FeCoNi-based alloy catalyst as well as preparation method and application thereof

Abstract

The invention relates to a FeCoNi-based alloy catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalytic electrolysis of water. The method comprises the following steps: mixing a raw material metal salt precursor and a complexing agent, and then carrying out ball milling to obtain a complexing intermediate; roasting the complexing intermediate to obtain a catalyst; wherein the complexing agent comprises urea; a high-energy ball milling auxiliary chemical method is adopted, ball milling is used for providing an instantaneous micro-scale high-energy environment, a complexing agent urea and a raw material metal salt precursor are subjected to a complexing effect, thermodynamic and dynamic conditions for forming high-entropy alloy nanoparticles are created, the nanoparticle catalyst is prepared, and the metal utilization rate and the active site exposure rate are increased.

Description

Technical Field

[0001] The present application relates to the technical field of catalytic electrolysis of water, and particularly relates to an FeCoNi-based alloy catalyst, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, reports on the catalytic electrolysis of water by FeCoNi-based high-entropy alloys have emerged continuously, including the catalytic cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER). Compared with single metals and the relatively well-reported binary alloy materials composed of two metals, high-entropy alloys composed of five or more metals have unique physical and chemical properties due to the strong electronic effects between multiple metals, and they perform excellently in aspects such as electrical conductivity, thermal conductivity, and corrosion resistance, and also have application potential in the field of electrocatalysis. Alloy materials with nanostructures have catalytic application potential, and their excellent catalytic performance not only requires the electronic effects and synergistic effects between multiple metals, but also depends on the quantum size effect of the nanostructures.

[0003] Fang et al. deposited FeCoNiCuPd films on a carbon cloth substrate by the "magnetron sputtering method", and the prepared high-entropy catalyst has excellent HER and OER catalytic activities and can be used as a stable bifunctional electrocatalyst to achieve efficient and stable overall water electrolysis under high-current conditions. Mei et al. synthesized FeCoNiMo with a diameter of 8 nanometers by the "thermochemical method", and this material has excellent OER catalytic performance. Cho et al. synthesized bulk CuCoNiFeMn materials by the "high-energy ball milling method", and this material has excellent HER and OER catalytic performances. Li et al. synthesized Pt 18 Ni 26 Fe 15 Co 14 Cu 27 nanoparticles with a diameter of 3.4 nanometers by the "thermochemical method", and this material has excellent HER and methanol oxidation (MOR) catalytic performances. Zhu et al. synthesized FeCoNiMnRu nanoparticles with a diameter of about 14 nanometers by the "electrospinning method", and this material has excellent HER and methanol oxidation (MOR) catalytic performances.

[0004] In summary, the currently reported FeCoNi-based high-entropy alloys mostly contain some noble metal atoms, and it is difficult for the materials to reach the nanoscale. Moreover, most FeCoNi-based high-entropy alloys are two-dimensional thin films or even micron-sized bulk structures, and the metal utilization rate and the exposure rate of active sites need to be improved, and the use of noble metals needs to be reduced. Summary of the Invention

[0005] The present application provides an FeCoNi-based alloy catalyst, a preparation method thereof, and an application thereof to improve the current problem of low metal utilization rate.

[0006] In a first aspect, the present application provides a method for preparing a FeCoNi-based alloy catalyst, the method comprising:

[0007] Mixing a raw material metal salt precursor and a complexing agent, and then performing ball milling to obtain a complex intermediate;

[0008] Roasting the complex intermediate to obtain a catalyst;

[0009] wherein, the complexing agent includes urea.

[0010] As an optional implementation manner, the raw material metal salt precursor includes metal chlorides.

[0011] As an optional implementation manner, the raw material metal salt precursor includes at least 5 metal salts.

[0012] As an optional implementation manner, the metal elements of the raw material metal salt precursor include iron, nickel, cobalt, molybdenum, and tungsten.

[0013] As an optional implementation manner, the raw material metal salt precursor includes ferric chloride, nickel chloride, cobalt chloride, molybdenum chloride, and tungsten chloride.

[0014] As an optional implementation manner, the mixing method includes grinding.

[0015] As an optional implementation manner, the grinding time is 4 to 6 minutes.

