High-entropy sulfide catalyst as well as preparation method and application thereof

Abstract

The invention discloses a high-entropy sulfide catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: pretreating foamed nickel NF with hydrochloric acid, a solvent and deionized water to obtain pretreated foamed nickel; the preparation method comprises the following steps: uniformly mixing water-soluble metal salts corresponding to at least five metals of Fe, Co, Ni, Cu, Al, Mn and Mo, NH4F and urea, and carrying out hydrothermal reaction to obtain an M hydroxide precursor / NF from foamed nickel; wherein M is at least five metals selected from Fe, Co, Ni, Cu, Al, Mn and Mo; and placing the M hydroxide precursor / NF at the downstream of a tubular furnace, placing sublimed sulfur powder at the upstream of the tubular furnace, and carrying out heating and heat preservation reaction through the tubular furnace to obtain an M-S / NF catalyst, namely the high-entropy sulfide catalyst. The catalyst provided by the invention has efficient HER and SOR activities, and can be applied to sulfur ion oxidation assisted water electrolysis for efficient energy-saving hydrogen production.

Description

Technical Field

[0001] The present invention relates to the technical field of efficient and energy-saving hydrogen production by sulfide ion oxidation-assisted water electrolysis, and in particular to a high-entropy sulfide catalyst, a preparation method and an application thereof. Background Art

[0002] Hydrogen has a high energy density (142MJ kg -1 ), zero carbon emissions and renewability, it is considered to be a clean energy with great development prospects. Electrochemical water splitting is a green, environmentally friendly and sustainable method for producing high-purity hydrogen. However, OER has inherent slow reaction kinetics and high theoretical potential (1.23V vs.RHE), which requires ultra-high potential to drive it, greatly reducing the energy conversion efficiency of water electrolysis to produce hydrogen, limiting its development. Sulfide ion oxidation reaction (SOR, S 2- -2e - →S, E0 = -0.48V vs. RHE) has a very low oxidation potential and fast kinetics. Therefore, SOR can replace OER and couple with the cathode hydrogen evolution reaction (HER), solving the problem of large energy input for electrochemical hydrogen production due to the thermodynamic and kinetic disadvantages of OER. However, since SOR is a complex reaction process involving multiple electron transfers and the formation of multiple polysulfide intermediates, and S 2- Ions can easily corrode or poison catalysts, resulting in poor catalyst activity and stability, which cannot meet practical applications. Therefore, the construction of highly active and stable bifunctional SOR and HER catalysts still faces great challenges.

[0003] In recent years, high-entropy alloys (HEAs) have become a research hotspot in the electrolysis field due to their intriguing cocktail effect, broad design space, customizable electronic structure, and entropy stabilization effect. They are typically composed of five or more basic elements with an atomic ratio between 5% and 35%. The synergistic effects among these elements facilitate optimal intermediate adsorption energies, thereby enhancing hydrogen evolution reaction (HER) and SOR activity. Compared to bimetallic or ternary metal compounds, HEAs possess superior structural and functional properties due to their thermodynamic high entropy effects, kinetic delayed diffusion effects, structural lattice distortion effects, and performance cocktail effects. Furthermore, the synergistic effects among these elements facilitate optimal intermediate adsorption energies, further enhancing catalytic activities for HER, OER, and SOR, making them highly promising in catalytic applications. For example, the journal Applied Catalysis B: Environment and Energy (DOI: 10.1016 / j.apcatb.2024.123875) reported that a FeCoNiMnAl hydroxide precursor was prepared by a hydrothermal method, which was then annealed in a muffle furnace at 350 ° C for 2 hours to obtain a high-entropy (FeCoNiMnAl) 3O 4 oxide catalyst with an overpotential of 274 and 295 mV @ 50 mA cm in alkaline fresh water and natural seawater electrolytes for anodic OER, respectively. -2 In the journal Chemical Engineering Journal (DOI: 10.1016 / j.cej.2024.153094), Liu et al. purchased commercial FeCoNiCrMn HEA and subsequently synthesized a sulfur-phosphorus co-doped FeCoNiCrMn high entropy alloy (HEA-SP) catalyst by hydrothermal sulfurization and vapor deposition. The catalyst showed moderate activity for SOR in alkaline brine, driving 10 mA cm -2 A current density of 0.61 (V vs. RHE) is required.

