Electrode catalyst, catalyst electrode and preparation method thereof

Abstract

The invention provides an electrode catalyst, a catalyst electrode and a preparation method thereof. The electrode catalyst has a hierarchical pore structure and comprises micropores, mesopores and macropores, the electrode catalyst comprises an activation product of a mixture, and the mixture comprises 1-80wt% of a first metal material, 1-80wt% of a second metal material and 1-80wt% of a third metal material. The content of the second metal material is 0.1-80 wt%, and the second metal material comprises one or more of a W-1 Raney alloy, a W-2 Raney alloy, a W-3 Raney alloy, a W-4 Raney alloy, a W-5 Raney alloy, a W-6 Raney alloy and a W-7 Raney alloy; and the content of the pore-forming agent is 0-20wt%. The electrode catalyst provided by the invention has excellent hydrogen evolution activity, mass transfer efficiency and mechanical binding force, and breaks through the technical bottlenecks that a traditional catalyst is fast in activity attenuation, blocked in mass transfer and easy to fall off in long-term operation under high current density.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, specifically relating to a one-electrode catalyst, a catalyst electrode, and a method for preparing the same. Background Technology

[0002] Hydrogen energy, as a clean energy source, relies on high-performance HER catalysts for efficient production to reduce the energy consumption and cost of hydrogen production through water electrolysis. Currently, commercially available HER catalysts are mainly composed of precious metals such as platinum (Pt) and palladium (Pd), but their low abundance in the Earth's crust and high cost severely restrict their large-scale commercial application.

[0003] Although non-precious metal catalysts are inexpensive, their limited specific surface area and simple pore structure result in an insufficient number of active sites per unit mass, and the reactants ( The long mass transfer path between the product (H2) and the catalytic activity results in severe concentration polarization, significantly impacting catalytic efficiency. To overcome these issues, existing research involves etching the Al component in Raney alloys with alkaline solutions to create a porous structure. While this method can improve activity, it suffers from poor mechanical strength and weakened bonding.

[0004] Therefore, it is necessary to provide an electrode catalyst, a catalyst electrode, and a preparation method to solve the technical problem of how to obtain an electrode catalyst with high activity, high mass transfer efficiency, and strong binding force. Summary of the Invention

[0005] To address the technical problem in existing technologies where electrode catalysts struggle to simultaneously possess high activity, high mass transfer efficiency, and strong binding force, this invention provides an electrode catalyst with a hierarchical pore structure, comprising micropores, mesopores, and macropores; the electrode catalyst includes the activation product of a mixture, the mixture comprising: The first metal material has a content of 1-80 wt%, and the first metal material includes one or more of nickel powder, molybdenum powder, chromium powder, titanium powder, nickel-based alloy, cobalt-based alloy, and iron-based alloy; The second metal material has a content of 0.1-80 wt%, and the second metal material includes one or more of W-1 Raney alloy, W-2 Raney alloy, W-3 Raney alloy, W-4 Raney alloy, W-5 Raney alloy, W-6 Raney alloy, and W-7 Raney alloy; Pore-forming agent, with a content not exceeding 20 wt%.

[0006] Compared with existing technologies, the electrode catalyst provided by this invention achieves significant improvements in hydrogen evolution activity, mass transfer efficiency, and mechanical bonding force, breaking through the technical bottlenecks of traditional catalysts such as rapid activity decay, hindered mass transfer, and easy detachment during long-term operation. The specific effects are as follows: High activity: Low hydrogen evolution potential, significantly reducing energy consumption. Under high current density (e.g., 5 kA / m²), the electrode catalyst prepared in this invention exhibits an extremely low hydrogen evolution potential of only 1.12 V (vs. Hg / HgO). Compared with conventional catalysts of similar composition and structure, the hydrogen evolution potential is significantly reduced, which means that a lower voltage is required to drive the hydrogen evolution reaction during water electrolysis, thereby significantly reducing energy consumption and lowering the cost of hydrogen production.

