CN117721488A - A high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water and its preparation method - Google Patents

Abstract

The invention provides a high-entropy alloy catalyst for hydrogen production by alkaline water electrolysis and a preparation method thereof, wherein metal elements in the high-entropy alloy catalyst comprise any five of Fe, ni, co, mn, cu, zn, mg, ti, W or Mo. In the reaction of hydrogen production by alkaline electrolysis of water, the high-entropy alloy catalyst provided by the invention has the advantages that the required electrolysis voltage is lower, the stability is higher, and the catalytic performance of the high-entropy alloy catalyst is not obviously reduced after the high-current density continuous reaction is carried out for 1000 hours; meanwhile, the high-entropy alloy catalyst has the advantages of easily available raw materials and low cost, and therefore, the high-entropy alloy catalyst also has the advantage of low preparation cost.

Description

A high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water and its preparation method

Technical field

The invention belongs to the technical field of catalysts and relates to a high-entropy alloy catalyst used for alkaline electrolysis of water to produce hydrogen, and in particular to a high-entropy alloy catalyst used for alkaline electrolysis of water to produce hydrogen and a preparation method thereof.

Background technique

The extensive use of traditional energy has caused problems such as energy crisis and environmental pollution. As an important chemical energy carrier, hydrogen is regarded as the clean energy with the greatest development potential in the 21st century due to its high mass energy density (120MJ/Kg), zero emissions and high conversion efficiency. In recent years, a variety of hydrogen production technologies including cracking and reforming, biomass cracking, and photo/electrocatalytic water splitting have been widely designed and developed. Among them, electrocatalytic water splitting is a very promising method. Electrocatalytic water splitting is composed of hydrogen evolution reaction (Hydrogen Evolution Reaction, HER) at the cathode and oxygen evolution reaction (Oxygen Evolution Reaction, OER) at the anode. Currently, platinum on carbon (Pt/C) is considered the best performing HER catalyst. Iridium oxide (IrO ₂ ) and ruthenium oxide (RuO ₂ ) are considered to be the best-performing OER catalysts due to their unique electronic structures. However, these catalysts have shortcomings such as high cost and easy corrosion, which limit their practical application.

CN117070782A discloses a low-Pt high-entropy alloy electrolytic water catalyst and its preparation method and application. Five metal elements selected from Mn, Ni, Cu, Pt and any one of La, Mo, Co, V, and Ti are used for combination. An efficient and stable high-entropy alloy catalyst is prepared. There is no need to adjust the pH during the process. The process is simple, easy to operate, and the preparation cost is low. Industrial production can be achieved. The MnNiCuPt (La, Mo, Co, V, Ti) high-entropy alloy prepared by this invention The alloy catalyst shows excellent water electrolysis performance, which not only reduces the cost of the catalyst, but also improves the catalytic performance. However, the Pt high-entropy alloy water electrolysis catalyst still contains Pt element, which has the problem of high cost.

CN116219480A discloses a high-entropy alloy water electrolysis catalyst and a preparation method thereof. The preparation method includes: a metal salt solution, a nitrogen source and a carbon material are mixed, dried and thermally shocked to obtain a high-entropy alloy water electrolysis catalyst; The mass ratio of nitrogen elements to carbon materials in the nitrogen source is (1-5):20; the high-entropy alloy electrolysis water catalyst includes at least 5 kinds of metal elements. The metal salts in the metal salt solution are reduced to elemental substances under the action of carbon materials, and then the thermal shock method is used to combine the metal elements together to form an alloy. At the same time, it can prevent the agglomeration of alloy particles, maintain its structural uniformity, and avoid phase segregation; The carbon material also serves as a carrier to improve the conductivity of the obtained high-entropy alloy water electrolysis catalyst. The carbon material is doped and modified with nitrogen by adding a nitrogen source to enhance the interaction between the metal and the carrier and further improve the catalytic activity and stability; The preparation method described above is simple in process and short in time, and is conducive to realizing large-scale production. However, the high-entropy alloy water electrolysis catalyst has poor corrosion resistance and short service life.

The currently disclosed high-entropy alloy catalysts all have certain defects, such as high preparation costs and poor corrosion resistance. Therefore, it is crucial to develop and design a new high-entropy alloy catalyst for hydrogen production from alkaline water electrolysis.

Contents of the invention

In view of the shortcomings of the existing technology, the object of the present invention is to provide a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water and a preparation method thereof. The high-entropy alloy catalyst provided in the present invention can be used for hydrogen production by alkaline electrolysis of water In the reaction, the required electrolysis voltage is low and has high stability. Under high current density (500~1000mA/cm ² ), after continuous reaction for 1000 hours, the catalytic performance of the high-entropy alloy catalyst does not decrease significantly; At the same time, the raw materials of the high-entropy alloy catalyst are easily available and cheap, so the high-entropy alloy catalyst also has the advantage of low preparation cost.

To achieve this goal, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. The metal elements in the high-entropy alloy catalyst include Fe, Ni, Co, Mn, Cu, Zn, Mg, Ti Any five of , W or Mo.

The metal elements in the high-entropy alloy catalyst in the present invention include any five of Fe, Ni, Co, Mn, Cu, Zn, Mg, Ti, W or Mo. For example, they can be Fe, Ni, Co, Mn and The combination of Cu, the combination of Co, Mn, Cu, Zn and Mg, the combination of Zn, Mg, Ti, W and Mo, the combination of Ni, Co, Mn, Cu and Zn, or the combination of Mn, Cu, Zn, Mg and Ti The combination.