[0004] In summary, high entropy alloys (HEAs) have a large number of diverse active sites. The diversity, variability and lattice distortion of elements change the adsorption of reactants. The wide composition control and inherent complex surface make it possible to obtain an almost continuous adsorption energy distribution. Through multi-component control, the interaction of different elements in high entropy catalytic materials provides unique surface binding sites, achieving selective adsorption of different reactants and intermediates, thereby maximizing catalytic performance. However, there is still little research on the preparation methods of high entropy alloys and their application in SOR catalysis. To obtain optimal catalytic activity, the key is to strike a balance between the interaction between active sites and intermediates, so that the relationship between catalytic performance and adsorption energy is similar to the shape of a volcano. However, the complex structure of HEAs poses a challenge to traditional experiments and DFT calculations, which make it difficult to accurately identify their active sites, let alone determine the catalytic activity of these active sites.

[0005] By exploring combinations of different elements to prepare high-entropy alloys for SOR catalysis, the diversity of their structural designs can be effectively expanded, and near-continuous regulation of adsorption energy and catalytic performance can be achieved. Comprehensively exploring the vast compositional space of high-entropy electrocatalysts and the diversity of elemental combinations provides important possibilities for developing high-entropy alloy catalysts with superior catalytic performance. More importantly, the application of machine learning (ML) in the design of electrocatalyst systems has attracted widespread attention. By establishing structure-activity relationships, ML can not only stably and rapidly predict catalyst performance, but also effectively explore the complex catalytic mechanisms in complex systems, which is of great significance in the exploration and development of highly active HEA catalysts. Summary of the Invention

[0006] In view of the above-mentioned shortcomings, the present invention provides a high-entropy sulfide catalyst, a preparation method and application thereof. The high-entropy sulfide catalyst prepared by the present invention has a single-phase structure, in which Cu, Co, Mn and Al atoms are embedded in the lattice of metal Ni, thereby causing the lattice constant of the CuCoNiMnAl-S catalyst to shift to a lower angle, and the edges of the nanosheets have many nanopores. These nanopores can further increase the surface area, have efficient HER and SOR activity, and can be applied to sulfide ion oxidation-assisted water electrolysis for efficient and energy-saving hydrogen production (including sulfide ion oxidation reaction (SOR) and hydrogen evolution reaction (HER)).

[0007] In order to achieve the above object, the present invention provides a method for preparing a high entropy sulfide catalyst, the preparation method comprising the following steps:

[0008] S1. Pretreating nickel foam NF with hydrochloric acid, solvent and deionized water to obtain pretreated nickel foam NF;

[0009] S2. Mixing water-soluble metal salts corresponding to at least five metals selected from Fe, Co, Ni, Cu, Al, Mn, and Mo, NH4F, and urea, and subjecting the mixture to a hydrothermal reaction to obtain M hydroxide precursor / NF in nickel foam NF; wherein M is at least five metals selected from Fe, Co, Ni, Cu, Al, Mn, and Mo;

[0010] S3. Place the M hydroxide precursor / NF in the downstream of the tube furnace and sublimed sulfur powder in the upstream. The tube furnace is heated at 2°C·min -1 The temperature was raised to 300-500°C at a rate of 10000°C and maintained in a N2 atmosphere for 2-5 hours. After the tube furnace was cooled to room temperature, the MS / NF catalyst, i.e., a high entropy sulfide catalyst, was obtained.

[0011] According to one aspect of the present invention, in step S1, the concentration of the hydrochloric acid is 3M, and the solvent is ethanol.

[0012] According to one aspect of the present invention, in step S2, the molar ratio of Fe, Co, Ni, Cu, Al, Mn and Mo is 2-3:2-3:2-3:2-3:2-3:2-3:2-3:2-3.

[0013] According to one aspect of the present invention, in step S2, the concentration of NH4F is 150-200 mM; the concentration of urea is 300-350 mM.

[0014] According to one aspect of the present invention, in step S2, the temperature of the hydrothermal reaction is 120-150° C., and the time is 12-16 hours.

[0015] According to one aspect of the present invention, in step S2, water-soluble metal salts corresponding to Fe, Co, Ni, Cu, and Mo, NH4F, and urea are mixed and subjected to a hydrothermal reaction on the pretreated nickel foam NF to obtain FeCoNiMoCu hydroxide precursor / NF in the nickel foam NF.

