Rough honeycomb-shaped foam nickel-iron catalyst as well as preparation method and application thereof
A rough honeycomb foam nickel-iron catalyst was prepared by a hydrothermal method using synergistic regulation of chloride and iodide ions. This method solved the problems of insufficient oxidation and catalytic performance of foamed iron materials, achieving high efficiency and low cost in improving catalytic performance. It is suitable for clean energy production and waste gas treatment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2026-03-13
AI Technical Summary
Existing foamed iron materials are prone to surface oxidation in their natural state and have limited catalytic performance. Traditional modification methods are energy-intensive and costly, which limits their application in the industrial field.
A rough honeycomb foam nickel-iron catalyst was prepared by a combined chloride and iodide ion induced hydrothermal method. By synergistically controlling the surface morphology and structure of the foam iron, a porous and rough honeycomb structure was formed, thereby improving the catalytic activity.
It significantly improves the oxygen evolution catalytic performance of foamed iron, increases the catalytic active sites and specific surface area, and reduces the preparation cost and energy consumption, making it suitable for large-scale industrial applications.
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Figure CN121653701A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalytic material modification technology, specifically relating to a rough honeycomb foam nickel-iron catalyst, its preparation method, and its application. Background Technology
[0002] Iron foam, as a catalytic and adsorbent material, plays a crucial role in industrial applications such as clean energy production and waste gas treatment. However, the surface of iron foam is easily oxidized in its natural state, and its catalytic performance is limited, which greatly restricts the breadth and efficiency of its applications. Currently, most industrial applications of iron foam involve the electrocatalytic oxygen evolution reaction (OER). The OER catalytic performance of iron foam is the key factor determining its practical application.
[0003] Currently, common methods for enhancing the catalytic performance of foamed iron materials include chemical vapor deposition and high-temperature heat treatment. While existing methods can improve catalytic performance, they are typically accompanied by high energy consumption, high costs, and complex processes, which are detrimental to environmental protection and increase the economic burden on industrial production.
[0004] Therefore, developing a surface modification technology for foamed iron that is more energy-efficient, lower-cost, and more environmentally friendly to improve its electrocatalytic oxygen evolution performance has become an urgent technical problem to be solved in the industry. Summary of the Invention
[0005] To overcome the shortcomings of the prior art, the first aspect of the present invention is to provide a method for preparing a rough honeycomb foam nickel-iron catalyst, which uses chloride ions and iodide ions to jointly induce the foamed iron to become a catalyst with a rough honeycomb structure, thereby effectively improving the electrocatalytic oxygen evolution performance of the catalyst.
[0006] A second aspect of the present invention is to provide a coarse honeycomb foam nickel-iron catalyst prepared by the above-described preparation method.
[0007] A third aspect of the present invention is to provide the application of the above-mentioned coarse honeycomb foam nickel-iron catalyst.
[0008] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution:
[0009] A method for preparing a coarse honeycomb foam nickel-iron catalyst includes the following steps:
[0010] The pretreated foamed iron and composite salt solution are mixed and subjected to hydrothermal reaction at 50-70℃, and then washed to obtain a rough honeycomb foamed nickel-iron catalyst.
[0011] The composite salt solution is prepared by dissolving sodium chloride, sodium iodide, and nickel chloride in water; the molar concentration ratio of sodium chloride, sodium iodide, and nickel chloride is (3.5-4.5):(0.5-1.5):(4.0-6.0).
[0012] Hydrothermal processes are chemical reaction techniques conducted at relatively low temperatures and have been widely applied in materials science in recent years, particularly showing great potential in the synthesis and modification of various catalytic materials. By enabling chemical reactions in a closed environment within a solution, hydrothermal processes can promote highly efficient chemical conversions at relatively low temperatures, thereby producing materials with excellent physical and chemical properties. This invention utilizes hydrothermal methods for the surface modification of foamed iron, which not only enhances its catalytic activity but also allows for precise control of the material's microstructure and surface properties through controlled reaction conditions, further optimizing its performance. Therefore, the foamed iron surface modification method provided by this invention has significant industrial application prospects and substantial economic benefits.
