101, a diffusion cell 102, and a catalyst 20, with the catalyst 20 located between the membrane cell 101 and the diffusion cell 102.

[0027] In some embodiments, as shown in FIG. 9, the catalyst of the present invention can be applied to a hydrogen production electrolyzer. The hydrogen production electrolyzer includes a membrane layer 101, at least two diffusion layers 102, and a catalyst. The diffusion layers 102 are located on opposite sides of the membrane layer 101. A catalyst 20 is formed between the membrane layer 101 and the diffusion layer 102. In one embodiment, the catalyst 20 can be formed on one side of the diffusion layer 102 and adjacent to the membrane layer 101. In another embodiment, the catalyst 20 can be formed on both sides of the diffusion layer 102. In yet another embodiment, the catalyst 20 can be formed on both sides of the diffusion layer 101. The membrane layer 101 can be a diaphragm, a proton exchange membrane (PEM), an anion exchange membrane, or other membrane layer used in hydrogen production electrolysis, and the diffusion layer 102 can be a nickel mesh, nickel foam, carbon mesh, or other porous layer.

[0028] In some embodiments, as shown in FIG. 9 , the hydrogen producing electrolyzer (or water electrolysis device) of the present invention includes multiple electrolysis units (or electrolysis cells), each of which includes a membrane layer 101, at least two diffusion layers 102, and a catalyst 20.

[0029] In some embodiments, as shown in Figure 10, the catalyst of the present invention can be applied to a hydrogen production electrolyzer, which can include a membrane layer 101, at least two diffusion layers 102, at least two electrode sheets 103, and an electrode plate 104. The diffusion layers 102 are located on opposite sides of the membrane layer 101. The electrode sheets 103 are formed between the membrane layer 101 and the diffusion layers 102. The electrode sheets 103 can be an anode electrode sheet and a cathode electrode sheet, respectively, and the electrode sheets 103 can include a catalyst 20 and a catalyst support 10. The catalyst 20 can be formed on one side of the catalyst support 10 and adjacent to the membrane layer 101, or the catalyst 20 can be formed on both sides of the catalyst support 10. In the embodiment of FIG. 10, the membrane layer 101 may be a diaphragm, a proton exchange membrane (PEM), an anion exchange membrane, or other membrane layer used in hydrogen production electrolysis, and the diffusion layer 102 and the catalyst support 10 may be nickel mesh, nickel foam, carbon mesh, or other porous layers.

[0030] In some embodiments, the electrode plate 104 may be, for example, a nickel-plated stainless steel plate, a nickel plate, or other metal / alloy plate.

[0031] In some embodiments, as shown in FIG. 10 , the hydrogen producing electrolyzer (or water electrolysis device) of the present invention may include multiple electrolysis units (or electrolysis cells), each of which may include a membrane layer 101, at least two diffusion layers 102, at least two electrode sheets 103, and an electrode plate 104.

[0032] In some embodiments, the membrane layer may be a membrane (eg, a composite membrane), and the primary component of the membrane may be, for example, polyphenylene sulfide, zirconium oxide, and / or polysulfone.

[0033] In some embodiments, the pore size index (PPI) of the diffusion layer is, for example, less than 100, and in other embodiments, less than 80. In some embodiments, the thickness of the diffusion layer is, for example, 1.5 mm-10 mm. In some embodiments, the nickel content per square meter of the nickel foam or nickel mesh is, for example, 500 g / m 2 Exceeds.

[0034] In different embodiments, the main component of the catalyst 20 deposited on the cathode electrode may be, for example, Pt, Ni, and / or other metals / alloys, and the main component of the catalyst deposited on the anode electrode may be, for example, Pt, Ni, Fe, and / or other metals / alloys.

[0035] It should be noted that the components of the catalyst 20 of the present invention are not limited to the above metals / alloys, but may be any other suitable metals / alloys / materials, such as high-entropy materials.

[0036] In conclusion, this invention proposes a water electrolysis catalyst and water electrolysis device. The catalyst can be formed into nanoparticles, for example, by in situ growth, and can be organized into regular nanowires. The gas channels are used to rapidly diffuse and transport the gas generated during the electrolysis process, improving the efficiency of water electrolysis. The application of the water electrolysis catalyst sheet manufactured by this invention to a water electrolysis device improves catalytic activity, reduces energy consumption, and improves stability.

[0037] The above embodiments are intended to illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Those skilled in the art may modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention shall still fall within the scope of the utility model claims of the present invention.

Claims

1. A water electrolysis catalyst, A nanowire or nanochain microstructure formed on the catalyst support; nanoparticles formed by stacking the nanowire or nanochain microstructures; The water electrolysis catalyst is characterized in that the nanoparticles have a diameter of 5 nm to 500 nm.

2. 2. The water electrolysis catalyst according to claim 1, wherein the catalyst comprises a first portion and a second portion, the second portion covering the first portion.

3. 3. The water electrolysis catalyst according to claim 2, wherein the first portion has a wire diameter of 0.1-1.2 μm and a length of 0.1-0.6 μm.

4. 3. The water electrolysis catalyst according to claim 2, wherein the second portion has a length of 0.1-100 μm.

5. The water electrolysis catalyst according to claim 2 , wherein the second portion includes a nanolamellar structure, and the nanolamellar structure covers the first portion.

6. 2. The water electrolysis catalyst according to claim 1, wherein the nanowires or nanochains have a diameter of 0.1-2.0 μm and a length of 0.1-200 μm.

7. 2. The water electrolysis catalyst according to claim 1, wherein the catalyst is distributed in a lattice pattern on the catalyst support, and the length or width of the lattice-shaped catalyst mesh is 1-100 cm.

8. The water electrolysis catalyst according to claim 1, wherein the catalyst support is square or circular.

9. 2. The water electrolysis catalyst according to claim 1, wherein the catalyst grows regularly on the catalyst support.

10. 2. The water electrolysis catalyst according to claim 1, wherein the catalyst support is a porous layer or a diffusion layer.

11. 2. The water electrolysis catalyst according to claim 1, wherein the catalyst support is a diaphragm, a proton exchange membrane, or an anion exchange membrane.

12. The water electrolysis catalyst according to claim 1 , wherein the catalyst is formed on one side of the catalyst support.

13. The water electrolysis catalyst according to claim 1 , wherein the catalyst is formed on both opposing sides of the catalyst support.

14. The water electrolysis catalyst according to claim 1 , further comprising a gas flow path formed in the catalyst support.

15. 2. The water electrolysis catalyst according to claim 1, wherein the catalyst contains at least 70% to 95% Ni by mass.

16. 2. The water electrolysis catalyst according to claim 1, wherein the catalytic nanowires or nanochains are formed on the catalyst support by an in-situ growth method.

17. A water electrolysis device, a membrane layer; At least two diffusion layers located on opposite sides of the membrane layer; a catalyst formed between the membrane layer and the diffusion layer; The catalyst is A nanowire or nanochain microstructure formed on the catalyst support; nanoparticles formed by stacking the nanowire or nanochain microstructures; A water electrolysis device, characterized in that the nanoparticles have a diameter of 5 nm to 500 nm.

18. 18. The water electrolysis device according to claim 17, wherein the catalyst components serving as the anode catalyst and the cathode catalyst are the same.

19. 18. The water electrolysis device according to claim 17, wherein the components of the catalysts serving as the anode catalyst and the cathode catalyst are different from each other.

20. 18. The water electrolysis apparatus according to claim 17, further comprising at least two electrode sheets respectively positioned between the membrane layer and the diffusion layer, the electrode sheets including the catalyst and a catalyst support.

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