[0016] According to one aspect of the present invention, in step S2, water-soluble metal salts corresponding to Co, Ni, Cu, Al, and Mn, NH4F, and urea are mixed and subjected to a hydrothermal reaction on the pretreated nickel foam NF to obtain a CuCoNiMnAl hydroxide precursor / NF in the nickel foam NF.

[0017] According to one aspect of the present invention, in step S2, the water-soluble metal salt corresponding to Fe, Co, Ni, Cu, Al, Mn, and Mo includes at least one of nitrate and chloride.

[0018] Based on the same inventive concept, the present invention also provides a high-entropy sulfide catalyst prepared by the above preparation method.

[0019] Based on the same inventive concept, the present invention also provides the use of the above-mentioned high-entropy sulfide catalyst in the efficient and energy-saving hydrogen production by sulfide ion oxidation-assisted water electrolysis.

[0020] Beneficial effects of the present invention:

[0021] The electronegativity of Fe, Co, Ni, and Cu in the catalyst of the present invention is similar, which contributes to their synergistic effect in the catalytic reaction; while the electronegativity of Mo is quite different, which adjusts the electronic structure and electron density distribution, and enhances its adsorption capacity for intermediates; the introduction of Mn and Al with different electronegativity plays an important role in regulating the electronic configuration of the material. The "soft acid" Cu ions and the "soft base" sulfur ions (S 2- ) and polysulfide intermediates (such as S2 2- 、S3 2- The catalyst prepared by the preparation method of the present invention has high HER and SOR activity and can be applied to the efficient and energy-saving hydrogen production from sulfide-assisted water electrolysis (including sulfide oxidation reaction (SOR) and hydrogen evolution reaction (HER)). BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a flow chart for preparing the high entropy sulfide catalyst according to Example 1 of the present invention;

[0023] Figure 2 This is a physical picture of the catalyst prepared in Comparative Example 2 and Example 2 of the present invention;

[0024] Figure 3 The figures are physical pictures of the catalysts prepared in Example 1, Comparative Example 3, Comparative Example 4 and Comparative Example 5 of the present invention;

[0025] Figure 4 The following are SEM images of some catalysts of the embodiments of the present invention and comparative examples; wherein, (a) is the CuCoNiMnAl hydroxide precursor of comparative example 1; (b) is the CuCoNiMnAl-S of embodiment 1; (c) is the SEM image of (b) after 5 times magnification; (d) is the CuCoNiAl-S of comparative example 3; (e) is the CuCoNiMn-S of comparative example 4; (f) is the CuCoNi-S of comparative example 5;

[0026] Figure 5 is the XRD pattern of the CuCoNiMnAl-S catalyst of Example 1 of the present invention;

[0027] Figure 6The SEM, TEM and element distribution spectrum of the CuCoNiMnAl-S catalyst of Example 1 of the present invention; (a) is an SEM image; (b) is an SEM image of (a) magnified 5 times; (c) is a TEM image; (d) is a 5-fold magnification of (c); (d) is a high-resolution TEM image of region 1 of the CuCoNiMnAl-S catalyst; (f) is a high-resolution TEM image of region 2 of the CuCoNiMnAl-S catalyst; (g) is an element distribution spectrum of Cu, Co, Ni, Mn, Al and S in the CuCoNiMnAl-S catalyst;

[0028] Figure 7 This is a comparison diagram of the SOR linear scanning curves of the catalysts prepared in Examples 1-2 of the present invention;

[0029] Figure 8 This is a comparison of the SOR linear scanning curves of the catalysts prepared in Example 1 of the present invention and Comparative Example 2 in an electrolyte containing 1.0 M Na2S and 1.0 M NaOH;

[0030] Figure 9 This is a comparison of the SOR linear scanning curves of the catalysts prepared in Example 1 of the present invention and Comparative Examples 3-5 in an electrolyte containing 1.0 M Na2S and 1.0 M NaOH;

[0031] Figure 10 The catalysts prepared in Example 1 and Comparative Examples 3-5 of the present invention were -2 and 300mA·cm -2 Comparison of SOR potential under different current densities;

[0032] Figure 11 is the SOR Tafel slope of the catalysts prepared in Example 1 of the present invention and Comparative Examples 3-5 in 1.0 M NaOH + 1.0 M Na2S electrolyte;