As a new type of alloy material, high-entropy alloy is a material composed of at least five metal elements in the same or similar molar proportions. Compared with traditional alloys, high-entropy alloys have the characteristics of highly disordered structure, high stability, and adjustable composition and electronic structure. These characteristics make high-entropy alloys very potential in the field of electrochemical catalysis; in addition, non-noble metal high-entropy alloys have the advantages of low price and high activity. The interaction of multiple metal elements makes them highly active and controllable. ; Therefore, in the present invention, a high-entropy alloy is used as a catalyst for hydrogen production by alkaline electrolysis of water.

The high-entropy alloy catalyst provided in the present invention requires a low electrolysis voltage and has high stability in the reaction of alkaline electrolysis of water to produce hydrogen. Under high current density (500-1000mA/cm ² ), After the reaction continued for 1000 hours, the catalytic performance of the high-entropy alloy catalyst did not decrease significantly. At the same time, the raw materials of the high-entropy alloy catalyst are easily available and cheap, so the high-entropy alloy catalyst also has the advantage of low preparation cost.

In a second aspect, the present invention provides a method for preparing the high-entropy alloy catalyst described in the first aspect. The preparation method includes:

The carrier is placed in an electrodeposition solution, and the high-entropy alloy catalyst is obtained through electrodeposition;

The electrodeposition solution includes metal salts, and the metal salts include any five of Fe salt, Ni salt, Co salt, Mn salt, Cu salt, Zn salt, Mg salt, Ti salt, W salt or Mo salt.

The metal salt described in the present invention includes any five of Fe salt, Ni salt, Co salt, Mn salt, Cu salt, Zn salt, Mg salt, Ti salt, W salt or Mo salt, for example, it can be Fe salt, Ni salt The combination of salt, Co salt, Mn salt and Cu salt, the combination of Ni salt, Co salt, Mn salt, Cu salt and Zn salt, the combination of Mn salt, Cu salt, Zn salt, Mg salt and Ti salt, Zn salt, A combination of Mg salt, Ti salt, W salt and Mo salt, or a combination of Cu salt, Zn salt, Mg salt, Ti salt and W salt.

The preparation method of the high-entropy alloy catalyst provided in the present invention has a simple process, low operating difficulty, low requirements on production equipment, and is easy to be promoted and used on a large scale.

Preferably, the difference between the highest and lowest concentrations of the five salts included in the electrodeposition solution is not higher than 0.3 mol/L, for example, it can be 0.3 mol/L, 0.28 mol/L, 0.26 mol/L, 0.24mol/L, 0.22mol/L, 0.2mol/L, 0.18mol/L, 0.16mol/L, 0.14mol/L, 0.12mol/L, 0.1mol/L, 0.08mol/L, 0.06 mol/L, 0.04mol/L, 0.02mol/L or 0.01mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Fe salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Ni salt in the electrodeposition solution is 0.01~0.5mol/L, for example, it can be 0.01mol/L, 0.02mol/L, 0.05mol/L, 0.1mol/L, 0.2mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Co salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Mn salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Cu salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Zn salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Mg salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Ti salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of W salt in the electrodeposition solution is 0.01-0.5 mol/L, for example, it can be 0.01 mol/L, 0.02 mol/L, 0.05 mol/L, 0.1 mol/L, 0.2 mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the concentration of Mo salt in the electrodeposition solution is 0.01~0.5mol/L, for example, it can be 0.01mol/L, 0.02mol/L, 0.05mol/L, 0.1mol/L, 0.2mol/L, 0.3 mol/L, 0.4mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the Fe salt includes any one or a combination of at least two of FeSO ₄ , FeCl ₂ or Fe(NO ₃ ) _2. Typical but non-limiting combinations include a combination of FeSO ₄ and FeCl ₂ , FeCl ₂ The combination with Fe(NO ₃ ) ₂ , the combination of FeSO ₄ and Fe(NO ₃ ) ₂ , or the combination of FeSO ₄ , FeCl ₂ and Fe(NO ₃ ) ₂ .

Preferably, the Ni salt includes any one or a combination of at least two of NiSO ₄ , NiCl ₂ or Ni(NO ₃ ) _2. Typical but non-limiting combinations include a combination of NiSO ₄ and NiCl _2. NiCl ₂ Combination with Ni(NO ₃ ) ₂ , or combination of NiSO ₄ , NiCl ₂ and Ni(NO ₃ ) ₂ .

Preferably, the Co salt includes any one or a combination of at least two of CoSO ₄ , CoCl ₂ or Co(NO ₃ ) ₂ , typical but non-limiting combinations include a combination of CoSO ₄ and CoCl ₂ , CoCl ₂ Combination with Co(NO ₃ ) ₂ , or combination of CoSO ₄ , CoCl ₂ and Co(NO ₃ ) ₂ .

Preferably, the Mn salt includes any one or a combination of at least two of MnSO ₄ , MnCl ₂ or Mn(NO ₃ ) _2. Typical but non-limiting combinations include a combination of MnSO ₄ and MnCl ₂ , MnCl ₂ The combination with Mn(NO ₃ ) ₂ , or the combination of MnSO ₄ , MnCl ₂ and Mn(NO ₃ ) ₂ .

Preferably, the Cu salt includes any one or a combination of at least two of CuSO ₄ , CuCl ₂ or Cu(NO ₃ ) ₂ . Typical but non-limiting combinations include a combination of CuSO ₄ and CuCl ₂ , CuCl ₂ Combination with Cu(NO ₃ ) ₂ , or combination of CuSO ₄ , CuCl ₂ and Cu(NO ₃ ) ₂ .

Preferably, the Zn salt includes any one or a combination of at least two of ZnSO ₄ , ZnCl ₂ or Zn(NO ₃ ) _2. Typical but non-limiting combinations include a combination of ZnSO ₄ and ZnCl ₂ , ZnCl ₂ The combination with Zn(NO ₃ ) ₂ , or the combination of ZnSO ₄ , ZnCl ₂ and Zn(NO ₃ ) ₂ .

Preferably, the Mg salt includes any one or a combination of at least two of MgSO ₄ , MgCl ₂ or Mg(NO ₃ ) _2. Typical but non-limiting combinations include a combination of MgSO ₄ and MgCl ₂ , MgCl ₂ The combination with Mg(NO ₃ ) ₂ , or the combination of MgSO ₄ , MgCl ₂ and Mg(NO ₃ ) ₂ .

Preferably, the Ti salt includes any one or a combination of at least two of Ti(SO ₄ ) ₂ , TiCl ₄ or TiO(acac) ₂ . Typical but non-limiting combinations include Ti(SO ₄ ) ₂ and The combination of TiCl ₄ , the combination of TiCl ₄ and TiO(acac) ₂ , the combination of Ti(SO ₄ ) ₂ , TiCl ₄ and TiO(acac) ₂ .

Preferably, the W salt includes any one or a combination of at least two of Na ₂ WO ₄ , (NH ₄ ) ₂ WO ₂ Cl ₄ , Na ₂ WO ₂ Cl _4. Typical but non-limiting combinations include Na The combination of ₂ WO ₄ and (NH ₄ ) ₂ WO ₂ Cl ₄ , the combination of (NH ₄ ) ₂ WO ₂ Cl ₄ and Na ₂ WO ₂ Cl ₄ , or Na ₂ WO ₄ , (NH ₄ ) ₂ WO ₂ Cl ₄ Combination with Na ₂ WO ₂ Cl ₄ .

Preferably, the Mo salt includes any one or a combination of at least two of Na ₂ MoO ₄ , (NH ₄ ) ₆ Mo ₇ O ₂₄ or (NH ₄ ) ₂ MoOCl _5. Typical but non-limiting combinations include The combination of Na ₂ MoO ₄ and (NH ₄ ) ₆ Mo ₇ O ₂₄ , the combination of (NH ₄ ) ₆ Mo ₇ O ₂₄ and (NH ₄ ) ₂ MoOCl ₅ , or Na ₂ MoO ₄ , (NH ₄ ) ₆ Mo ₇ Combination of O ₂₄ and (NH ₄ ) ₂ MoOCl ₅ .

Preferably, the carrier includes any one of conductive glass, nickel foam, carbon paper, carbon cloth or woven nickel mesh.

Preferably, the method for preparing the electrodeposition solution includes:

The metal salt and the solvent are mixed to obtain a preliminary mixed liquid. The obtained preliminary mixed liquid is mixed with a regulator and a stabilizer to obtain a remixed liquid. An acid and/or alkali is then used to adjust the remixed liquid to a set pH value to obtain the electrodeposition solution.

Preferably, the solvent includes water.

Preferably, the regulator includes any one or a combination of at least two of boric acid, silicic acid or acetic acid. Typical but non-limiting combinations include a combination of boric acid and silicic acid, a combination of silicic acid and acetic acid, and a combination of boric acid and acetic acid. A combination of acetic acid, or a combination of boric acid, silicic acid and acetic acid.

Preferably, the concentration of the regulator in the electrodeposition solution is 0.5-2mol/L, for example, it can be 0.5mol/L, 0.7mol/L, 0.9mol/L, 1mol/L, 1.2mol/L, 1.4mol/L. L, 1.6mol/L, 1.8mol/L or 2mol/L, but are not limited to the listed values, and other unlisted values within this range are also applicable.

Preferably, the stabilizer includes sodium citrate and/or potassium citrate.

Preferably, the concentration of the stabilizer in the electrodeposition solution is 0.1 to 0.5 mol/L, for example, it can be 0.1 mol/L, 0.15 mol/L, 0.2 mol/L, 0.25 mol/L, 0.3 mol/L, 0.35 mol/L, 0.4mol/L, 0.45mol/L or 0.5mol/L, but are not limited to the listed values. Other unlisted values within this range of values are also applicable.

Preferably, the acid includes any one or a combination of at least two of sulfuric acid, hydrochloric acid or nitric acid. Typical but non-limiting combinations include a combination of sulfuric acid and hydrochloric acid, a combination of hydrochloric acid and nitric acid, a combination of sulfuric acid, hydrochloric acid and nitric acid. combination.

Preferably, the base includes sodium hydroxide and/or potassium hydroxide.

Preferably, the set pH value is 2 to 10, for example, it can be 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 , but not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the electrodeposition includes galvanostatic electrodeposition, constant voltage electrodeposition or pulsed voltage electrodeposition.

Preferably, the potential of the electrodeposition is -0.6~-2V, and the time is 100~7200s.

The potential of electrodeposition in the present invention is -0.6~-2V, for example, it can be -0.6V, -0.7V, -0.8V, -0.9V, -1V, -1.1V, -1.2V, -1.3V, -1.4V, -1.5V, -1.6V, -1.7V, -1.8V, -1.9V or -2V, but are not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the interval time of the pulse voltage electrodeposition is 1 to 10s, for example, it can be 1s, 1.5s, 2s, 2.5s, 3s, 3.5s, 4s, 4.5s, 5s, 5.5s, 6s, 6.5s, 7s, 7.5s, 8s, 8.5s, 9s, 9.5s or 10s, but not limited to the listed values, other unlisted values within this range are also applicable.

Preferably, the preparation method further includes sequential washing and drying after the electrodeposition.

Preferably, the solution used for washing includes water and/or ethanol.

Preferably, the drying method includes infrared lamp irradiation or vacuum drying.

As a preferred technical solution of the preparation method of the present invention, the preparation method includes:

Mix the metal salt and water to obtain a preliminary mixed liquid, mix the obtained preliminary mixed liquid with a regulator with a concentration of 0.5 to 2 mol/L and a stabilizer with a concentration of 0.1 to 0.5 mol/L to obtain a remixed liquid, and then use acid and/or Adjust the remixed solution with alkali until the pH is 2 to 10 to obtain the electrodeposition solution; place any one of conductive glass, nickel foam, carbon paper, carbon cloth or woven nickel mesh into the electrodeposition solution, at -0.6V Conduct electrodeposition for 100s to 7200s at a potential of ~-2V, wash with water and/or ethanol, and then dry by infrared lamp irradiation or vacuum drying to obtain the high-entropy alloy catalyst;

The electrodeposition solution includes metal salts, and the metal salts include Fe salts with a concentration of 0.01-0.5 mol/L, Ni salts with a concentration of 0.01-0.5 mol/L, and Co salts with a concentration of 0.01-0.5 mol/L. , Mn salt with a concentration of 0.01~0.5mol/L, Cu salt with a concentration of 0.01~0.5mol/L, Zn salt with a concentration of 0.01~0.5mol/L, Mg salt with a concentration of 0.01~0.5mol/L, concentration It is any five of Ti salts with a concentration of 0.01-0.5 mol/L, W salts with a concentration of 0.01-0.5 mol/L, or Mo salts with a concentration of 0.01-0.5 mol/L. The metal salts in the electrodeposition solution include The difference between the highest and lowest concentrations of the five salts is not higher than 0.3mol/L.

Compared with the existing technology, the present invention has the following beneficial effects:

The high-entropy alloy catalyst provided in the present invention requires a low electrolysis voltage and has high stability in the reaction of alkaline electrolysis of water to produce hydrogen. Under high current density (500-1000mA/cm ² ), After the reaction continued for 1000 hours, the catalytic performance of the high-entropy alloy catalyst did not decrease significantly. At the same time, the raw materials of the high-entropy alloy catalyst are easily available and cheap, so the high-entropy alloy catalyst also has the advantage of low preparation cost.

Description of the drawings

Figure 1 is a TEM image of the high-entropy alloy catalyst in Example 1.

Figure 2 is the LSV curve of OER of the high-entropy alloy catalyst in Example 1.

Figure 3 is the LSV curve of HER of the high-entropy alloy catalyst in Example 1.

Figure 4 is an LSV curve of total hydrolysis performance of the high-entropy alloy catalyst in Example 1.

Detailed ways

The technical solution of the present invention will be further described below through specific implementations. Those skilled in the art should understand that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

Example 1

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. The metal elements in the high-entropy alloy catalyst include Fe, Ni, Co, Mn and Cu;

The preparation method of the high-entropy alloy catalyst is:

Mix the metal salt and water to obtain a preliminary mixed liquid, mix the obtained preliminary mixed liquid with boric acid with a concentration of 1.2 mol/L and sodium citrate with a concentration of 0.3 mol/L to obtain a remixed liquid, and then use sulfuric acid to adjust the remixed liquid to a pH of 3. Obtain the electrodeposition solution; place the foamed nickel in the electrodeposition solution, conduct electrodeposition for 3600s at a potential of -1.3V, wash with ethanol, and dry by infrared light irradiation to obtain the high entropy alloy catalyst;

The electrodeposition solution includes metal salts, and the metal salts include FeSO ₄ with a concentration of 0.1 mol/L, NiSO 4 with a concentration of 0.1 mol/L, CoSO ₄ with a concentration of 0.1 mol/L, and CoSO ₄ with a concentration of 0.1 mol/L. L of MnSO ₄ and CuSO ₄ with a concentration of 0.1 mol/L.

Example 2

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. The metal elements in the high-entropy alloy catalyst include Co, Mn, Cu, Zn and Mg;

The preparation method of the high-entropy alloy catalyst is:

Mix the metal salt and water to obtain a preliminary mixed liquid, mix the obtained preliminary mixed liquid with boric acid with a concentration of 0.8 mol/L and sodium citrate with a concentration of 0.4 mol/L to obtain a remixed liquid, and then use hydrochloric acid to adjust the remixed liquid until the pH is 2. Obtain the electrodeposition solution; place the conductive glass in the electrodeposition solution, perform electrodeposition for 5200s at a potential of -1V, wash with water, and then dry by vacuum drying to obtain the high-entropy alloy. catalyst;

The electrodeposition solution includes metal salts, and the metal salts include CoCl ₂ with a concentration of 0.05 mol/L, MnCl ₂ with a concentration of 0.05 mol/L, CuCl 2 with a concentration of 0.05 mol/L, and CuCl _{2 with a concentration of 0.05 mol/L} . L of ZnCl ₂ and MgCl ₂ with a concentration of 0.05mol/L.

