Porous single-crystalline multi-component alloy catalyst and its preparation and application in HER catalysis

Abstract

The present invention belongs to the field of hydrogen electrolysis materials, and particularly relates to a porous single crystal multi-element alloy catalyst and its preparation and application in HER catalysis. The preparation steps are as follows: an electrolyte solution containing metal ions of M1, M2, and M3 is obtained, and a carrier is placed in the electrolyte solution for constant current electrodeposition treatment to deposit an M1-M2-M3 multi-element alloy on the carrier. Among them, M1 includes at least one of zinc, gallium, indium, and tin; M2 includes at least one of iron, cobalt, nickel, copper, zinc, manganese, and chromium; M3 includes at least one of platinum, gold, silver, palladium, and iridium; the total number of types of metal elements of M1, M2, and M3 is more than 3. The carrier deposited with the M1-M2-M3 multi-element alloy is subjected to a transformation treatment at a temperature of 450-850 °C, and then subjected to a modification treatment in an alkaline solution to obtain the product. The material described in the present invention can still exhibit excellent long-cycle stability under acidic and high-current conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic water hydrogen production catalysts, and particularly relates to an acidic HER catalytic material. Background Art

[0002] Hydrogen is a multifunctional energy carrier, which can be produced by various methods. Among them, electrolytic water hydrogen production driven by renewable electricity generated from renewable energy sources such as wind energy and solar energy is an effective and clean method, and it is the most promising technology for large-scale application of hydrogen energy and transfer to industrial production.

[0003] Proton exchange membrane electrolytic water (PEMWE) is an advanced electrolytic water technology. It uses an ultra-thin proton exchange membrane to transport protons and isolate the positive and negative electrodes, ensuring the safety of the electrolytic cell, and has advantages such as high current density and high conversion efficiency, which has attracted wide attention. However, the strongly corrosive acidic environment of PEMWE makes only a few noble metal-based electrocatalysts have excellent activity and stability. The representative catalyst in the hydrogen evolution reaction (HER) at the cathode is Pt / C. However, the scarcity of noble metals leads to a high cost of the catalyst, which to a certain extent limits the development of PEMWE. Therefore, some researchers have proposed to form highly active catalysts with low noble metal loadings by alloying with other transition metals. When different metals or non-metals form alloys, due to the difference in chemical properties, electrons are induced to redistribute around the metals. Incorporating a small amount of transition metals can improve the catalytic activity while reducing the application cost, which is a feasible solution.

[0004] Multi-component alloys (alloys of three or more metal elements, among which alloys formed by 3 - 4 metals are usually identified as medium-entropy alloys; alloys formed by five or more metals are usually identified as high-entropy alloys) have gradually come into people's view as a new type of material. Multi-component alloys have certain advantages in the field of electrocatalysis. The main reason is that the synergistic effect between elements makes the hydrogen adsorption and desorption ability on the catalyst surface close to equilibrium, the hydrogen adsorption free energy is close to 0, and the performance of the catalyst is further improved.

[0005] Some high-entropy alloy HER catalytic technologies have also been disclosed in the prior art. For example, the Chinese patent document with the publication number CN118166391A discloses an FeCoNiWCuOOH@Cu electrocatalyst and its preparation method and application. Another example is that the Chinese patent document with the publication number CN116288477A discloses a bifunctional high-entropy nano-alloy electrocatalyst and its preparation method. The high-entropy electrode materials prepared by these technologies are usually applied under alkaline conditions.

[0006] In summary, existing multi-component alloys such as high-entropy alloy HER materials are still mainly adapted to alkaline hydrogen evolution applications, and it is difficult to meet the requirements of acidic HER applications. It is difficult to obtain good hydrogen evolution activity and stability in acidic systems. Summary of the Invention

[0007] Aiming at the problems existing in the existing electrocatalytic electrodes, the first object of the present invention is to provide a preparation method of a porous single-crystalline multi-component alloy catalyst, aiming to prepare a HER catalytic material that meets the requirements of acidic HER applications and takes into account excellent hydrogen evolution activity and acidic stability.

[0008] The second object of the present invention is to provide the porous single-crystalline multi-component alloy catalyst prepared by the above preparation method and its application in HER catalysis.