[0033] Figure 12 The CuCoNiMnAl-S catalyst of Example 1 of the present invention was heated at a current density of 100 mA·cm -2 SOR stability test curve in 1.0M NaOH+1.0M Na2S electrolyte under the conditions;

[0034] Figure 13 The SOR and OER linear scanning curves of the CuCoNiMnAl-S catalyst of Example 1 of the present invention are shown;

[0035] Figure 14 HER linear scanning curves of the catalysts of Example 1 and Comparative Examples 3-5 of the present invention in 1.0 M NaOH electrolyte;

[0036] Figure 15 HER Tafel slopes of the catalysts of Example 1 and Comparative Examples 3-5 in 1.0 M NaOH electrolyte;

[0037] Figure 16 The catalysts of Example 1 and Comparative Examples 3-5 of the present invention were tested at 100 mA·cm -2 and 300mA·cm -2 Comparison of HER overpotential at different current densities;

[0038] Figure 17 This is the HER stability test curve of the catalyst prepared in Example 1 of the present invention in 1.0 M NaOH electrolyte at a current density of 100 mA cm-2;

[0039] Figure 18 Diagram of the CuCoNiMnAl-S(+)||CuCoNiMnAl-S(-)SOR-assisted seawater electrolysis system assembled with the catalyst prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0040] To make the present invention easier to understand, the present invention is further described below with reference to specific examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the professional terms used below are consistent with the meanings understood by professional and technical personnel in this field; unless otherwise specified, the raw materials and reagents involved in this article can be purchased from the market or prepared by known methods.

[0041] Example 1

[0042] A method for preparing a high entropy sulfide catalyst, the preparation flow chart of which is as follows Figure 1 As shown, the following steps are included:

[0043] Pretreatment of nickel foam:

[0044] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60°C to obtain pretreated nickel foam NF;

[0045] Preparation of CuCoNiMnAl hydroxide precursor / NF:

[0046] 1 mmol Cu(NO3)3·3H2O, 1 mmol Co(NO3)2·6H2O, 1 mmol Ni(NO3)2·6H2O, 1 mmol Mn(NO3)2·4H2O, and 1 mmol Al(NO3)2·9H2O were weighed, along with 170 mM NH4F and 340 mM urea, and dissolved in 30 mL of deionized water. The solution was stirred vigorously for 30 minutes to fully dissolve the pretreated nickel foam NF. The solution was then transferred to a 50 mL polytetrafluoroethylene-lined autoclave and maintained at 140°C for 16 hours. After the reaction was completed, the sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light bluish-white CuCoNiMnAl hydroxide precursor / NF catalyst.

[0047] Preparation of CuCoNiMnAl-S / NF:

[0048] The CuCoNiMnAl hydroxide precursor / NF obtained above was cut into 1×1 cm 2 The small piece was placed in a porcelain boat, and then the sample was placed downstream of the tube furnace, and 0.5g of sublimed sulfur powder was placed upstream. The tube furnace was heated at 2℃·min -1 The tube furnace was heated to 300 °C at a heating rate of 100 °C and maintained in a N2 atmosphere for 2 h. After the tube furnace was cooled to room temperature, the black CuCoNiMnAl-S / NF catalyst was taken out.

[0049] Example 2

[0050] A method for preparing a high entropy sulfide catalyst comprises the following steps:

[0051] Pretreatment of nickel foam:

[0052] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60° C. to obtain pretreated nickel foam NF.

[0053] Preparation of FeCoNiMoCu hydroxide precursor / NF:

[0054] 1 mmol of Fe(NO3)3·9H2O, 1 mmol of Co(NO3)2·6H2O, 1 mmol of Ni(NO3)2·6H2O, 1 mmol of Na2MoO4·2H2O, and 1 mmol of Cu(NO3)3·3H2O were weighed, dissolved in 30 mL of deionized water, and stirred vigorously for 30 minutes to fully dissolve. The pretreated nickel foam NF was placed in the above solution and transferred to a 50 mL polytetrafluoroethylene-lined autoclave. The solution was maintained at 140°C for 16 hours. After the reaction was completed, the obtained sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light blue-white CuCoNiMnAl hydroxide precursor / NF catalyst.

[0055] Preparation of FeCoNiMoCu-S / NF:

[0056] The FeCoNiMoCu hydroxide precursor / NF obtained above was cut into 1×1 cm 2 The small piece was placed in a porcelain boat, and then the sample was placed downstream of the tube furnace, and 0.5g of sublimed sulfur powder was placed upstream. The tube furnace was heated at 2℃·min -1 The tube furnace was heated to 300 °C at a heating rate of 100 °C and maintained in a N2 atmosphere for 2 h. After the tube furnace was cooled to room temperature, the black FeCoNiMoCu-S / NF catalyst was taken out.

[0057] Comparative Example 1

[0058] A method for preparing a CuCoNiMnAl hydroxide precursor / NF catalyst comprises the following steps:

[0059] Pretreatment of nickel foam:

[0060] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60° C. to obtain pretreated nickel foam NF.

[0061] Preparation of CuCoNiMnAl hydroxide precursor / NF:

[0062] 1 mmol Cu(NO3)3·3H2O, 1 mmol Co(NO3)2·6H2O, 1 mmol Ni(NO3)2·6H2O, 1 mmol Mn(NO3)2·4H2O, and 1 mmol Al(NO3)2·9H2O were weighed, along with 170 mM NH4F and 340 mM urea, and dissolved in 30 mL of deionized water. The solution was stirred vigorously for 30 minutes to fully dissolve the pretreated nickel foam NF. The solution was then transferred to a 50 mL polytetrafluoroethylene-lined autoclave and maintained at 140°C for 16 hours. After the reaction was completed, the sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light bluish-white CuCoNiMnAl hydroxide precursor / NF catalyst.

[0063] Comparative Example 2

[0064] A method for preparing a CuCoNiMnAl-O / NF catalyst comprises the following steps:

[0065] Pretreatment of nickel foam:

[0066] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60° C. to obtain pretreated nickel foam NF.

[0067] Preparation of CuCoNiMnAl hydroxide precursor / NF:

[0068] 1 mmol Cu(NO3)3·3H2O, 1 mmol Co(NO3)2·6H2O, 1 mmol Ni(NO3)2·6H2O, 1 mmol Mn(NO3)2·4H2O, and 1 mmol Al(NO3)2·9H2O were weighed, along with 170 mM NH4F and 340 mM urea, and dissolved in 30 mL of deionized water. The solution was stirred vigorously for 30 minutes to fully dissolve the pretreated nickel foam NF. The solution was then transferred to a 50 mL polytetrafluoroethylene-lined autoclave and maintained at 140°C for 16 hours. After the reaction was completed, the sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light bluish-white CuCoNiMnAl hydroxide precursor / NF catalyst.

[0069] Preparation of CuCoNiMnAl-O / NF:

[0070] The CuCoNiMnAl hydroxide precursor / NF obtained above was cut into 1×1 cm 2 The small pieces were placed in a porcelain boat, and then the samples were placed in a muffle furnace, and the tube furnace was heated at 2℃·min -1The temperature was raised to 350 °C at a rate of 1000 ℃ and maintained for 2 h. After the muffle furnace was cooled to room temperature, the black CuCoNiMnAl-O / NF catalyst was taken out.

[0071] Comparative Example 3

[0072] A method for preparing a CuCoNiAl-S / NF catalyst comprises the following steps:

[0073] Pretreatment of nickel foam:

[0074] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60° C. to obtain pretreated nickel foam NF.

[0075] Preparation of CuCoNiAl hydroxide precursor / NF:

[0076] 1 mmol Cu(NO3)3·3H2O, 1 mmol Co(NO3)2·6H2O, 1 mmol Ni(NO3)2·6H2O, 1 mmol Al(NO3)2·9H2O, 170 mM NH4F, and 340 mM urea were weighed and dissolved in 30 mL of deionized water. The solution was stirred vigorously for 30 minutes to fully dissolve. The pretreated nickel foam NF was placed in the above solution and transferred to a 50 mL polytetrafluoroethylene-lined autoclave. The solution was maintained at 140°C for 16 hours. After the reaction was completed, the obtained sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light blue-white CuCoNiMn hydroxide precursor / NF catalyst.

