A high-performance nickel-based catalyst, its preparation method, and its application in industrial-grade seawater electrolysis
The preparation of nickel-based catalysts is solved through a simple and controllable method, and the high efficiency and stability of OER catalysts in seawater environments is achieved, high performance under high current density is achieved, and the development of offshore wind energy-seawater electrolytic systems is supported.
Patent Information
- Application Number
- CN202510803779.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-17
- Publication Date
- 2025-08-22
- Estimated Expiration
- 2045-06-17
AI Technical Summary
The prior art is difficult to prepare efficient and stable oxygen evolution reaction (OER) electrocatalysts in seawater environments, especially at high current density, and traditional synthesis methods consume time and energy, making it difficult to meet the needs of renewable energy-coupled seawater electrolysis systems such as industrial-grade offshore wind energy.
By soaking a self-supported nickel-based metal material in an aqueous solution containing heteropoly acids, iron salts and cobalt salts, and performing simple and controllable treatment, a high-performance nickel-based catalyst was prepared. The doping of trace amounts of Fe and Co and leaching and re-adsorption of heteropoly acids was enhanced to enhance the OER activity and stability of the catalyst in alkaline seawater.
The high stability of the catalyst at a current density of 1000 mA cm-2 is achieved, the preparation process is simplified, the production cost is reduced, and the key material support is provided for offshore wind energy-seawater electrolytic catalysts is promoted.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of seawater electrolysis, and in particular to a high-performance nickel-based catalyst, a preparation method thereof, and application in industrial-grade seawater electrolysis. Background Art
[0002] In recent years, the rapid development of offshore wind power technology and the regional scarcity of fresh water have promoted the development of renewable energy coupled with direct electrolysis of seawater to produce green hydrogen. Compared with the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER) is a higher energy process in the water decomposition reaction because it essentially involves more complex multiple proton / electron coupling steps. Therefore, the development of efficient OER electrocatalysts is very important for the overall efficiency of the water decomposition reaction. In addition, compared with the freshwater environment, the oxidation and precipitation of a large amount of chloride ions in seawater at the anode reduces the OER selectivity, and the strong binding between chloride ions and other dissolved ions and impurities and the active sites of the electrocatalyst accelerates the corrosion and failure of the catalyst, resulting in poor durability of the catalyst. This deteriorates the performance of seawater electrolysis electrocatalysts. In addition, electrolysis at high current density is crucial for the practical application of seawater electrolysis technology, but the above problems are more serious than at low current density (<200 mA cm -2 The highest current density of most seawater electrocatalysts reported so far for continuous operation is still below 500 mA cm -2 The industrial requirements of electrocatalysts are met, and it is rare for electrocatalysts to work stably for more than 100 hours. Therefore, there is an urgent need for poison-resistant oxygen evolution catalysts with sufficient catalytic activity and stability that can work normally in harsh seawater environments and meet industrial current densities.
[0003] Currently, Liu et al. [https: / / doi.org / 10.1016 / j.apcatb.2024.124140] disclosed a NiFe-LDH@Co9S8-Ni3S2 / NF OER electrocatalyst with a low overpotential of 298 mV (1000 mAcm) in alkaline seawater. -2 ), which can be used in alkaline seawater at 500 mA cm -2 Qi et al. [https: / / doi.org / 10.1016 / j.apcatb.2024.124259] synthesized a NiFeV / NF OER electrocatalyst that can operate stably at a current density of 500 mA cm in alkaline seawater environment. -2The OER electrode was operated stably at a current density of 100 nm for 240 h, achieving an OER selectivity of up to 99%. However, the highly active and stable OER electrode materials suitable for operation at high current densities are all prepared through time-consuming and energy-intensive one-step or multi-step synthesis processes, such as solvothermal, electrodeposition, or high-temperature calcination. These processes are not economically viable and are difficult to transition to for stable and controllable OER catalyst production. Therefore, the development of efficient seawater electrolysis catalysts that meet industrial needs through a simple and scalable synthesis strategy remains a challenge. Zhou et al. [https: / / doi.org / 10.1002 / aenm.202301921] soaked nickel foam in an aqueous solution containing ferric nitrate at room temperature for a period of time and dried it to obtain an oxygen evolution electrode. They then attempted to apply this to hydrogen production from seawater electrolysis. However, in a seawater environment, this simply synthesized catalyst showed poor resistance to seawater poisoning, especially at high current densities, resulting in poor OER activity and durability. This current situation makes it difficult to meet the demand for high-performance electrodes in industrial-scale seawater electrolysis systems coupled with renewable energy sources such as offshore wind power. Therefore, the development of seawater electrolysis OER catalysts that can be quickly and scalably prepared and have both high activity and high stability remains a key technical challenge that needs to be overcome. Summary of the Invention
[0004] The present invention solves the problems existing in the prior art, provides a high-performance nickel-based catalyst and a preparation method thereof, and its application in industrial-grade seawater electrolysis, providing reliable technical support for solving the problem of offshore wind power consumption.