Example 3

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. The metal elements in the high-entropy alloy catalyst include Cu, Zn, Mg, Ti and W;

The preparation method of the high-entropy alloy catalyst is:

Mix the metal salt and water to obtain a preliminary mixed liquid, mix the obtained preliminary mixed liquid with boric acid with a concentration of 1.6 mol/L and sodium citrate with a concentration of 0.2 mol/L to obtain a remixed liquid, and then use sodium hydroxide to adjust the remixed liquid to The pH is 9, and the electrodeposition solution is obtained; the carbon paper is placed in the electrodeposition solution, and electrodeposition is performed for 1500s at a potential of -1.6V. After washing with ethanol, it is dried by irradiation with an infrared lamp to obtain the electrodeposition solution. High entropy alloy catalyst;

The electrodeposition solution includes metal salts, and the metal salts include CuSO ₄ with a concentration of 0.3 mol/L, ZnSO 4 with a concentration of 0.3 mol/L, MgSO ₄ with a concentration of 0.1 mol/L, and MgSO ₄ with a concentration of 0.3 mol/L. L of Ti(SO ₄ ) ₂ and Na ₂ WO ₄ with a concentration of 0.3 mol/L.

Example 4

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. The metal elements in the high-entropy alloy catalyst include any five of Zn, Mg, Ti, W and Mo;

The preparation method of the high-entropy alloy catalyst is:

Mix the metal salt and water to obtain a preliminary mixed liquid, mix the obtained preliminary mixed liquid with boric acid with a concentration of 0.5 mol/L and sodium citrate with a concentration of 0.5 mol/L to obtain a remixed liquid, and then use sodium hydroxide to adjust the remixed liquid to The pH is 10, and the electrodeposition solution is obtained; the woven nickel mesh is placed in the electrodeposition solution, and electrodeposition is performed for 7200s at a potential of -0.6V. After washing with water, it is dried by vacuum drying to obtain the result. The high entropy alloy catalyst;

The electrodeposition solution includes metal salts, and the metal salts include Zn(NO ₃ ) ₂ with a concentration of 0.01 mol/L, Mg(NO 3 ) 2 with a concentration of 0.01 mol/L, and Zn(NO ₃ ) ₂ with a concentration of 0.01 mol/L. TiCl ₄ , Na ₂ WO ₂ Cl ₄ with a concentration of 0.01 mol/L, and Na ₂ MoO ₄ with a concentration of 0.01 mol/L.

Example 5

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. The metal elements in the high-entropy alloy catalyst include Fe, Ni, Zn, Mg and Ti;

The preparation method of the high-entropy alloy catalyst is:

Mix the metal salt and water to obtain a preliminary mixed liquid, mix the obtained preliminary mixed liquid with boric acid with a concentration of 2 mol/L and sodium citrate with a concentration of 0.1 mol/L to obtain a remixed liquid, and then use nitric acid to adjust the remixed liquid to a pH of 5 , to obtain the electrodeposition solution; place the carbon paper in the electrodeposition solution, perform electrodeposition for 100s at a potential of -2V, wash with ethanol, and then dry by irradiation with an infrared lamp to obtain the high-entropy alloy catalyst ;

The electrodeposition solution includes metal salts, and the metal salts include FeSO ₄ with a concentration of 0.5 mol/L, Ni(NO ₃ ) ₂ with a concentration of 0.5 mol/L, ZnSO ₄ with a concentration of 0.5 mol/L, and The concentration of Mg(NO ₃ ) ₂ is 0.5 mol/L and the concentration of Ti(SO ₄ ) ₂ is 0.5 mol/L.

Example 6

This embodiment provides a high-entropy alloy catalyst for alkaline electrolysis of water for hydrogen production, except that the metal salt includes FeSO ₄ with a concentration of 0.45 mol/L, that is, the metal salt in the electrodeposition solution includes FeSO 4 _4. Except that the concentration difference with other salts is higher than 0.3 mol/L, the rest are the same as Example 1.

Example 7

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water, except that the metal salt includes FeSO ₄ with a concentration of 0.005 mol/L, NiSO 4 with a concentration of 0.005 mol/L, and NiSO ₄ with a concentration of 0.005 mol/L. Except for CoSO ₄ in mol/L, MnSO ₄ in concentration 0.005 mol/L, and CuSO ₄ in concentration 0.005 mol/L, the rest are the same as in Example 1.

Example 8

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water, except that the metal salt includes FeSO _{4 with a concentration of 0.6 mol/L, NiSO 4} with a concentration of 0.6 mol/L, and NiSO ₄ with a concentration of 0.6 mol/L. Except for CoSO ₄ at mol/L, MnSO ₄ at a concentration of 0.6 mol/L, and CuSO ₄ at a concentration of 0.6 mol/L, the rest are the same as in Example 1.

Example 9

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. Except that the concentration of boric acid is 0.3 mol/L, the rest are the same as in Example 1.

Example 10

This embodiment provides a high-entropy alloy catalyst for alkaline electrolysis of water to produce hydrogen. Except that the concentration of boric acid is 2.5 mol/L, the rest are the same as in Example 1.