[0016] As an optional implementation manner, the rotation speed of the ball milling is 800 to 1600 revolutions per minute; and / or

[0017] the motor power of the ball milling is 100 to 500 watts; and / or

[0018] the ball milling time is 5 to 35 minutes.

[0019] As an optional implementation manner, the rotation speed of the ball milling is 1000 to 1400 revolutions per minute; and / or

[0020] the motor power of the ball milling is 200 to 400 watts; and / or

[0021] the ball milling time is 10 to 30 minutes.

[0022] As an optional implementation manner, the rotation speed of the ball milling is 1100 to 1300 revolutions per minute; and / or

[0023] the motor power of the ball milling is 250 to 350 watts; and / or

[0024] the ball milling time is 15 to 25 minutes.

[0025] As an alternative embodiment, the atmosphere for the calcination includes an inert gas.

[0026] As an alternative embodiment, the atmosphere for the calcination includes argon.

[0027] As an alternative embodiment, the temperature for the calcination is 600 - 1000 °C; and / or

[0028] the time for the calcination is 1 - 3 hours.

[0029] As an alternative embodiment, the temperature for the calcination is 700 - 900 °C; and / or

[0030] the time for the calcination is 1.5 - 2.5 hours.

[0031] As an alternative embodiment, the temperature for the calcination is 750 - 850 °C; and / or

[0032] the time for the calcination is 1.8 - 2.2 hours.

[0033] As an alternative embodiment, the heating rate for the calcination is 2 - 8 °C / minute.

[0034] As an alternative embodiment, the heating rate for the calcination is 3 - 7 °C / minute.

[0035] As an alternative embodiment, the heating rate for the calcination is 4 - 6 °C / minute.

[0036] In a second aspect, the present application provides an FeCoNi-based alloy catalyst, which is prepared by using the preparation method of the FeCoNi-based alloy catalyst described in the first aspect.

[0037] In a third aspect, the present application provides an application of an FeCoNi-based alloy catalyst, which is prepared by using the preparation method of the FeCoNi-based alloy catalyst described in the first aspect, and the application includes using the catalyst for catalyzing electrolytic water.

[0038] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0039] For the method provided by the embodiments of the present application, through the high-energy ball milling-assisted chemical method, by using ball milling to provide a high-energy environment at the instantaneous microscale, the complexing agent urea and the raw material metal salt precursor undergo a complexing effect, creating the thermodynamic and kinetic conditions for the formation of high-entropy alloy nanoparticles, and preparing a nanoparticle catalyst, thereby improving the metal utilization rate and the exposure rate of active sites. Description of the Drawings

[0040] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and, together with the specification, are used to explain the principles of the present application.

[0041] To more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a flowchart of the method provided by the embodiment of the present application;

[0043] Figure 2 It is an XRD diagram of the catalyst and carbide nanoparticle material provided by Embodiment 1 of the present application;

[0044] Figure 3 It is the transmission electron microscope of the catalyst provided by Embodiment 1 of the present application Figure 1 ;

[0045] Figure 4 It is the transmission electron microscope of the catalyst provided by Embodiment 1 of the present application Figure 2 ;

[0046] Figure 5 It is the EDS elemental energy spectrum analysis result diagram of the catalyst provided by Embodiment 1 of the present application;

[0047] Figure 6 It is the LSV polarization curve diagram of the catalyst provided by Embodiment 1 of the present application;

[0048] Figure 7 It is the stability curve diagram of the catalyst provided by Embodiment 1 of the present application. Detailed Embodiments

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0050] Unless otherwise specifically stated, various raw materials, reagents, instruments, and equipment used in the present application can all be obtained through market purchases or can be prepared by existing methods.

[0051] In recent years, there have been continuous reports on FeCoNi-based high-entropy alloys for catalytic electrolysis of water, including catalytic hydrogen evolution reaction (HER) at the cathode and oxygen evolution reaction (OER) at the anode. Compared with single metals and binary alloy materials that have been reported more frequently, high-entropy alloys composed of five or more metals have unique physical and chemical properties due to the strong electronic effects among multiple metals. They perform excellently in aspects such as electrical conductivity, thermal conductivity, and corrosion resistance, and also have application potential in the field of electrocatalysis. Alloy materials with nanostructures have catalytic application potential. Their excellent catalytic performance not only requires the electronic effects and synergistic effects among multiple metals but also depends on the quantum size effect of the nanostructures.

