Two-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material, preparation method thereof and water electrolysis hydrogen production method

Abstract

The invention discloses a dual-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material, a preparation method thereof and a method for producing hydrogen by electrolyzing water. According to the preparation method disclosed by the invention, coexistence of the PtMn intermetallic compound and the CoNiRu solid solution is successfully realized by accurately regulating and controlling the calcining temperature, and a highly dispersed structure is formed in a carbon nanofiber substrate. The unique structural design endows the catalytic material with extremely excellent performance in an alkaline electrolytic water hydrogen evolution reaction, and the hydrogen evolution activity of the catalytic material is remarkably superior to that of a commercial Pt / C catalyst. In addition, the material also shows excellent stability, and can maintain efficient catalytic performance even in long-time operation. Due to the characteristic, the dosage of precious metal is effectively reduced, the efficient catalytic effect is ensured, and remarkable advantages and wide application prospects are provided for practical application.

Description

Technical Field

[0001] The present invention belongs to the field of catalytic material preparation, and in particular relates to a dual-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material and a preparation method thereof, and a method for producing hydrogen by electrolysis of water. Background Art

[0002] With the continuous growth of global energy demand and the increasing attention to environmental protection, the development of clean and efficient energy conversion technologies has become a top priority. Hydrogen, as a high-energy-density, environmentally friendly energy carrier, is considered an important component of the future sustainable energy system. Hydrogen production by water electrolysis is one of the important ways to obtain hydrogen at present, among which alkaline water electrolysis has attracted much attention due to its low corrosiveness, high safety and compatibility with existing industrial infrastructure. However, in alkaline media, the kinetics of the hydrogen evolution reaction are relatively slow, which seriously limits the improvement of the efficiency of hydrogen production by water electrolysis.

[0003] Among numerous catalysts, precious metal platinum (Pt)-based materials are considered one of the most ideal catalysts for the alkaline hydrogen evolution reaction (HER) due to their exceptional catalytic activity and stability. However, the scarce reserves and high cost of Pt significantly limit its large-scale application. Therefore, the development of high-performance, low-cost Pt-containing alloy catalysts to improve the efficiency of the alkaline HER and reduce the amount of Pt required has become a hot topic and a key research direction.

[0004] In recent years, researchers have combined Pt with other metal elements through alloying strategies to prepare a series of Pt-containing alloy catalysts. These alloy catalysts not only inherit the high activity of Pt, but also can further enhance catalytic performance by regulating electronic structure and optimizing surface active sites through the alloying effect. For example, by introducing transition metal elements into Pt-based catalysts, the amount of Pt can be effectively reduced while improving the stability and activity of the catalyst in alkaline media. In addition, some studies have also shown that the rational design of the composition and microstructure of the alloy can significantly improve the catalyst's ability to adsorb and desorb reaction intermediates, thereby accelerating the rate of the alkaline hydrogen evolution reaction.

[0005] Dual-phase high-entropy alloys (DHAs) exhibit excellent performance in catalytic reactions due to their unique structural design. Dual-phase HEAs are composed of two distinct phases, each with distinct electronic structures and catalytic properties. This structure effectively exploits the synergistic effects between the different metals, thereby enhancing the catalytic activity and selectivity of the catalyst.

[0006] This invention aims to develop a novel Pt-containing dual-phase high-entropy alloy for the alkaline hydrogen evolution reaction. By thoroughly exploring the relationship between the alloy's composition, structure, and catalytic performance, it is hoped that a catalyst with high activity, high stability, and a high cost-effectiveness under alkaline conditions can be designed, providing strong support for the industrial development of hydrogen production technology through water electrolysis. Summary of the Invention

[0007] In order to overcome the shortcomings of the existing technology, the present invention provides a dual-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material and its preparation method, and a method for producing hydrogen by electrolysis of water. The prepared PtMnCoNiRu / CNFs exhibits excellent performance in hydrogen production by electrolysis of water and has good long-term stability.

