Electrolytic media and acidic oxygen evolution non-precious metal manganese-based catalysts, processes and applications

Abstract

Electrolytic medium and acidic oxygen evolution non-precious metal manganese-based catalyst, process and application, belonging to the field of water electrolysis for hydrogen production; the preparation process includes the following steps: (1) dissolving the metal salt of M, the metal salt of Mn, sodium sulfate, sulfuric acid and sodium acetate in deionized water as the electrolyte; (2) using an electrochemical workstation at room temperature, using a three-electrode system to carry out the electrodeposition reaction, and loading the manganese-based component onto the conductive carrier; (3) washing the conductive carrier loaded with manganese-based component in deionized water and drying it; calcining the loaded manganese-based component in air at 300-500℃; the molar ratio between M and Mn is <1:5, and the metal manganese-based catalyst is manganese oxide M-MnO doped with metal elements. x When the molar ratio is ≥1:5, the manganese-based catalyst is manganese oxide (MO) coupled with a metal oxide. x / MnO x This solution addresses the shortcomings in the activity and stability of existing MnO2 catalysts used directly as excellent acidic oxygen evolution catalysts.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production by water electrolysis, and more particularly to an electrolysis medium and an acidic oxygen evolution non-precious metal manganese-based catalyst, process, and application. Background Technology

[0002] The rapid depletion of fossil fuels has triggered a global energy crisis, accompanied by a series of environmental pollution problems. Furthermore, the development of renewable and clean energy sources is urgently needed. Hydrogen (H2), as a fuel, produces only water as a combustion product, making it green and pollution-free, and is considered an ideal renewable green energy source to replace fossil fuels. Among the many current hydrogen production methods, water electrolysis (H2O → H2 + O2) shows great application potential due to its simple and clean process and high-purity hydrogen produced. Common water electrolysis methods include alkaline electrolyzers, proton exchange membrane electrolyzers, anion exchange membrane electrolyzers, and high-temperature solid oxide electrolyzers. Among these, proton exchange membrane electrolyzers offer several significant advantages, such as lower ohmic loss, higher H2 purity, higher current density, and simpler design, making them more suitable for large-scale industrial production. However, one of its main bottlenecks is the slow kinetics of the oxygen evolution reaction at the anode and the highly acidic environment, which greatly limits the development of efficient anode catalysts. Therefore, developing highly active and stable acidic oxygen evolution catalysts is crucial for accelerating the widespread use of proton exchange membrane electrolyzers for hydrogen production through water electrolysis, thereby alleviating the energy crisis.

[0003] The acidic oxygen evolution reaction (OER) is a complex four-electron reaction with sluggish kinetics, leading to excessively high overpotentials and reduced energy conversion efficiency. Highly active catalysts can effectively reduce the overpotential and accelerate the reaction kinetics. During the OER, the presence of a strongly acidic environment makes it difficult for non-noble metal catalysts to remain stable under anodic oxidation potentials and strong acidic conditions. Noble metal catalysts IrO2 and RuO2 have become widely used acidic OER catalysts due to their good activity and stability. However, the low abundance and high cost of Ir and Ru significantly hinder their widespread use. Currently, the highly efficient acidic OER catalysts reported in the literature are usually Ir / Ru-based noble metal catalysts. Therefore, designing and preparing high-performance and inexpensive non-noble metal acidic OER catalysts is of great significance for promoting hydrogen production through proton exchange membrane electrolyzers and represents a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to propose a preparation process for an acidic oxygen evolution non-precious metal manganese-based catalyst, which is used to prepare metal manganese-based catalysts. This preparation process is simple to operate, does not require high pressure or an oxygen-free environment, has low synthesis cost, is environmentally friendly, and is suitable for large-scale preparation.

[0005] The present invention also proposes an acidic oxygen evolution non-precious metal manganese-based catalyst, which is prepared by the above-described preparation process.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A process for preparing an acidic oxygen evolution non-noble metal manganese-based catalyst includes the following steps:

[0008] (1) Dissolve the metal salt of M, the metal salt of Mn, sodium sulfate, sulfuric acid and sodium acetate in deionized water to make an electrolyte;

[0009] The molar ratio between M and Mn is 1:(1-10), the molar ratio between sodium sulfate and Mn is (0.5-2):1, the molar amount of sulfuric acid is 0.05-0.15 times that of Mn, and the molar amount of sodium acetate is 0.1-3 times the total molar amount of M and Mn.