[0009] The third object of the present invention is to provide an electrolyzed water device comprising the porous single-crystalline multi-component alloy catalyst of the present invention.

[0010] The systems of acidic HER and alkaline HER are different, and the problems faced are different. For example, for acidic HER, it is necessary to focus on solving problems such as unsatisfactory activity and stability caused by the migration of alloy elements in acidic conditions, especially in high-current acidic conditions. In response to these industry problems, the present invention first attempts to propose an improved idea of constructing a porous and single-crystalline multi-component alloy in the industry. However, early research and development showed that successfully implementing this idea requires solving problems such as difficult synchronous construction and regulation of porous-single crystals, easy segregation of multi-metals, low mixing entropy caused by easy clustering, and unsatisfactory homogenization. In response to this problem, the present invention provides the following solutions after in-depth research:

[0011] A preparation method of a porous single-crystalline multi-component alloy catalyst, obtaining an electrolyte solution in which metal ions of M1, M2, and M3 are dissolved, placing a carrier in the electrolyte solution for constant current electrodeposition treatment, and depositing an M1-M2-M3 multi-component alloy on the carrier; wherein, M1 includes at least one element of Zn, Ga, In, Sn; M2 includes at least one non-precious metal element of Fe, Co, Ni, Cu, Zn, Mn, Cr; M3 includes at least one precious metal element of Pt, Au, Ag, Pd, Ir; the total number of types of metal elements of M1, M2, and M3 is more than 3; the current in the constant current electrodeposition stage is 5~300 mA / cm 2 , and the time of constant current electrodeposition is 2 min~2 h;

[0012] The carrier deposited with the M1-M2-M3 multi-component alloy is subjected to a transformation treatment at a temperature of 450~850 °C, and then subjected to a modification treatment in an alkaline solution to obtain the porous single-crystalline multi-component alloy catalyst.

[0013] The present invention shows that the innovative combination of the metals of the types M1 to M3, further combined with the constant current electrodeposition method, the current and time, and the subsequent transformation process and temperature and the subsequent alkali solution-assisted modification can achieve synergy, solve the problems of low mixing entropy of metals, easy formation of nanoclusters, easy segregation of metals, etc., and in situ construction of single crystals and new catalytic materials that are porous. Studies have shown that the catalytic materials with the characteristics obtained by the preparation method can unexpectedly adapt to the requirements of acidic HER applications, not only showing excellent catalytic activity, but also taking into account excellent acid resistance and stability, and can still show excellent long-cycle stability under acidic and high current conditions.

[0014] In the present invention, the combination of the metal M1-M3 elements, constant current electrodeposition, transformation and alkali solution modification is the key to solving the alloy nanoclustering and metal segregation, constructing porous and single crystal morphology, and improving its HER performance in an acidic system. Studies have also shown that the innovative use of metal M1 can be combined with the process to help optimize the mixing entropy of the metal, reduce metal nanoclustering, reduce the segregation of metal elements, optimize single crystal and porous structures, and help improve the interface bonding effect between the high entropy alloy and the carrier.

[0015] In the present invention, the total number of metal elements of M1, M2 and M3 is 3 to 6. For example, when the total number of types is 3 to 4, the obtained multi-element alloy catalyst can be understood as a medium entropy alloy, and when the number of types is 5 to 6, a high entropy alloy can be obtained.

[0016] In the present invention, the total number of types of metal elements of M1, M2 and M3 is 5 to 6.

[0017] In the present invention, the use of the M1, in combination with the constant current electrodeposition, transformation and alkali solution modification, can achieve synergy, facilitate the construction of the porous-single crystal multi-element alloy, and facilitate the improvement of the entropy value and homogenization effect, which helps to improve the activity and stability of the prepared material under acidic HER. Preferably, the M1 contains zinc.

[0018] The M2 comprises one or more of Fe, Co, Ni, Cu, Zn, Mn, and Cr, for example, Fe. Further, the M2 comprises 4 to 5 of the above elements. When M2 is multiple, the content of each element is ±10% of the average molar percentage in M2; for example, the molar amount of each element in M2 is the same.

[0019] The metal M3 includes Pt.

[0020] In the present invention, the molar ratio of M1, M2 and M3 is 500:1-10:1-10; further 500:4-5:1-5.