[0005] The present invention is achieved through the following technical solutions:
[0006] The first object of the present invention is to provide a method for preparing a high-performance nickel-based catalyst, comprising the following steps: placing a pretreated self-supporting nickel-based metal material in a mixed aqueous solution containing a heteropoly acid, an iron salt, and a cobalt salt for immersion reaction; after the reaction is completed, washing and drying to obtain the high-performance nickel-based catalyst.
[0007] The present invention obtains a high-performance seawater OER catalyst (i.e., a nickel-based electrode) by immersing a self-supporting nickel-based metal material in an aqueous solution containing heteropolyacids, cobalt salts, and iron salts for a period of time. The doping of trace amounts of Fe and Co and the leaching and re-adsorption of heteropolyacids enhance the OER activity and stability of the catalyst in alkaline seawater, achieving a high OER performance at 1000 mA cm -2 It can stably electrolyze for 100 hours at an ampere-level current density.
[0008] This invention leverages the synergistic effect of heteropolyacids and metal salts to overcome the stability bottleneck of traditional nickel-based catalysts in seawater environments, enabling the rapid preparation of highly active and stable OER catalysts for seawater electrolysis, providing key material support for offshore wind power-seawater electrolysis coupling systems. This technological breakthrough not only promotes the industrial development of OER catalysts for seawater electrolysis but also lays a material foundation for the commercial application of offshore wind power hydrogen production technology.
[0009] Preferably, the pretreatment step of the pretreated self-supporting nickel-based metal material comprises: cutting the self-supporting nickel-based metal material and immersing it in hydrochloric acid, acetone, and deionized water, respectively, and then drying it in a vacuum oven at 50° C. to obtain the pretreated self-supporting nickel-based metal material. Further preferably, the self-supporting nickel-based metal material is immersed in hydrochloric acid, acetone, and deionized water, respectively, and ultrasonically treated for 15 minutes, and then dried in a vacuum oven at 50° C.
[0010] Preferably, the self-supporting nickel-based metal material is selected from one of nickel foam, nickel mesh and nickel felt.
[0011] Preferably, the concentration of the heteropoly acid in the mixed aqueous solution is 0.001-0.1 mol / L, and the heteropoly acid is selected from one or more of phosphotungstic acid, silicotungstic acid, borotungstic acid, phosphotungstovanadic acid, phosphomolybdic acid, phosphomolybdicvanadic acid, phosphotungstomolybdic acid and silicomolybdic acid.
[0012] More preferably, the concentration of the heteropoly acid in the mixed aqueous solution is 0.001-0.002 mol / L. When the heteropoly acid is a mixture of two or more acids, the concentrations of the added acids are equal.
[0013] Preferably, the concentration of the iron salt in the mixed aqueous solution is 0.001-1 mol / L, and the iron salt is selected from one of ferric nitrate, ferric sulfate and ferric chloride; the concentration of the cobalt salt in the mixed aqueous solution is 0.001-1 mol / L, and the cobalt salt is selected from one of cobalt nitrate and cobalt chloride.
[0014] More preferably, the concentration of the iron salt in the mixed aqueous solution is 0.05-1 mol / L, and the concentration of the cobalt salt in the mixed aqueous solution is 0.05-1 mol / L.
[0015] Preferably, the surface area (cm 2 ) and the ratio of the amount of the mixed aqueous solution added (mL) is 0.1-2:1. Further preferably, the surface area (cm 2 The ratio of the dosage (mL) of the aqueous solution to that of the mixed solution was 1:1.
[0016] Preferably, the soaking reaction time is 10-3600 s.
[0017] More preferably, the soaking reaction time is 30-360 s.
[0018] The specific conditions of washing and drying are: washing with deionized water and ethanol and drying with air; the air drying temperature is 50° C.-80° C., and the drying time is 0.5-6.0 h.
[0019] The second object of the present invention is to provide a high-performance nickel-based catalyst prepared by the preparation method.