[0077] Preparation of CuCoNiAl-S / NF:

[0078] The CuCoNiAl hydroxide precursor / NF obtained above was cut into 1×1 cm 2 The small piece was placed in a porcelain boat, and then the sample was placed downstream of the tube furnace, and 0.5g of sublimed sulfur powder was placed upstream. The tube furnace was heated at 2℃·min -1 The tube furnace was heated to 300 °C at a heating rate of 100 °C and maintained in a N2 atmosphere for 2 h. After the tube furnace was cooled to room temperature, the black CuCoNiAl-S / NF catalyst was taken out.

[0079] Comparative Example 4

[0080] A method for preparing a CuCoNiMn-S / NF catalyst comprises the following steps:

[0081] Pretreatment of nickel foam:

[0082] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60° C. to obtain pretreated nickel foam NF.

[0083] Preparation of CuCoNiMn hydroxide precursor / NF:

[0084] 1 mmol Cu(NO3)3·3H2O, 1 mmol Co(NO3)2·6H2O, 1 mmol Ni(NO3)2·6H2O, 1 mmol Mn(NO3)2·4H2O, 170 mM NH4F, and 340 mM urea were weighed and dissolved in 30 mL of deionized water. The solution was stirred vigorously for 30 minutes to fully dissolve. The pretreated nickel foam NF was placed in the above solution and transferred to a 50 mL polytetrafluoroethylene-lined autoclave. The solution was maintained at 140°C for 16 hours. After the reaction was completed, the obtained sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light bluish-white CuCoNiMn hydroxide precursor / NF catalyst.

[0085] Preparation of CuCoNiMn-S / NF:

[0086] The CuCoNiMn hydroxide precursor / NF obtained above was cut into 1×1 cm 2 The small piece was placed in a porcelain boat, and then the sample was placed downstream of the tube furnace, and 0.5g of sublimed sulfur powder was placed upstream. The tube furnace was heated at 2℃·min -1 The tube furnace was heated to 300 °C at a heating rate of 100 °C and maintained in a N2 atmosphere for 2 h. After the tube furnace was cooled to room temperature, the black CuCoNiMn-S / NF catalyst was taken out.

[0087] Comparative Example 5

[0088] A method for preparing a CuCoNi-S / NF catalyst comprises the following steps:

[0089] Pretreatment of nickel foam:

[0090] The nickel foam was ultrasonically treated in 3 mol / L hydrochloric acid for 10 minutes to remove surface impurities, then washed with deionized water and ethanol for more than three times, and dried in an oven at 60° C. to obtain pretreated nickel foam NF.

[0091] Preparation of CuCoNi hydroxide precursor / NF:

[0092] 1 mmol Cu(NO3)3·3H2O, 1 mmol Co(NO3)2·6H2O, 1 mmol Ni(NO3)2·6H2O, 1 mmol Al(NO3)2·9H2O, 170 mM NH4F, and 340 mM urea were weighed and dissolved in 30 mL of deionized water. The solution was stirred vigorously for 30 minutes to fully dissolve. The pretreated nickel foam NF was placed in the above solution and transferred to a 50 mL polytetrafluoroethylene-lined autoclave. The solution was maintained at 140°C for 16 hours. After the reaction was completed, the obtained sample was rinsed with deionized water and dried at 60°C for 12 hours to obtain a light blue-white CuCoNiMn hydroxide precursor / NF catalyst.

[0093] Preparation of CuCoNi-S / NF:

[0094] The CuCoNiAl hydroxide precursor / NF obtained above was cut into 1×1 cm 2 The small piece was placed in a porcelain boat, and then the sample was placed downstream of the tube furnace, and 0.5g of sublimed sulfur powder was placed upstream. The tube furnace was heated at 2℃·min -1 The tube furnace was heated to 300 °C at a heating rate of 100 °C and maintained in a N2 atmosphere for 2 h. After the tube furnace was cooled to room temperature, the black CuCoNi-S / NF catalyst was taken out.