[0021] In the present invention, the water-soluble salts of metals M1 to M3 can be dissolved in water to obtain the electrolyte. The water-soluble salts are, for example, at least one of sulfates, nitrates, organic acid salts, chlorides, etc. of each metal.

[0022] In the present invention, the carrier can be any carrier known in the industry. For example, it can be a carbonaceous carrier, and further can be at least one of carbon felt, carbon cloth, carbon paper, and titanium foam.

[0023] The weight ratio of the carrier to the M1-M2-M3 multi-alloy is 1:0.001 to 0.1; further, it can be 1:0.003 to 0.02, and still further, it is 1:0.003 to 0.005.

[0024] In the present invention, with the innovative use of metals M1 to M3 and the combination of the constant current electrodeposition process, further combined with the joint control of current and time, it is helpful to combine with other processes, beneficial to improving the entropy value of the material, improving the homogeneous distribution of elements, and conducive to constructing a suitable porous and single crystal structure, and beneficial to improving the long-cycle performance of the material under acidic HER and high current.

[0025] In the present invention, the current of the constant current electrodeposition is 40 to 100 mA / cm 2 ; further preferably 45 to 55 mA / cm 2 ; the time of constant current electrodeposition is 15 min to 1 h, and further preferably 20 to 25 min. Research shows that under the preferred conditions, it can be further combined and coordinated with the process, which is helpful to further improve the physical and chemical structure of the prepared material and improve its HER under acidic conditions and cycle stability under high current.

[0026] In the present invention, due to the combination of metals M1 to M3 and constant current electrodeposition, further combined with subsequent transformation treatment, it is beneficial to improve the mixing entropy of the alloy, improve the homogeneous distribution of metals, and contribute to the collaborative construction of single crystal porous materials. Research also shows that further optimizing the transformation process is expected to further synergistically improve the HER activity of the material under acidic conditions and the stability under high current.

[0027] Preferably, the transformation temperature is 450 to 600 °C, and further 480 to 520 °C. The heat preservation time at the transformation temperature is 0.5 to 10 h; preferably 1 to 1.3 h. Research shows that under the preferred conditions, it can be further combined and coordinated with the process, which is helpful to further improve the physical and chemical structure of the prepared material and improve its HER under acidic conditions and cycle stability under high current.

[0028] The research also shows that at the preferred transformation temperature and time, it is expected to further synergistically improve the HER activity of the material under acidic conditions and the stability under high current.

[0029] The atmosphere in the transformation stage is a reducing atmosphere. For example, it can be a hydrogen-containing atmosphere, where the hydrogen content can be 2 - 20 v%; further, it can be 10 - 15 v%.

[0030] In the present invention, based on the constant current electrodeposition and transformation involving the metals M1 - M3, further combined with the modification treatment assisted by an alkali solution, it helps to endow the material with abundant sites and synergistically construct the porous - single crystal multi - component catalytic material, which helps to improve the HER activity of the material under acidic conditions and the stability under high current.

[0031] In the present invention, the alkali solution is an aqueous solution of an alkaline solute, and the alkaline solute includes at least one of hydroxides and carbonates of alkali metals; for example, it can be at least one of sodium hydroxide and potassium hydroxide. More preferably, it is potassium hydroxide. Research shows that under preferred conditions, it can be further combined synergistically with the process, which helps to further improve the physical and chemical structure of the prepared material and improve its HER under acidic conditions and the cyclic stability under high current.

[0032] In the alkali solution, the concentration of the alkaline solute is 0.1 - 5 M, further it can be 1 - 4.5 M; more preferably, it can be 3 - 4.5 M. Research shows that under preferred conditions, it can be further combined synergistically with the process, which helps to further improve the physical and chemical structure of the prepared material and improve its HER under acidic conditions and the cyclic stability under high current.

[0033] During the alkali solution modification process of the present invention, the transformed material is completely immersed in the alkali solution.

[0034] The time for modifying the product after the transformation treatment in the alkali solution (alkali solution modification time) is 2 - 24 h, further it can be 10 - 15 h. Research shows that under preferred conditions, it can be further combined synergistically with the process, which helps to further improve the physical and chemical structure of the prepared material and improve its HER under acidic conditions and the cyclic stability under high current.

[0035] The present invention also provides a porous single crystal multi - component alloy catalyst prepared by the above - mentioned preparation method.