[0007] Furthermore, the activity enhancement mechanism in this invention mainly lies in the synergistic effect of hierarchical pores and specific surface area. A hierarchical pore interconnection structure of micropores-mesopores-macropores is formed on the surface of the electrode catalyst, which greatly increases the specific surface area of ​​the catalyst, providing more active sites for the hydrogen evolution reaction. This allows the reactants to fully contact the catalyst, thereby accelerating the hydrogen evolution reaction. In contrast, traditional catalysts with only macroporous structures have insufficient reactivity and relatively high hydrogen evolution potential due to their simple pore structure, low specific surface area, and limited number of active sites.

[0008] High mass transfer efficiency: Hierarchical pore structure optimizes reactant diffusion paths. Under high current density (5kA / m²) operating conditions, the hierarchical pore structure of the electrode catalyst of this invention effectively shortens the diffusion path of reactants inside the electrode, while reducing the concentration gradient of reactants on the electrode surface. The polarization curves show that in the high current density region, the curve of the electrode catalyst of this invention is the steepest and shows no obvious plateau, fully demonstrating its minimal mass transfer resistance and extremely slow increase in mass transfer overpotential. In contrast, traditional pure Ni / Al mixed powders, due to their single pore size (only macropores), suffer from hindered reactant diffusion, high mass transfer resistance, and high mass transfer overpotential; while traditional Raney alloy (Ni - 48 wt%Al), although forming a porous structure through alkaline etching, has poor mechanical bonding, and the coating is prone to peeling off during operation, making long-term stable operation difficult and hindering efficient mass transfer.

[0009] Strong Binding Force: Chemical Bonding Ensures Long-Term Stable Operation. Through chemical bonding, the catalyst electrode prepared in this invention exhibits excellent mechanical binding force. Ultrasonic weight loss testing shows that its binding force is excellent, effectively suppressing catalyst detachment during long-term operation. In contrast, traditional Raney alloy (Ni-48 wt%Al) shows higher binding force values ​​in the ultrasonic weight loss test, and the catalyst completely detaches during operation. This fully demonstrates the significant advantage of the electrode catalyst of this invention in terms of mechanical binding force, ensuring catalyst stability during long-term use and extending its service life.

[0010] Furthermore, the first metal material includes one or more of nickel powder, chromium powder, titanium powder, and nickel-based alloys.

[0011] Furthermore, the pore-forming agent includes one or more of aluminum powder, zinc powder, magnesium powder, and silicon powder.

[0012] Furthermore, the specific surface area of ​​the electrode catalyst is not less than 100 m² / g, and the HER hydrogen evolution potential of the electrode catalyst is less than 1.2V.

[0013] The present invention provides a catalyst electrode, the catalyst electrode comprising a conductive substrate and an electrode catalyst as described in any one of the above.

[0014] The advantages of the catalyst electrode provided by this invention are as follows: The catalyst electrode provided by this invention exhibits an extremely low hydrogen evolution potential under high current density (e.g., 5 kA / m²) operating conditions, effectively reducing energy loss during the reaction process and improving energy utilization efficiency, thanks to its unique hierarchical pore structure.

[0015] When operating at high current density (5 kA / m²), the hierarchical pore structure of the catalyst electrode further optimizes the diffusion path of reactants inside the electrode, effectively reducing the concentration gradient difference of reactants on the electrode surface.

[0016] The hierarchical pore structure of the catalyst electrode also significantly enhances its structural stability. This unique structure can uniformly distribute stress, avoiding electrode structural damage caused by localized stress concentration during the reaction process. Under high current density and long-term operating conditions, the electrode can still maintain its original morphology and performance without significant deformation, cracking, or pulverization, ensuring the performance stability and reliability of the electrode throughout its entire service life.

[0017] Through chemical bonding, the catalyst electrode of this invention possesses excellent mechanical bonding strength. During long-term operation, the electrode firmly maintains its structural integrity, effectively resisting various external forces and preventing catalyst detachment. Rigorous ultrasonic weight loss testing has verified that the electrode's bonding strength is stable and reliable, providing a solid guarantee for long-term stable operation under complex conditions, significantly extending the electrode's service life, and reducing the frequency and cost of electrode replacement.

