IrSnOx / Ti porous transmission electrode and preparation method and application thereof
By growing an IrSnOx layer in situ on a titanium substrate to form an IrSnOx/Ti porous transport electrode, the problems of high iridium-based catalyst loading and easy oxidation of titanium felt were solved, achieving efficient redox reaction catalysis and improved electrode stability.
Patent Information
- Application Number
- CN202511726586.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-01-13
AI Technical Summary
In existing proton exchange membrane electrolysis water production hydrogen technology, iridium-based catalysts have high loading, uneven catalyst layer structure, difficulty in bubble removal, and easy catalyst failure. Furthermore, titanium felt is easily oxidized under acidic conditions, affecting electrode stability.
An IrSnOx/Ti porous transport electrode was used, which formed a three-dimensional porous structure by in-situ growth of an IrSnOx layer on a titanium substrate. The molar ratio of Ir to Sn was 1:1-10, the loading of Ir was 0.2 mg/cm2, and the loading of Sn was 0.3 mg/cm2-2 mg/cm2. The preparation method included acid washing, tin deposition and iridium oxide electrodeposition, and after heat treatment, a uniformly covered IrSnOx layer was formed.
The amount of precious metals used was reduced, water vapor transport was enhanced, the exposure of catalytic active sites and the long-term stability of titanium felt were improved, the overpotential was reduced, and the durability of the electrode was enhanced.
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Figure CN121321024A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of materials technology for hydrogen production by water electrolysis, specifically relating to an IrSnOx / Ti porous transport electrode, its preparation method, and its application. