Electrode of electrolytic cell, and application thereof

Abstract

An electrode of an electrolytic cell, and an application thereof. The electrode comprises: a substrate (102); a surface treatment layer (106), which is formed on the substrate (102); and a catalyst layer (20), which is formed on the surface treatment layer (106). The surface structure and / or surface properties of the substrate can be modified by means of the surface treatment layer, so that the surface area of a subsequent electrode is increased, allowing more active sites to be exposed, thereby effectively improving the electrochemical performance of the electrode.

Description

Electrode of an electrolytic cell and its application Technical Field

[0001] This application relates to the field of electrochemical technology, specifically to an electrode for an electrolytic cell and an electrolytic cell for its application. Background Technology

[0002] Hydrogen energy is considered a highly promising clean energy source due to its environmental friendliness, high energy density, zero carbon emissions, and recyclability. Currently, there are many ways to produce hydrogen, including water electrolysis, coal gasification, and catalytic conversion of heavy oil and natural gas into hydrogen via steam. Among these, electrolysis is the most practical and cleanest method.

[0003] However, current hydrogen production technology still suffers from problems such as low electrolysis efficiency and high cost, which limit its development.

[0004] Utility Model Content

[0005] This application provides an electrode for an electrolytic cell, comprising:

[0006] Substrate;

[0007] A surface treatment layer is formed on the substrate; and

[0008] A catalyst layer is formed on the surface treatment layer.

[0009] In summary, this application proposes an electrode catalyst, its preparation method, and its application, which can ensure the performance and stability of the electrode sheet. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figures 1-3 show scanning electron microscope (SEM) images of the electrode catalysts in the embodiments of this application.

[0012] Figure 4 shows a physical image and performance curve of the membrane electrode prepared by the electrode catalyst shown in Figure 1.

[0013] Figure 5 is a structural diagram of the electrodes of an electrolytic cell in one embodiment of this application.

[0014] Figure 6 is a schematic diagram of an electrode observed with a magnification of 10,000 using a scanning electron microscope in one embodiment of this application.

[0015] Figure 7 is a schematic diagram of the electrodes of a hydrogen electrolyzer observed by scanning electron microscopy at a magnification of 50x in one embodiment of this application.

[0016] Figure 8 is a comparison diagram of the performance tests of the electrodes of the hydrogen production electrolyzer in an embodiment of this application and a comparative example.

[0017] Figures 9-11 are schematic diagrams of the electrolytic cells in the embodiments of this application.

[0018] Figures 12-15 are schematic diagrams of the electrodes in the embodiments of this application.

[0019] Figures 16-17 are schematic diagrams of the surface treatment layer in one embodiment of this application.

[0020] Figure 18 is a schematic diagram of an electrolytic cell in one embodiment of this application.

[0021] Figures 19-24 are scanning electron microscope images of the heteromorphic nanocatalysts in the examples. Detailed Implementation

[0022] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application.

[0023] In one embodiment, the electrode catalyst of this application has a nanosheet catalyst structure, wherein the surface of the nanosheet catalyst structure has multiple pores with a pore size of less than 80 nm.

[0024] In one embodiment, the nanosheet catalyst structure comprises a coral-like dealloyed nanowire array structure with a coral-like porous structure. The length of the nanowire array is, for example, 10 μm to 1100 μm, and the diameter of the nanowires is, for example, 120 nm to 200 nm. In this embodiment, the electrode catalyst includes at least elements M and N, wherein element M is selected from at least one transition metal such as Mn, Cr, Fe, Co, Ni, or Cu, and element N is selected from noble metals such as Ir. The electrocatalyst, for example, comprises the following components by mass percentage: 50% to 70% M, 20% to 50% N, and the remainder being oxygen. By forming a coral-like porous structure, the specific surface area of ​​the electrode catalyst is increased, thereby increasing the contact area with water and improving the catalytic efficiency for the same mass.

[0025] In one embodiment, the specific surface area of ​​the electrode catalyst may be greater than or equal to 10 m². 2 / g. This increases the electrochemical specific surface area of ​​the electrode catalyst, resulting in high exposure of active sites and numerous mass transfer channels, thus improving the catalytic performance of the electrode catalyst. Using the electrode catalyst to form a membrane electrode significantly reduces the amount of precious metals required in the catalyst layer, leading to a substantial decrease in cost.

[0026] In another embodiment, the nanosheet catalyst structure includes a hollow spherical structure or a hollow chain structure. In the hollow spherical structure, the diameter of the hollow spheres is, for example, 3 nm to 25 nm. In the hollow chain structure, the length of the hollow chain is, for example, 10 μm to 1100 μm, and the diameter of the hollow spheres on the hollow chain is, for example, 0.5 μm to 1.5 μm. The hollow structure of the electrode catalyst has a regular shape and uniform size, which is beneficial for fluid transport.