[0018] Furthermore, the conductive substrate includes one or more of nickel mesh, nickel punched mesh, nickel felt, and nickel foam; The electrode catalyst is coated onto the surface of the conductive substrate by a thermal spraying process, which includes one or more of flame spraying, arc spraying, plasma spraying, and supersonic spraying.

[0019] Furthermore, the ultrasonic weight loss bonding force test value of the catalyst electrode is no greater than 3.0 mg / cm. 2 .

[0020] This invention provides a method for preparing a catalyst electrode with a hierarchical pore structure as described in any one of the above claims, comprising the following steps: Mechanical mixing: The first metal material, the second metal material, and the pore-forming agent are mechanically mixed in proportion to prepare a spraying powder; Thermal spraying: The spraying powder is applied to the surface of the conductive substrate to form an initial coating; Activation treatment: The initial coating is immersed in an alkaline solution to dissolve and form a hierarchical porous structure, thereby obtaining the catalyst electrode with the hierarchical porous structure.

[0021] The catalyst electrode preparation method provided by this invention has a simple and clear overall process, with each step closely connected and highly operable. The mechanical mixing step rapidly and uniformly mixes the first metal material, the second metal material, and the pore-forming agent in a specific ratio to prepare a stable spray powder, laying a good foundation for subsequent steps. Thermal spraying technology efficiently and uniformly coats the spray powder onto the surface of the conductive substrate, forming an initial coating. The entire process is easy to control, ensuring the quality and consistency of the coating. The activation treatment step, through a simple alkaline immersion operation, dissolves and forms a hierarchical porous structure, requiring no complex equipment or harsh conditions, greatly improving preparation efficiency, reducing production costs, and making it suitable for large-scale industrial production.

[0022] Furthermore, the concentration of alkaline substances in the alkaline solution is 5-30 wt%; the alkaline substances include one or more of NaOH and KOH.

[0023] Furthermore, the activation treatment temperature is 0-60℃, and the activation treatment duration is 0.5-48 h. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a SEM image of the catalyst electrode prepared in Example 1 of the present invention; Figure 2 This is a SEM image of the catalyst electrode prepared in Comparative Example 1 of the present invention. Figure 3 This is a SEM image of the catalyst electrode prepared in Comparative Example 2 of the present invention. Figure 4The polarization curves (LSV) of the catalyst electrodes prepared in Examples 1-3 and Comparative Examples 1-4 of this invention are shown.

[0026] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0029] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of the invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to the methods, devices, and materials in the embodiments of the present invention.

[0030] This invention provides an electrode catalyst with a hierarchical pore structure, including micropores, mesopores, and macropores. The electrode catalyst comprises an activation product of a mixture, the mixture comprising: The first metal component has a content of 1-80 wt%. The second metal component has a content of 0.1-80 wt%. Pore-forming agent, with a content of no more than 20 wt%.

[0031] It should be noted that the micropore diameter is <2 nm, the mesopore diameter is 2-50 nm, and the macropore diameter is greater than 50 nm.

[0032] In this invention, the second metal material includes one or more of the following: W-1 Raney alloy, W-2 Raney alloy, W-3 Raney alloy, W-4 Raney alloy, W-5 Raney alloy, W-6 Raney alloy, and W-7 Raney alloy.

[0033] All W-1, W-2, W-3, W-4, W-5, W-6, and W-7 Raney alloys used in the embodiments and comparative examples of this invention were purchased from Jiangsu Raney Metal Technology Co., Ltd., and their definitions are shown in Table 1. Table 1 Definition of Raney Alloy In some embodiments, the content of the second metal material in the mixture may be 10%-80%, 20%-80%, 30%-80%, 40%-80%, 50%-80%, 60%-80%, 10%-70%, 10%-60%, 30%-50%, 20%-60%, 0.1%-50%, or 0.1%-30%.

