Ir-mn-based composite catalyst, preparation method and application thereof
Patent Information
- Application Number
- CN202311058504.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-21
- Publication Date
- 2026-09-11
- Estimated Expiration
- 2043-08-21
AI Technical Summary
然而，含有贵金属的催化剂的广泛应用受到地壳储量稀缺带来的高成本问题的限制
[0004] This invention aims to at least partially address one of the technical problems in related technologies. To this end, embodiments of this invention propose an Ir-Mn-based composite catalyst, its preparation method, and its application.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalyst preparation and electrocatalysis technology. Specifically, this invention relates to an Ir-Mn based composite catalyst, its preparation method, and its application. Background Technology
[0002] Over the past few decades, hydrogen energy has been considered one of the most important clean energy sources to replace conventional fossil fuels. As a direct and economical source of hydrogen, water splitting involves two half-reactions with different mechanisms: the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode, making it a key focus of research in the renewable energy field. Despite significant progress in developing novel HER and OER processes, achieving catalyst compatibility with the anode and cathode remains quite challenging due to dissolution and redeposition issues, which can affect the overall water splitting performance of the catalyst. Currently, noble metal-based electrodes (such as platinum cathodes and Ru / Ir oxide electrodes) exhibit high HER and OER activity due to their favorable binding energies to key intermediates. However, the widespread application of noble metal-containing catalysts is limited by the high cost resulting from the scarcity of crustal reserves.
[0003] Therefore, developing universal catalysts with low precious metal content has important practical significance. Summary of the Invention
[0004] This invention aims to at least partially address one of the technical problems in related technologies. To this end, embodiments of this invention propose an Ir-Mn-based composite catalyst, its preparation method, and its application.
[0005] In a first aspect, embodiments of the present invention provide an Ir-Mn-based composite catalyst, the Ir-Mn-based composite catalyst comprising: a substrate and manganese atoms and iridium atoms deposited on the substrate; wherein the substrate is a polyhexamethylene benzo[a]kJ network material.
[0006] Polyhexamethylene benzo[a]methyl ether (PCB) network material is an amorphous carbon material. In this invention, manganese and iridium atoms are deposited on a PCB network substrate. The C atoms on the PCB network can gain additional electrons from the Ir atoms, while the incorporated Mn atoms optimize the charge structure of the Ir atoms, forming a strong C-Ir-Mn interaction. This interaction further increases the charge density of Ir, resulting in an Ir-Mn-based composite catalyst with excellent electrocatalytic performance. Furthermore, by doping with Mn atoms, the amount of precious metal Ir used can be reduced, lowering production costs and providing guidance for designing high-performance, highly stable, and inexpensive next-generation commercial catalysts.
[0007] In some embodiments, the polyhexamethylene benzo[a]coral network material has a hexagonal porous structure.
[0008] In some embodiments, the polyhexamethylenetetramine network material is prepared by a method comprising the following steps:
[0009] S1, after drying hexa(4-bromophenyl)benzene, it was dissolved in dehydrated N,N-dimethylformamide along with 2,2-bipyridine. Then, bis(1,5-cyclooctadiene)nickel(0) and 1,5-cyclooctadiene were added, and the mixture was heated to react. After the reaction was completed, concentrated hydrochloric acid was added to the mixture, and the residue was filtered. The residue was washed successively with methanol, tetrahydrofuran, and water, and then dried under vacuum to obtain the intermediate.
[0010] S2, add dichloromethane and ferric chloride solution to the intermediate, stir and react, add methanol and filter, then wash and dry the filter residue with methanol and tetrahydrofuran in sequence; then mix the filter residue with nitric acid and sonicate, then wash with water until the mixture is neutral;
[0011] S3, the water-washed mixture is filtered and dried under reduced pressure to obtain the polyhexamethylenetetramine network material.
[0012] In some embodiments, in step S1, the heating reaction is carried out in a dark environment, the temperature of the heating reaction is 80-90°C, and the reaction time is 90-100 hours.
[0013] In some embodiments, in step S2, the temperature of the stirring reaction is room temperature, the stirring reaction time is 20-30 hours, and the ultrasonic treatment time is 1-5 hours.