[0036] The research of the present invention shows that the special preparation method can synergistically construct the special physical and chemical characteristics of the product, and the material with such characteristics prepared by the preparation method can unexpectedly improve the HER activity of the material under acidic conditions and the stability under high current.

[0037] The present invention also provides an application of a porous single crystal multi-element alloy catalyst prepared by the preparation method, which is used as a HER catalytic active component for catalyzing a hydrogen evolution reaction in an acidic solution.

[0038] The present invention also provides a water electrolysis device, which comprises the porous single crystal multi-element alloy catalyst prepared by the preparation method of the present invention, or is prepared by the porous single crystal multi-element alloy catalyst.

[0039] The device described in the present invention, in addition to comprising the new material described in the present invention, other components and structural relationships may be well-known, or may be reasonably controlled based on known means.

[0040] In the present invention, the device is any device that can achieve efficacy based on the HER reaction, such as a battery, a water electrolysis device, etc.

[0041] Beneficial Effects

[0042] The present invention innovatively combines the M1~M3 type metals in multiple combinations, further cooperates with the constant current electrodeposition method, the combination of current and time, and then cooperates with the subsequent transformation process and temperature and the subsequent alkali solution assisted modification, so that synergy can be achieved, and the problems of low mixing entropy of metals and metal segregation can be solved. In addition, a new catalytic material that is single crystal and porous can be constructed in situ. Studies have shown that the catalytic material with the characteristics prepared by the preparation method has excellent acidic HER catalytic activity and long cycle stability under high current.

[0043] The material of the present invention has a lower cost. For example, the precious metal content can be reduced to 16.1 μg / cm 2 , which greatly reduces the cost of the catalytic electrode.

[0044] The preparation method of the present invention is simple and efficient, and the processes of electrodeposition, transformation and modification can all be realized in industrial production, wherein the electrodeposition can adopt the industrially mature roll-to-roll electrodeposition process to realize continuous production, which is conducive to the large-scale preparation of this type of catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a transmission electron microscope (TEM) image of the porous single crystal high entropy alloy catalyst prepared in Example 1.

[0046] Figure 2 This is the element distribution diagram of the porous single crystal high entropy alloy catalyst prepared in Example 1.

[0047] Figure 3 This is a high-resolution transmission electron microscope (HRTEM) image and Fourier spectrum of the porous single crystal high entropy alloy catalyst prepared in Example 1.

[0048] Figure 4 The linear sweep voltammetry (LSV) curves after activation of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 and the commercial Pt / C catalyst are shown.

[0049] Figure 5 This is the I-T curve of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 at a current of 500 mA / cm 2 current. Detailed implementation manners

[0050] The present invention will be further described and illustrated below in conjunction with specific examples and the accompanying drawings of the specification:

[0051] A typical preparation method of a porous single-crystalline multi-component alloy catalyst of the present invention includes the following steps:

[0052] Step (1): Using a self-supporting carrier of a certain size as the working electrode and a platinum sheet as the counter electrode, placing them in an electrolyte containing metals M1, M2, and M3, adjusting the current and time, and obtaining a polycrystalline multi-component alloy loaded on carriers such as carbon felt, carbon cloth, carbon paper, and titanium foam by constant current electrodeposition.

[0053] Step (2): Taking out the sample obtained in step (1) and drying it in a vacuum oven.

[0054] Step (3): Placing the electrode material loaded with the multi-component alloy obtained in step (2) in a tubular furnace for transformation, adjusting the transformation time and temperature to obtain a transformed material.

[0055] Step (4): Modifying the transformed material obtained in step (3) in an alkaline solution, where the alkaline solution used is a KOH solution or an NaOH solution, to obtain a porous single-crystalline multi-component alloy loaded on the substrate.

[0056] M1 includes at least one element among Zn, Ga, In, and Sn; M2 includes at least one non-precious metal element among Fe, Co, Ni, Cu, Zn, Mn, and Cr; M3 includes at least one precious metal element among Pt, Au, Ag, and Pd; the total number of metal elements of M1, M2, and M3 is more than 3. As an optional solution, the metals in the electrolyte include Zn, Fe, Co, Ni, Cu, and Pt.