Example 11

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. Except that the concentration of sodium citrate is 0.05 mol/L, the rest are the same as in Example 1.

Example 12

This embodiment provides a high-entropy alloy catalyst for hydrogen production by alkaline electrolysis of water. Except that the concentration of sodium citrate is 0.8 mol/L, the rest are the same as in Example 1.

Example 13

This embodiment provides a high-entropy alloy catalyst for alkaline electrolysis of water to produce hydrogen. The catalyst is the same as in Embodiment 1 except that electrodeposition is performed at a potential of -2.4V.

Example 14

This embodiment provides a high-entropy alloy catalyst for alkaline electrolysis of water to produce hydrogen. The catalyst is the same as in Embodiment 1 except that electrodeposition is performed at a potential of -0.2V.

Comparative example 1

This comparative example provides an alloy catalyst for hydrogen production by alkaline electrolysis of water, except that the FeSO ₄ included in the metal salt in the electrodeposition solution is omitted, that is, the high-entropy alloy catalyst only includes four types: Ni, Co, Mn and Cu. Except for the metal elements, the rest are the same as in Example 1.

Comparative example 2

This comparative example provides an alloy catalyst for hydrogen production by alkaline electrolysis of water, except that NiSO _{4 and} NiSO 4 included in the metal salts in the electrodeposition solution are omitted, that is, the high-entropy alloy catalyst only includes Fe, Co, Mn and Cu 4 Except for the metal elements, the rest are the same as in Example 1.

The high-entropy alloy catalyst in Example 1 was subjected to a transmission electron microscope test, and the TEM image of the high-entropy alloy catalyst in Example 1 was obtained as shown in Figure 1.

Conduct HER performance test, OER performance test, total hydrolysis performance test and stability test on the high-entropy alloy catalysts in Examples 1 to 14 and Comparative Examples 1 and 2;

The test methods of the HER performance test and OER performance test are as follows: pour 1 mol/L KOH solution as the electrolyte into a single-chamber electrolytic cell, and use a three-electrode system to perform the performance test. The working electrodes are Examples 1 to 14 and the pair. For the high-entropy alloy catalysts in proportions 1 and 2, the reference electrode is Hg/HgO and the counter electrode is a carbon rod. The HER and OER performance of the catalyst is tested by linear scan voltammetry. When the current density is 100mA/ ^cm2 , The HER overpotential and OER overpotential of the high-entropy alloy catalysts in Examples 1 to 14 and Comparative Examples 1 and 2 are shown in Table 1; the LSV curve of the OER of the high-entropy alloy catalyst in Example 1 is obtained by testing as shown in Figure 2 As shown, the LSV curve of HER is shown in Figure 3

The method for testing the total hydrolysis performance is: pour 1 mol/L KOH solution as the electrolyte into the H-type electrolytic cell, and the anode and cathode are the high-entropy alloy catalysts in Examples 1 to 14 and Comparative Examples 1 and 2, The total hydrolysis performance of the catalyst was evaluated by linear sweep voltammetry. When the current density was 100mA/ ^cm2 , the required voltage was shown in Table 1. The total hydrolysis performance of the high-entropy alloy catalyst in Example 1 was tested. The LSV curve is shown in Figure 4;

The method of the stability test is: under a high current density of 500mA/ ^cm2 , after continuous reaction for 1000h, the HER performance test, the OER performance test and the total hydrolysis performance test are performed again, and the obtained HER overpotential, OER overpotential and After setting the required voltage at a current density of 100mA/ ^cm2 , the calculated HER change rate, OER change rate and voltage change rate are shown in Table 2, where the change rate of HER overpotential = | HER overpotential after reaction - HER overpotential before reaction Potential | / HER overpotential before reaction; change rate of OER overpotential = | OER overpotential after reaction - OER overpotential before reaction | / OER overpotential before reaction; voltage change rate = | voltage after reaction - voltage before reaction | / Voltage before reaction;

Table 1

HER overpotential (mV) OER overpotential (mV) Voltage(V) Example 1 173 290 1.7 Example 2 183 292 1.72 Example 3 192 293 1.73 Example 4 187 293 1.75 Example 5 180 290 1.73 Example 6 199 310 1.79 Example 7 195 307 1.80 Example 8 193 293 1.75 Example 9 194 294 1.76 Example 10 191 293 1.74 Example 11 190 295 1.77 Example 12 196 300 1.75 Example 13 192 302 1.79 Example 14 198 301 1.82 Comparative example 1 220 325 1.9 Comparative example 2 215 330 1.88

Table 2

From Table 1 and Table 2 we can get:

(1) The high-entropy alloy catalyst provided in this application for hydrogen production by alkaline electrolysis of water shows a smaller HER overpotential and a smaller OER overpotential in the alkaline electrolysis of water for hydrogen production, at a current density of 100mA/ The total hydrolysis voltage required at cm ² is small, and the HER change rate, OER change rate and total hydrolysis voltage change rate after the continuous reaction with high current density are small;

(2) It can be seen from the comparison between Example 1 and Example 6 that the concentration difference between the salt with the highest concentration and the salt with the lowest concentration among the metal salts in the electrodeposition solution of the present invention will affect the performance of the high-entropy alloy catalyst; when the concentration difference When it is too large, it will cause the HER overpotential to become larger, the OER overpotential to become larger, and the total hydrolysis voltage to become larger. After the continuous reaction with high current density, the HER change rate will become larger, the OER change rate will become larger, and the total hydrolysis voltage will change. This is because when the concentration difference is too large, under the same electrodeposition time, the metal ion reduction amount of the salt with the lowest concentration becomes less, and its proportion in the alloy becomes lower, thus affecting the catalyst performance;