[0013] Chloride ions play a crucial role in the surface modification and performance regulation of foamed iron using hydrothermal methods. Due to their small ionic radius and strong electronegativity, chloride ions can significantly influence the surface morphology and oxygen evolution reaction (OER) catalytic performance of foamed iron during hydrothermal reactions. Specifically, chloride ions can regulate the surface structure of foamed iron by altering the nucleation and growth processes, promoting the formation of specific microstructures, which is significant for the generation of active sites in catalytic reactions. Introducing chloride ions into the hydrothermal environment can form a more uniform foamed iron surface with specific geometric morphologies, which often exhibits high catalytic activity in the OER. However, another characteristic of chloride ions is their strong corrosiveness. During the hydrothermal treatment of foamed iron materials, chloride ions readily undergo redox reactions with iron, leading to severe iron corrosion. This corrosion not only weakens the foamed iron structure and affects its mechanical stability but also triggers the chlorine generation side reaction (CER), thereby reducing the efficiency of the OER and adversely affecting the environment. Therefore, although using chloride ions alone can optimize the morphology of foamed iron to some extent, its negative impact on material stability cannot be ignored.
[0014] To address the aforementioned problems, this invention proposes a novel preparation strategy for the first time. Specifically, during the modification of foamed iron, both iodide and chloride ions are introduced simultaneously during the hydrothermal reaction to overcome the corrosion problem caused by the introduction of chloride ions alone and to further improve the oxygen evolution catalytic performance of the material. Compared with chloride ions, iodide ions have a larger ionic radius and lower oxidizing power, exhibiting better stability on the material surface. By introducing iodide ions, this invention can form a more stable and catalytically beneficial structure on the surface of foamed iron, while inhibiting excessive corrosion caused by chloride ions. Iodide ions can synergistically interact with chloride ions during the growth of foamed iron, inducing the formation of a rough, honeycomb-like porous structure. This structure helps increase surface active sites and improve the catalytic performance of the material.
[0015] As a preferred embodiment, the pretreatment involves cutting and washing the foamed iron raw material.
[0016] To further improve the electrocatalytic oxygen evolution performance of the catalyst, as a preferred embodiment, the molar concentration ratio of sodium chloride, sodium iodide, and nickel chloride is 4:1:5.
[0017] As a preferred embodiment, the hydrothermal reaction time is 8 to 16 hours.
[0018] As a preferred embodiment, the hydrothermal reaction is carried out in a closed reaction vessel.
[0019] As a preferred embodiment, the hydrothermal reaction is carried out by vertically placing the pretreated foamed iron into the reactor and completely immersing it in the composite salt solution.
[0020] As a preferred embodiment, the bottom of the reactor is provided with a polytetrafluoroethylene (PTFE) slot to ensure that the foamed iron stands vertically inside the reactor. By placing the foamed iron vertically inside the reactor, the uniformity of the reaction can be guaranteed.
[0021] As a preferred embodiment, the cleaning process involves alternating between anhydrous ethanol and pure water. More preferably, the cleaning process is followed by a drying step.
[0022] The second aspect of the present invention adopts the following technical solution:
[0023] The rough honeycomb foam nickel-iron catalyst prepared by the above preparation method.
[0024] The third aspect of this invention adopts the following technical solution:
[0025] The above-mentioned rough honeycomb foam nickel-iron catalyst is used as a catalyst in the electrocatalytic oxygen evolution reaction.
[0026] The technical solution of the present invention has the following advantages and beneficial effects:
[0027] (1) Significantly improved oxygen evolution reaction catalytic performance: This invention utilizes a synergistic regulation strategy of chloride and iodide ions to form a rough honeycomb structure on the surface of foamed iron, increasing the number of catalytic active sites and significantly improving the catalytic performance of the oxygen evolution reaction. Compared with traditional foamed iron materials, the modified material exhibits higher current density and lower overpotential.