[0014] Secondly, the present invention also proposes a method for preparing the above-mentioned Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing a manganese source, an iridium source and a polyhexamethylenetetramine network material, and then heating the mixture to obtain the Ir-Mn-based composite catalyst.
[0015] In this embodiment of the invention, Mn and Ir atoms were successfully deposited on a polyhexamethylene benzo[a]methyl ether network material by means of atomic layer deposition, thereby achieving atomic dispersion of Mn and Ir on the polyhexamethylene benzo[a]methyl ether network material to form a multi-atom structure; moreover, the preparation method is simple, easy to operate, and has good repeatability, making it suitable for large-scale industrial production.
[0016] In some embodiments, the heating reaction is carried out in an inert gas atmosphere, the inert gas including at least one of argon, nitrogen, and helium;
[0017] Furthermore, the reaction temperature of the heating reaction is 250–350°C, and the reaction time is 5–10 h.
[0018] In some embodiments, the mass ratio of the manganese source, the iridium source and the polyhexamethylenetetramine network material is (1-3):(1-3):(10-15).
[0019] In some embodiments, the manganese source is manganese pentacarbonyl bromide; the iridium source is iridium tricarbonyl chloride.
[0020] Thirdly, the embodiments of the present invention also propose the application of the above-mentioned Ir-Mn-based composite catalyst in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). When the Ir-Mn-based composite catalyst is used in the OER and HER reactions, it not only exhibits high OER and HER activities but also excellent durability, showing great application potential in the field of hydrogen energy research. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the structure of the Ir-Mn-based composite catalyst in an embodiment of the present invention.
[0022] Figure 2 This is an elemental distribution diagram of the Ir-Mn-based composite catalyst prepared in Example 1 of the present invention.
[0023] Figure 3 The graph shows the electrocatalytic hydrogen evolution (HER) performance test results of various catalysts under acidic conditions.
[0024] Figure 4 Under acidic conditions, the Ir-Mn-based composite catalyst prepared in Example 1 of this invention operates at 10 mA / cm². 2 LSV curve at current density.
[0025] Figure 5 The graph shows the electrocatalytic oxygen evolution (OER) performance test results of various catalysts under alkaline conditions.
[0026] Figure 6 Under alkaline conditions, the Ir-Mn-based composite catalyst prepared in Example 1 of this invention operates at 10 mA / cm². 2 LSV curve at current density.
[0027] Figure 7 The graph shows the performance of the full-cell Ir-Mn@PBN||Ir-Mn@PBN and the commercial full-cell Pt / C|IrO2 electrolysis of water in this embodiment of the invention.
[0028] Figure 8 The graph shows the stability test results of the full-cell Ir-Mn@PBN||Ir-Mn@PBN and the commercial full-cell Pt / C|IrO2 in this embodiment of the invention. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of the present invention.
[0030] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0031] In this document, when values are described as ranges, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as the specific numerical values falling within that range, regardless of whether the specific numerical value or specific subrange is explicitly specified.
[0032] In this article, the words “contain” and “include” and their various variations mean that other elements or wholes may be included but not specifically described.
[0033] In a first aspect, embodiments of the present invention provide an Ir-Mn-based composite catalyst, which comprises: a substrate and manganese atoms and iridium atoms deposited on the substrate; wherein the substrate is a polyhexamethylene benzo[a]kJ network material.
[0034] Figure 1 This is a schematic diagram of the structure of the Ir-Mn based composite catalyst in an embodiment of the present invention. As can be seen from the figure, Mn atoms and Ir atoms are deposited on the polyhexabenzo[a]benzo[a]carbonyl network material, and one Mn atom is located in the middle and two Ir atoms are located on both sides of the Mn atom in a triangular arrangement within the carbon defect of the polyhexabenzo[a]benzo[a]carbonyl network material.
[0035] This invention utilizes a polyhexamethylene benzo[a]methyl ether (PHE) network as a substrate, depositing Mn and Ir atoms onto the substrate to achieve atomic-level dispersion of Mn and Ir on the PHE network, forming a multi-atom structure. Specifically, the C atoms on the PHE network can gain additional electrons from the Ir atoms, while the incorporated Mn atoms optimize the charge structure of the Ir atoms, forming a strong C-Ir-Mn interaction. This interaction further increases the charge density of Ir, resulting in an Ir-Mn-based composite catalyst that exhibits not only high OER and HER activities but also excellent durability. Furthermore, by doping with Mn atoms, the amount of precious metal Ir used can be reduced, lowering production costs and providing a new approach for designing high-performance, highly stable, and inexpensive next-generation commercial catalysts.