[0052] Fang et al. deposited FeCoNiCuPd thin films on carbon cloth substrates by using the "magnetron sputtering method". The prepared high-entropy catalyst has excellent catalytic activities for HER and OER and can be used as a stable bifunctional electrocatalyst to achieve efficient and stable overall water electrolysis under high-current conditions. Mei et al. synthesized FeCoNiMo with a diameter of 8 nanometers by using the "thermochemical method". This material has excellent catalytic performance for OER. Cho et al. synthesized bulk CuCoNiFeMn materials by using the "high-energy ball milling method". This material has excellent catalytic performances for HER and OER. Li et al. synthesized Pt 18 Ni 26 Fe 15 Co 14 Cu 27 nanoparticles with a diameter of about 3.4 nanometers by using the "thermochemical method". This material has excellent catalytic performances for HER and methanol oxidation reaction (MOR). Zhu et al. synthesized FeCoNiMnRu nanoparticles with a diameter of about 14 nanometers by using the "electrospinning method". This material has excellent catalytic performances for HER and MOR.

[0053] In summary, most of the currently reported FeCoNi-based high-entropy alloys contain some noble metal atoms, and it is difficult to achieve the nanoscale for the materials. Moreover, most FeCoNi-based high-entropy alloys are two-dimensional thin films or even bulk structures with micron sizes. The metal utilization rate and the exposure rate of active sites need to be improved, and the use of noble metals needs to be reduced.

[0054] A high-energy ball mill is a commonly used mechanical energy-assisted synthesis device. The inventors found that by using ball milling to drive the complexation of urea and metal salts, and using the high-energy environment at the instantaneous microscale provided by ball milling to cause the complexation effect between urea and metal salts, thermodynamic and kinetic conditions for the formation of high-entropy alloy nanoparticles are created. The prepared nanoparticle catalyst can improve the metal utilization rate and the exposure rate of active sites.

[0055] As Figure 1 shown, the embodiments of the present application provide a preparation method for an FeCoNi-based alloy catalyst. The method includes:

[0056] S1. Mix the raw material metal salt precursor and the complexing agent, and then perform ball milling to obtain a complex intermediate; wherein, the complexing agent includes urea.

[0057] In some embodiments, the raw material metal salt precursor includes metal chlorides. Metal chlorides are conducive to complexing with the complexing agent urea under the action of ball milling.

[0058] In some embodiments, the raw material metal salt precursor includes at least 5 metal salts. Compared with single metals and binary alloy materials with more reports, high-entropy alloys composed of five or more metals have unique physical and chemical properties due to the strong electron effect between multiple metals. They perform well in aspects such as electrical conductivity, thermal conductivity, and corrosion resistance, and also have good catalytic performance.

[0059] Furthermore, the metal elements of the raw material metal salt precursor include iron, nickel, cobalt, molybdenum, and tungsten. Using iron, nickel, cobalt, molybdenum, and tungsten can achieve good catalytic performance, and at the same time, no precious metals are introduced, which is beneficial to cost control in catalyst preparation. Further, the raw material metal salt precursor includes ferric chloride, nickel chloride, cobalt chloride, molybdenum chloride, and tungsten chloride.

[0060] In some embodiments, the mixing method includes grinding. Further, the grinding time is 4 to 6 minutes. Exemplarily, the grinding time can be 4 minutes, 4.1 minutes, 4.2 minutes, 4.3 minutes, 4.4 minutes, 4.5 minutes, 4.6 minutes, 4.7 minutes, 4.8 minutes, 4.9 minutes, 5 minutes, 5.1 minutes, 5.2 minutes, 5.3 minutes, 5.4 minutes, 5.5 minutes, 5.6 minutes, 5.7 minutes, 5.8 minutes, 5.9 minutes, or 6 minutes, etc. It can also be any value within the range of 4 to 6 minutes.