[0008] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing a dual-phase high entropy alloy PtMnCoNiRu / CNFs catalytic material, the method comprising the following steps:

[0009] (1) dispersing manganese salt, cobalt salt, nickel salt, ruthenium salt, platinum salt and carbon nanofiber precursor in an organic solvent to prepare a spinning solution;

[0010] (2) spinning the spinning solution prepared in step (1) by electrospinning to obtain a nanofiber membrane;

[0011] (3) placing the nanofiber membrane prepared in step (2) in an air atmosphere and calcining it at a constant heating rate for pre-oxidation treatment;

[0012] (4) The pre-oxidized fiber membrane prepared in step (3) is heated to 750-1100°C at a heating rate of 5-10°C / min under an inert gas atmosphere and kept constant at that temperature for 3-5 hours. After the constant temperature is reached, the temperature is lowered to room temperature to finally prepare a carbon nanofiber in-situ loaded PtMnCoNiRu / CNFs electrocatalytic material.

[0013] Furthermore, the precursor solution in step (1) contains a carbon fiber precursor in an amount of 10 to 15% by mass.

[0014] Furthermore, the total molar concentration of manganese salt, cobalt salt, nickel salt, ruthenium salt and platinum salt in the spinning solution in step (1) is 0.05-0.08 mmol / g.

[0015] Furthermore, the heating rate in step (3) is 5-10°C / h, the pre-oxidation is to heat to 180-230°C, and keep the temperature for 6-10 h.

[0016] Furthermore, the carbon nanofiber precursor in step (1) is one or more of polyacrylonitrile, polyvinyl pyrrolidone, and polyvinyl alcohol; the manganese salt precursor in step (1) is one or more of manganese chloride, manganese acetate, manganese nitrate, and manganese acetylacetonate; the cobalt salt precursor in step (1) is one or more of cobalt chloride, cobalt acetate, cobalt nitrate, and cobalt acetylacetonate; the nickel salt precursor in step (1) is one or more of nickel chloride, nickel acetate, nickel nitrate, and nickel acetylacetonate; the ruthenium salt precursor in step (1) is one or both of ruthenium chloride and ruthenium acetylacetonate; and the platinum salt precursor in step (1) is one or both of chloroplatinic acid and platinum acetylacetonate.

[0017] Furthermore, the organic solvent in step (1) is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethanol, water, and acetone; the organic solvent in step (1) is N,N-dimethylformamide.

[0018] Furthermore, in step (2), the spinning voltage is 16 to 25 kV, the distance from the receiving device to the spinning needle is 10 to 20 cm, and the solution flow rate is 0.02 to 0.04 mL / h; in step (4), the diameter of the carbon nanofibers in the carbon nanofiber membrane is 200 to 300 nm; and the inert gas in step (4) is one of argon and nitrogen.

[0019] Furthermore, the heating rate of the high temperature treatment in step (4) is 5°C / min, or 7°C / min, or 10°C / min.

[0020] The present invention also discloses a dual-phase high entropy alloy PtMnCoNiRu / CNFs catalytic material, which is prepared by the above method.

[0021] The present invention further discloses a method for producing hydrogen by electrolyzing water, which utilizes the above-mentioned dual-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material.

[0022] The beneficial effects of the present invention are as follows: 1) The present invention successfully synthesized the PtMnCoNiRu / CNFs catalyst by combining electrospinning technology with high-temperature calcination. In the composite structure, a significant synergistic effect is formed between the PtMn intermetallic compound and the CoNiRu solid solution, which greatly improves the electrocatalytic performance of the catalyst; 2) The preparation method is not only simple to operate and the conditions are controllable, but also has good scalability, making it very suitable for large-scale industrial production; 3) The PtMnCoNiRu / CNFs catalyst of the present invention exhibits excellent electrocatalytic performance and stability, with a charge transfer rate of 200 mA cm -2 At a current density of 1.5 Å, the overpotential of the catalyst is only 68 mV, and the Tafel slope is 59.9 mV dec.-1 , indicating that it has extremely high catalytic efficiency. In addition, the PtMnCoNiRu / CNFs catalyst has a high -2 It can operate stably for up to 1100 hours at a high current density. This excellent stability gives it great potential in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a microscopic morphology of the catalyst PtMnCoNiRu / CNFs obtained in Example 1 of the present invention; wherein, Figure 1 (a) is the scanning electron microscopy (SEM) image of PtMnCoNiRu / CNFs. Figure 1 (b) Transmission electron microscopy (TEM) image of PtMnCoNiRu / CNFs. Figure 1 (c) is the high-resolution transmission electron microscopy (HRTEM) image of PtMnCoNiRu / CNFs. Figure 1 (d) Mapping spectrum of PtMnCoNiRu / CNFs.