[0034] This invention activates and forms hierarchical pores by adding a second metal material, namely W-1 Raney alloy, W-2 Raney alloy, W-3 Raney alloy, W-4 Raney alloy, W-5 Raney alloy, W-6 Raney alloy, and W-7 Raney alloy, which effectively increases the specific surface area of ​​the electrode catalyst and provides abundant HER active sites, significantly improving hydrogen evolution activity and mass transfer efficiency.

[0035] Specifically, Al in the second metal material is selectively dissolved in the alkaline solution during activation treatment to form a stable microporous + mesoporous structure, thereby improving the hydrogen evolution catalytic activity; in conjunction with the pore-forming agent, Al is selectively dissolved during activation treatment to form a stable macroporous structure, together constituting a hierarchical pore structure of micropore-mesopore-macropore, which significantly improves the hydrogen mass transfer efficiency.

[0036] It should also be noted that the second metal material in this invention significantly optimizes the binding force of the electrode catalyst.

[0037] In some specific embodiments of the present invention, the second metal material can be W-7 Raney alloy. W-7 Raney alloy powder, due to its optimized low-temperature and low-pressure activity, is suitable for highly selective hydrogenation scenarios, but must strictly adhere to safety regulations. W-7 Raney alloy has a high preparation cost and rapid activity decay, making it suitable for fine synthesis fields sensitive to reaction conditions.

[0038] In this invention, the first metal material includes one or more of nickel powder, molybdenum powder, chromium powder, titanium powder, nickel-based alloys, cobalt-based alloys, and iron-based alloys; in other embodiments, the first metal material includes one or more of nickel powder, chromium powder, titanium powder, and nickel-based alloys. By adding the first metal material, this invention, on the one hand, provides stable support for the entire hierarchical porous structure, providing a smooth channel for the transport of reactants and products; on the other hand, it effectively optimizes the bonding force between the catalyst and the conductive substrate, ensuring the operational stability and reliability of the catalyst electrode.

[0039] In some embodiments, the content of the first metal material in the mixture may be 10%-80%, 20%-80%, 30%-80%, 40%-80%, 50%-80%, 60%-80%, 10%-70%, 10%-60%, 30%-50%, or 20%-60%.

[0040] In this invention, the pore-forming agent includes at least one selected from aluminum powder, zinc powder, magnesium powder, or silicon powder. In some specific embodiments, aluminum powder may be selected as the pore-forming agent. In some embodiments, the content of the pore-forming agent may be 0.1%-20%, 0.1%-10%, 0.1%-15%, 1%-20%, 1%-10%, 1%-15%, 5%-20%, 5%-10%, or 5%-15%.

[0041] In this invention, the total mass percentage of the first metal material, the second metal material, and the pore-forming agent in the mixture is 100%.

[0042] It should be noted that the hierarchical pore synergistic mechanism is as follows: Micropores: provide high specific surface area, adsorption And reduce its concentration polarization; Mesopores: Serving as reactant transport channels, they connect micropores and macropores, avoiding mass transfer dead zones caused by closed pores; Large pores: serve as buffer chambers to reduce the accumulation of H2 bubbles under high current density.

[0043] In some embodiments, the first metal material and the second metal material in this invention may exist in the form of powder.

[0044] In this invention, the activated product is the product of the activation treatment. In some embodiments, the activation treatment includes an alkaline leaching treatment. In some embodiments, the activation treatment includes the step of: introducing the mixture into an alkaline solution to dissolve and form a hierarchical porous structure, thereby obtaining the catalyst electrode having the hierarchical porous structure.

[0045] In some embodiments, the alkaline solution comprises a NaOH solution or KOH solution with a concentration of 5-30 wt%, the activation treatment temperature is 0-60°C, and the activation treatment duration is 0.5-48 h; in some embodiments, the activation treatment temperature is 20-60°C, 0-50°C, 20-30°C, 20-40°C, or 10-60°C; the activation treatment duration can be 0.5-48 h, 0.5-10 h, 0.5-20 h, 1-20 h, 20-40 h, 30-40 h, or 1-10 h.

[0046] The electrode catalyst provided by this invention significantly improves hydrogen evolution activity, mass transfer efficiency and mechanical binding force, breaking through the technical bottlenecks of traditional catalysts such as rapid activity decay, hindered mass transfer and easy detachment during long-term operation.