[0061] In some embodiments, the rotation speed of the ball milling is 800 - 1600 revolutions per minute; the motor power of the ball milling is 100 - 500 watts; the time of the ball milling is 5 - 35 minutes. Further, the rotation speed of the ball milling is 1000 - 1400 revolutions per minute; the motor power of the ball milling is 200 - 400 watts; the time of the ball milling is 10 - 30 minutes. Still further, the rotation speed of the ball milling is 1100 - 1300 revolutions per minute; the motor power of the ball milling is 250 - 350 watts; the time of the ball milling is 15 - 25 minutes. Exemplarily, the rotation speed of the ball milling can be 800 revolutions per minute, 850 revolutions per minute, 900 revolutions per minute, 950 revolutions per minute, 1000 revolutions per minute, 1050 revolutions per minute, 1100 revolutions per minute, 1150 revolutions per minute, 1200 revolutions per minute, 1250 revolutions per minute, 1300 revolutions per minute, 1350 revolutions per minute, 1400 revolutions per minute, 1450 revolutions per minute, 1500 revolutions per minute, 1550 revolutions per minute or 1600 revolutions per minute, etc., and it can also be any value within the range of 800 - 1600 revolutions per minute. The motor power of the ball milling can be 110 watts, 120 watts, 130 watts, 140 watts, 150 watts, 160 watts, 170 watts, 180 watts, 190 watts, 200 watts, 210 watts, 220 watts, 230 watts, 240 watts, 250 watts, 260 watts, 270 watts, 280 watts, 290 watts, 300 watts, 310 watts, 320 watts, 330 watts, 340 watts, 350 watts, 360 watts, 370 watts, 380 watts, 390 watts, 400 watts, 410 watts, 420 watts, 430 watts, 440 watts, 450 watts, 460 watts, 470 watts, 480 watts, 490 watts or 500 watts, etc., and it can also be any value within the range of 100 - 500 watts. The time of the ball milling can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes or 25 minutes, etc., and it can also be any value within the range of 15 - 25 minutes.

[0062] Specifically, in this embodiment, metal chlorides with analytical pure AR purity are selected, including ferric chloride FeCl3, nickel chloride NiCl2, cobalt chloride CoCl3, molybdenum chloride MoCl5, tungsten chloride WCl6 as metal salt precursors, and urea is selected as the complexing agent. The metal salt and urea are ground for 5 minutes to be fully mixed, and the mixture is placed in the ball mill pot of a high-energy ball mill. At 1200 revolutions per minute and a motor power of 300 watts, ball milling for 20 minutes forms a colloidal intermediate, that is, a complex intermediate.

[0063] S2. Calcinate the complex intermediate to obtain the catalyst.

[0064] In some embodiments, the atmosphere for roasting includes an inert gas. Further, the atmosphere for roasting includes argon.

[0065] In some embodiments, the temperature for roasting is 600 - 1000 °C; the time for roasting is 1 - 3 hours. Further, the temperature for roasting is 700 - 900 °C; the time for roasting is 1.5 - 2.5 hours. Still further, the temperature for roasting is 750 - 850 °C; the time for roasting is 1.8 - 2.2 hours. The temperature for roasting can be 600 °C, 610 °C, 620 °C, 630 °C, 640 °C, 650 °C, 660 °C, 670 °C, 680 °C, 690 °C, 700 °C, 710 °C, 720 °C, 730 °C, 740 °C, 750 °C, 760 °C, 770 °C, 780 °C, 790 °C, 800 °C, 810 °C, 820 °C, 830 °C, 840 °C, 850 °C, 860 °C, 870 °C, 880 °C, 890 °C, 900 °C, 910 °C, 920 °C, 930 °C, 940 °C, 950 °C, 960 °C, 970 °C, 980 °C, 990 °C or 1000 °C, etc., and it can also be any value within the range of 600 - 1000 °C. The time for roasting can be 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours, etc., and it can also be any value within the range of 1 - 3 hours.

[0066] In some embodiments, the heating rate for roasting is 2 - 8 °C / minute. Further, the heating rate for roasting is 3 - 7 °C / minute. Still further, the heating rate for roasting is 4 - 6 °C / minute. The heating rate for roasting can be 2 °C / minute, 2.2 °C / minute, 2.4 °C / minute, 2.6 °C / minute, 2.8 °C / minute, 3 °C / minute, 3.2 °C / minute, 3.4 °C / minute, 3.6 °C / minute, 3.8 °C / minute, 4 °C / minute, 4.2 °C / minute, 4.4 °C / minute, 4.6 °C / minute, 4.8 °C / minute, 5 °C / minute, 5.2 °C / minute, 5.4 °C / minute, 5.6 °C / minute, 5.8 °C / minute, 6 °C / minute, 6.2 °C / minute, 6.4 °C / minute, 6.6 °C / minute, 6.8 °C / minute, 7 °C / minute, 7.2 °C / minute, 7.4 °C / minute, 7.6 °C / minute, 7.8 °C / minute or 8 °C / minute, etc., and it can also be any value within the range of 2 - 8 °C / minute.