[0024] Figure 2 This is the X-ray diffraction pattern (XRD) of the catalyst PtMnCoNiRu / CNFs obtained in Example 1 of the present invention.

[0025] Figure 3 The crystal structure of the catalyst PtMnCoNiRu / CNFs obtained in Example 2 of the present invention changes with temperature; Figure 3 (a) is the in situ X-ray diffraction pattern (In situ XRD) of PtMnCoNiRu / CNFs at 750-1100℃. Figure 3 (b) Schematic diagram of the evolution of PtMnCoNiRu / CNFs under thermal driving.

[0026] Figure 4 This is the X-ray photoelectron spectroscopy (XPS) spectrum of the catalyst PtMnCoNiRu / CNFs obtained in Example 1 of the present invention;

[0027] Figure 5 The electrocatalytic performance of the catalysts PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs and commercial Pt / C obtained in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention was tested in 1 M KOH. Figure 5 (a) is the hydrogen evolution reaction polarization curve of PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs and commercial Pt / C. Figure 5(b) Tafel slope curves of PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs and commercial Pt / C. Figure 5 (c) Tafel slopes and 200 cm-1 of PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs, and commercial Pt / C. -2 Overpotential histogram under Figure 5 (d) Electrochemical impedance spectroscopy (EIS) diagrams of PtMnCoNiRu / CNFs, PtMn / CNFs, and CoNiRu / CNFs at a test voltage of -0.03 V vs. RHE.

[0028] Figure 6 Comparison of polarization curves of the catalyst PtMnCoNiRu / CNFs obtained in Example 1 of the present invention before and after 10,000 CV cycles.

[0029] Figure 7 The catalyst PtMnCoNiRu / CNFs obtained in Example 1 of the present invention has a -2 Stability test under .

[0030] Figure 8 (a) LSV curves of PtMnCoNiRu / CNFs with different metal salt concentrations. Figure 8 (b) Tafel curve of PtMnCoNiRu / CNFs with different metal salt concentrations. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] Example 1

[0033] The preparation method of PtMnCoNiRu / CNFs material comprises the following steps:

[0034] (1) 0.1 mmol manganese acetylacetonate, 0.1 mmol cobalt acetylacetonate, 0.1 mmol nickel acetylacetonate, 0.05 mmol ruthenium chloride, and 0.4 mmol chloroplatinic acid were added to a 12 g N,N-dimethylformamide / ethanol (mass ratio 2:1) solution of 10 wt% polyvinyl pyrrolidone. A uniform and transparent solution was obtained by magnetic stirring. The above solution was spun by electrospinning. The positive electrode voltage was controlled to 18 kV, the distance between the positive electrode and the receiver was set to 20 cm, and the solution pushing speed was 0.2 mL h -1 , that is, the PtMnCoNiRu precursor nanofiber membrane is prepared.

[0035] (2) 0.6 g of the prepared nanofiber membrane was sandwiched between graphite sheets and placed in a tube furnace. The temperature was raised to 230°C at a rate of 5°C / h in air and maintained for 3 h to allow the fiber membrane to form a stable structure and effectively prevent the fiber from being damaged during the carbonization process. The temperature was then raised to 1100°C at a rate of 5°C / min in an argon atmosphere and maintained at this temperature for 3 h. After the temperature was lowered to room temperature, the catalytic material PtMnCoNiRu / CNFs was prepared.

[0036] A method for producing hydrogen by electrolysis of water utilizes the aforementioned dual-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material. Specifically, a three-electrode system and an electrolytic cell were used on a CHI 660E electrochemical workstation. The prepared PtMnCoNiRu / CNFs catalyst material served as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The electrolyte was a 1 M KOH solution. High-purity argon was continuously introduced into the electrolytic cell until the electrolyte reached saturation. The voltage range for the electrocatalytic hydrogen evolution test was -0.4-0.1 V vs. RHE.