(3) It can be seen from the comparison between Example 1 and Examples 7 and 8 that the concentration of salts in the metal salts in the electrodeposition solution of the present invention will affect the performance of the high-entropy alloy catalyst; when the concentration of all the salts in the metal salts in the electrodeposition solution When the concentration is low, it will cause the HER overpotential to become larger and the OER overpotential to become larger. This is because when the concentration of all metal salts is low, under the same electrodeposition time, the amount of alloy reduced on the carrier is small, which affects the catalytic performance; When the concentration of all salts in the metal salts in the electrodeposition solution is high, it will cause the HER overpotential to become larger, the OER overpotential to change little, and the total hydrolysis voltage to become larger. This is because when the concentrations of all metal salts are high, the same electric potential will Under the deposition time, too much alloy is reduced on the support, hindering the performance of the catalyst;

(4) From the comparison between Example 1 and Examples 9 and 10, it can be seen that the concentration of the regulator in the present invention will affect the performance of the high-entropy alloy catalyst; when the concentration of the regulator in the electrodeposition solution is low, it will lead to HER overproduction. The potential becomes larger, the OER overpotential changes little and the total hydrolysis voltage becomes larger. This is because when the concentration of the regulator is low, the pH of the electrolyte changes during the electrodeposition process, which is not conducive to the synthesis of the catalyst; when the electrodeposition solution When the concentration of the medium regulator is too high, it will cause the HER overpotential to increase, the OER overpotential to change little, and the total hydrolysis voltage to increase. This is because when the concentration of the regulator is too high, crystals tend to precipitate, which is not conducive to the synthesis of the catalyst;

(5) From the comparison between Example 1 and Examples 11 and 12, it can be seen that the concentration of the stabilizer in the present invention will affect the performance of the high-entropy alloy catalyst; when the concentration of the stabilizer is low, it will cause the HER overpotential to become larger. The OER overpotential and the total hydrolysis voltage increase. This is due to the low concentration of the stabilizer, which causes the pH of the solution to change during the reduction process, which is not conducive to catalyst synthesis. When the concentration of the stabilizer is high, it will lead to the HER overpotential. becomes larger, the OER overpotential becomes larger, and the total hydrolysis voltage becomes larger. This is because when the stabilizer concentration is high, it hinders the reduction of metal ions;

(6) From the comparison between Example 1 and Examples 13 and 14, it can be seen that the voltage during electrodeposition in the present invention will affect the performance of the high-entropy alloy catalyst; when the voltage during electrodeposition is low, it will cause the HER overpotential to become larger. The OER overpotential becomes larger, the total hydrolysis voltage becomes larger, and after the continuous reaction with high current density, the HER change rate becomes larger, the OER change rate becomes larger, and the total hydrolysis voltage change rate becomes larger. This is due to the low electrodeposition voltage. At this time, some metal salt ions cannot be reduced, resulting in the resulting alloy not being a high-entropy alloy, and thus the catalytic performance is unstable; when the voltage during electrodeposition is high, it will cause the HER overpotential to become larger and the OER overpotential to change little. The total hydrolysis voltage becomes larger. This is because when the electrodeposition voltage is high, a large amount of alloy is reduced on the carrier under the same deposition time, thus inhibiting the overall performance of the catalyst;

(7) From the comparison between Example 1 and Comparative Examples 1 and 2, it can be seen that the high-entropy alloy catalyst provided in the present invention requires a low electrolysis voltage in the reaction of alkaline electrolysis of water to produce hydrogen, and has High stability. Under high current density (500-1000mA/cm ² ), after continuous reaction for 1000 hours, the catalytic performance of the high-entropy alloy catalyst does not decrease significantly; at the same time, the raw materials of the high-entropy alloy catalyst are easily available and affordable. It is cheap, so the high-entropy alloy catalyst also has the advantage of low preparation cost.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the technical field should understand that any person skilled in the technical field, within the technical scope disclosed in the present invention, Changes or substitutions that can be easily imagined fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. A high-entropy alloy catalyst for hydrogen production by alkaline water electrolysis, which is characterized in that metal elements in the high-entropy alloy catalyst comprise any five of Fe, ni, co, mn, cu, zn, mg, ti, W or Mo.

2. A method of preparing the high entropy alloy catalyst of claim 1, comprising:

placing a carrier in an electrodeposition solution, and obtaining the high-entropy alloy catalyst through electrodeposition;

the electrodeposition solution includes a metal salt including any five of a Fe salt, a Ni salt, a Co salt, a Mn salt, a Cu salt, a Zn salt, a Mg salt, a Ti salt, a W salt, or a Mo salt.

3. The method according to claim 2, wherein the difference between the highest and lowest values of the concentrations of the five salts included in the metal salt in the electrodeposition solution is not more than 0.3mol/L;

the concentration of Fe salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Ni salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Co salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Mn salt in the electrodeposition solution is 0.01 to 0.5mol/L;

preferably, the concentration of Cu salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Zn salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Mg salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Ti salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of W salt in the electrodeposition solution is 0.01-0.5 mol/L;

preferably, the concentration of Mo salt in the electrodeposition solution is 0.01 to 0.5mol/L.