[0095] Performance testing and result analysis:

[0096] Part of the physical diagram of the catalyst obtained in Example 1-2 and Comparative Example 1-5 is as shown in Figure 2-3 As shown. Figure 2-3 It can be seen that the catalysts prepared in Examples 1-2, Comparative Example 1 and Comparative Examples 3-5 can all be successfully attached to the nickel foam NF, indicating that the preparation method of the present application is a general method for preparing catalysts. The catalysts obtained in Examples 1-2 and Comparative Examples 1-5 were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the results are as follows: Figure 4-6 As shown. Figure 5 It can be seen that the two main peaks of the CuCoNiMnAl-S catalyst prepared in Example 1 of the present invention at 45.4° and 52.6° correspond to the metal sulfide NiS 1.03 (JCPDS 02-1273) (102) and (110) planes, compared to standard NiS 1.03 The diffraction peaks of CuCoNiMnAl-S are slightly shifted to the left. This is because the Cu, Co, Mn and Al atoms are embedded in the lattice of the metal Ni, which causes the lattice constant of the CuCoNiMnAl-S catalyst to shift to a lower angle. Figure 6It can be seen that the edges of the CuCoNiMnAl-S catalyst nanosheets of Example 1 of the present invention have many nanopores, which can further increase the surface area. Figure 6 (e)-6(f) show that the lattice fringes of the CuCoNiMnAl-S catalyst of Example 1 of the present invention (interplanar spacing of 0.264 and 0.258 nm) correspond to those of NiS 1.03 The (101) crystal plane and the lattice fringes with interplanar spacing of 0.203 and 0.176 nm are attributed to NiS 1.03 The (102) and (110) crystal planes of the CuCoNiMnAl-S catalyst were found to be single-phase in structure.

[0097] The catalysts obtained in Examples 1-2 and Comparative Examples 2-5 were reacted in a 1.0 M NaOH + 1.0 M Na2S solution using a three-electrode electrophoresis system at 2 mV·s -1 The SOR linear sweep voltammetry (LSV) test was carried out at a scan rate of Figure 7-11 As shown in Table 1. Figure 7-11 As can be seen from Table 1, the SOR catalytic activity of the catalyst of the present invention is higher than that of the catalysts of Comparative Examples 2-5. Figure 7 It can be seen that the SOR activities of the CuCoNiMnAl-S catalyst of Example 1 and the FeCoNiMoCu-S catalyst of Example 2 are different in the electrolyte containing 1.0M Na2S and 1.0M NaOH. In comparison, the CuCoNiMnAl-S catalyst of Example 1 has a better SOR activity, requiring only 0.287V (vs. RHE) to drive 100mA·cm -2 The current density indicates that the selection of different elements in the high-entropy material has different effects on the SOR activity.

[0098] Table 1 Different catalysts driving 100 mA·cm -2 and 300mA·cm -2 SOR voltage required for current density

[0099]

[0100] The CuCoNiMnAl-S catalyst of Example 1 of the present invention was placed in a solution of 1.0 M NaOH + 1.0 M Na2S using a three-electrode system by chronoamperometry (CP) at 100 mA cm -2 The stability test was carried out at a current density of Figure 12 As shown. Figure 12It can be seen that the CuCoNiMnAl-S catalyst of Example 1 of the present invention has excellent stability and can be used at a high current density of 100 mA cm -2 It can run stably for more than 100 hours under high current conditions, which can meet the requirements of actual industrial high current applications.

[0101] The SOR linear scanning curve of the CuCoNiMnAl-S catalyst of Example 1 of the present invention is compared with its OER linear scanning curve. The results are as follows: Figure 13 As shown. Figure 13 It can be seen that the CuCoNiMnAl-S catalyst of Example 1 of the present invention requires a voltage of 1.56 V (vs. RHE) to drive 100 mA·cm in the OER in the 1.0 M NaOH electrolyte. -2 The current density is 0.287 V (vs. RHE) to drive 100 mA cm for SOR in an electrolyte containing 1.0 M Na2S and 1.0 M NaOH. -2 This indicates that the CuCoNiMnAl-S catalyst of Example 1 of the present invention can significantly reduce energy consumption in SOR and achieve energy-saving hydrogen production.

[0102] The materials prepared in Example 1 of the present invention and Comparative Examples 3-5 were subjected to three-electrode electrolysis at 2 mV·s in 1.0 M NaOH electrolyte. -1 HER linear sweep voltammetry (LSV) test was carried out at a scan rate of Figure 14-16 and Table 2. Figure 14-16 As shown in Table 2, the CuCoNiMnAl-S catalyst of Example 1 of the present invention only requires a potential of 0.284 and 0.428 V (vs. RHE) to drive current densities of 100 and 300 mA cm in 1.0 M NaOH electrolyte. -2 , its HER catalytic activity is not much different from that of the comparative examples CuCoNiAl-S / NF, CuCoNiMn-S / NF and CuCoNi-S / NF.