[0020] The third object of the present invention is to provide the application of the high-performance nickel-based catalyst in industrial-grade seawater electrolysis.
[0021] Preferably, the high-performance nickel-based catalyst is used as the working electrode, the Hg / HgO electrode is used as the reference electrode, and the platinum electrode is used as the counter electrode.
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] (1) The doping of trace iron and cobalt elements in the nickel-based catalyst proposed in the present invention and the leaching and re-adsorption of heteropolyacids in alkaline electrolytes promote the rapid reconstruction of the nickel substrate surface and enhance the resistance to seawater chloride ion corrosion and other impurity poisoning, thereby improving the stability of the catalyst at high current density in an alkaline seawater environment.
[0024] (2) The catalyst proposed in this invention is simple and controllable to prepare, saving time and energy, and can be scaled up for production. This can significantly reduce the production cost of seawater electrolysis catalysts, promote the development of industrial-grade seawater electrolysis hydrogen production technology, and promote the consumption of offshore wind power. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 : SEM image of the catalyst obtained in Example 1.
[0026] Figure 2 : SEM image of the catalyst prepared in Comparative Example 5.
[0027] Figure 3 : SEM image of the catalyst prepared in Comparative Example 6.
[0028] Figure 4 : SEM image of the catalyst prepared in Comparative Example 7.
[0029] Figure 5 : Stability diagram of the catalyst obtained in Example 1 in alkaline seawater electrolyte. DETAILED DESCRIPTION
[0030] The present invention will be described in further detail below with reference to the examples. These examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. Experimental methods in the following examples, where specific conditions are not specified, are generally performed in accordance with conventional conditions in the art or the conditions recommended by the manufacturer; raw materials and reagents used, unless otherwise specified, are deemed to be commercially available through conventional markets. The concentration of hydrochloric acid is 1 mol / L.
[0031] Example 1
[0032] A method for preparing a high-performance nickel-based catalyst for industrial-grade seawater electrolysis comprises the following steps:
[0033] S1. Cut the nickel foam into 3 cm × 5 cm pieces and immerse them in hydrochloric acid, acetone, and deionized water for ultrasonic treatment for 15 min respectively. Then dry them in a vacuum oven at 50°C to complete the pretreatment operation.
[0034] S2. Prepare 15 mL of a mixed aqueous solution containing 0.001 mol / L phosphomolybdicvanadic acid, 0.001 mol / L borotungstic acid, 0.05 mol / L ferric chloride, and 0.05 mol / L cobalt chloride. Place the nickel foam obtained by the pretreatment in step S1 into the mixed aqueous solution and soak for 60 s. After the reaction, wash with deionized water and ethanol in sequence, and dry with air at 70°C for 2 h to finally obtain a high-performance nickel-based catalyst.
[0035] Example 2
[0036] A method for preparing a high-performance nickel-based catalyst for industrial-grade seawater electrolysis comprises the following steps:
[0037] S1. Cut the nickel foam into 3 cm × 5 cm pieces and immerse them in hydrochloric acid, acetone, and deionized water for ultrasonic treatment for 15 min respectively. Then dry them in a vacuum oven at 50°C to complete the pretreatment operation.
[0038] S2. Prepare 15 mL of a mixed aqueous solution containing 0.001 mol / L phosphomolybdic acid, 0.001 mol / L borotungstic acid, 0.05 mol / L ferric chloride, and 0.05 mol / L cobalt chloride. Place the nickel foam obtained by the pretreatment in step S1 into the mixed aqueous solution and soak for 60 s. After the reaction, wash with deionized water and ethanol in sequence, and dry with air at 70°C for 2 h to finally obtain a high-performance nickel-based catalyst.
[0039] Example 3
[0040] A method for preparing a high-performance nickel-based catalyst for industrial-grade seawater electrolysis comprises the following steps:
[0041] S1. Cut the nickel foam into 3 cm × 5 cm pieces and immerse them in hydrochloric acid, acetone, and deionized water for ultrasonic treatment for 15 min respectively. Then dry them in a vacuum oven at 50°C to complete the pretreatment operation.
[0042] S2. Prepare 15 mL of a mixed aqueous solution containing 0.001 mol / L phosphotungstovanadic acid, 0.001 mol / L silicomolybdic acid, 0.05 mol / L ferric chloride, and 0.05 mol / L cobalt chloride. Place the nickel foam obtained in S1 into the mixed aqueous solution and soak for 60 seconds. After the reaction, wash with deionized water and ethanol and dry with air at 70°C for 2 hours to finally obtain a high-performance nickel-based catalyst.