[0027] In another embodiment, the electrode catalyst comprises at least two of a transition metal, a lanthanide rare earth element, and a platinum group noble metal element. The transition metal includes, for example, at least one of Mn, Cr, Zr, Fe, Co, Ni, Cu, Zn, Mo, or W. The platinum group noble metal element includes at least one of Ru, Rh, Pd, Ag, Os, Ir, Pt, or Au. In one embodiment, the electrocatalyst comprises, for example, the following components by mass percentage: 50%–80% transition metal, 20%–40% lanthanide rare earth element and / or platinum group noble metal element, with the remainder being oxygen. In one embodiment, the specific surface area of ​​the electrode catalyst is, for example, 20 m². 2 / g. By forming hollow spherical electrode catalysts, the electrochemical specific surface area of ​​the electrode catalyst can be increased. At the same time, the hollow structure improves the mass transfer efficiency and strength of the catalyst, thereby enhancing the catalytic performance of the electrode catalyst.

[0028] In one embodiment, a method for preparing an electrode catalyst is provided, comprising at least steps S11-S14.

[0029] Step S11: Prepare the metal precursor solution.

[0030] Step S12: Add a morphology inducer to the metal precursor solution.

[0031] Step S13: Under alkaline conditions, the mixture is kept at a preset temperature and stirred for a preset time to obtain an intermediate.

[0032] Step S14: Perform pore-forming treatment on the intermediate to obtain the electrode catalyst.

[0033] In one embodiment, in step S11, the metal precursor solution contains at least two of the following metal elements: transition metals, lanthanide rare earth elements, and platinum group noble metals. Transition metals include, for example, at least one of Mn, Cr, Zr, Fe, Co, Ni, Cu, Zn, Mo, or W. Platinum group noble metals include at least one of Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au. The solvent for the metal precursor solution includes pure water, ultrapure water, deionized water, or tap water. The metal elements are derived from water-soluble metal salts such as metal salts, metal halides, metal sulfates, or metal nitrates. Metal salts are, for example, anions containing metal elements, such as tungstate, molybdate, chloroplatinate, and chloroaurate. The metal salt is added to the solvent, for example, by ultrasonic stirring for 2 to 5 minutes to obtain the metal precursor solution. The total concentration of metal ions in the metal precursor solution is, for example, 0.01 to 1 M.

[0034] In one embodiment, in step S11, different metal precursor solutions can be selected to obtain electrode catalysts with different morphologies. In a specific embodiment of this application, to obtain an electrode catalyst with a coral-like porous structure, the metal precursor solution includes at least one transition metal such as Mn, Cr, Fe, Co, Ni, or Cu, and a noble metal such as Ir. In another embodiment, to obtain an electrode catalyst with a hollow spherical structure or a hollow chain structure, the metal precursor solution includes at least two of transition metals, lanthanide rare earth elements, and platinum group noble metal elements, wherein the transition metals include at least one of Mn, Cr, Zr, Fe, Co, Ni, Cu, Zn, Mo, or W, and the platinum group noble metal elements include at least one of Ru, Rh, Pd, Ag, Os, Ir, Pt, or Au.

[0035] In one embodiment, in step S12, different morphology inducers are added to the metal precursor solution to obtain nanosheet catalyst structures with different morphologies. In one embodiment, to obtain an electrode catalyst with a coral-like porous structure, a first inducer and a second inducer are added sequentially. The first inducer includes solvents such as metal salts, metal halides, metal sulfates, and metal nitrates, and the metal is selected from at least two of Mn, Cr, Fe, Co, Ni, Cu, Zn, and platinum group noble metals. The second inducer is selected from at least one organic solvent such as methanol, ethanol, propanol, acetone, dimethylformamide, cyclohexane, ethyl acetate, and dimethyl sulfoxide. In one embodiment, the concentration of metal ions in the first inducer is, for example, 0.5 M, and the molar ratio of the metal precursor solution, the first inducer, and the second inducer is, for example, 1:1.

[0036] In another embodiment, in step S12, to obtain an electrode catalyst with a hollow spherical structure or a hollow chain structure, an organic inducing agent is added, for example, selected from isophthalic acid esters, phthalates, 1,4-diazabicyclo[2.2.2]octane, triethylenediamine, 1,4-dimethylpiperazine, hexamethylenetetramine, pyromellitic acid, pyromellitic tricarboxylic acid, 1,4-bis(1H-pyrazol-4-yl)benzene, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetracarboxylic acid, 2,4,6-tris(4-pyridyl) At least one of the following: 1,3,5-triazine, tris(isobutylaminoethyl)amine, bis(3,5-dicarboxyphenyl)azo, biphenylcarboxylic acid, 2,5-dihydroxyterephthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-phenylene diacetic acid, 1,1,2,2-tetra(4-carboxyphenyl)ethylene, 1,3,5-tris(4-carboxyphenyl)benzene, 2-(diphenylphosphino)terephthalic acid, 2-amino-4-hydroxy-6-methylpyrimidine, 2-methylimidazolium, 2-aminoterephthalic acid, terephthalic acid, fumaric acid, and trioctyl trimellitate. The molar ratio of the organic inducer to the total metal ion concentration in the metal precursor solution is, for example, 1:10000 to 100:1.

[0037] In one embodiment, in step S12, the metal precursor solution and the morphology inducer are mixed uniformly, for example, by ultrasonic stirring for a time of 2 to 5 minutes. In other embodiments, mixing can also be performed by other methods.

[0038] In one embodiment, different metal precursor solutions and morphology inducers are selected according to the preset morphology or performance requirements of the electrode catalyst to be obtained, so as to achieve the production requirements of different morphologies.