[0067] Specifically, in this embodiment, the colloidal complex intermediate obtained by ball milling is heated to 800 °C at a rate of 5 °C / minute in an argon (Ar) atmosphere and roasted at a high temperature for 2 hours to obtain FeCoNiMoW-N supported on a C3N4 carrier. xA five - element non - noble - metal high - entropy alloy nitride / carbide nanoparticle, i.e., a catalyst.

[0068] This method is a high - energy ball - milling assisted chemical method. By using ball - milling to provide a high - energy environment at the instantaneous micro - scale, a complexing effect occurs between the complexing agent urea and the raw metal salt precursor, creating the thermodynamic and kinetic conditions for the formation of high - entropy alloy nanoparticles, preparing the nanoparticle catalyst, and improving the metal utilization rate and the exposure rate of active sites.

[0069] Based on a general inventive concept, the embodiments of the present application also provide an FeCoNi - based alloy catalyst, which is prepared by using the preparation method of the FeCoNi - based alloy catalyst provided above.

[0070] This catalyst is prepared based on the above - mentioned method. The specific steps of this method can be referred to the above - mentioned embodiments. Since this catalyst adopts some or all of the technical solutions of the above - mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above - mentioned embodiments, which will not be elaborated one by one here.

[0071] Based on a general inventive concept, the embodiments of the present application also provide an application of the FeCoNi - based alloy catalyst, which is prepared by using the preparation method of the FeCoNi - based alloy catalyst provided above, and the application includes using the catalyst for catalytic electrolysis of water.

[0072] This application is realized based on the above - mentioned method. The specific steps of this method can be referred to the above - mentioned embodiments. Since this application adopts some or all of the technical solutions of the above - mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above - mentioned embodiments, which will not be elaborated one by one here.

[0073] Specifically, applying the catalyst to prepare a catalytic electrode, the manufacturing method of the catalytic electrode includes: dissolving 5 mg of the catalyst in 920 μL of ethanol, after ultrasonic treatment for 30 minutes, adding 80 μL of Nafion, and using a pipette to vertically drop 20 μL of the suspension onto a disk electrode of 0.196 cm 2 and then allowing it to air - dry naturally in the air.

[0074] The following further elaborates the present application in combination with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods without specific conditions noted in the following embodiments are usually determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0075] Example 1

[0076] A preparation method of an FeCoNi - based alloy catalyst, the method includes:

[0077] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 5 minutes to mix them thoroughly, and place the mixture in the ball mill tank of a high-energy ball mill. Under the conditions of 1200 revolutions per minute and a motor power of 300 watts, ball mill for 20 minutes to form a colloidal complex intermediate.

[0078] Place the colloidal intermediate in a porcelain boat, and under an argon (Ar) atmosphere, heat it to 800 °C at a rate of 5 °C per minute and calcine it at a high temperature for 2 hours to obtain FeCoNiMoW five-component non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 support, that is, the catalyst.

[0079] Perform X-ray diffraction testing on this catalyst, and the results are as Figure 2 shown. Figure 2 This is the XRD pattern of the catalyst and carbide nanoparticle material provided in Example 1 of this application. From the figure, it can be seen that the X-ray diffraction peaks show the lattice diffraction peaks of the two materials. One group corresponds to the C3N4 material, which is generated by the high-temperature calcination of urea; the other group of diffraction peaks is close to the diffraction peaks of the Ni3MoN material. Since the material synthesized by this method is a new material and there is no XRD standard card for the FeCoNiMoW high-entropy material, it is necessary to jointly determine the material phase with the help of characterizations such as transmission electron microscopy.