[0047] The specific effects are as follows: High activity: Low hydrogen evolution potential, significantly reducing energy consumption. Analysis of Example 1 shows that at a current density of 5 kA / m², the hydrogen evolution potential of the electrode catalyst prepared in this invention can be as low as 1.12 V (vs. Hg / HgO), which is 90 mV lower than that of Comparative Example 1 (1.210 V).

[0048] The mechanism of activity enhancement mainly lies in the exposure of active sites in hierarchical pores and the increase in specific surface area: such as Figure 1 As shown, the electrode surface of Example 1 forms a hierarchical interconnected pore structure of micropores-mesopores-macropores, and the specific surface area of ​​the electrode catalyst prepared in Example 1 reaches 100 m² / g, which is 10 times higher than that of Comparative Example 1 (macropores only, specific surface area of ​​10 m² / g). That is, the traditional Ni-Al mixed powder in Comparative Example 1 has a low specific surface area and insufficient active sites due to its single pore size, resulting in a 90 mV increase in hydrogen evolution potential.

[0049] High mass transfer efficiency: Hierarchical pore structure optimizes reactant diffusion paths. Analysis of Example 1 shows that at high current densities (5 kA / m²), the hierarchical pore structure effectively shortens the diffusion path of reactants within the electrode, reduces the concentration gradient at the electrode surface, and thus lowers the mass transfer overpotential. Figure 4 As can be observed from the polarization curves, in the high current density region, the curve of Example 1 is the steepest and does not show a clear plateau, indicating that it has the lowest mass transfer resistance and the slowest increase in mass transfer overpotential. In contrast, the traditional pure Ni and Al mixed powder in Comparative Example 1 has a single pore structure with only macropores, resulting in higher mass transfer resistance and mass transfer overpotential; although the traditional Raney alloy (Ni-48 wt%Al) in Comparative Example 2 forms a porous structure through alkaline etching, its mechanical bonding is poor, the coating peels off, and it cannot operate stably for a long time.

[0050] Strong binding force: Chemical bonding inhibits detachment during long-term operation. In Example 1, the catalyst electrode prepared according to this invention showed a binding force of 2.0 mg / cm² after ultrasonic weight loss testing, while in Comparative Example 2, the binding force (ultrasonic weight loss) was 23 mg / cm². 2 Furthermore, the catalyst completely detached.

[0051] The present invention provides a catalyst electrode with a hierarchical pore structure, comprising a conductive substrate and an electrode catalyst as described above, wherein the electrode catalyst is coated on the surface of the conductive substrate by a thermal spraying process.

[0052] The catalyst electrode provided by this invention, due to the use of the specifically designed electrode catalyst described above, exhibits excellent binding performance with its test value precisely controlled at no more than 3.0 mg / cm² after ultrasonic weight loss binding force testing.

[0053] Specifically, in the preparation process, the mixture used in this invention includes a key first metal material. The first metal material plays a dual role: on the one hand, it provides stable support for the entire hierarchical porous structure, providing a smooth channel for the transport of reactants and products; on the other hand, it can effectively optimize the bonding force between the catalyst and the conductive substrate, ensuring the operational stability and reliability of the catalyst electrode.

[0054] Meanwhile, this invention strictly controls the type of the second metal material, limiting it to one or more of the following: W-1 Raney alloy, W-2 Raney alloy, W-3 Raney alloy, W-4 Raney alloy, W-5 Raney alloy, W-6 Raney alloy, and W-7 Raney alloy. This careful selection further significantly optimizes the hydrogen evolution activity, mass transfer efficiency, and catalyst binding force of the catalyst electrode.

[0055] In this invention, the thermal spraying process includes flame spraying, arc spraying, plasma spraying, and supersonic spraying; in some embodiments of this invention, plasma spraying can be selected as the thermal spraying process. The thermal spraying process can precisely control porosity and bonding strength, which is superior to traditional cold spraying or electrodeposition.

[0056] At the same time, thermal spraying can achieve metallurgical bonding between the first metal material and the second metal material.