[0037] Example 2

[0038] The only difference from Example 1 is that in step (2), the temperatures during graphitization calcination are adjusted to 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C and 1150°C, respectively. Other parameters and conditions are the same as those in Example 1.

[0039] Example 3

[0040] The preparation method of PtMnCoNiRu / CNFs materials with different metal contents comprises the following steps:

[0041] Step (1) Referring to Example 1, the molar ratio of each metal salt was kept unchanged during the preparation of the spinning solution, and only the total metal molar concentration was changed to 0.05 and 0.08 mmol / g, respectively, to obtain PtMnCoNiRu-0.05 precursor nanofiber membrane and PtMnCoNiRu-0.08 precursor nanofiber membrane.

[0042] Step (2) is the same as in Example 1, and PtMnCoNiRu-0.05 / CNFs and PtMnCoNiRu-0.08 / CNFs catalytic materials are prepared respectively.

[0043] Comparative Example 1

[0044] The preparation method of PtMn / CNFs material comprises the following steps:

[0045] (1) 0.1 mmol manganese acetylacetonate and 0.4 mmol platinic acid chloride were added to a 12 g N,N-dimethylformamide / ethanol (mass ratio 2:1) solution of 10 wt% polyvinyl pyrrolidone, and a uniform and transparent solution was obtained by magnetic stirring. The above solution was spun by electrospinning, with the positive electrode voltage controlled at 18 kV, the distance between the positive electrode and the receiver set to 20 cm, and the solution pushing speed set at 0.2 mL h -1 , that is, the PtMn precursor nanofiber membrane is prepared.

[0046] (2) 0.6 g of the prepared nanofiber membrane was sandwiched between graphite sheets and placed in a tube furnace. The temperature was raised to 230°C at a rate of 5°C / h in air and maintained for 3 h to allow the fiber membrane to form a stable structure and effectively prevent the fiber from being damaged during the carbonization process. The temperature was then raised to 1100°C at a rate of 5°C / min in an argon atmosphere and maintained at this temperature for 3 h. After the temperature was lowered to room temperature, the catalytic material PtMn / CNFs was prepared.

[0047] Comparative Example 2

[0048] The preparation method of CoNiRu / CNFs material comprises the following steps:

[0049] (1) 0.1 mmol of cobalt acetylacetonate, 0.1 mmol of nickel acetylacetonate, and 0.05 mmol of ruthenium chloride were added to a 12 g solution of 10 wt% polyvinylpyrrolidone in N,N-dimethylformamide / ethanol (mass ratio 2:1), and a uniform and transparent solution was obtained by magnetic stirring. The above solution was spun by electrospinning, with the positive electrode voltage controlled at 18 kV, the distance between the positive electrode and the receiver set to 20 cm, and the solution pushing speed set at 0.2 mL h -1 , that is, the CoNiRu precursor nanofiber membrane is obtained.

[0050] (2) 0.6 g of the prepared nanofiber membrane was sandwiched between graphite sheets and placed in a tube furnace. The temperature was raised to 230°C at a rate of 5°C / h in air and maintained for 3 h to allow the fiber membrane to form a stable structure and effectively prevent the fiber from being damaged during the carbonization process. The temperature was then raised to 1100°C at a rate of 5°C / min in an argon atmosphere and maintained at this temperature for 3 h. After the temperature was lowered to room temperature, the catalytic material CoNiRu / CNFs was prepared.