[0039] In one embodiment, in step S13, under alkaline conditions, the intermediate is obtained by stirring at a preset temperature for a preset time. For example, alkaline substances such as ammonia and potassium hydroxide are added to a mixed solution of a metal precursor solution and a morphology inducer, the pH value is controlled at 8-14, and the mixture is stirred at a preset temperature to obtain solid intermediates with different morphologies.

[0040] In one embodiment, different preset temperatures are used to obtain different morphologies of the electrode catalyst. In one specific embodiment of this application, a coral-like dealloyed nanowire array structure is obtained under the conditions of a first inducing agent and a second inducing agent, at a preset temperature of, for example, 40°C to 80°C and a preset stirring time of, for example, 5 min to 1200 min. In another specific embodiment of this application, a spherical or spherical chain structure is obtained under the conditions of an organic inducing agent, at a preset temperature of, for example, 40°C to 90°C and a preset stirring time of, for example, 5 min to 1200 min.

[0041] In one embodiment, before step S14, the intermediate is first cleaned and filtered to remove impurities. For example, deionization is used for cleaning. When creating pores in the intermediate, methods such as acid washing or calcination are used to remove some metals and form pores on the catalyst surface to obtain a porous electrode catalyst. The specific method is selected based on the desired morphology of the prepared electrode catalyst.

[0042] In one embodiment, when creating pores in the coral-like dealloyed nanowire array structure, pores are created, for example, by acid washing. Specifically, for example, one or more of sulfuric acid, hydrochloric acid, or nitric acid with a concentration of 0.01 to 1 M are selected and soaked at room temperature for 1 min to 60 min to obtain a coral-like porous structure.

[0043] In another embodiment, when creating pores in the spherical or spherical chain structure, pores are created, for example, by acid washing or calcination, to obtain a hollow structure. The acid-washed electrode catalyst is then cleaned and dried before storage, for example, by rinsing with deionized water, followed by drying at, for example, 80°C. When calcination is chosen, the calcination temperature is, for example, 300°C to 900°C, and the calcination time is, for example, 1 min to 240 min. Calcination is carried out, for example, in a mixed atmosphere of one or more of N2, Ar, NH4, or air. After calcination, the catalyst is dried into powder for storage.

[0044] As shown in Figure 1, the microstructure of the electrode catalyst, as revealed by scanning electron microscopy (SEM), is a coral-like nanowire array structure comprising a nanosheet catalyst structure. The length of the nanowire array is, for example, 10 μm to 1100 μm, and the diameter of the nanowires is, for example, 120 nm to 200 nm. Analysis showed that the electrode catalyst prepared in this embodiment contains 70% M, 20% N, and 10% oxygen, with a uniform elemental distribution, improving the consistency of the catalytic effect.

[0045] As shown in Figures 2 and 3, the electrode catalyst has a hollow spherical structure with a diameter of, for example, 3 nm to 25 nm. Figure 3 shows that the electrode catalyst prepared in this embodiment has a hollow chain structure with a length of, for example, 10 μm to 1100 μm, and the diameter of the hollow spheres on the hollow chains is, for example, 0.5 μm to 1.5 μm.

[0046] As shown in Figure 4, the electrode catalyst can be uniformly distributed on the substrate to form a membrane electrode or electrode sheet, and the membrane electrode product has high quality. At 60°C, with an Ir loading of 0.1 mg Ir·cm⁻¹... -2 Under these conditions, it can be seen from the voltage as a function of current density that 2A·cm-2 The electrolysis voltage is 2.02V, which is relatively low, indicating that the amount of Ir used can be reduced, thus lowering the manufacturing cost.

[0047] As shown in Figures 5 to 7, this application also provides an electrode for an electrolytic cell. The electrode includes, for example, a substrate 30, a catalyst layer 20, and a spinel-like structure layer 40. The catalyst layer 20 is on the substrate 30, and the spinel-like structure layer 40 is formed on the top of the catalyst layer 20 and protrudes away from the catalyst layer 20. In the electrode of the electrolytic cell provided in this application, the catalyst layer 20 serves as the substrate supporting the spinel-like structure layer 40, which has the advantages of high integrity, low internal stress, and high catalytic activity. It can smoothly cope with complex operating conditions and better couple the fluctuating inputs of photovoltaic and wind power.

[0048] In the embodiments, the substrate 30 may be, for example, a nickel mesh, nickel foam, nickel felt, carbon cloth, diffusion layer substrate or porous substrate, etc., but is not limited thereto, and can be selected according to actual needs.

[0049] As shown in Figures 5 to 7, a catalyst layer 20 is disposed on a substrate 30, and the catalyst layer 20 may include a top end 201 and a bottom end 202. The bottom end 202 is in contact with the substrate 30, and the top end 201 extends from the bottom end 202 in a direction away from the substrate 30. Specifically, in one embodiment, the catalyst layer may be formed of nanowires, for example, with nanowire tips. The nanowire tips have the smallest size in the cross-sectional direction of the nanowires, and the nanowire tips are, for example, the top end 201, disposed away from the substrate 30. The nanowires may be metal nanowires. Specifically, in this embodiment, the nanowire precursor is, for example, NiCo nanowires. In the cross-sectional direction of the nanowire precursor, the size of the nanowire precursor is, for example, 2μm-3μm, the length of the nanowire precursor is, for example, 50μm-500μm, and the size of the nanowire tip is, for example, 0.5μm-1μm.