[0036] In some specific embodiments, the polyhexamethylene benzo[a]coral network material has a hexagonal porous structure.
[0037] In some specific embodiments, the polyhexabenzo[a]chloroform network material is prepared by a method comprising the following steps:
[0038] S1, after drying hexa(4-bromophenyl)benzene, it was dissolved in dehydrated N,N-dimethylformamide along with 2,2-bipyridine. Then, bis(1,5-cyclooctadiene)nickel(0) and 1,5-cyclooctadiene were added, and the mixture was heated to react. After the reaction was completed, concentrated hydrochloric acid was added to the mixture, and the residue was filtered. The residue was washed successively with methanol, tetrahydrofuran, and water, and then dried under vacuum to obtain the intermediate.
[0039] S2, add dichloromethane and ferric chloride solution to the intermediate, stir and react, add methanol and filter, then wash and dry the filter residue with methanol and tetrahydrofuran in sequence; then mix the filter residue with nitric acid and sonicate, then wash with water until the mixture is neutral;
[0040] S3. The mixture after washing with water is filtered and dried under reduced pressure to obtain polyhexamethylenetetramine network material.
[0041] In some specific embodiments, in step S1, the heating reaction is carried out in a dark environment, and the heating reaction temperature is 80-90°C, such as 80°C, 85°C, 88°C, 90°C, etc.; the reaction time is 90-100h, such as 90h, 92h, 95h, 100h, etc.
[0042] In some specific embodiments, in step S2, the stirring reaction temperature is room temperature, and the stirring reaction time is 20-30 hours, with non-limiting examples such as 20 hours, 24 hours, 28 hours, 30 hours, etc.; the ultrasonic treatment time is 1-5 hours, with non-limiting examples such as 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, etc.
[0043] In the following specific examples and comparative examples, the polyhexabenzo[a]chloroform network materials were all prepared by a method including the following steps:
[0044] S1, First, hexa(4-bromophenyl)benzene was dried under vacuum at 120°C for 2 hours. Then, the dried hexa(4-bromophenyl)benzene (2.1 g, mmol.) and 2,2-bipyridine (2.56 g, 16.4 mmol.) were dissolved in dehydrated N,N-dimethylformamide (300 mL). Then, bis(1,5-cyclooctadiene)nickel (0) (5.00 g, 40.9 mmol) and 1,5-cyclooctadiene (1.6 mL, 12.7 mmol) were added. The mixture quickly turned dark purple. Then, the flask containing the mixture was rapidly evacuated and refilled three times. The mixture was then heated at 85°C for 96 hours in the dark. After the reaction was completed, the mixture was cooled to room temperature. Concentrated hydrochloric acid (50 mL) was added to the mixture. The residue was filtered and washed successively with methanol (30 × 5 mL), tetrahydrofuran (30 × 5 mL), and water (30 × 5 mL). After vacuum drying, a grayish-white intermediate (452 mg, yield 85%) was obtained.
[0045] S2, add dichloroform (400 mL) and ferric chloride solution (3.6 g, 22.4 mmol) to the intermediate (758 mg), quickly disperse the mixture in the flask, and refill the flask three times. Then stir at room temperature for 24 h, add methanol, filter, and wash the filter residue with methanol and tetrahydrofuran in turn. Then dry in air. Mix the filter residue with 0.5 M nitric acid and sonicate for 2 h. Wash with water until the mixture is neutral.
[0046] S3. After washing the mixture with water, filter and dry it under reduced pressure to obtain a dark brown solid polyhexamethylenetetramine network material, denoted as PBN (242 mg, yield 93%).
[0047] Secondly, the present invention also proposes a method for preparing the above-mentioned Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing a manganese source, an iridium source and a polyhexabenzo[a]pyroxene]coarse network material, and then heating the mixture to obtain the Ir-Mn-based composite catalyst.