[0051] Figure 1 (a) and Figure 1 (b) are scanning electron microscopy and transmission electron microscopy images of PtMnCoNiRu / CNFs, respectively. It can be seen from these two images that the diameter of carbon nanofibers (CNFs) is 200-300 nm, and CNFs are randomly distributed to form a three-dimensional network structure. PtMnCoNiRu / CNFs nanoparticles can be evenly distributed on carbon nanofibers (CNFs) and have relatively uniform size, which is conducive to the catalytic reaction. Figure 1 (c) is a high-resolution transmission electron microscopy (HRTEM) image of PtMnCoNiRu / CNFs. It can be seen from the figure that PtMnCoNiRu / CNFs has an obvious two-phase interface, where the (110) interplanar spacing of PtMn is 2.01 Å, and the Ni 0.8 Ru 0.2 The (111) interplanar spacing is 2.03 Å. In addition, Figure 1 (d) STEM-EDS elemental distribution of PtMnCoNiRu / CNFs. It is clearly observed that Pt and Mn exhibit a concentrated distribution pattern, while Co, Ni, and Ru exhibit a different concentrated distribution pattern. This difference in elemental distribution further confirms the typical dual-phase structure of PtMnCoNiRu / CNFs, indicating that PtMn and CoNiRu form a clear spatial stratification or partitioning, providing a structural basis for the unique properties of this catalyst.

[0052] Figure 2The X-ray diffraction pattern (XRD) of PtMnCoNiRu / CNFs shows that the diffraction peaks of PtMnCoNiRu / CNFsNPs at 2θ = 24.5°, 31.8°, 40.4°, 45.6°, 49.7°, 52.3°, and 60.4° correspond to the (001), (100), (101), (110), (002), (111), and (102) crystal planes, respectively, proving the existence of face-centered tetragonal PtMn intermetallic compounds (PDF#04-003-5268). At the same time, the diffraction peaks at 2θ = 43.5°, 50.6°, and 74.2° correspond to the (111), (200), and (220) crystal planes, respectively, corresponding to the Ni 0.8 Ru 0.2 Alloy (PDF#04-001-2914), with Ni 0.8 Ru 0.2 Compared with the alloy, the diffraction peak shifts slightly to low angles, which is because the incorporation of Co atoms causes lattice expansion. The XRD results show that there are two phase structures, namely PtMn intermetallic compound and CoNiRu solid solution.

[0053] Figure 3 The crystal structure of PtMnCoNiRu / CNFs changes with temperature. Figure 3 (a) It can be seen that at 750℃, the temperature is too low to drive the atomic alloying, so there is no obvious metal diffraction peak. When the temperature reaches 800℃, two obvious phases appear in the XRD spectrum, namely PtMn intermetallic compound (PDF#04-003-5268) and Mn 0.5 Ni 0.5 Solid solution (PDF#04-002-7519), in which the solid solution is the dominant phase. In the range of 800-1000℃, with the gradual increase of temperature, the PtMn phase gradually increases and the solid solution phase gradually decreases, indicating that the two undergo atomic diffusion under thermal driving. It can be observed that the diffraction peak of the solid solution gradually shifts to high angles at 1000℃, corresponding to Ni 0.8 Ru 0.2 (PDF#04-001-2914), indicating that Mn atoms overflow from the solid solution phase. As the temperature further increases, the diffraction peaks of the two phases remain basically unchanged. Therefore, it can be inferred that at 1000℃, the Mn element in the solid solution has been completely transferred to the PtMn intermetallic compound, eventually forming the PtMn intermetallic compound and CoNiRu solid solution. The growth mechanism of the dual-phase high entropy alloy PtMnCoNiRu / CNFs under thermal drive is as follows Figure 3As shown in (b), under low temperature conditions, the metal salt is decomposed to form small clusters and attached to the carbon fiber. As the temperature rises, since the electronegativity of Mn is the largest difference from that of Pt, it is beneficial to reduce the surface Gibbs energy. The two diffuse into each other to form PtMn intermetallic compounds. Since the diffusion rate of atoms in the solid solution is relatively slow, a higher temperature is required to drive the migration of Mn atoms in the solid solution phase to the PtMn intermetallic compound.