[0050] As shown in Figures 5 to 7, a spinel-like structure layer 40 is disposed on the top end 201 of the catalyst layer 20 and protrudes in a direction away from the catalyst layer 20. Specifically, in this embodiment, the spinel-like structure layer 40 is disposed on the tip of the nanowire and protrudes in a direction away from the catalyst layer 20. The material of the spinel-like structure layer 40 includes at least one of non-precious metal materials such as nickel, iron, or cobalt. Furthermore, the spinel-like structure layer 40 may have a porous structure, so that the electrode of the electrolyzer has a large specific surface area, facilitating the entry of electrolyte into the interior of the spinel-like structure layer 40. The metal material in the spinel-like structure layer 40 acts as a catalyst, catalyzing the electrolytic hydrogen production reaction. Moreover, the porous nature of the spinel-like structure layer 40 facilitates the smooth discharge of hydrogen generated by electrolysis to the outside of the electrode of the electrolyzer, achieving rapid gas-liquid separation, reducing system resistance, and exposing more active sites. Compared with precious metal electrodes, the electrolyzer electrode provided in this application uses a non-precious metal material as a catalyst, which has the advantages of low preparation cost and large-scale application.

[0051] This application also provides a method for preparing electrodes for an electrolytic cell, which includes at least steps S21-S24.

[0052] Step S21: Provide substrate 30.

[0053] Step S22: Form a catalyst layer 20 on the substrate 30.

[0054] Step S23: Immerse the substrate 30 with the catalyst layer 20 in the electrodeposition solution and pass a fluctuating current into the electrodeposition solution to perform electrodeposition.

[0055] Step S24: A spinel-like structure layer 40 is obtained on the top 201 of the catalyst layer 20, and the spinel-like structure layer 40 is arranged to protrude in a direction away from the catalyst layer 20.

[0056] In one embodiment, after obtaining the substrate 30, in step S22, specifically taking nanowires as an example, the formation process of the catalyst layer 20 will be described. For example, nanowires can be prepared by spraying, coating, physical vapor deposition, chemical vapor deposition, template method, and solvothermal method. Specifically, for example, taking the preparation of NiCo nanowires by solvothermal method as an example, the preparation process of nanowires will be described, and the preparation steps of nanowires may include steps S121-S123.

[0057] Step S121: Mix the nickel source, cobalt source and urea in a solvent until homogeneous to obtain a mixed solution.

[0058] Step S122: After adding the substrate 30 to the mixed solution, heat it to a preset temperature and keep it at that temperature for a preset time to obtain the reaction product.

[0059] Step S123: The reaction product is cleaned and dried to obtain a substrate 30 loaded with nanowires.

[0060] In one embodiment, in step S121, the nickel source includes, for example, at least one nickel salt such as nickel nitrate, nickel chloride, and nickel sulfate; the cobalt source includes, for example, at least one cobalt salt such as cobalt nitrate, cobalt chloride, and cobalt sulfate; the solvent is, for example, at least one deionized water, methanol, and ethanol; and the molar ratio of the nickel source, cobalt source, and urea is, for example, (0.1-0.2):(0.05-0.15):(5-10). Specifically, in this embodiment, the nickel source is, for example, nickel nitrate hexahydrate; the cobalt source is, for example, cobalt nitrate hexahydrate; and the molar ratio of the nickel source, cobalt source, and urea is, for example, 0.15:0.1:7.2.

[0061] In one embodiment, after obtaining the nanowires and substrate 30, in steps S23 and S24, the substrate 30 with nanowires is immersed in an electrodeposition solution, and a fluctuating current is passed through the electrodeposition solution. The metal ions in the electrodeposition solution are reduced to metal atoms and electrodeposited onto the nanowires. Furthermore, during the electrodeposition process, due to the current concentration phenomenon, the current tends to concentrate at the tip of the nanowire, and the electrode spacing at the tip of the nanowire is small. Therefore, metal atoms tend to deposit on the tip of the nanowire, thereby obtaining a spinel-like structure layer 40 on the tip of the nanowire, and the spinel-like structure layer 40 protrudes away from the nanowire. The electrodeposition solution includes, for example, at least one of nickel sulfate, nickel chloride, nickel sulfamate, nickel nitrate, ferrous sulfate, ferrous chloride, cobalt sulfate, cobalt nitrate, or cobalt chloride; the waveform of the fluctuating current includes, for example, at least one of square wave, ramp wave, triangular wave, or sine wave; the fluctuating period of the fluctuating current is, for example, 0.5h-2h; the peak value of the fluctuating current is, for example, 15A-20A; and the valley value is, for example, 1A-5A.

[0062] In some embodiments, multiple electrodeposited layers may be formed, for example, multiple electrodeposited layers may be stacked on a substrate, and the materials of the multiple electrodeposited layers may be the same or different. In some embodiments, the electrodeposited layers may also be formed directly on the diffusion layer 102 and / or the substrate 30, serving as the catalyst layer 20.