[0048] In some specific embodiments, the heating reaction is carried out in an inert gas atmosphere, including at least one of argon, nitrogen, and helium;
[0049] Furthermore, the reaction temperature of the heating reaction is 250–350°C, and non-limiting examples include 250°C, 280°C, 300°C, 350°C, etc.; the reaction time is 5–10 h, and non-limiting examples include 5 h, 6 h, 8 h, 10 h, etc.
[0050] In some specific embodiments, the mass ratio of manganese source, iridium source and polyhexamethylenetetramine network material is (1-3):(1-3):(10-15), and non-limiting examples include: 1:1:10, 1:1:15, 1:2:10, 2:2:15, 2:3:15, etc.
[0051] In some specific embodiments, the manganese source is manganese pentacarbonyl bromide; the iridium source is iridium tricarbonyl chloride.
[0052] Thirdly, the embodiments of the present invention also propose the application of the above-mentioned Ir-Mn-based composite catalyst in oxygen evolution reaction and hydrogen evolution reaction.
[0053] The following are non-limiting embodiments and comparative examples of the present invention. It should be noted that the schemes in the comparative examples are not prior art, but are only set up for comparison with the schemes in the embodiments, and are not intended to limit the present invention. Unless otherwise stated, all raw materials used in the embodiments and comparative examples are conventional commercially available products, or can be prepared by known methods.
[0054] Example 1
[0055] This embodiment provides a method for preparing an Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing 1 mg of pentacarbonyl manganese bromide, 1 mg of tricarbonyl iridium chloride and 10 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) evenly, and reacting at a constant temperature of 300°C for 6 h under an argon atmosphere to obtain the Ir-Mn-based composite catalyst, denoted as Ir-Mn@PBN(Ⅰ).
[0056] The elemental distribution of the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in this example was characterized by EDS using aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (ACHAADF-STEM). The results are as follows: Figure 2 As shown. From Figure 2 As can be seen, Mn atoms and Ir atoms are uniformly distributed on the polyhexamethylene benzo[a]pyroxene] network material (PBN) substrate, which indicates the potential bonding between Mn atoms and Ir atoms.
[0057] The structural parameters of the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in this embodiment were determined in detail by quantitative least squares EXAFS (X-ray absorption fine structure spectroscopy) fitting, and the results are shown in Table 1 and Table 2.
[0058] Table 1 shows the structural information of Ir extracted from EXAFS.
[0059]
[0060]
[0061] Table 2. Structural information of manganese extracted from EXAFS.
[0062]
[0063] The results in Tables 1 and 2 show that Mn and Ir are atomically dispersed on the polyhexamethylene benzo[a]pyrene (PBN) substrate, and the coordination numbers of Mn and Ir were accurately determined: there are 2.3 Ir atoms near Mn, and 1.2 Mn atoms around Ir. Figure 1 In the carbon defect of the polyhexabenzo[a]pyroxene network material (PBN), one Mn atom and two Ir atoms are arranged in a triangular pattern.
[0064] Example 2
[0065] This embodiment provides a method for preparing an Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing 1 mg of pentacarbonyl manganese bromide, 1 mg of tricarbonyl iridium chloride and 10 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) evenly, and reacting at a constant temperature of 250°C for 6 h under an argon atmosphere to obtain the Ir-Mn-based composite catalyst, denoted as Ir-Mn@PBN(II).
[0066] Example 3
[0067] This embodiment provides a method for preparing an Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing 1 mg of pentacarbonyl manganese bromide, 1 mg of tricarbonyl iridium chloride and 10 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) evenly, and reacting at a constant temperature of 350°C for 5 h under an argon atmosphere to obtain the Ir-Mn-based composite catalyst, denoted as Ir-Mn@PBN(III).
[0068] Example 4
[0069] This embodiment provides a method for preparing an Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing 1 mg of pentacarbonyl manganese bromide, 1 mg of tricarbonyl iridium chloride and 15 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) evenly, and reacting at a constant temperature of 280°C for 8 h under an argon atmosphere to obtain the Ir-Mn-based composite catalyst, denoted as Ir-Mn@PBN(IV).