4. A method according to claim 2 or 3, wherein the Fe salt comprises FeSO ₄ 、FeCl ₂ Or Fe (NO) ₃ ) ₂ Any one or a combination of at least two of the following;

preferably, the Ni salt comprises NiSO ₄ 、NiCl ₂ Or Ni (NO) ₃ ) ₂ Any one or a combination of at least two of the following;

preferably, the Co salt comprises CoSO ₄ 、CoCl ₂ Or Co (NO) ₃ ) ₂ Any one or a combination of at least two of the following;

preferably, the Mn salt comprises MnSO ₄ 、MnCl ₂ Or Mn (NO) ₃ ) ₂ Any one or a combination of at least two of the following;

preferably, the Cu salt comprises CuSO ₄ 、CuCl ₂ Or Cu (NO) ₃ ) ₂ Any one or a combination of at least two of the following;

preferably, the Zn salt comprises ZnSO ₄ 、ZnCl ₂ Or Zn (NO) ₃ ) ₂ Any one or a combination of at least two of them；

Preferably, the Mg salt comprises MgSO ₄ 、MgCl ₂ Or Mg (NO) ₃ ) ₂ Any one or a combination of at least two of the following;

preferably, the Ti salt comprises Ti (SO ₄ ) ₂ 、TiCl ₄ Or TiO (acac) ₂ Any one or a combination of at least two of the following;

preferably, the W salt comprises Na ₂ WO ₄ 、(NH ₄ ) ₂ WO ₂ Cl ₄ 、Na ₂ WO ₂ Cl ₄ Any one or a combination of at least two of the following;

preferably, the Mo salt comprises Na ₂ MoO ₄ 、(NH ₄ ) ₆ Mo ₇ O ₂₄ Or (NH) ₄ ) ₂ MoOCl ₅ Any one or a combination of at least two of these.

5. The method according to any one of claims 2 to 4, wherein the carrier comprises any one of conductive glass, foamed nickel, carbon paper, carbon cloth, or woven nickel mesh.

6. The method of any one of claims 2 to 5, wherein the method of preparing the electrodeposition solution comprises:

mixing the metal salt with a solvent to obtain a primary mixed solution, mixing the primary mixed solution with a regulator and a stabilizer to obtain a remixed solution, and regulating the remixed solution to a set pH value by using acid and/or alkali to obtain the electrodeposition solution.

7. The method of preparation of claim 6, wherein the solvent comprises water;

preferably, the modifier comprises any one or a combination of at least two of boric acid, silicic acid or acetic acid;

preferably, the concentration of the regulator in the electrodeposition solution is 0.5-2 mol/L;

preferably, the stabilizer comprises any one or a combination of at least two of sodium citrate and/or potassium citrate;

preferably, the concentration of the stabilizer in the electrodeposition solution is 0.1 to 0.5mol/L;

preferably, the acid comprises any one or a combination of at least two of sulfuric acid, hydrochloric acid or nitric acid;

preferably, the base comprises any one or a combination of at least two of sodium hydroxide and/or potassium hydroxide;

preferably, the set pH is 2 to 10.

8. The method of any one of claims 2 to 7, wherein the electrodeposition comprises constant current electrodeposition, constant voltage electrodeposition, or pulsed voltage electrodeposition;

preferably, the electric potential of the electrodeposition is-0.6 to-2V for 100 to 7200s;

preferably, the pulse voltage electrodeposition is performed at an interval of 1 to 10 seconds.

9. The production method according to any one of claims 2 to 8, characterized in that the production method further comprises washing and drying performed sequentially after the electrodeposition;

preferably, the solution used for the washing comprises water and/or ethanol;

preferably, the drying method comprises infrared lamp irradiation or vacuum drying.

10. The production method according to any one of claims 2 to 9, characterized in that the production method comprises:

mixing the metal salt with water to obtain a primary mixed solution, mixing the primary mixed solution with a regulator with the concentration of 0.5-2 mol/L and a stabilizer with the concentration of 0.1-0.5 mol/L to obtain a remixed solution, and regulating the remixed solution to pH value of 2-10 by using acid and/or alkali to obtain the electrodeposition solution; placing any one of conductive glass, foam nickel, carbon paper, carbon cloth or woven nickel screen into an electrodeposition solution, performing electrodeposition for 100-7200 s at a potential of-0.6V to-2V, washing with water and/or ethanol, and drying by irradiation of an infrared lamp or vacuum drying to obtain the high-entropy alloy catalyst;

the electrodeposition solution includes a metal salt including any five of an Fe salt having a concentration of 0.01 to 0.5mol/L, a Ni salt having a concentration of 0.01 to 0.5mol/L, a Co salt having a concentration of 0.01 to 0.5mol/L, an Mn salt having a concentration of 0.01 to 0.5mol/L, a Cu salt having a concentration of 0.01 to 0.5mol/L, a Zn salt having a concentration of 0.01 to 0.5mol/L, a Mg salt having a concentration of 0.01 to 0.5mol/L, a Ti salt having a concentration of 0.01 to 0.5mol/L, a W salt having a concentration of 0.01 to 0.5mol/L, or a Mo salt having a concentration of 0.01 to 0.5mol/L, and a difference between the highest concentration and the lowest concentration of the five salts included in the electrodeposition solution is not higher than 0.3mol/L.