[0063] This application also provides an embodiment and a comparative example. The embodiment refers to the electrode of the electrolytic cell provided in this application. In the embodiment, the substrate 30 is, for example, a nickel mesh, the nanowires are, for example, NiCo nanowires, the diameter of the nanowires is, for example, 2μm-3μm, the diameter of the nanowire tips is, for example, 0.5μm-1μm, and the material of the spinel-like structure layer 40 includes nickel. The comparative example is a Raney nickel electrode, and in the Raney nickel electrode of the comparative example, the mass content of nickel is, for example, 85wt%, and the mass content of aluminum is, for example, 15wt%. Then, the electrochemical performance of the electrodes of the embodiment and the comparative example is tested. Specifically, using the electrode in the embodiment or the comparative example as the working electrode, a 1mol / L potassium hydroxide solution as the electrolyte, at 25°C, using a Hg / HgO electrode as the reference electrode, and a nickel mesh electrode as the counter electrode, a linearly changing voltage is applied to the working electrode using linear scanning voltammetry, and the change of the electrolytic current of the working electrode with the voltage is measured.

[0064] As shown in Figure 8, in one embodiment, based on the linear scan voltammetry of the two working electrodes in the embodiment and comparative examples, it can be concluded that at 3000 A / m 2 In the examples, the overpotential of the electrodes in the electrolyzer is, for example, 220 mV, while the overpotential of the Raney nickel electrode in the comparative example is, for example, 375 mV. Compared with the Raney nickel electrode in the comparative example, the electrodes of the electrolyzer in the examples have better catalytic ability and catalytic activity for the hydrogen evolution reaction. Therefore, the electrodes of the electrolyzer provided in this application have advantages such as high integrity, low internal stress, and high catalytic activity, and can smoothly cope with complex operating conditions, better couple the fluctuating input of photovoltaic and wind power, and can be applied to high-electric-density electrolyzers, for example.

[0065] In one embodiment, the membrane is, for example, a polyphenylene sulfide (PPS) membrane, an organic-inorganic composite membrane, or a hydroxide ion exchange membrane, etc. The thickness of the PPS membrane is, for example, 0.5 mm to 1 mm, and the thickness of the organic-inorganic composite membrane is, for example, 0.2 mm to 0.8 mm.

[0066] It is worth noting that the electrode and catalyst layer 20 of this application can be applied in an electrolytic cell suitable for a catalyst electrode. An electrolytic device (such as an electrolytic cell) or system using the catalyst of this application may include a film layer 101, a diffusion layer 102 and a catalyst layer 20, wherein the catalyst layer 20 is located between the film layer 101 and the diffusion layer 102.

[0067] In some embodiments, as shown in FIG9, the catalyst layer 20 of this application can be applied in an electrolyzer, which includes a membrane layer 101, at least two diffusion layers 102, and a catalyst layer 20. The diffusion layers 102 are located on opposite sides of the membrane layer 101. The catalyst layer 20 is formed between the membrane layer 101 and the diffusion layers 102. In one embodiment, the catalyst layer 20 may be formed on one side surface of the diffusion layer 102, close to the membrane layer 101. In another embodiment, the catalyst layer 20 may also be formed on both sides of the diffusion layer 102. In yet another embodiment, the catalyst layer 20 may be formed on both sides of the membrane layer 101. It is worth noting that the membrane layer 101 can be a diaphragm, a proton exchange membrane (PEM), an anion exchange membrane, a bipolar membrane, a cation exchange membrane, or other membranes used for electrolysis, and the diffusion layer 102 can be a nickel mesh, nickel foam, nickel felt, carbon cloth, a diffusion layer substrate, or a porous substrate, etc.

[0068] As shown in Figure 9, the electrolytic cell (or electrolytic device) of this application may include multiple electrolytic units (or electrolytic chambers), and each electrolytic unit may include a membrane layer 101, at least two electrodes and a catalyst layer 20.

[0069] In some embodiments, as shown in FIG10, the catalyst layer 20 of this application can be applied in an electrolytic cell, which may include a film layer 101, at least two diffusion layers 102, at least two electrode plates 103, and an electrode plate 104. The diffusion layers 102 are located on opposite sides of the film layer 101. The electrode plates 103 are formed between the film layer 101 and the diffusion layers 102. The electrode plates 103 may be anode electrode plates and cathode electrode plates, respectively, and the electrode plates 103 may include the catalyst layer 20 and a substrate 30. The catalyst layer 20 may be formed on one side surface of the substrate 30 and close to the film layer 101, or the catalyst layer 20 may be formed on both sides surface of the substrate 30 to form cathode or anode electrode plates.

[0070] In some embodiments, the substrate 30 of the electrode sheet in FIG10 can also serve as a diffusion layer.

[0071] In one embodiment, as shown in FIG11, the electrolyzer is, for example, an AEM electrolyzer, which may include a membrane layer 101, at least two diffusion layers 102, at least two catalyst layers 20, and electrode plates 104. The diffusion layers 102 are located on opposite sides of the membrane layer 101. The membrane layer 101 is an anion exchange membrane. The catalyst layers 20 are respectively formed on the surface of the diffusion layers 102 and close to the membrane layer 101. Alternatively, the catalyst layers 20 may be formed on both sides of the diffusion layers 102, serving as an anode electrode and a cathode electrode, respectively. The anode electrode may further include a hydrogen removal layer 105, which may be formed on the catalyst layer 20 on the anode side and close to the membrane layer 101, for removing hydrogen gas leaking to the anode side. The catalyst layer 20 and / or the hydrogen removal layer 105 can be formed by means of coating, spraying, thermal spraying, scraping, spin coating, printing, heat treatment, in-situ growth, electrodeposition, vapor deposition, transfer printing, or dip coating.