[0043] Example 4
[0044] A method for preparing a high-performance nickel-based catalyst for industrial-grade seawater electrolysis comprises the following steps:
[0045] S1. Cut the nickel foam into 3 cm × 5 cm pieces and immerse them in hydrochloric acid, acetone, and deionized water for ultrasonic treatment for 15 min respectively. Then dry them in a vacuum oven at 50°C to complete the pretreatment operation.
[0046] S2. Prepare 15 mL of a mixed aqueous solution containing 0.0005 mol / L phosphomolybdic acid, 0.0005 mol / L silicomolybdic acid, 0.0005 mol / L phosphotungstovanadic acid, 0.05 mol / L ferric chloride, and 0.05 mol / L cobalt chloride. Place the nickel foam obtained in S1 into the mixed aqueous solution and soak for 60 s. After the reaction, wash with deionized water and ethanol and dry with air at 70°C for 2 h to finally obtain a seawater electrolysis catalyst.
[0047] Example 5
[0048] The same as Example 1, except that the concentration of phosphomolybdic vanadic acid in the mixed aqueous solution is 0.0005 mol / L, the concentration of borotungstic acid is 0.0005 mol / L, the concentration of ferric chloride is 0.025 mol / L, the concentration of cobalt chloride is 0.025 mol / L, and the surface area of nickel foam (cm 2 The ratio of the dosage (mL) of the aqueous solution to the mixed solution was 0.1:1, the reaction time was 10 s, the forced air drying temperature was 50 °C, and the drying time was 6 h.
[0049] Example 6
[0050] The same as Example 1, except that the concentration of phosphomolybdic vanadic acid in the mixed aqueous solution is 0.05 mol / L, the concentration of borotungstic acid is 0.05 mol / L, the concentration of ferric chloride is 1 mol / L, the concentration of cobalt chloride is 1 mol / L, and the surface area (cm2 The ratio of the dosage of ) and the mixed aqueous solution (mL) was 2:1, the reaction time was 3600 s, the forced air drying temperature was 80 °C, and the drying time was 0.5 h.
[0051] Comparative Example 1
[0052] The difference between Comparative Example 1 and Example 1 is that borotungstic acid is not added to S2, and the amount of phosphomolybdovanadic acid added is changed to 0.002 mol / L. The rest is the same as Example 1.
[0053] Comparative Example 2
[0054] The difference between Comparative Example 2 and Example 1 is that no phosphomolybdic vanadic acid is added to S2, and the amount of borotungstic acid added is changed to 0.002 mol / L. The rest is the same as Example 1.
[0055] Comparative Example 3
[0056] The difference between Comparative Example 3 and Example 1 is that no cobalt chloride is added to S2, and the amount of ferric chloride added is changed to 0.1 mol / L. The rest is the same as Example 1.
[0057] Comparative Example 4
[0058] The difference between Comparative Example 4 and Example 1 is that no ferric chloride is added to S2, and the amount of cobalt chloride added is changed to 0.1 mol / L. The rest is the same as Example 1.
[0059] Comparative Example 5
[0060] Comparative Example 5 differs from Example 1 in that borotungstic acid and phosphomolybdovanadic acid are not added to S2, the amount of ferric chloride added is changed to 0.051 mol / L, and the amount of cobalt chloride added is changed to 0.051 mol / L. The rest is the same as Example 1.
[0061] Comparative Example 6
[0062] Comparative Example 6 differs from Example 1 in that ferric chloride and cobalt chloride are not added to S2, the amount of borotungstic acid added is changed to 0.051 mol / L, and the amount of phosphomolybdovanadic acid added is changed to 0.051 mol / L. The rest is the same as Example 1.
[0063] Comparative Example 7
[0064] The difference between Comparative Example 7 and Example 1 is that borotungstic acid, phosphomolybdovanadic acid, ferric chloride and cobalt chloride are not added to S2. The rest is the same as Example 1.
[0065] The scanning electron microscope (SEM) was used to examine the Figure 1 )、Comparative Example 5( Figure 2 )、Comparative Example 6( Figure 3 ) and Comparative Example 7 ( Figure 4Morphological characterization of the catalyst prepared using a 200 nm CMOS process clearly demonstrates a synergistic effect between the heteropolyacid and the metal salt, promoting its deposition on the nickel foam surface. Inductively coupled plasma optical emission spectroscopy (ICP-OES, Table 1) also confirms that the use of the metal salt promotes heteropolyacid deposition on the nickel foam surface, increasing the loading of electrochemically active species on the nickel foam surface.