[0054] Figure 4 The 1s XPS spectrum of C in (a) shows that there are three different hybrid states of carbon in carbon fiber, namely C sp 2 、C sp 3 and CO. This indicates that carbon fibers have rich chemical compositions and structural characteristics. Figure 4 The XPS spectra of Co, Ni, and Ru in (bd) show that these elements exist in both zero-valent and high-valent states in the catalyst. This diversity of valence states may be related to their chemical environment in the solid solution. Figure 4 The XPS spectrum of Mn in (e) shows that it exists mainly in a high-valence state. This may be due to the electron transfer between Mn and other elements during the alloying process, resulting in a change in its oxidation state. Figure 4 The XPS spectrum of Pt in (d) shows that it exists primarily in its zero-valence state. This indicates that Pt maintains high metallic activity in the catalyst, which is crucial for catalytic performance. This distribution of elemental valence states and electronic structures is primarily due to the low electronegativity of Mn, which readily forms intermetallic compounds with the more electronegative Pt. During the alloying process, strong electronic interactions occur between Mn and Pt, with electrons transferred from Mn to Pt, thereby lowering the Pt d-band center. This electron transfer not only optimizes the catalytic activity of Pt but also enhances the synergistic effect of the entire dual-phase structure, providing the basis for the catalyst's excellent performance.

[0055] Figure 5 (a) Polarization curves of the electrocatalytic hydrogen evolution test of PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs, and commercial Pt / C in 1 mKOH. As can be seen from the figure, PtMnCoNiRu / CNFs performs best in terms of potential response, significantly outperforming the other catalysts, thus demonstrating significantly superior performance. Figure 5 (b) Tafel slope curves of the electrocatalytic hydrogen evolution test of catalysts PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs and commercial Pt / C in 1 M KOH. As can be seen from this figure, PtMnCoNiRu / CNFs exhibits the lowest Tafel slope of 59.9 mV dec -1, which is better than PtMn / CNFs (117.8 mV dec -1 ), CoNiRu / CNFs (98.5 mV dec -1 ) and commercial Pt / C catalyst (192.4 mV dec -1 ), indicating that PtMnCoNiRu / CNFs have faster reaction kinetics and higher catalytic efficiency. Figure 5 (c) Tafel slope and 200 cm-1 of the electrocatalytic hydrogen evolution test of PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs, and commercial Pt / C in 1 M KOH. -2 Overpotential histogram at 200 mA cm -2 At a current density of 1.5 Å, the overpotential of PtMnCoNiRu / CNFs is only 68 mV, which is much lower than that of commercial Pt / C catalysts (494 mV), PtMn / CNFs catalysts (185 mV), and CoNiRu / CNFs catalysts (170 mV). This result indicates that PtMnCoNiRu / CNFs has higher efficiency and lower energy consumption in electrocatalytic hydrogen evolution, showing its great potential as a highly efficient electrocatalyst. Figure 5 (d) Electrochemical impedance spectroscopy (EIS) measurements of PtMnCoNiRu / CNFs, PtMn / CNFs, CoNiRu / CNFs, and commercial Pt / C in 1 M KOH. As shown in this figure, the charge transfer resistance (Rct) of PtMnCoNiRu / CNFs is 1.1 Ω, which is superior to that of PtMn / CNFs (3.9 Ω) and CoNiRu / CNFs (2.6 Ω), indicating that PtMnCoNiRu / CNFs possess a high electron transfer rate. The superior performance of the PtMnCoNiRu / CNFs catalyst in the electrocatalytic hydrogen evolution reaction (HER) is primarily attributed to the synergistic effect between the PtMn and CoNiRu phases. This synergistic effect not only reduces the reaction overpotential but also enhances reaction kinetics and electron transfer rate, significantly improving the catalytic efficiency and energy efficiency of the catalyst. Therefore, PtMnCoNiRu / CNFs demonstrate great potential as a highly efficient electrocatalyst and provide an important reference for the design of future HER catalysts.

[0056] Figure 6 Comparison of the polarization curves of the PtMnCoNiRu / CNFs catalyst before and after 10,000 CV cycles. It can be seen that the performance changes little after cycling, indicating that the PtMnCoNiRu / CNFs catalyst has good stability.

[0057] Figure 7The stability test of the catalyst PtMnCoNiRu / CNFs under high current can be seen. -2 The catalyst PtMnCoNiRu / CNFs has excellent stability in alkaline solution.