[0080] Perform transmission electron microscopy scanning and EDS elemental energy spectrum analysis on this catalyst, and the results are as Figure 3 and Figure 4 and Figure 5 shown. Figure 3 This is the transmission electron microscopy Figure 1 of the catalyst provided in Example 1 of this application; Figure 4 This is the transmission electron microscopy Figure 2 of the catalyst provided in Example 1 of this application; From the figure, it can be seen that the material obtained by calcining the colloidal complex intermediate obtained by ball milling under argon shows spherical nanoparticles dotted on the support, and the diameter of the spherical particles is about 10 nanometers. Figure 5 This is the EDS elemental energy spectrum analysis result diagram of the catalyst provided in Example 1 of this application; From the figure, it can be seen that the synthesized material contains five metal elements of Fe, Co, Ni, Mo, and W, and also contains C and N elements. The remaining Cu element is attributed to the copper mesh supporting the sample, and O, Si, and Ca are caused by the interference of the electron microscope system. Through TEM transmission characterization and EDS elemental energy spectrum analysis of the material synthesized by this method, the material phase and morphology of the material are further proved. Combining with the XRD analysis results, it is proved that the FeCoNiMoW-N x five-component non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on C3N4 are obtained.

[0081] 5 mg of the synthesized material was used to prepare a catalytic electrode. The preparation method of the catalytic electrode included: 5 mg of the catalyst was dissolved in 920 μL of ethanol, ultrasonicated for 30 minutes, and then 80 μL of Nafion was added. 20 μL of the suspension was selected with a pipette and vertically dropped onto a 0.196 cm 2 The sample was placed on a disk electrode and then allowed to air dry.

[0082] The polarization curve of the anodic oxidation reaction (OER) of catalytic water electrolysis was tested. The reaction was carried out in an electrochemical workstation using a standard three-electrode system, with Hg / HgO as the reference electrode and platinum as the counter electrode. The test was carried out in a glass cell containing 200 mL of 1.0 M KOH as the electrolyte. The RHE potential was calculated by the formula E(RHE) = E(Hg / HgO) + 0.0591 × pH + 0.097 V. The HER polarization curve was obtained by linear sweep voltammograms (LSVs) with a scan rate of 5 mV s -1 , measured at a rate of 1600 rpm between 0.7 and 1.9 V (vs. RHE). Before each measurement, the electrolyte was purged with N2 for 20 minutes to blow away the internal oxygen. The voltage and current of the oxidation reaction were compared to analyze the catalytic activity and stability of the material.

[0083] The results are as follows Figure 6 and 7 As shown, Figure 6 This is the LSV polarization curve of the catalyst provided in Example 1 of the present application; the two curves are the original data and the data after resistance correction. The test results show that the synthetic material has good performance in catalyzing OER, reaching 10mA cm at an overpotential of about 300mV. -2 , which is at an intermediate level among the reported non-precious metal-based catalysts. Figure 7 The stability curve of the catalyst provided in Example 1 of the present application; it can be seen from the figure that the catalyst material can still work after continuous catalysis for 14 hours, 10mA cm -2 The lower potential increase does not exceed 20mV, 50mA cm -2 The lower potential increase does not exceed 50 mV; it can be seen that the catalytic material exhibits excellent catalytic stability.

[0084] In summary, this method uses the mechanical energy generated by the high-energy ball mill during the ball milling process to generate an instantaneous high-temperature environment at the microscopic scale, driving the urea molecules and various metal salt ions Fe under room temperature. 3+ 、Co 3+ 、Ni 2+ 、Mo 5+ , W 6+Complexation was carried out, and a colloidal intermediate was formed by high-energy ball milling for 20 minutes, followed by calcination in an argon (Ar) atmosphere at 800 °C for nitrogen / carbonization. By performing X-ray diffraction patterns, transmission electron microscopy images, and EDS elemental scanning analysis on the synthesized catalyst material, the analysis results demonstrated that the present method synthesized FeCoNiMoW high-entropy alloy nanoparticles with a diameter of approximately 10 nm containing 5 metals. In 1 mol L -1 KOH solution, the overpotential of this material for catalyzing the oxygen evolution reaction (OER) could reach 300 mV vs. RHE at 10 mA cm -2 , showing a catalytic advantage among FeCoNi-based materials.