[0072] In different embodiments, as shown in Figures 12-15, the cross-sectional structure of the catalyst layer 20 may have different structures or textures, such as sheet-like stacked structures, porous structures, filamentous textured structures, particle stacked structures, coral-like textured structures, and / or other cross-sectional structures or textures. In one embodiment, the catalyst layer 20 may have different structural textures in different regions. Specifically, in one embodiment, the catalyst layer 20 may include a plurality of first catalyst regions 201 and a plurality of second catalyst regions 202, wherein the structural texture of the catalyst layer 20 in the first catalyst regions 201 is different from that in the second catalyst regions 202. However, this is not the only possibility; in one embodiment, the catalyst layer 20 may also include a third catalyst region with a different structure or texture, or more catalyst regions with different structures or textures.

[0073] In different embodiments, as shown in Figures 14-15, the catalyst structure of the catalyst layer 20 can have different growth directions. Specifically, the growth direction of the catalyst structure in the first catalyst region 201 of the catalyst layer 20 is different from the growth direction of the catalyst structure in the second catalyst region 202. The angle between the growth direction of the catalyst structure in the first catalyst region 201 and the substrate is, for example, between 45 degrees and 90 degrees, or between 75 degrees and 90 degrees. The angle between the growth direction of the catalyst structure in the second catalyst region 202 and the substrate is, for example, between 0.1 degrees and 45 degrees, or between 0.1 degrees and 30 degrees. However, this is not the only possibility. In some embodiments, the catalyst layer 20 may include more variations in the growth direction of the catalyst structure. The catalyst layer 20 can be formed by methods such as coating, spraying, thermal spraying, scraping, spin coating, printing, heat treatment, in-situ growth, electrodeposition, vapor deposition, transfer printing, and dip coating.

[0074] In one embodiment, the growth direction of the catalyst structure can be altered, for example, by selective printing, coating, or spraying process conditions or directions. In one embodiment, the growth direction of the catalyst structure can be altered, for example, by heat treatment process conditions (e.g., slowing diffusion growth rate through low temperature, annealing) or heating location. In one embodiment, the addition of specific surfactants or ligands (e.g., carboxylic acids, amines) can promote the growth of the catalyst structure in other directions. In one embodiment, the morphology of metal nanoparticles and the growth direction of the catalyst structure can be controlled, for example, by electric fields, magnetic fields, or light fields (e.g., photochemical reduction). In one embodiment, the precursor concentration can be adjusted to promote anisotropic growth (e.g., nanowires) through low concentration. In one embodiment, a template (e.g., porous alumina, silica) can be used to confine the growth space or guide the directional alignment of the catalyst structure.

[0075] In different embodiments, as shown in Figures 12-13, the first catalyst region 201 and / or the second catalyst region 202 are, for example, strip-shaped regions, and the width of the first catalyst region 201 and / or the second catalyst region 202 is, for example, 0.1–5 mm, or, for example, 0.3–2.5 mm. The first catalyst region 201 and the second catalyst region 202 can be staggered, for example, the first catalyst region 201 and the second catalyst region 202 can be staggered or arbitrarily arranged stripes. However, this is not limited to this; the first catalyst region 201 and / or the second catalyst region 202 can also be, for example, grid-shaped, speckled, concentric circles, wavy, or other any suitable combination of shapes.

[0076] In different embodiments, multiple microchannels 203 may be formed between the first catalyst region 201 and / or the second catalyst region 202. Specifically, the microchannels 203 may be formed between multiple first catalyst regions 201 or multiple second catalyst regions 202, or the microchannels 203 may be formed between the first catalyst region 201 and the second catalyst region 202. The width of the microchannels 203 may be 0.01–5 mm, for example, 0.01–1 mm, or even 0.1–0.9 mm. The microchannels 203 may expose a portion of the surface of the substrate 30 for rapid diffusion and transport of the gas generated by electrolysis.

[0077] Catalyst regions with different structures or textures can increase the active sites of the catalyst layer 20 and effectively disperse the distribution of active catalyst on the substrate, avoiding excessive agglomeration in local areas and effectively improving the utilization rate of precious metals. Furthermore, the microchannels 203 can also improve electrode performance and reduce the amount of precious metals used (cost).

[0078] In some embodiments, as shown in Figures 16-17, before forming the catalyst layer 20 on the diffusion layer 102 or the substrate 30, a surface treatment layer 106 may be formed on the surface of the diffusion layer 102 and / or the substrate 30, and then the catalyst layer 20 may be formed on the surface treatment layer 106. This is to ensure the stability of the catalyst layer 20 on the diffusion layer 102 and / or the substrate 30, making the catalyst layer 20 less prone to falling off, thus ensuring the performance and stability of the electrode sheet. The surface treatment layer 106 may be formed on the surface of the diffusion layer 102 and / or the substrate 30 by means of coating, spraying, thermal spraying, scraping, spin coating, printing, heat treatment, in-situ growth, electrodeposition, vapor deposition, transfer printing, dip coating, etc. The material of the surface treatment layer 106 may be the same as or partially the same as the material of the catalyst layer 20, the diffusion layer 102, and / or the substrate 30. The surface roughness of the surface treatment layer 106 can be greater than that of the diffusion layer 102 and the substrate 30. The surface roughness of the surface treatment layer 106 can be 1μm-50μm, for example, 10μm-50μm, or even 20μm-45μm. The specific surface area of ​​the surface treatment layer 106 can be, for example, greater than or equal to 10m². 2 / g, for example, 15m 2 / g-30m 2 The surface area of ​​the surface treatment layer 106 can be greater than that of the diffusion layer 102 and the substrate 30, and the surface stress of the surface treatment layer 106 can be less than that of the diffusion layer 102 and the substrate 30.