[0057] In some embodiments, sandblasting can be used to roughen the surface of the conductive substrate to further optimize the bonding force between the conductive substrate and the electrode catalyst, thereby preventing desorption.

[0058] In some embodiments, the conductive substrate may include one or more of nickel mesh, nickel punched mesh, nickel felt, and nickel foam; in some specific embodiments, the conductive substrate may be nickel mesh.

[0059] In this invention, the ultrasonic weight loss bonding force test value of the above-mentioned catalyst electrode is no greater than 3.0 mg / cm. 2 .

[0060] This invention provides a method for preparing the catalyst electrode as described above, comprising the following steps: S1. Mechanical mixing: The first metal material, the second metal material, and the pore-forming agent are mechanically mixed in proportion to prepare a spray powder.

[0061] In some embodiments, the second metal material includes one or more of W-1 Raney alloy, W-2 Raney alloy, W-3 Raney alloy, W-4 Raney alloy, W-5 Raney alloy, W-6 Raney alloy, and W-7 Raney alloy; in some more specific embodiments, the second metal material may be W-7 Raney alloy.

[0062] In some embodiments, the first metal material includes one or more of nickel powder, molybdenum powder, chromium powder, titanium powder, nickel-based alloy, cobalt-based alloy, and iron-based alloy; in other embodiments, the first metal material includes one or more of nickel powder, chromium powder, titanium powder, and nickel-based alloy.

[0063] In some embodiments, the pore-forming agent includes at least one of aluminum powder, zinc powder, magnesium powder, or silicon powder; in some more specific embodiments, the pore-forming agent may be aluminum powder.

[0064] S2. Substrate pretreatment: The conductive substrate is roughened by sandblasting.

[0065] In this invention, the conductive substrate includes one or more of nickel mesh, nickel punched mesh, nickel felt, and nickel foam; in this invention, the conductive substrate can be nickel mesh, and the nickel mesh skeleton can enhance the mechanical strength and bonding force of the catalyst and prevent it from falling off.

[0066] S3. Thermal spraying: The spraying powder is applied to the roughened surface of the conductive substrate using a thermal spraying process to form an initial coating.

[0067] In this invention, the thermal spraying process includes flame spraying, arc spraying, plasma spraying, and supersonic spraying. In some embodiments of this invention, the thermal spraying process can be plasma spraying, that is, using plasma spraying to spray powder onto the surface of the roughened conductive substrate. Plasma spraying and supersonic flame spraying can precisely control porosity and bonding strength, which is superior to traditional cold spraying or electrodeposition.

[0068] S4. Activation treatment: The initial coating is immersed in an alkaline solution to dissolve and form a hierarchical porous structure, thereby obtaining the catalyst electrode with the hierarchical porous structure.

[0069] In this invention, the alkaline solution comprises a NaOH solution or KOH solution with a concentration of 5-30 wt%, the activation treatment temperature is 0-60℃, and the activation treatment duration is 0.5-48 h; in some embodiments, the activation treatment temperature is 20-60℃, 0-50℃, 20-30℃, 20-40℃, or 10-60℃; the activation treatment duration can be 0.5-48 h, 0.5-10 h, 0.5-20 h, 1-20 h, 20-40 h, 30-40 h, or 1-10 h.

[0070] In summary, in this invention, the first metal material and the second metal material are metallurgically bonded by high-temperature spraying of thermal spraying process. The skeleton formed by the first alloy supports the pore structure and improves the catalyst bonding force, while the hierarchical pores improve the hydrogen mass transfer efficiency and the exposure rate of active sites, thereby achieving a comprehensive improvement in hydrogen evolution activity, mass transfer efficiency and mechanical bonding force.

[0071] To facilitate a further understanding of the present invention by those skilled in the art, the following examples are provided: Example 1 Preparation of catalyst electrodes with hierarchical porosity structure: Mechanical mixing: The first metal material (nickel powder), the second metal material (W-7 Raney alloy powder), and the pore-forming agent (aluminum powder) are mechanically mixed in proportion to obtain a mixture for spraying powder; in the mixture, nickel powder is 60 wt%, aluminum powder is 2 wt%, and W-7 Raney alloy powder is 38 wt%.