[0103] Table 2 Different catalysts driving 100 mA·cm -2 and 300mA·cm -2 HER voltage required for current density

[0104] Serial number catalyst <![CDATA[100mA·cm -2 (V)]]> <![CDATA[300mA·cm -2 (V)]]> Example 1 CuCoNiMnAl-S / NF 0.284 0.428 Comparative Example 3 CuCoNiAl-S / NF 0.287 0.416 Comparative Example 4 CuCoNiMn-S / NF 0.276 0.402 Comparative Example 5 CuCoNi-S / NF 0.270 0.380

[0105] The CuCoNiMnAl-S catalyst of Example 1 of the present invention was placed in a 1.0 M NaOH solution using a three-electrode system by chronoamperometry (CP) at 100 mA cm -2 The stability test was carried out at a current density of Figure 17 As shown. Figure 17 It can be seen that the CuCoNiMnAl-S catalyst of Example 1 of the present invention has excellent stability and can be used at a high current density of 100 mA cm -2 The catalyst can operate stably for more than 280 hours under high temperature and has excellent stability. The catalyst prepared by the present invention is suitable for large-scale industrial electrolysis of water to produce hydrogen.

[0106] Based on the high HER and SOR activity of the CuCoNiMnAl-S catalyst of Example 1, it was used for cathode electrolysis of water for hydrogen evolution (1.0 M NaOH) and anode sulfide ion oxidation (1.0 M NaOH + 1.0 M Na2S). Figure 18 The SOR-assisted water electrolysis system shown in the figure can realize energy-saving hydrogen production by water electrolysis and sulfur-containing wastewater treatment. Figure 18 As shown, the cation exchange membrane (Nafion 117) is Na + Channels are provided to separate both the cathode and anode regions.

[0107] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a high entropy sulfide catalyst, characterized in that: The preparation method comprises the following steps: S1. Pretreating nickel foam NF with hydrochloric acid, solvent and deionized water to obtain pretreated nickel foam NF; S2. Mixing water-soluble metal salts corresponding to at least five metals selected from Fe, Co, Ni, Cu, Al, Mn, and Mo, NH4F, and urea, and subjecting the mixture to a hydrothermal reaction to obtain M hydroxide precursor / NF in nickel foam NF; wherein M is at least five metals selected from Fe, Co, Ni, Cu, Al, Mn, and Mo; S3. Place the M hydroxide precursor / NF in the downstream of the tube furnace and sublimed sulfur powder in the upstream. The tube furnace is heated at 2°C·min -1 The temperature was raised to 300-500°C at a rate of 10000°C and maintained in a N2 atmosphere for 2-5 hours. After the tube furnace was cooled to room temperature, the MS / NF catalyst, i.e., a high entropy sulfide catalyst, was obtained.

2. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S1, the concentration of the hydrochloric acid is 3M, and the solvent is ethanol.

3. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S2, the molar ratio of Fe, Co, Ni, Cu, Al, Mn, and Mo is 2-3:2-3:2-3:2-3:2-3:2-3:2-3:2-3.

4. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S2, the concentration of NH4F is 150-200 mM; the concentration of urea is 300-350 mM.

5. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S2, the temperature of the hydrothermal reaction is 120-150° C., and the time is 12-16 hours.

6. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S2, water-soluble metal salts corresponding to Fe, Co, Ni, Cu, and Mo, NH4F, and urea are mixed and subjected to a hydrothermal reaction on the pretreated nickel foam NF to obtain FeCoNiMoCu hydroxide precursor / NF on the nickel foam NF.

7. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S2, water-soluble metal salts corresponding to Co, Ni, Cu, Al, and Mn, NH4F, and urea are mixed and subjected to a hydrothermal reaction on the pretreated nickel foam NF to obtain CuCoNiMnAl hydroxide precursor / NF on the nickel foam NF.

8. The method for preparing a high entropy sulfide catalyst according to claim 1, wherein: In step S2, the water-soluble metal salt corresponding to Fe, Co, Ni, Cu, Al, Mn, and Mo includes at least one of nitrate and chloride.

9. The high entropy sulfide catalyst prepared according to the preparation method according to any one of claims 1 to 8.

10. Use of the high entropy sulfide catalyst according to claim 9 in sulfide ion oxidation-assisted water electrolysis for efficient and energy-saving hydrogen production.

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