[0079] The surface treatment layer 106 can alter the surface structure and / or surface properties of the diffusion layer 102 or the substrate 30. For example, the surface treatment layer 106 can have a porous structure to increase the surface area of ​​the subsequent electrode, exposing more active sites and accelerating the diffusion and reaction process of reactants, thereby effectively improving the electrochemical performance of the electrode. Furthermore, the surface treatment layer 106 can reduce the internal stress of the subsequent electrode and significantly improve the electrode sheet's resistance to current fluctuations.

[0080] In one embodiment, as shown in FIG17, the surface treatment layer 106 may include, for example, an island-like structure composed of nanoparticles, but is not limited thereto. The surface structure of the surface treatment layer 106 may include, for example, one or a combination of several of the following: polyhedral, needle-like, pointed prism-like, spherical, coral-like, sheet-like, porous, hollow spherical, chain-like, or fused spherical, irregular shapes, etc. In one embodiment, the surface of a specific diffusion layer 102 and the substrate 30 may also be selectively etched by an oxidant or acid to form the surface treatment layer 106.

[0081] In some embodiments, as shown in FIG18, a structural layer grown on one side of the diffusion layer 102 and / or the substrate 30, and near the film layer 101 (or located between the diffusion layer 102 and the electrode 104), can serve as a support layer 107 to support the space between the diffusion layer 102 and the electrode 104. This support layer 107 can be formed by the catalyst layer 20 or the surface treatment layer 106. However, it is not limited to these methods; the support layer 107 can also be additionally provided and different from the catalyst layer 20 or the surface treatment layer 106. The support layer 107 can be formed on the diffusion layer 102 and / or the substrate 30 by, for example, coating, spraying, thermal spraying, blade coating, spin coating, printing, heat treatment, in-situ growth, electrodeposition, vapor deposition, transfer printing, or dip coating.

[0082] As shown in Figures 19-24, in one embodiment, the heteromorphic nanocatalyst includes a heteromorphic nanocatalyst structure 10 and a morphology-inducing layer 11, the morphology-inducing layer 11 being formed on a portion of the surface of the heteromorphic nanocatalyst structure 10. In one embodiment of the present invention, the morphology-inducing layer 11 is, for example, at least one layer; when the morphology-inducing layer 11 is multilayered, the multilayer morphology-inducing layers 11 are sequentially stacked on the heteromorphic nanocatalyst structure 10. In one embodiment of the present invention, the specific surface area of ​​the heteromorphic nanocatalyst can be, for example, greater than or equal to 100 m² / g, or, for example, 100 to 1000 m² / g. By forming a heteromorphic nanocatalyst, the catalyst has a larger specific surface area, increasing catalytic performance. Simultaneously, during the formation of the membrane electrode, it can increase the porosity, reduce the bed pressure drop, facilitate water diffusion, accelerate catalytic efficiency, and improve processing performance during the formation of the membrane electrode.

[0083] In one embodiment, the shape of the irregular nanocatalyst is, for example, one or a combination of several of the following: polyhedral, needle-shaped, pointed prism-shaped, spherical, chain-like, or fused spherical, and can be specifically controlled according to the fabrication process. The size of the irregular nanocatalyst varies depending on its shape, and is determined based on the morphology of the formed irregular nanocatalyst. By forming irregular nanocatalysts of different shapes and sizes, membrane electrodes with different catalytic capabilities can be formed during membrane electrode formation, meeting the needs of different environments or requirements.

[0084] The heteromorphic nanocatalyst comprises at least two of transition metals, lanthanide rare earth elements, and platinum group noble metals. The transition metals include, for example, at least one selected from Mn, Cr, Zr, Fe, Co, Ni, Cu, Zn, Mo, or W. The platinum group noble metals include at least one selected from Ru, Rh, Pd, Ag, Os, Ir, Pt, or Au. In one embodiment of the invention, the electrocatalyst comprises, for example, the following components by mass percentage: 40%–60% transition metal, 20%–50% lanthanide rare earth elements and / or platinum group noble metal elements, and 5%–20% oxygen.

[0085] The material of the irregular nanocatalyst structure is at least one of metal, alloy, or metal oxide, and the material of the morphology-inducing layer 11 is at least one of metal, alloy, or metal oxide. The material of the irregular nanocatalyst structure 10 and the material of the morphology-inducing layer 11 may be the same or different. For example, a metal or alloy can be used in the hydrogen-producing cathode, and a metal oxide can be used in the oxygen-producing anode.