[0072] Thermal spraying: Plasma spraying is used to spray powder onto the surface of the nickel mesh to form an initial coating.

[0073] Activation treatment: The initial coating is immersed in 30 wt% KOH solution at 10-40℃ for 6 hours to dissolve and form a hierarchical porous structure, thus obtaining a catalyst electrode with a hierarchical porous structure.

[0074] Experimental results: The hydrogen evolution potential of HER (5kA / m² VsHg / HgO) was 1.12V, and the binding force test (ultrasonic weight loss) was 2.0mg / cm³. 2 .

[0075] The SEM display electrode surface morphology obtained in this embodiment exhibits a hierarchical pore structure (micropores-mesopores-macropores) as shown in the figure. Figure 1 As shown, the electrode catalyst prepared in this embodiment has a specific surface area of ​​approximately 100 m² / g.

[0076] Example 2 Compared to Example 1, all other conditions remain the same in this example, except that the composition of the mixture is adjusted to: 80 wt% nickel powder, 10 wt% aluminum powder, and 10 wt% W-7 Raney alloy powder.

[0077] Experimental results: The catalyst electrode surface prepared in this embodiment has a hierarchical pore structure of micropores-mesopores-macropores. The HER hydrogen evolution potential (5kA / m² VsHg / HgO) is 1.15 V, and the binding force test (ultrasonic weight loss) is 2.5 mg / cm. 2 .

[0078] Example 3 Compared to Example 1, all other conditions remain the same in this example, except that the first metal material is replaced by chromium instead of nickel.

[0079] The mixture consists of 60 wt% chromium powder, 2 wt% aluminum powder, and 38 wt% W-7 Reni alloy powder.

[0080] Experimental results: The catalyst electrode surface prepared in this embodiment has a hierarchical pore structure of micropores-mesopores-macropores. The HER hydrogen evolution potential (5kA / m² VsHg / HgO) is 1.18 V, and the binding force test (ultrasonic weight loss) is 2.8 mg / cm. 2 .

[0081] Comparative Example 1 Compared to Example 2, all other conditions remained the same in this comparative example, except that the composition of the mixture was adjusted to: 80 wt% nickel powder and 20 wt% aluminum powder.

[0082] Experimental results: The hydrogen evolution potential of HER (5kA / m² VsHg / HgO) was 1.210V, and the binding force test (ultrasonic weight loss) was 4.6mg / cm³. 2 .

[0083] The SEM display electrode surface prepared in this comparative example did not form hierarchical pores, only macropores, with a morphology as shown in the figure. Figure 2 As shown, the electrode catalyst prepared in this comparative example has a specific surface area of ​​approximately 10 m² / g.

[0084] Comparative Example 2 Compared to Example 1, all other conditions remained the same in this comparative example, except that the second metal material was replaced by conventional Raney alloy powder (Ni-48 wt% Al alloy) instead of W-7 Raney alloy powder.

[0085] The mixture consists of: 60 wt% Ni powder, 2 wt% aluminum powder, 38 wt% Ni-48 wt% Al alloy powder.

[0086] Experimental results: The hydrogen evolution potential of HER (5kA / m² VsHg / HgO) was 1.152V, and the binding force test (ultrasonic weight loss) was 23mg / cm. 2 (The catalyst has completely detached).

[0087] The SEM display electrode surface morphology obtained in this comparative example has a hierarchical pore structure (micropores-mesopores-macropores) as shown in the figure. Figure 3 As shown.

[0088] Comparative Example 3 Compared to Example 1, all other conditions remain the same in this comparative example, except that the first metal material is replaced with iron powder instead of nickel powder.

[0089] The mixture consists of 60 wt% iron powder, 2 wt% aluminum powder, and 38 wt% W-7 Reni alloy powder.

[0090] Experimental results: The catalyst electrode surface prepared in this comparative example has a hierarchical pore structure of micropores-mesopores-macropores. The HER hydrogen evolution potential (5kA / m² VsHg / HgO) is 1.41 V, and the binding force test (ultrasonic weight loss) is 6.2 mg / cm. 2 .