[0028] (2) Optimized porous structure: Chloride ions promote uniform nucleation on the surface of the foamed iron in the hydrothermal process, while iodide ions further stabilize and regulate the microstructure. The synergistic effect of the two results in a rough, porous honeycomb morphology on the surface of the foamed iron. This structure effectively increases the specific surface area and mass transport channels of the material, thereby improving the oxygen evolution catalytic efficiency.
[0029] (3) Low-temperature and environmentally friendly preparation method: The hydrothermal method used in this invention is carried out at a lower temperature, avoiding the high energy consumption problem caused by high temperature in traditional methods, which is in line with the concept of green environmental protection. At the same time, the process of this invention is simple and suitable for large-scale industrial applications, effectively reducing preparation costs and energy consumption.
[0030] In summary, this invention, through the synergistic effect of chloride and iodide ions, significantly reduces the adverse effects of corrosion while maintaining the high activity and porous structure of foamed iron materials, ultimately achieving dual optimization of the morphology and oxygen evolution reaction performance of foamed iron. The ion regulation strategy of chloride-iodine coexistence proposed in this invention represents a novel approach for the modification of foamed iron. Therefore, the method for modifying and preparing foamed iron catalysts provided by this invention not only possesses theoretical innovation but also offers a new pathway for developing novel, highly efficient, self-supporting electrocatalysts, showing broad application prospects in the field of oxygen evolution catalyst preparation. Attached Figure Description
[0031] Figure 1 The image shows a SEM image of the foamed iron catalyst (0NaI-CF) prepared in Comparative Example 1 of this invention; the right image is a partial enlarged SEM image of the left image.
[0032] Figure 2 The image shows a SEM image of the rough honeycomb foam nickel-iron catalyst (100NaI-CF) prepared in Example 1 of this invention; the right image is a partial enlarged SEM image of the left image.
[0033] Figure 3 Transmission electron microscopy (TEM) image and elemental distribution map of the rough honeycomb foam nickel-iron catalyst (100NaI-CF) prepared in Example 1 of this invention; wherein, Figure 3 a is a transmission electron microscope image. Figure 3 b~3d are the elemental surface distribution maps of energy-dispersive X-ray spectra (3b is the distribution map of Ni, 3c is the distribution map of Fe, and 3d is the distribution map of O).
[0034] Figure 4 The LSV test results are for the foamed iron catalysts prepared in Examples 1-3 and Comparative Example 1 of this invention. Detailed Implementation
[0035] The technical solutions and effects of the present invention will be clearly and completely described below with reference to specific embodiments and test examples. However, those skilled in the art should understand that the embodiments are only used to illustrate the technical solutions of the present invention and should not be regarded as limiting the scope of protection of the present invention. Unless otherwise specified, the test methods used in the following embodiments are conventional methods; unless otherwise specified, the raw materials used are items commonly used in the art, publicly available, or commercially obtainable.
[0036] In the following embodiments, the foamed iron raw material used comes from Kunshan Tengerhui Electronic Technology Co., Ltd.
[0037] Example 1
[0038] This embodiment provides a coarse honeycomb foam nickel-iron catalyst, the preparation method of which includes the following steps:
[0039] (1) Pretreatment of foamed iron: Cut the foamed iron raw material into rectangular thin slices with a size of 2cm×0.8cm and a thickness of 1.5mm; place the cut foamed iron in anhydrous ethanol and ultrasonically clean for 10 minutes to remove surface organic contaminants; then immerse the foamed iron in 0.1mol / L dilute hydrochloric acid solution and ultrasonically clean for 15 minutes to remove surface oxides; finally rinse the foamed iron several times with deionized water and anhydrous ethanol alternately to ensure thorough cleaning, and place it in a dry environment to air dry for later use.
[0040] Preparation of the compound salt solution: Weigh sodium chloride, sodium iodide, and nickel chloride, and use deionized water to prepare a 60 mL compound salt solution containing sodium chloride, sodium iodide, and nickel chloride. During the preparation of the solution, stir and sonicate until the solution is completely transparent. The molar concentrations of each salt in the compound salt solution are: 400 mmol / L sodium chloride, 100 mmol / L sodium iodide, and 500 mmol / L nickel chloride.
[0041] (2) Hydrothermal reaction: The two pieces of foamed iron after cleaning are placed vertically into the reactor. The bottom of the reactor has a polytetrafluoroethylene slot. The foamed iron is inserted into the slot to ensure that it stands vertically in the reactor. Then the composite salt solution prepared in step (1) is poured into the reactor to ensure that the foamed iron is completely immersed in the composite salt solution. After the reactor is sealed, the hydrothermal reaction is carried out. The hydrothermal reaction temperature is set to 60℃ and the reaction time is 10 hours.
[0042] (3) Post-reaction treatment: After the hydrothermal reaction is completed, the reactor is removed and allowed to cool naturally to room temperature. The hydrothermal foamed iron sample is removed and washed three times alternately with pure water and anhydrous ethanol to ensure the removal of residual substances; then the washed foamed iron sample is air-dried to obtain the rough honeycomb foamed nickel-iron catalyst of Example 1, named 100NaI-CF.
[0043] Example 2
[0044] This embodiment provides a rough honeycomb foam nickel-iron catalyst, the preparation method of which is basically the same as that of Example 1. The only difference is that in step (1), the concentrations of each salt in the composite salt solution are: 450 mmol / L sodium chloride, 50 mmol / L sodium iodide, and 500 mmol / L nickel chloride. Other processes and parameters are the same as in Example 1. The rough honeycomb foam nickel-iron catalyst prepared is named 50NaI-CF.
[0045] Example 3
[0046] This embodiment provides a rough honeycomb foam nickel-iron catalyst, the preparation method of which is basically the same as that of Example 1. The only difference is that in step (1), the concentrations of each salt in the composite salt solution are: 350 mmol / L sodium chloride, 150 mmol / L sodium iodide, and 500 mmol / L nickel chloride. Other processes and parameters are the same as in Example 1. The rough honeycomb foam nickel-iron catalyst prepared is named 150NaI-CF.
[0047] Comparative Example 1
[0048] This comparative example provides a foamed iron catalyst, the preparation method of which is basically the same as that of Example 1. The only difference is that in step (1), the mixed salt solution used is a composite salt solution containing only sodium chloride and nickel chloride; the concentration of each salt in the composite salt solution is: 500 mmol / L sodium chloride and 500 mmol / L nickel chloride. Other processes and parameters are the same as in Example 1. The foamed nickel-iron catalyst prepared is named 0NaI-CF.
[0049] Experimental Example 1: Structural Characterization
[0050] The structures of the foamed iron catalysts prepared in Comparative Example 1 (0NaI-CF) and Example 1 (100NaI-CF) were characterized using scanning electron microscopy (SEM). The SEM images are shown below. Figure 1 and Figure 2 As shown. Further characterization of the chemical elements of the foamed nickel-iron catalyst prepared in Example 1 (100NaI-CF) was performed using transmission electron microscopy (TEM), and the results are as follows. Figure 3 As shown.
[0051] Depend on Figure 1 and Figure 2 It can be seen that both the iron foam catalyst (0NaI-CF) of Comparative Example 1 and the iron foam catalyst (100NaI-CF) of Example 1 have a honeycomb-like three-dimensional sheet structure. However, in the presence of only chloride ions, the iron foam in Comparative Example 1 exhibits a smooth honeycomb-like three-dimensional sheet structure (e.g., Figure 1 (As shown). In this invention, when chloride ions and iodide ions coexist, the prepared nickel-iron foam exhibits a rough, honeycomb-like three-dimensional sheet-like structure on its surface (as shown). Figure 2 (As shown).
[0052] Figure 3 The transmission electron microscope (TEM) images and energy-dispersive X-ray spectroscopy (EDX) results further confirm that the rough honeycomb-like three-dimensional sheet structure synthesized in this invention is a nickel-iron catalyst.