[0010] (2) At room temperature, using an electrochemical workstation, at a constant voltage of 0–2 V or 0.1–100 mA / cm². -2 The current density was measured, and an electrodeposition reaction was carried out using a three-electrode system comprising a working electrode, a counter electrode, and a reference electrode, with a manganese-based component loaded on a conductive carrier.

[0011] (3) The conductive support loaded with manganese-based components is washed with deionized water and dried; the manganese-based support is calcined in air at 300-500°C to obtain a metallic manganese-based catalyst.

[0012] The molar ratio of M to Mn is <1:5, and the manganese-based catalyst is manganese oxide M-MnO doped with metal elements. x ;

[0013] The molar ratio of M to Mn is ≥1:5, and the manganese-based catalyst is manganese oxide (MO) coupled with a metal oxide. x / MnO x .

[0014] Optimally, in step (1), M is one or more of Ni, Fe, Co, Mo, La, Cu, V, Ce, Ti, Pb, Cr, Y, Nb, Zr, Sb, Sn, Pb, Ca, Sr and Ba.

[0015] Optimally, in step (1), the metal salts of M and Mn are chlorides, nitrates, acetates, or sulfates or their hydrated salts.

[0016] Alternatively, the conductive carrier can be carbon cloth, carbon paper, ITO conductive glass, or FTO conductive glass.

[0017] An acidic oxygen evolution non-precious metal manganese-based catalyst is prepared by the above-mentioned preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst.

[0018] An acidic electrolytic medium for producing hydrogen by water electrolysis, wherein the above-mentioned acidic oxygen evolution non-precious metal manganese-based catalyst is added.

[0019] The application of non-precious metal manganese-based catalysts in acidic oxygen evolution reaction (OER), wherein the non-precious metal manganese-based catalyst is prepared by the above-mentioned preparation process of an acidic OER non-precious metal manganese-based catalyst.

[0020] The application of non-precious metal manganese-based catalysts in the preparation of acidic electrolytic media for hydrogen production by water electrolysis, wherein the non-precious metal manganese-based catalysts are prepared by the above-mentioned preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst.

[0021] Compared with the prior art, one of the above technical solutions has the following beneficial effects:

[0022] This solution provides a preparation process for an acidic oxygen evolution non-precious metal manganese-based catalyst, which is used to prepare a metal manganese-based catalyst. The preparation process is simple to operate, does not require a high pressure or oxygen-free environment, has low synthesis cost, is environmentally friendly, and is suitable for large-scale preparation. It solves the problem of insufficient activity and stability of existing MnO2 as an excellent acidic oxygen evolution catalyst. Attached Figure Description

[0023] Figure 1 MnO before and after air calcination x Comparison of the acidic oxygen evolution performance of catalysts;

[0024] Figure 2 These are SEM images of the catalysts prepared in Examples 1-3;

[0025] Figure 3 It is MnO x and Ni-MnO x Graphs of the acidic oxygen evolution chronovoltaic stability test of the catalyst;

[0026] Figure 4 It is MnO x NiO x / MnO x and CoO x / MnO x X-ray diffraction pattern of the catalyst;

[0027] Figure 5 It is carbon cloth CC, MnO x CoO x NiO x NiO x / MnO xand CoO x / MnO x Acidic oxygen evolution polarization curve of the catalyst. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0029] To facilitate understanding of the present invention, a more comprehensive description is provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0030] A process for preparing an acidic oxygen evolution non-noble metal manganese-based catalyst includes the following steps:

[0031] (1) Dissolve the metal salt of M, the metal salt of Mn, sodium sulfate, sulfuric acid and sodium acetate in deionized water to make an electrolyte;

[0032] The molar ratio between M and Mn is 1:(1-10), the molar ratio between sodium sulfate and Mn is (0.5-2):1, the molar amount of sulfuric acid is 0.05-0.15 times that of Mn, and the molar amount of sodium acetate is 0.1-3 times the total molar amount of M and Mn.

[0033] (2) At room temperature, using an electrochemical workstation, at a constant voltage of 0–2 V (compared to a saturated calomel electrode) or 0.1–100 mA / cm². -2 The current density was measured, and an electrodeposition reaction was carried out using a three-electrode system comprising a working electrode, a counter electrode, and a reference electrode, with a manganese-based component loaded on a conductive carrier.