[0086] As shown in Figure 19, the microstructure of the irregular nanocatalyst is hexagonal, with side lengths ranging from 0.1 μm to 1.5 μm. As shown in Figure 20, the microstructure of the irregular nanocatalyst is needle-shaped, with lengths ranging from 0.2 μm to 5 μm. As shown in Figure 21, the microstructure of the irregular nanocatalyst is pointed prismatic, with lengths ranging from 0.01 μm to 2 μm. As shown in Figure 22, the microstructure of the irregular nanocatalyst is fused spherical, with diameters ranging from 0.01 μm to 0.5 μm. That is, by selecting different metal precursors and morphology inducers, irregular nanocatalysts with different morphologies can be obtained.

[0087] As shown in Figure 23, the microstructure of the heteromorphic nanocatalyst is a chain-like structure with chain lengths ranging from 8 μm to 1000 μm; only a portion of the chain lengths are shown in the figure. Testing revealed that the heteromorphic nanocatalyst structure prepared in this embodiment comprises 50% transition metal, 45% noble metal, and 5% oxygen. The material of the morphology-inducing layer is the same as that of the heteromorphic nanocatalyst structure.

[0088] As shown in Figure 24, the heteromorphic nanocatalyst structure may include 50% transition metal, 45% noble metal, and 5% oxygen. The material of the morphology-inducing layer is the same as that of the heteromorphic nanocatalyst structure.

[0089] In various embodiments, the above-mentioned electrode catalyst can be applied in electrolysis units or electrolyzers, such as proton exchange membrane (PEM) electrolyzers, anion exchange membrane (AEM) electrolyzers, alkaline electrolyzers, solid oxide electrolyzers (SOEC), seawater electrolyzers, and high-voltage electrolyzers (e.g., 6,000 A / m). 2 Above or 10,000 A / m 2 The above-mentioned electrode catalysts can be used in the electrodes of electrolyzers, chlorine-producing electrolyzers, salt-precipitating electrolyzers, chlor-alkali electrolyzers, hydrogen-producing electrolyzers, or other electrolyzers that use catalyst electrodes. Specifically, the electrode catalysts of this application can be formed on different substrates to form electrode sheets or membrane electrodes. However, this is not the only limitation. In other embodiments, the above-mentioned electrode catalysts can also be applied to the electrodes of other electrochemical devices, such as the electrodes of fuel cells or other electrochemical electrolyzers.

[0090] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. An electrode for an electrolytic cell, comprising: Substrate; A surface treatment layer is formed on the substrate; as well as A catalyst layer is formed on the surface treatment layer.

2. The electrode of the electrolytic cell according to claim 1, wherein the material of the surface treatment layer is the same as or partially the same as the material of the catalyst layer and / or the substrate.

3. The electrode of the electrolytic cell according to claim 1, wherein the surface roughness of the surface treatment layer is greater than the surface roughness of the substrate.

4. The electrode of the electrolytic cell according to claim 1, wherein the surface roughness of the surface treatment layer is 1μm-50μm.

5. The electrode of the electrolytic cell according to claim 4, wherein the surface roughness of the surface treatment layer is 10 μm-50 μm.

6. The electrode of the electrolytic cell according to claim 1, wherein the specific surface area of ​​the surface treatment layer is greater than the specific surface area of ​​the substrate.

7. The electrode of the electrolytic cell according to claim 1, wherein the specific surface area of ​​the surface treatment layer is greater than 10 m². 2 / g.

8. The electrode of the electrolytic cell according to claim 1, wherein the surface stress on the surface of the surface treatment layer is less than the surface stress on the substrate.

9. The electrode of the electrolytic cell according to claim 1, wherein the surface treatment layer has a porous structure.

10. The electrode of the electrolytic cell according to claim 1, wherein the surface treatment layer comprises an island structure composed of nanoparticles.

11. The electrode of the electrolytic cell according to claim 1, wherein the surface treatment layer comprises one or a combination of several of the following: polyhedral, needle-shaped, pointed prism-shaped, spherical, coral-like, sheet-like, porous, hollow spherical, chain-like, fused spherical, or irregular shapes.

12. The electrode of the electrolytic cell according to claim 1 further includes a plurality of electrodeposited layers stacked together.

13. The electrode of the electrolyzer according to claim 1, wherein the catalyst layer comprises catalyst structures with different growth directions.

14. The electrode of the electrolytic cell according to claim 13, wherein the catalyst layer comprises a plurality of first catalyst regions and a plurality of second catalyst regions with different growth directions.

15. The electrode of the electrolytic cell according to claim 14, wherein the angle between the growth direction of the catalyst structure in the first catalyst region and the substrate is between 45 degrees and 90 degrees.

16. The electrode of the electrolytic cell according to claim 14, wherein the angle between the growth direction of the catalyst structure in the second catalyst region and the substrate is between 0.1 degrees and 45 degrees.

17. The electrode of the electrolyzer according to claim 14, wherein the first catalyst region and the second catalyst region are arranged at intervals.

18. The electrode of the electrolyzer according to claim 14, wherein the first catalyst region and / or the second catalyst region is a strip-shaped region.

19. The electrode of the electrolyzer according to claim 14, wherein a plurality of microchannels are formed between the plurality of first catalyst regions and the plurality of second catalyst regions.

20. An electrolytic cell, characterized in that, Includes the electrode as described in claim 1.

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