[0053] Experimental Example 2: Electrocatalytic Performance Test
[0054] This experiment evaluated the electrocatalytic performance of the samples in a standard three-electrode system. A platinum sheet was used as the counter electrode, a mercury-mercury oxide electrode (Hg / HgO) as the reference electrode, and the nickel-iron foam catalyst samples synthesized in Examples 1-3 and Comparative Example 1 were used as the working electrodes. The current density of different iron foam samples in the oxygen evolution reaction (OER) was measured using linear sweep voltammetry (LSV). The test results are shown below. Figure 4 As shown.
[0055] Depend on Figure 4 The test results show that, compared to Comparative Example 1 where only chloride ions were present, the oxygen evolution catalytic performance of the samples in Examples 1-3 was significantly enhanced when both chloride and iodide ions were present. Among them, the foamed iron catalyst (100NaI-CF) sample in Example 1 exhibited the best oxygen evolution catalytic performance, indicating that the ion ratio of 400 mmol / L sodium chloride, 100 mmol / L sodium iodide, and 500 mmol / L nickel chloride was the optimal scheme. Further analysis showed that both excessively low and excessively high iodide ion concentrations weakened the oxygen evolution catalytic performance of the samples.
[0056] Therefore, the synergistic regulation strategy of chloride and iodide ions proposed in this invention successfully constructs a rough, honeycomb-like three-dimensional sheet structure on the surface of foamed iron. This unique structure significantly increases the number of active sites in the electrocatalytic reaction, effectively improving the catalytic performance of the oxygen evolution reaction.
[0057] In summary, the preparation method of the rough honeycomb foamed nickel-iron catalyst provided by this invention introduces both chloride and iodide ions simultaneously in the hydrothermal reaction, and proposes for the first time a synergistic regulation strategy for chloride and iodide ions. Through synergistic action, they not only improve the porous honeycomb structure of the foamed iron, but also effectively increase the surface roughness and active sites, thereby significantly enhancing the oxygen evolution catalytic performance of the material. Therefore, the preparation strategy of this invention not only overcomes the corrosion problem caused by the introduction of chloride ions alone, but also achieves dual optimization of morphology and oxygen evolution catalytic activity, providing a new approach for the development of novel, highly efficient self-supporting electrocatalysts, and has broad application prospects in the field of oxygen evolution catalyst preparation.
[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a coarse honeycomb foam nickel-iron catalyst, characterized in that, Includes the following steps: The pretreated foamed iron and composite salt solution are mixed and subjected to hydrothermal reaction at 50-70℃, and then washed to obtain a rough honeycomb foamed nickel-iron catalyst. The composite salt solution is prepared by dissolving sodium chloride, sodium iodide, and nickel chloride in water; the molar concentration ratio of sodium chloride, sodium iodide, and nickel chloride is (3.5-4.5):(0.5-1.5):(4.0-6.0).
2. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to claim 1, characterized in that, The pretreatment involves cutting and washing the foamed iron raw material.
3. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to claim 1, characterized in that, The molar ratio of sodium chloride, sodium iodide, and nickel chloride is 4:1:
5.
4. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to any one of claims 1 to 3, characterized in that, The hydrothermal reaction takes 8 to 16 hours.
5. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to any one of claims 1 to 3, characterized in that, The hydrothermal reaction is carried out in a closed reaction vessel.
6. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to any one of claims 1 to 3, characterized in that, The hydrothermal reaction is carried out by vertically placing the pretreated foamed iron into the reactor and completely immersing it in the composite salt solution.
7. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to claim 6, characterized in that, The bottom of the reactor is equipped with a polytetrafluoroethylene (PTFE) slot to ensure that the foamed iron stands vertically inside the reactor.
8. The method for preparing the coarse honeycomb foam nickel-iron catalyst according to any one of claims 1 to 3, characterized in that, The cleaning process involves alternating between anhydrous ethanol and pure water; the cleaning process is followed by a drying step.
9. A coarse honeycomb foam nickel-iron catalyst prepared by the preparation method according to any one of claims 1 to 8.
10. The application of the coarse honeycomb foam nickel-iron catalyst as described in claim 9, characterized in that, Application of catalysts in the electrocatalytic oxygen evolution reaction.