[0034] (3) The conductive support loaded with manganese-based components is washed with deionized water and dried at 50-70°C; the manganese-based support is calcined in air at 300-500°C to obtain a metallic manganese-based catalyst.

[0035] The molar ratio of M to Mn is <1:5, and the manganese-based catalyst is manganese oxide M-MnO doped with metal elements. x ;

[0036] When the molar ratio of M to Mn is <1:5, for example 1:1, 1:2, 1:3, or 1:4, step (3) mainly produces metal-doped manganese oxide (M-MnO). x ( ) metal manganese-based catalyst.

[0037] The molar ratio of M to Mn is ≥1:5, and the manganese-based catalyst is manganese oxide (MO) coupled with a metal oxide. x / MnO x .

[0038] When the molar ratio of M to Mn is ≥1:5, such as 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10, step (3) mainly produces manganese oxide (MO) coupled with metal oxides. x / MnO x ( ) metal manganese-based catalyst.

[0039] This solution provides a preparation process for an acidic oxygen evolution non-precious metal manganese-based catalyst, which is used to prepare a metal manganese-based catalyst. The preparation process is simple to operate, does not require a high pressure or oxygen-free environment, has low synthesis cost, is environmentally friendly, and is suitable for large-scale preparation. It solves the problem of insufficient activity and stability of existing MnO2 as an excellent acidic oxygen evolution catalyst.

[0040] Specifically, manganese oxide possesses multiple valence states and diverse crystal structures, exhibiting excellent electrocatalytic activity and stability in many electrochemical reactions. The Purbay diagram of the Mn-H2O system shows that MnO2 exhibits good acidic stability at the oxygen evolution potential, making it a promising alternative to IrO2 and RuO2 as an excellent acidic oxygen evolution catalyst. However, the activity and stability of MnO2 as a direct excellent acidic oxygen evolution catalyst still have shortcomings. To address this, this preparation process utilizes a simple electrodeposition and low-temperature air calcination method. Based on the molar ratio of M to Mn, additional components are introduced through heteroatom doping or interface engineering. The low-temperature air calcination strategy is then used to improve its crystallinity, enhancing the activity and stability of the manganese-based catalyst in the acidic oxygen evolution reaction. This manganese-based catalyst, used in the acidic oxygen evolution reaction, exhibits excellent activity and stability, showing great potential to replace the noble metals Ru and Ir. It can effectively reduce the cost of hydrogen production through proton exchange membrane electrolyzers and accelerate the promotion of this hydrogen production technology. The non-noble metal manganese-based catalyst prepared by this method exhibits significantly better activity and stability than single-component manganese oxide catalysts in the acidic oxygen evolution reaction (OER). x The addition of [a specific ingredient] and the improvement of crystallinity effectively enhanced the acidic oxygen evolution activity and stability of the catalyst.

[0041] Optimally, in step (1), M is one or more of Ni, Fe, Co, Mo, La, Cu, V, Ce, Ti, Pb, Cr, Y, Nb, Zr, Sb, Sn, Pb, Ca, Sr and Ba.

[0042] The manganese-based catalyst in this scheme is manganese oxide (M-MnO) doped with metal elements. x Manganese oxide (MO) coupled with metal oxides x / MnO x The doped or coupled M is a non-noble metal element such as Ni, Fe, Co, Mo, La, Cu, V, Ce, Ti, Pb, Cr, Y, Nb, Zr, Sb, Sn, Pb, Ca, Sr, Ba, etc.; it should be noted that MnO in this scheme x It is a general term for manganese oxide, where x represents the undefined number of oxygen atoms, and the actual number of M atoms is determined by pairing the metal valence with the number of oxygen atoms, MnO x In practice, it can be a mixture of one or more manganese oxides such as MnO2, Mn2O3, or Mn3O4.

[0043] Optimally, in step (1), the metal salts of M and Mn are chlorides, nitrates, acetates, or sulfates or their hydrated salts.

[0044] The metal salts of M and Mn can be divalent or trivalent chlorides, nitrates, acetates, or sulfates, or they can be hydrated salts of chlorides, nitrates, acetates, or sulfates; hydrated salts refer to the inorganic salts mentioned above that combine with water molecules to form stable compounds.

[0045] Alternatively, the conductive carrier can be carbon cloth, carbon paper, ITO conductive glass, or FTO conductive glass.