[0057] In the optional electrolyte, zinc salts such as ZnSO 4 , and other non-precious metal salts such as FeCl 3 , CoCl 2 , NiCl 2 , CuCl 2 , and precious metal salts such as H 2 PtCl6 . As an alternative, in the electrolyte, the concentration of ZnSO 4 is 0.1 to 1 mol / L; the concentrations of FeCl 3 , CoCl 2 , NiCl 2 , and CuCl 2 are 0.5 to 200 mmol / L, further 0.5 to 10 mmol / L; the concentration of H 2 PtCl 6 is 0.1 to 40 mmol / L, further 0.1 to 2.5 mmol / L.

[0058] Preferably, the time of constant current electrodeposition is 2 min to 2 h, further 15 min to 1 h.

[0059] Preferably, the current magnitude is 5 to 300 mA / cm 2 , further 40 to 100 mA / cm 2 .

[0060] In the present invention, during the transformation process, a reducing gas H 2 / Ar atmosphere is introduced into the tubular atmosphere furnace.

[0061] Preferably, the ratio of hydrogen to argon in the H 2 / Ar atmosphere is 2:98 to 20:80.

[0062] Preferably, the transformation temperature of the tubular atmosphere furnace is 450 to 850 °C, further 450 to 600 °C.

[0063] Preferably, the transformation time is 0.5 to 10 h, further 0.5 to 2 h.

[0064] In the present invention, the alkali solution used during the modification process is a 0.1 to 4 M KOH solution or NaOH solution;

[0065] Preferably, the modification time is 2 to 24 h, further 10 to 15 h.

[0066] The present invention also provides a porous single-crystal multi-component alloy catalyst prepared by the described preparation method.

[0067] Example 1

[0068] The preparation of a porous single-crystal high-entropy alloy catalyst includes the following steps:

[0069] Step (1): Using a carbon felt of 1×1.3 cm 2 as the working electrode (wherein, the area immersed in the electrolyte can be 1×1 cm 2), A platinum sheet is used as a counter electrode and placed in an electrolyte (electrodeposition solution) for constant current electrodeposition to form a polycrystalline high-entropy alloy on the carbon felt.

[0070] Among them, the electrodeposition solution includes M1 metal salt (in this case, ZnSO 4 ), M2 metal salts (including FeCl with a molar ratio of 1:1:1:1 3 , CoCl 2 , NiCl 2 and CuCl 2 ), M3 metal salt (H 2 PtCl 6 ); among them, the concentration of the total metal elements (the sum of metals M1, M2, and M3) in the electrodeposition solution is 0.1042 mol / L;

[0071] The molar ratio of metal M1: metal M2 and metal M3 is 500:5:1.

[0072] The ratio of the weight of the carbon felt to the total metal elements is 1:0.003;

[0073] The current of the constant current electrodeposition is 50 mA / cm 2 , and the time of the constant current electrodeposition is 20 min.

[0074] Step (2): Take out the sample obtained in step (1) and place it in a vacuum oven at 60 °C for drying.

[0075] Step (3): Place the carbon felt loaded with the high-entropy alloy obtained in step (2) in a tube furnace for transformation. The transformation temperature is 500 °C, and the transformation time is 1 h. A reducing gas (H 2 / Ar atmosphere, where the volume ratio of hydrogen to argon is 10:90) is introduced during the transformation process to obtain a transformation product.

[0076] Step (4): Immerse the transformation product obtained in step (3) in a 4 M KOH solution for modification. The modification time is 12 h (the modification temperature is room temperature, for example, 10 - 45 °C) to obtain a catalyst loaded with a porous single-crystalline high-entropy alloy (Example 1). The TEM, elemental distribution, and HRTEM of the material are shown in Figures 1 to 3 .

[0077] Figure 1 is the TEM image of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 of the present invention. It can be seen that the multi-element alloy adheres to the surface of the carbon fiber, presenting an obvious porous spatial structure.

[0078] Figure 2It is the elemental distribution map of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 of the present invention. It can be intuitively seen that the distributions of the six elements are relatively uniform within a small size range, proving the successful preparation of the multi-element alloy.