[0091] Comparative Example 4 Compared to Example 1, all other conditions remain the same in this comparative example, except that the first metal material is replaced with cobalt powder instead of nickel powder.

[0092] The mixture consists of 60 wt% cobalt powder, 2 wt% aluminum powder, and 38 wt% W-7 Raney alloy powder.

[0093] Experimental results: The catalyst electrode surface prepared in this embodiment has a hierarchical pore structure of micropores-mesopores-macropores. The HER hydrogen evolution potential (5kA / m² Vs Hg / HgO) is 1.31V, and the binding force test (ultrasonic weight loss) is 11 mg / cm. 2 .

[0094] Analysis example 1 The polarization curves (LSV) of the catalyst electrodes prepared in Examples 1-3 and Comparative Examples 1-4 are shown below. Figure 4 As shown; from Figure 4 It can be observed on the polarization curves that in the high current density region, the curve of Example 1 is the steepest and there is no obvious plateau, which indicates that its mass transfer resistance is the smallest and the mass transfer overpotential increases the slowest.

[0095] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An electrode catalyst having a hierarchical pore structure, characterized by, The electrode catalyst has a hierarchical pore structure, including micropores, mesopores, macropores; the electrode catalyst comprises an activation product of a mixture, the mixture comprising: a first metal material, content of 1-80 wt%, the first metal material comprising one or more of nickel powder, molybdenum powder, chromium powder, titanium powder, nickel-based alloy, cobalt-based alloy, iron-based alloy; a second metal material, content of 0.1-80 wt%, the second metal material comprising one or more of W-1 Raney alloy, W-2 Raney alloy, W-3 Raney alloy, W-4 Raney alloy, W-5 Raney alloy, W-6 Raney alloy, W-7 Raney alloy; a pore-forming agent, content of no more than 20 wt%.

2. The electrode catalyst with hierarchical porosity according to claim 1, characterized in that, The first metal material comprises one or more of nickel powder, chromium powder, titanium powder, nickel-based alloy.

3. The electrode catalyst with hierarchical porosity according to claim 1, wherein, The pore-forming agent comprises one or more of aluminum powder, zinc powder, magnesium powder, silicon powder.

4. The electrode catalyst with hierarchical porosity according to claim 1, wherein, The specific surface area of the electrode catalyst is no less than 100 m² / g, and the HER hydrogen evolution potential of the electrode catalyst is less than 1.2 V.

5. A catalyst electrode characterized by, The catalyst electrode comprises a conductive substrate and the electrode catalyst according to any one of claims 1-4.

6. The catalyst electrode according to claim 5, characterized in that The conductive substrate comprises one or more of nickel mesh, nickel expanded mesh, nickel felt, nickel foam; The electrode catalyst is coated on the surface of the conductive substrate by a thermal spraying process, the thermal spraying process comprising one or more of flame spraying, arc spraying, plasma spraying, supersonic spraying.

7. The catalyst electrode according to claim 5, wherein The ultrasonic weight loss bonding force test value of the catalyst electrode is not more than 3.0 mg / cm 2 .

8. A method of producing a catalyst electrode as claimed in any one of claims 5 to 7, characterized in that The method comprises the steps of: mechanical mixing: mechanically mixing the first metal material, the second metal material, and the pore-forming agent in proportion to prepare a spraying powder; thermal spraying: coating the spraying powder on the surface of the conductive substrate to form an initial coating layer; activation treatment: immersing the initial coating layer in an alkali solution to dissolve and form a hierarchical pore structure to obtain the catalyst electrode with the hierarchical pore structure.

9. The method of producing a catalyst electrode according to claim 8, characterized by, The concentration of the alkaline substance in the alkali solution is 5-30 wt%, and the alkaline substance comprises one or more of NaOH and KOH.

10. The method of producing a catalyst electrode according to claim 8, wherein The temperature of the activation treatment is 0-60℃, and the duration of the activation treatment is 0.5-48 h.

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