[0046] The counter electrode and reference electrode can be replaced by known electrodes, such as a carbon rod as the counter electrode and a saturated calomel electrode as the reference electrode. The conductive carrier is loaded with manganese-based components. The conductive carrier can be replaced by known conductive carriers, such as carbon cloth, carbon paper, ITO conductive glass, or FTO conductive glass. There are many types of conductive carriers to choose from, and the synthesis cost of the preparation process is low, making it suitable for large-scale preparation.

[0047] An acidic oxygen evolution non-precious metal manganese-based catalyst is prepared by the above-mentioned preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst.

[0048] An acidic electrolytic medium for producing hydrogen by water electrolysis, wherein the above-mentioned acidic oxygen evolution non-precious metal manganese-based catalyst is added.

[0049] The application of non-precious metal manganese-based catalysts in acidic oxygen evolution reaction (OER), wherein the non-precious metal manganese-based catalyst is prepared by the above-mentioned preparation process of an acidic OER non-precious metal manganese-based catalyst.

[0050] The application of non-precious metal manganese-based catalysts in the preparation of acidic electrolytic media for hydrogen production by water electrolysis, wherein the non-precious metal manganese-based catalysts are prepared by the above-mentioned preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst.

[0051] Example 1, Preparation of MnO x catalyst:

[0052] 1.23 g of Mn(Ac)₂·4H₂O and 0.71 g of Na₂SO₄ were dissolved in 50 mL of deionized water, and then 10 mL of 0.05 mol / L H₂SO₄ solution was added and stirred until homogeneous to form the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C. The carbon cloth and its loaded manganese-based component were calcined in air at 400 °C to obtain MnO. x catalyst.

[0053] Comparative Example 1, Preparation of MnO x catalyst:

[0054] 1.23 g of Mn(Ac)₂·4H₂O and 0.71 g of Na₂SO₄ were dissolved in 50 mL of deionized water, and then 10 mL of 0.05 mol / L H₂SO₄ solution was added and stirred until homogeneous to form the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C to obtain uncalcined MnO. x catalyst.

[0055] The stability of Example 1 and Comparative Example 1 underwent acidic oxygen evolution chronoamperometry (OER) testing: An electrochemical workstation was used in a three-electrode system. The electrolyte consisted of a solution of 0.005 mol / L H₂SO₄ and 0.5 mol / L Na₂SO₄. The carbon cloth, carbon rod, and saturated calomel electrode, supporting the manganese-based catalyst, served as the working electrode, counter electrode, and reference electrode, respectively. Reaction conditions: Polarization curves were obtained using linear sweep voltammetry at a scan rate of 5 mV / s. The reaction was carried out at 10 mA cm⁻¹. −2 The stability test was performed using the chronovoltammetry method, such as... Figure 1 (a) and Figure 1 (b). Among them, (a) MnO after air calcination x and uncalcined MnO x (a) Acidic oxygen evolution polarization curve of the catalyst; (b) MnO after air calcination x and uncalcined MnO x Stability test results of the catalyst under acidic oxygen evolution chronoamperometry at 1.55V (relative to the reversible hydrogen electrode).

[0056] Note: MnO prepared by air calcination in Example 1 x Uncalcined MnO prepared in Comparative Example 1 x Catalyst, which is at 10 mAcm -2 The required voltages are 1.605 V and 1.788 V (relative to the reversible hydrogen electrode), respectively, and the MnO calcined in air is 1.55 V (relative to the reversible hydrogen electrode). x The catalyst can operate stably for more than 24 hours in the acidic oxygen evolution reaction, but uncalcined MnO x The acidic oxygen evolution current density of the catalyst rapidly approaches 0. The results indicate that air calcination to increase crystallinity can effectively improve the crystallinity of MnO. x The acidic oxygen evolution activity and stability of the catalyst.

[0057] The following is a description of manganese oxide M-MnO doped with metal elements. x Manganese oxide MO coupled with metal oxide x / MnO x Furthermore, M is used as an example of Ni and Co for verification and illustration.

[0058] Example 2, Preparation of Ni-MnO x catalyst:

[0059] 1.23 g of Mn(Ac)₂·4H₂O and 0.71 g of Na₂SO₄ were dissolved in 50 mL of deionized water, followed by the addition of 10 mL of 0.05 mol / L H₂SO₄ solution, then 0.62 g of Ni(Ac)₂·4H₂O and 0.41 g of NaAc. The mixture was stirred until homogeneous and used as the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C. The carbon cloth and its loaded manganese-based component were calcined in air at 400 °C to obtain Ni-MnO. x catalyst.