[0079] Figure 3 It is the HRTEM ( Figure 3 left figure) and Fourier spectrum ( Figure 3 right figure) of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 of the present invention. By calculating the lattice spacing, it is obtained that in the significantly porous and hollow part, the interplanar spacing is 0.220 nm, which is close to the lattice spacing of Pt(111), indicating partial etching of non-Pt elements after modification and activity testing, and Pt dominates in the porous structure. And from the Fourier transform, the lattice dot pattern of the multi-element alloy particles presents a single-crystalline structure, indicating the synthesis of the single-crystalline porous multi-element alloy.

[0080] The hydrogen evolution test of the electrolyzed water of the said material is as follows:

[0081] The electrochemical test was carried out on Gamry Interface 1010E, and the measurement was carried out at room temperature using a three-electrode system. Among them, the prepared porous single-crystalline high-entropy alloy catalyst was used as the working electrode, and the area in contact with the electrolyte was 1 cm 2 , the platinum sheet was used as the counter electrode, and Ag / AgCl was used as the reference electrode. The linear sweep voltammetry curve was tested in 0.5M H 2 SO 4 electrolyte, and the scanning rate was 10 mV / s. During the process of testing the stability on the electrochemical workstation, the prepared electrode was activated, still using a three-electrode system, setting the current to -500 mA / cm 2 , recording the change of the overpotential of the working electrode with time, and testing the linear sweep voltammetry curve after 200 h of operation to obtain the hydrogen evolution performance data after activation.

[0082] Figure 4 It is the LSV curve of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 of the present invention and commercial PtC (Comparative Example 5). The figure shows that the catalyst of the present invention reached an overpotential of 98 mV at a current of 1 A and exceeded the commercial platinum carbon catalyst.

[0083] Figure 5 It is the I-T curve of the porous single-crystalline high-entropy alloy catalyst prepared in Example 1 of the present invention and commercial platinum carbon. The figure shows that at a current of 500 mA, the voltage of this catalyst remained stable after 1000 h, while the voltage of the commercial platinum carbon catalyst increased significantly after 150 h and the catalytic activity gradually decreased. It can be seen that this porous single-crystalline high-entropy alloy catalyst has excellent stability.

[0084] Example 2

[0085] Compared with Example 1, the only difference is that during the constant-current electrodeposition process in step (1), the applied current is 50 mA / cm 2 , the time is 10 min, and other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 2.

[0086] Example 3

[0087] Compared with Example 1, the only difference is that during the constant-current electrodeposition process in step (1), the applied current is 50 mA / cm 2 , the time is 30 min, and other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 3.

[0088] Example 4

[0089] Compared with Example 1, the only difference is that during the constant-current electrodeposition process in step (1), the applied current is 75 mA / cm 2 , the time is 20 min, and other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 4.

[0090] Example 5

[0091] Compared with Example 1, the only difference is that during the constant-current electrodeposition process in step (1), the applied current is 100 mA / cm 2 , the time is 20 min, and other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 5.

[0092] The hydrogen evolution potentials of the materials in Examples 1 to 5 are shown in Table 1:

[0093] ;

[0094] Note: is the overpotential (mV) at 100 mA / cm 2 ; is the overpotential (mV) at 500 mA / cm 2 .

[0095] From Examples 1 to 5, it can be seen that by performing the constant-current electrodeposition described in the present invention and combining it with other processes, the acidic HER performance of the prepared materials can be improved. In addition, the research also shows that the current of the constant-current electrodeposition is 45 - 55 mA / cm 2 ; the time of the constant-current electrodeposition is 20 - 25 min. Better process synergy can be obtained, which helps to further improve the HER of the material under acidic conditions and the cycle stability at high current.

[0096] Example 6

[0097] Compared with Example 1, the only difference is that during the high-temperature transformation process in step (3), the temperature is 500 °C and the transformation time is 0.5 h, while other operations and parameters are the same as those in Example 1. The prepared sample is named as Example Sample 6.

[0098] Example 7

[0099] Compared with Example 1, the only difference is that during the high-temperature transformation process in step (3), the temperature is 500 °C and the transformation time is 2 h, while other operations and parameters are the same as those in Example 1. The prepared sample is named as Example Sample 7.

[0100] Example 8

[0101] Compared with Example 1, the only difference is that during the high-temperature transformation process in step (3), the temperature is 400 °C and the transformation time is 1 h, while other operations and parameters are the same as those in Example 1. The prepared sample is named as Example Sample 8.