[0058] Figure 8 (a) is the LSV curve of the catalyst PtMnCoNiRu / CNFs with different metal salt concentrations. It can be seen that PtMnCoNiRu-0.065 / CNFs (Example 1) has a high conductivity at 200 mA cm -2 The overpotential under the conditions of PtMnCoNiRu-0.05 / CNFs (149 mV) and PtMnCoNiRu-0.08 / CNFs (129 mV) is much lower. Figure 8 (b) is the Tafel curve of catalyst PtMnCoNiRu / CNFs with different metal salt concentrations. It can also be seen that the Tafel slope of PtMnCoNiRu-0.065 / CNFs (Example 1) is much lower than that of PtMnCoNiRu-0.05 / CNFs (138.2 mV dec -1 ) and PtMnCoNiRu-0.08 / CNFs (132.6 mV dec -1 ). Therefore, when the total metal salt concentration is 0.065 mmol / g, the hydrogen evolution catalytic performance is the best.

[0059] The above specific embodiments are used to illustrate the present invention rather than to limit the present invention. Any modifications and changes made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a dual-phase high entropy alloy PtMnCoNiRu / CNFs catalytic material, characterized in that: The method comprises the following steps: (1) dispersing manganese salt, cobalt salt, nickel salt, ruthenium salt, platinum salt and carbon nanofiber precursor in an organic solvent to prepare a spinning solution; (2) spinning the spinning solution prepared in step (1) by electrospinning to obtain a nanofiber membrane; (3) placing the nanofiber membrane prepared in step (2) in an air atmosphere and calcining it at a constant heating rate for pre-oxidation treatment; (4) The pre-oxidized fiber membrane prepared in step (3) is heated to 750-1100°C at a heating rate of 5-10°C / min under an inert gas atmosphere and kept constant at that temperature for 3-5 hours. After the constant temperature is reached, the temperature is lowered to room temperature to finally prepare a carbon nanofiber in-situ loaded PtMnCoNiRu / CNFs electrocatalytic material.

2. The method according to claim 1, characterized in that The precursor solution in step (1) contains a carbon fiber precursor in an amount of 10 to 15% by mass.

3. The method according to claim 1, characterized in that The total molar concentration of manganese salt, cobalt salt, nickel salt, ruthenium salt and platinum salt in the spinning solution in step (1) is 0.05-0.08 mmol / g.

4. The method according to claim 1, wherein The heating rate in step (3) is 5-10°C / h, the pre-oxidation is to heat to 180-230°C, and keep the temperature for 6-10 hours.

5. The preparation method according to claim 1, characterized in that The carbon nanofiber precursor described in step (1) is one or more of polyacrylonitrile, polyvinyl pyrrolidone, and polyvinyl alcohol; the manganese salt precursor described in step (1) is one or more of manganese chloride, manganese acetate, manganese nitrate, and manganese acetylacetonate; the cobalt salt precursor described in step (1) is one or more of cobalt chloride, cobalt acetate, cobalt nitrate, and cobalt acetylacetonate; the nickel salt precursor described in step (1) is one or more of nickel chloride, nickel acetate, nickel nitrate, and nickel acetylacetonate; the ruthenium salt precursor described in step (1) is one or both of ruthenium chloride and ruthenium acetylacetonate; the platinum salt precursor described in step (1) is one or both of chloroplatinic acid and platinum acetylacetonate.

6. The preparation method according to claim 1, characterized in that The organic solvent in step (1) is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, ethanol, water, and acetone; the organic solvent in step (1) is N,N-dimethylformamide.

7. The preparation method according to claim 1, characterized in that In step (2), the spinning voltage is 16 to 25 kV, the distance from the receiving device to the spinning needle is 10 to 20 cm, and the solution flow rate is 0.02 to 0.04 mL / h. In step (4), the diameter of the carbon nanofibers in the carbon nanofiber membrane is 200 to 300 nm. The inert gas in step (4) is one of argon and nitrogen.

8. The preparation method according to claim 1, characterized in that The heating rate of the high temperature treatment in step (4) is 5°C / min, or 7°C / min, or 10°C / min.

9. A dual-phase high-entropy alloy PtMnCoNiRu / CNFs catalytic material, characterized by: Prepared by the method described in any one of 1-8.

10. A method for producing hydrogen by electrolysis of water, characterized in that: The dual-phase high entropy alloy PtMnCoNiRu / CNFs catalytic material of claim 9 is utilized.

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