[0060] Ni-MnO from Example 2 x Catalyst and MnO from Example 1 xCatalyst at 10 mA cm −2 The stability test was performed using the chronovoltammetry method, and the results are as follows: Figure 3 As shown.

[0061] illustrate:

[0062] like Figure 3 Ni-MnO in Example 2 x 10 mAcm -2 A voltage of 1.518 V (relative to the reversible hydrogen electrode) is required, and at 10 mAcm -2 The MnO in Example 1 operated stably for 48 hours under the acidic oxygen evolution current density, indicating good stability; however, the MnO in Example 1... x Its voltage increased rapidly after 24 hours, indicating that its stability was not good enough.

[0063] Example 3, Preparation of Co-MnO x catalyst:

[0064] 1.23 g of Mn(Ac)₂·4H₂O and 0.71 g of Na₂SO₄ were dissolved in 50 mL of deionized water, followed by the addition of 10 mL of 0.05 mol / L H₂SO₄ solution, then 0.62 g of Co(Ac)₂·4H₂O and 0.41 g of NaAc. The mixture was stirred until homogeneous and used as the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C. The carbon cloth and its loaded manganese-based component were calcined in air at 400 °C to obtain Co-MnO. x catalyst.

[0065] The catalysts of Examples 1, 2, and 3 were scanned using a scanning electron microscope (SEM) to obtain SEM images; the MnO in Example 1 was also examined. x Catalysts such as Figure 2 (a)-(c); Ni-MnO of Example 2 x Catalysts such as Figure 2 (d)-(f); Co-MnO of Example 3 x Catalysts such as Figure 2 in (g)-(i).

[0066] Note: By Figure 2 It can be seen that MnO x Ni-MnO x and Co-MnO x The catalyst is uniformly grown on the surface of carbon cloth fiber, and its morphology is similar to that of a corn cob.

[0067] Example 4, Preparation of NiO x / MnO x catalyst:

[0068] 3.68 g of Mn(Ac)₂·4H₂O and 2.13 g of Na₂SO₄ were dissolved in 50 mL of deionized water, followed by the addition of 10 mL of 0.15 mol / L H₂SO₄ solution, then 0.62 g of Ni(Ac)₂·4H₂O and 1.44 g of NaAc. The mixture was stirred until homogeneous and used as the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C. The carbon cloth and its loaded manganese-based component were calcined in air at 400 °C to obtain NiO. x / MnO x catalyst.

[0069] Example 5, Preparation of CoO x / MnO x catalyst:

[0070] 3.68 g of Mn(Ac)₂·4H₂O and 2.13 g of Na₂SO₄ were dissolved in 50 mL of deionized water, followed by the addition of 10 mL of 0.15 mol / L H₂SO₄ solution, then 0.62 g of Co(Ac)₂·4H₂O and 1.44 g of NaAc. The mixture was stirred until homogeneous and used as the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C. The carbon cloth and its loaded manganese-based component were calcined in air at 400 °C to obtain CoO. x / MnO x catalyst.

[0071] Comparative Example 2, Preparation of MnO x catalyst:

[0072] 1.23 g of Mn(Ac)₂·4H₂O and 0.71 g of Na₂SO₄ were dissolved in 50 mL of deionized water, and then 10 mL of 0.05 mol / L H₂SO₄ solution was added and stirred until homogeneous to form the electrolyte. Electrodeposition was performed using a three-electrode system, with carbon cloth as the working electrode, a carbon rod as the counter electrode, and a saturated calomel electrode as the reference electrode. The reaction was carried out at 1.5 V (relative to the saturated calomel electrode) for 2700 seconds. Subsequently, the carbon cloth was washed with deionized water and dried at 60 °C. The carbon cloth and its loaded manganese-based component were calcined in air at 400 °C to obtain MnO. x catalyst.

[0073] ①The NiO from Example 4 x / MnO x Catalyst, CoO from Example 5 x / MnO x Catalyst, MnO (Comparative Example 2) x The catalyst was subjected to X-ray diffraction experiments to obtain X-ray diffraction patterns, such as... Figure 4 .