[0102] Example 9

[0103] Compared with Example 1, the only difference is that during the high-temperature transformation process in step (3), the temperature is 600 °C and the transformation time is 1 h, while other operations and parameters are the same as those in Example 1. The prepared sample is named as Example Sample 9.

[0104] The hydrogen production performances of Examples 6 to 9 are shown in Table 2:

[0105] ;

[0106] Research shows that through the described transformation treatment, it can cooperate synergistically with the process to optimize the acidic HER performance of the material. In addition, the research also shows that the transformation temperature is 480 - 520 °C. The heat preservation time at the transformation temperature is 1 - 1.3 h, which can further cooperate and contribute to further improving the physicochemical structure of the prepared material and improving its HER under acidic conditions and cycle stability under high current.

[0107] Example 10

[0108] Compared with Example 1, the only difference is that during the electrodeposition process in step (1), the concentration of the total metal elements (the sum of metals M1, M2, and M3) in the electrodeposition solution is 0.521 mol / L, and the weight ratio of the total metal elements is 1:0.015; the ratios of other components and other operations and parameters are the same as those in Example 1. The prepared sample is named as Example Sample 10.

[0109] Example 11

[0110] Compared with Example 1, the only difference is that in step (1), the molar ratio of metal M1, metal M2, and metal M3 is controlled to be 500:4:5. The total metal and other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 11.

[0111] Example 12

[0112] Compared with Example 1, the only difference is that in step 1, metal M2 is single FeCl 3 . The ratios of metals M1, M2, and M3 and other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 12.

[0113] The electrolytic hydrogen production activities of Examples 10 - 12 are shown in Table 3.

[0114] ;

[0115] Through the control of Example 1 and Examples 10 - 12, the multi - component alloys (medium - entropy alloys and high - entropy alloys) described in the present invention can all exhibit good acidic hydrogen evolution activity, but the high - entropy alloy has a better effect.

[0116] Example 13

[0117] Compared with Example 1, the only difference is that in the alkali solution modification process of step (4), the alkali used is 4M NaOH and the modification time is 12h. Other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 13.

[0118] Example 14

[0119] Compared with Example 1, the only difference is that in the alkali solution modification process of step (4), the alkali used is 1M KOH and the modification time is 12h. Other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 14.

[0120] Example 15

[0121] Compared with Example 1, the only difference is that in the alkali solution modification process of step (4), the alkali used is 4M KOH and the modification time is 6h. Other operations and parameters are the same as those in Example 1. The prepared sample is named Sample 15.

[0122] The acidic hydrogen evolution results of Examples 13 - 15 are shown in Table 4:

[0123] ;

[0124] In the present invention, based on the constant-current electrodeposition and transformation involving the metals M1 to M3, an alkali solution-assisted modification treatment is further carried out, which is beneficial to endowing the material with abundant sites and synergistically constructing the porous-single crystal multi-component catalytic material, and helps to improve the HER activity of the material under acidic conditions and the stability under high current. The research also shows that when the alkali solution is potassium hydroxide solution, further synergy can be achieved, which helps to further improve the physical and chemical structure of the prepared material and improve its HER under acidic conditions and cyclic stability under high current.

[0125] Comparative Example 1

[0126] Compared with Example 1, the difference is only that in step (1), constant-voltage electrodeposition is adopted, the voltage is controlled at -4.5 V, and the time is 20 min, and other operations and parameters are the same as those in Example 1. The prepared sample is named Comparative Sample 1.

[0127] Comparative Example 2

[0128] Compared with Example 1, the difference is only that the transformation process in step (3) is not carried out, and after step 2, it is directly subjected to step 4 modification, and other operations and parameters are the same as those in Example 1. The prepared sample is named Comparative Sample 2.

[0129] Comparative Example 3

[0130] Compared with Example 1, the difference is only that the modification process in step (4) is not carried out, and the electrode material is obtained after transformation and directly subjected to electrochemical testing. Other operations and parameters are the same as those in Example 1. The prepared sample is named Comparative Sample 3.

[0131] Comparative Example 4

[0132] Compared with Example 1, the difference is only that the treatments in steps 1 to 4 are not carried out, and its carbon felt is directly used for subsequent testing.

[0133] Comparative Example 5

[0134] Commercial platinum-carbon catalyst (Pt / C) with a mass percentage of 20%.