[0085] Example 2

[0086] A preparation method of an FeCoNi-based alloy catalyst, the method includes:

[0087] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 4 minutes to mix them thoroughly, and place the mixture in the ball mill of a high-energy ball mill. Under a rotation speed of 800 revolutions per minute and a motor power of 100 watts, ball mill for 35 minutes to form a colloidal complex intermediate.

[0088] Place the colloidal intermediate in a porcelain boat, and under an argon (Ar) atmosphere, heat it to 750 °C at a rate of 2 °C per minute and calcine it at a high temperature for 3 hours to obtain FeCoNiMoW five-element non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 carrier, which is the catalyst.

[0089] Example 3

[0090] A preparation method of an FeCoNi-based alloy catalyst, the method includes:

[0091] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 6 minutes to mix them thoroughly, and place the mixture in the ball mill of a high-energy ball mill. Under a rotation speed of 1600 revolutions per minute and a motor power of 500 watts, ball mill for 5 minutes to form a colloidal complex intermediate.

[0092] Place the colloidal intermediate in a porcelain boat, and under an argon (Ar) atmosphere, heat it to 1000 °C at a rate of 8 °C per minute and calcine it at a high temperature for 1 hour to obtain FeCoNiMoW five-element non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 carrier, which is the catalyst.

[0093] Example 4

[0094] A preparation method of an FeCoNi-based alloy catalyst, the method includes:

[0095] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 5 minutes to mix them thoroughly, and place the mixture in the ball mill tank of a high-energy ball mill. Under the conditions of 1000 revolutions per minute and a motor power of 250 watts, ball mill for 25 minutes to form a colloidal complex intermediate.

[0096] Place the colloidal intermediate in a porcelain boat. Under an argon (Ar) atmosphere, heat it at a rate of 3 °C per minute to 700 °C and calcine it at a high temperature for 2.5 hours to obtain FeCoNiMoW quinary non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 support, which is the catalyst.

[0097] Example 5

[0098] A preparation method of an FeCoNi-based alloy catalyst, the method comprising:

[0099] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 5 minutes to mix them thoroughly, and place the mixture in the ball mill tank of a high-energy ball mill. Under the conditions of 1400 revolutions per minute and a motor power of 400 watts, ball mill for 10 minutes to form a colloidal complex intermediate.

[0100] Place the colloidal intermediate in a porcelain boat. Under an argon (Ar) atmosphere, heat it at a rate of 7 °C per minute to 900 °C and calcine it at a high temperature for 1.5 hours to obtain FeCoNiMoW quinary non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 support, which is the catalyst.

[0101] Example 6

[0102] A preparation method of an FeCoNi-based alloy catalyst, the method comprising:

[0103] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 5 minutes to mix them thoroughly, and place the mixture in the ball mill tank of a high-energy ball mill. Under the conditions of 1100 revolutions per minute and a motor power of 150 watts, ball mill for 25 minutes to form a colloidal complex intermediate.

[0104] Place the colloidal intermediate in a porcelain boat. Under an argon (Ar) atmosphere, heat it at a rate of 4 °C per minute to 750 °C and calcine it at a high temperature for 1.8 hours to obtain FeCoNiMoW quinary non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 support, which is the catalyst.

[0105] Example 7

[0106] A preparation method of a FeCoNi-based alloy catalyst, the method comprising:

[0107] Weigh 2 mmol of FeCl3, NiCl2, CoCl3, MoCl5, and WCl6, and weigh 20 mmol of urea. Grind the metal salts and urea for 5 minutes to fully mix them, and place the mixture in the ball mill of a high-energy ball mill. Under the conditions of 1300 revolutions per minute and a motor power of 400 watts, ball mill for 10 minutes to form a colloidal complex intermediate.

[0108] Place the colloidal intermediate in a porcelain boat, and under an argon (Ar) atmosphere, heat it to 850 °C at a rate of 6 °C per minute, and calcine it at a high temperature for 2.2 hours to obtain FeCoNiMoW five-element non-precious metal high-entropy alloy nitride / carbide nanoparticles supported on a C3N4 support, that is, the catalyst.