[0074] ② Stability test by chronoamperometry of acidic oxygen evolution reaction: An electrochemical workstation was used in a three-electrode system. The electrolyte was a solution composed of 0.005 mol / L H₂SO₄ and 0.5 mol / L Na₂SO₄. The carbon cloth, carbon rod, and saturated calomel electrode supporting the manganese-based catalyst were used as the working electrode, counter electrode, and reference electrode, respectively. Reaction conditions: Polarization curves were obtained using linear sweep voltammetry at a scan rate of 5 mV / s, at a reaction temperature of 10 mA cm⁻¹. −2 The stability test was performed using the chronovoltammetry method. Figure 5 Carbon cloth CC, MnO x CoO x NiO x NiO x / MnO x and CoO x / MnO x Acidic oxygen evolution polarization curve of the catalyst;

[0075] illustrate:

[0076] As shown in Figure 4, Figure 4 Diffraction peaks of MnO2 (PDF#23-1046) were observed, but no CoO was found. x The presence of diffraction peaks in NiOx indicates that the amorphous structure lacks long-range ordered crystal structure. The atomic arrangement exhibits short-range order but long-range disorder, thus failing to produce obvious diffraction peaks, suggesting that MnO... x The main component is MnO2, while CoO xand NiO x It mainly exhibits an amorphous structure.

[0077] Depend on Figure 5 It can be seen that the coupling of NiO x and CoO x MnO after composition x Catalyst, compared to single-component NiO x CoO x and MnO x The catalyst exhibits higher acidic oxygen evolution activity. The results indicate that the NiO coupled catalyst... x and CoO x It can effectively improve the acidic oxygen evolution activity and stability of manganese oxide catalysts, among which NiO x / MnO x CoO x / MnO x It has better acidic oxygen evolution performance.

[0078] In summary, this scheme can enhance the activity and stability of manganese-based catalysts in the acidic oxygen evolution reaction (OER). The manganese-based catalyst exhibits excellent activity and stability in the OER and has great potential to replace noble metals Ru and Ir. It can effectively reduce the cost of hydrogen production by proton exchange membrane electrolyzers and accelerate the promotion of this hydrogen production technology.

[0079] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A preparation process for an acidic oxygen evolution non-noble metal manganese-based catalyst, characterized in that, Includes the following steps: (1) Dissolve the metal salt of M, the metal salt of Mn, sodium sulfate, sulfuric acid and sodium acetate in deionized water to make an electrolyte; Wherein, the molar ratio between M and Mn is 1:(1-10), the molar ratio between sodium sulfate and Mn is (0.5-2):1, the molar amount of sulfuric acid is 0.05-0.15 times that of Mn, and the molar amount of sodium acetate is 0.1-3 times the total molar amount of M and Mn; M is Ni or Co; the metal salts of M and Mn are chlorides, nitrates, acetates, sulfates, or their hydrated salts; (2) at room temperature, using an electrochemical workstation, at a constant voltage of 0 ~ 2 V or a current density of 0.1 ~ 100 mAcm -2 , the three electrode system including working electrode, counter electrode and reference electrode is used to carry out electrodeposition reaction, and the conductive carrier is loaded with manganese-based components; (3) The conductive support loaded with manganese-based components is washed with deionized water and dried; the manganese-based support is calcined in air at 300-500°C to obtain a metallic manganese-based catalyst. The molar ratio of M to Mn is <1:5, and the manganese-based catalyst is manganese oxide M-MnO doped with metal elements. x ; The molar ratio of M to Mn is ≥1:5, and the manganese-based catalyst is manganese oxide (MO) coupled with a metal oxide. x / MnO x .

2. The preparation process of an acidic oxygen evolution non-noble metal manganese-based catalyst according to claim 1, characterized in that, The conductive carrier is carbon cloth, carbon paper, ITO conductive glass or FTO conductive glass.

3. An acidic oxygen evolution non-precious metal manganese-based catalyst, characterized in that, It is prepared by the preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst according to any one of claims 1-2.

4. An acidic electrolytic medium for producing hydrogen by electrolysis of water, characterized in that, Add the acidic oxygen evolution non-precious metal manganese-based catalyst as described in claim 3.

5. The application of non-precious metal manganese-based catalysts in acidic oxygen evolution reactions, characterized in that, The non-precious metal manganese-based catalyst is prepared by the preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst according to any one of claims 1-2.

6. The application of non-precious metal manganese-based catalysts in the preparation of acidic electrolytic media for hydrogen production by water electrolysis, characterized in that, The non-precious metal manganese-based catalyst is prepared by the preparation process of an acidic oxygen evolution non-precious metal manganese-based catalyst according to any one of claims 1-2.

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