[0070] Example 5
[0071] This embodiment provides a method for preparing an Ir-Mn-based composite catalyst, comprising the following steps: grinding and mixing 1 mg of pentacarbonyl manganese bromide, 1.5 mg of tricarbonyl iridium chloride and 10 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) evenly, and then reacting at a constant temperature of 300°C for 10 h under an argon atmosphere to obtain the Ir-Mn-based composite catalyst, denoted as Ir-Mn@PBN(V).
[0072] Comparative Example 1
[0073] This comparative example provides a method for preparing a Mn-based catalyst, comprising the following steps: grinding and mixing 1 mg of manganese pentacarbonyl bromide and 10 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) until uniform, and then reacting at a constant temperature of 300 °C for 6 h under an argon atmosphere to obtain the Mn-based catalyst, denoted as Mn@PBN.
[0074] Comparative Example 2
[0075] This comparative example provides a method for preparing an Ir-based catalyst, comprising the following steps: grinding and mixing 1 mg of iridium tricarbonyl chloride and 10 mg of polyhexamethylene benzo[a]pyroxene] network material (PBN) until uniform, and then reacting at a constant temperature of 300 °C for 6 h under an argon atmosphere to obtain the Ir-based catalyst, denoted as Ir@PBN.
[0076] The electrocatalytic performance of the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention, the Mn@PBN catalyst prepared in Comparative Example 1, the Ir@PBN catalyst prepared in Comparative Example 2, and some commercial catalysts were tested, as follows:
[0077] (1) HER performance test: In 0.5M H2SO4 electrolyte, with Ag / AgCl as the reference electrode and carbon rod as the counter electrode, the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention, the Mn@PBN catalyst prepared in Comparative Example 1, the Ir@PBN catalyst prepared in Comparative Example 2, and a separate polyhexamethylenetetramine network material (PBN) and commercial Pt / C were used as working electrodes, at a current density of 10mA / cm². 2 The electrocatalytic activity of the above catalyst for HER was tested under the specified conditions, and the results are as follows: Figure 3 As shown. From Figure 3 It can be seen from this that at 10mA / cm 2 At the specified current density, the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention has the lowest overpotential, which is only 11mV, thus indicating that it has superior HER electrocatalytic activity.
[0078] Figure 4 The Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention is used at 10 mA / cm 2 The LSV (linear sweep voltammetry) curves at current density show that the overpotentials before and after stabilization are essentially the same, indicating that the Ir-Mn@PBN(Ⅰ) composite catalyst possesses good stability. Furthermore, from... Figure 4As can be seen from the illustrations, the potential of the Ir-Mn@PBN(Ⅰ) composite catalyst remains basically unchanged after 100 h of HER reaction in a strong acid electrolyte, indicating that it has good durability.
[0079] (2) OER performance test: In 1M KOH electrolyte, with a platinum sheet as the counter electrode, mercury / mercury oxide as the reference electrode, and a glassy carbon electrode as the substrate, an OER test was conducted at a current density of 10 mA / cm². 2 Under the specified conditions, the OER performance of the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention, the Mn@PBN catalyst prepared in Comparative Example 1, the Ir@PBN catalyst prepared in Comparative Example 2, the commercial Ir / C catalyst, and the commercial IrO2 catalyst were tested respectively. The results are as follows: Figure 5 As shown. By Figure 5 It can be seen that when the current density is 10 mA / cm² 2 At that time, the Ir-Mn-based composite catalyst prepared in Example 1 of the present invention exhibited the best OER activity and the lowest overpotential (220mV).
[0080] Figure 6 The Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention is used at 10 mA / cm 2 LSV curves at current densities, with the inset showing the LSV at 10 mA / cm². 2 Long-term durability of Ir-Mn@PBN(Ⅰ) composite catalyst under current density. As shown in the figure, the potential difference change before and after the chronopotential method E test is small, indicating that the Ir-Mn@PBN(Ⅰ) composite catalyst has good overcurrent stability; and from... Figure 6 As can be seen from the illustration, the potential of the Ir-Mn@PBN(Ⅰ) composite catalyst remained at around 1.5V during continuous operation for 45 hours, further demonstrating its long-term durability.