[0135] Comparative Example 6

[0136] Compared with Example 1, the difference is only that in the electrodeposition solution during the electrodeposition process in step (1), nickel sulfate is used to 4 equimolarly replace the zinc sulfate, and other operations and parameters are the same as those in Example 1. The prepared sample is named Comparative Sample 6.

[0137] Comparative Example 7

[0138] Compared with Example 1, the difference is only that in the electrodeposition solution during the electrodeposition process in step (1), sodium2 MoO 4 The zinc sulfate was replaced by an equal molar amount. Other operations and parameters were the same as those in Example 1. The prepared sample was named comparative sample 7.

[0139] The acidic hydrogen evolution results of each comparative example are shown in Table 5:

[0140] ;

[0141] It can be seen from Example 1 and the comparative example that the present invention innovatively combines the M1~M3 type metal multi-combinations, further cooperates with the constant current electrodeposition method, the combination of current and time, and then cooperates with the subsequent transformation process and temperature and the subsequent alkali solution assisted modification, so that synergy can be achieved, and the problems of low mixing entropy of metals and metal segregation can be solved. In addition, a new catalytic material that is single crystal and porous can be constructed in situ. Studies have shown that the catalytic material with the characteristics prepared by the preparation method has excellent acidic HER catalytic activity and long cycle stability under high current.

Claims

1. A method for preparing a porous single crystal multi-element alloy catalyst, characterized in that: Obtain an electrolyte in which metal ions of M1, M2 and M3 are dissolved, place a carrier in the electrolyte for constant current electrodeposition treatment, and deposit M1-M2-M3 multi-element alloy on the carrier; wherein M1 includes at least one element of Zn, Ga, In and Sn; M2 includes at least one non-precious metal element of Fe, Co, Ni, Cu, Zn, Mn and Cr; M3 includes at least one precious metal element of Pt, Au, Ag, Pd and Ir; the total number of metal elements of M1, M2 and M3 is more than 3; the current in the constant current electrodeposition stage is 5-300 mA / cm 2 , the constant current electrodeposition time is 2min~2h; The molar ratio of M1, M2 and M3 is 500:1~10:1~10; The carrier on which the M1-M2-M3 multi-element alloy is deposited is subjected to transformation treatment at a temperature of 450-850° C., and then subjected to modification treatment in an alkaline solution to obtain the porous single crystal multi-element alloy catalyst.

2. The method for preparing a porous single crystal multi-element alloy catalyst according to claim 1, characterized in that: The M1 contains zinc; The M2 comprises at least one of Fe, Co, Ni, Cu, Zn, Mn and Cr; The metal M3 includes Pt.

3. The method for preparing the porous single crystal multi-element alloy catalyst according to claim 1, characterized in that: The carrier is at least one of carbon felt, carbon cloth, carbon paper and titanium foam; The weight ratio of the carrier to the M1-M2-M3 multi-element alloy is 1:0.001-0.

1.

4. The method for preparing a porous single crystal multi-element alloy catalyst according to claim 1, characterized in that: The current of the constant current electrodeposition is 40~100 mA / cm 2 ; The constant current electrodeposition time is 15min~1h.

5. The method for preparing a porous single crystal multi-element alloy catalyst according to claim 1, characterized in that: The transformation temperature is 450~600℃; The atmosphere during the transition phase is a reductive one; The holding time at the transition temperature is 0.5~10h.

6. The method for preparing a porous single crystal multi-element alloy catalyst according to claim 1, characterized in that: The alkali solution is an aqueous solution of an alkaline solute, wherein the alkaline solute includes at least one of an alkali metal hydroxide and a carbonate; In the alkali solution, the concentration of the alkaline solute is 0.1~5M; The time for modification of the product after transformation treatment in alkaline solution is 2~24h.

7. A porous single crystal multi-element alloy catalyst prepared by the preparation method according to any one of claims 1 to 6.

8. An application of a porous single crystal multi-element alloy catalyst prepared by the preparation method according to any one of claims 1 to 6, characterized in that: It is used as a HER catalytic active component to catalyze the hydrogen evolution reaction in acidic solutions.

9. A water electrolysis device, characterized in that: A porous single crystal multi-element alloy catalyst prepared by the preparation method according to any one of claims 1 to 6, or prepared by the porous single crystal multi-element alloy catalyst.

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