[0109] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, which applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0110] In this application, unless otherwise specified, the orientation terms such as "upper" and "lower" specifically refer to the drawing directions in the attached drawings. Additionally, in the description of this application's specification, terms such as "comprising" and "including" mean "including but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. In this text, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone. Here, A and B can be singular or plural. In this text, "at least one" means one or more, and "multiple" means two or more. "At least one kind", "at least one item (one) of the following" or similar expressions refer to any combination of these items, including any combination of single item (one) or plural items (ones). For example, "at least one item (one) of a, b, or c", or, "at least one item (one) of a, b, and c" can both mean: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0111] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A preparation method of a FeCoNi-based alloy catalyst, characterized in that, The method includes: Mixing a raw material metal salt precursor and a complexing agent, and then performing ball milling to obtain a complex intermediate; Calcining the complex intermediate to obtain a catalyst; Wherein, the complexing agent includes urea.

2. The preparation method of the FeCoNi-based alloy catalyst according to claim 1, characterized in that, The raw material metal salt precursor includes a metal chloride.

3. The preparation method of the FeCoNi-based alloy catalyst according to claim 1 or 2, characterized in that, The raw material metal salt precursor includes at least 5 metal salts.

4. The preparation method of the FeCoNi-based alloy catalyst according to claim 3, characterized in that, The metal elements of the raw material metal salt precursor include iron, nickel, cobalt, molybdenum, and tungsten.

5. The preparation method of the FeCoNi-based alloy catalyst according to claim 4, characterized in that, The raw material metal salt precursor includes ferric chloride, nickel chloride, cobalt chloride, molybdenum chloride, and tungsten chloride.

6. The preparation method of the FeCoNi-based alloy catalyst according to claim 1, wherein, The mixing method includes grinding.

7. The preparation method of the FeCoNi-based alloy catalyst according to claim 6, characterized in that, The grinding time is 4 to 6 minutes.

8. The preparation method of the FeCoNi-based alloy catalyst according to claim 1, wherein, The rotation speed of the ball milling is 800 to 1600 revolutions per minute; and / or The motor power of the ball milling is 100 to 500 watts; and / or The ball milling time is 5 to 35 minutes.

9. The preparation method of the FeCoNi-based alloy catalyst according to claim 8, wherein, The rotation speed of the ball milling is 1000 to 1400 revolutions per minute; and / or The motor power of the ball milling is 200 to 400 watts; and / or The ball milling time is 10 to 30 minutes.

10. The preparation method of the FeCoNi-based alloy catalyst according to claim 9, characterized in that, The rotation speed of the ball milling is 1100 to 1300 revolutions per minute; and / or The motor power of the ball milling is 250 to 350 watts; and / or The ball milling time is 15 to 25 minutes.

11. The preparation method of the FeCoNi-based alloy catalyst according to claim 1, wherein The calcination atmosphere includes an inert gas.

12. The preparation method of the FeCoNi-based alloy catalyst according to claim 11, wherein, The calcination atmosphere includes argon.

13. The preparation method of the FeCoNi-based alloy catalyst according to claim 1, wherein The calcination temperature is 600 to 1000 °C; and / or The calcination time is 1 to 3 hours.

14. The preparation method of the FeCoNi-based alloy catalyst according to claim 13, wherein, The calcination temperature is 700 to 900 °C; and / or The calcination time is 1.5 to 2.5 hours.

15. The preparation method of the FeCoNi-based alloy catalyst according to claim 14, wherein, The calcination temperature is 750 to 850 °C; and / or The calcination time is 1.8 to 2.2 hours.

16. The preparation method of the FeCoNi-based alloy catalyst according to claim 1, wherein, The heating rate of the calcination is 2 to 8 °C per minute.

17. The preparation method of the FeCoNi-based alloy catalyst according to claim 16, wherein, The heating rate of the calcination is 3 to 7 °C per minute.

18. The preparation method of the FeCoNi-based alloy catalyst according to claim 17, wherein, The heating rate of the calcination is 4 to 6 °C per minute.

19. A FeCoNi-based alloy catalyst, characterized in that, The catalyst is prepared by the preparation method of the FeCoNi-based alloy catalyst according to any one of claims 1 to 18.

20. Application of a FeCoNi-based alloy catalyst, characterized in that, The catalyst is prepared by the preparation method of the FeCoNi-based alloy catalyst according to any one of claims 1 to 18, and the application includes using the catalyst for catalytic electrolysis of water.

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