[0081] (3) Electrolysis performance test: Using the Ir-Mn@PBN(Ⅰ) composite catalyst prepared in Example 1 of this invention as the anode and cathode, a (0.5M H2SO4)Ir-Mn@PBN||Ir-Mn@PBN(1M KOH) full cell was prepared, and the electrolysis performance was tested at a constant operating current density of 10mA / cm². 2 Under these conditions, a whole-scale water splitting test was performed, and the polarization curve of the entire water splitting process is as follows: Figure 7 As shown. From Figure 7 As can be seen from the above, the activity of the full cell prepared with the Ir-Mn@PBN(Ⅰ) composite catalyst in Example 1 of this invention is obviously better than that of the commercial (0.5M H2SO4)Pt / C||IrO2(1M KOH) full cell.
[0082] In addition, at a constant cathode current density of -10 mA / cm 2 The durability of the catalyst for water splitting was tested under the following conditions, and the results are as follows: Figure 8 As shown in the figure, compared with commercial Pt / C||IrO2 full cells, the Ir-Mn@PBN||Ir-Mn@PBN full cells prepared in this invention do not show any significant performance loss within 100 hours, demonstrating exceptional stability.
[0083] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0084] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. An Ir-Mn based composite catalyst, characterized in that, The Ir-Mn-based composite catalyst comprises: a substrate and manganese atoms and iridium atoms deposited on the substrate; wherein the substrate is a polyhexamethylene benzo[a]chloroform network material with a hexagonal porous structure; the manganese atoms and the iridium atoms are dispersed at the atomic level on the polyhexamethylene benzo[a]chloroform network material to form a multi-atom structure; and within the carbon defects of the polyhexamethylene benzo[a]chloroform network material, one manganese atom is located in the middle, and two iridium atoms are located on both sides of the manganese atom, arranged in a triangular pattern.
2. The Ir-Mn-based composite catalyst according to claim 1, characterized in that, The polyhexamethylenetetramine network material is prepared by a method comprising the following steps: S1, after drying hexa(4-bromophenyl)benzene, it was dissolved in dehydrated N,N-dimethylformamide along with 2,2-bipyridine. Then, bis(1,5-cyclooctadiene)nickel(0) and 1,5-cyclooctadiene were added, and the mixture was heated to react. After the reaction was completed, concentrated hydrochloric acid was added to the mixture, and the residue was filtered. The residue was washed successively with methanol, tetrahydrofuran, and water, and then dried under vacuum to obtain the intermediate. S2, add dichloromethane and ferric chloride solution to the intermediate, stir and react, add methanol and filter, then wash and dry the filter residue with methanol and tetrahydrofuran in sequence; then mix the filter residue with nitric acid and sonicate, then wash with water until the mixture is neutral; S3, the water-washed mixture is filtered and dried under reduced pressure to obtain the polyhexamethylenetetramine network material.
3. The Ir-Mn-based composite catalyst according to claim 2, characterized in that, In step S1, the heating reaction is carried out in a dark environment, the temperature of the heating reaction is 80~90℃, and the reaction time is 90~100h.
4. The Ir-Mn-based composite catalyst according to claim 2, characterized in that, In step S2, the stirring reaction is carried out at room temperature for 20-30 hours; the ultrasonic treatment is carried out for 1-5 hours.
5. The method for preparing the Ir-Mn-based composite catalyst according to any one of claims 1-4, characterized in that, The process includes the following steps: grinding and mixing manganese source, iridium source and polyhexamethylene benzo[a]methyl ether network material, and then heating and reacting at 250~350℃ for 5~10h to obtain the Ir-Mn-based composite catalyst.
6. The method for preparing the Ir-Mn-based composite catalyst according to claim 5, characterized in that, The mass ratio of the manganese source, the iridium source and the polyhexamethylenetetramine network material is (1~3):(1~3):(10~15).
7. The method for preparing the Ir-Mn-based composite catalyst according to claim 5, characterized in that, The manganese source is pentacarbonyl manganese bromide; the iridium source is tricarbonyl iridium chloride.
8. The application of the Ir-Mn-based composite catalyst according to any one of claims 1-4 in the oxygen evolution reaction and hydrogen evolution reaction.