[0066] Table 1. Comparison of ICP-OES test results of Example 1 and Comparative Examples 5-7
[0067]
[0068] In addition, OER tests were performed on the seawater electrolysis catalysts prepared in Examples 1-6 and Comparative Examples 1-7. The electrochemical tests were performed on an electrochemical workstation (CHI660E) using a standard three-electrode system, with the Hg / HgO electrode as the reference electrode, the platinum electrode as the counter electrode, and the high-performance nickel-based catalysts obtained in Examples 1-6 and Comparative Examples 1-7 of the present invention as the working electrode (cut to 1 cm × 1 cm). The electrolytes were 1 M KOH and 1 M KOH + seawater. 100 mA / cm 2 The overpotentials under different current densities were compared, and the results are shown in Table 2. In addition, the electrode obtained in Example 1 was used to test the stability of alkaline seawater electrolysis ( Figure 5 ).
[0069] Table 2. Examples 1-6 and Comparative Examples 1-7 in electrolyte at 100 mA cm -2 Comparison of overpotential data under current density
[0070]
[0071] It can be clearly seen from the SEM test results that there is a synergistic effect between heteropolyacids and metal salts, which can promote their surface modification on nickel foam. The ICP-OES test results further confirm that the use of metal salts promotes the deposition of heteropolyacids on the surface of nickel foam, thereby increasing the loading amount of electrochemically active substances on the surface of nickel foam. It can be seen from Table 2 that in the process of the three-electrode OER test, the catalyst prepared in the embodiment has excellent OER activity both in alkaline pure water and alkaline seawater electrolyte. From the comparison of the overpotential of the catalysts prepared in Example 1 and Comparative Examples 1-7, it can be seen that there is a synergistic effect between heteropolyacids, cobalt salts and iron salts, which can significantly enhance the anti-poisoning ability of the catalyst in a seawater environment and improve the OER activity of the catalyst in electrolysis of seawater. In addition, the catalyst prepared in Example 1 has an OER activity of 1000 mA / cm 2The chronoamperometric curve at the current density shows almost no decay during the electrolysis of seawater for up to 100 h. This indicates that the electrocatalyst prepared by this invention has excellent catalytic activity and stability and is promising for industrial seawater electrolysis.
[0072] The description of the above embodiments is only used to help understand the technical solution and core ideas of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention. These improvements and modifications also fall within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a high-performance nickel-based catalyst, characterized in that: The invention comprises the following steps: placing a pretreated self-supporting nickel-based metal material into a mixed aqueous solution containing a heteropoly acid, an iron salt and a cobalt salt for immersion reaction, and after the reaction is completed, washing and drying to obtain the high-performance nickel-based catalyst; the concentration of the heteropoly acid in the mixed aqueous solution is 0.001-0.1 mol / L, and the heteropoly acid is selected from one or more of phosphotungstic acid, silicotungstic acid, borotungstic acid, phosphotungstovanadic acid, phosphomolybdic acid, phosphomolybdicvanadic acid, phosphotungstomolybdic acid and silicomolybdic acid; the concentration of the iron salt in the mixed aqueous solution is 0.001-1 mol / L, and the iron salt is selected from one of ferric nitrate, ferric sulfate and ferric chloride; the concentration of the cobalt salt in the mixed aqueous solution is 0.001-1 mol / L, and the cobalt salt is selected from one of cobalt nitrate and cobalt chloride; the surface area of the self-supporting nickel-based metal material is cm 2 The ratio of the dosage of the mixed aqueous solution to that of the aqueous solution is 0.1-2:1; and the soaking reaction time is 10-3600 s.
2. The preparation method according to claim 1, characterized in that The pretreatment steps of the pretreated self-supporting nickel-based metal material are as follows: cutting the self-supporting nickel-based metal material and immersing it in hydrochloric acid, acetone and deionized water respectively, and then drying it at 50° C. in vacuum to obtain the pretreated self-supporting nickel-based metal material.
3. The preparation method according to claim 1 or 2, characterized in that The self-supporting nickel-based metal material is selected from one of nickel foam, nickel mesh and nickel felt.
4. A high-performance nickel-based catalyst prepared by the preparation method according to any one of claims 1 to 3.
5. Use of the high-performance nickel-based catalyst according to claim 4 in industrial-grade seawater electrolysis.
6. The use according to claim 5, characterized in that The high-performance nickel-based catalyst is used as an oxygen evolution electrode.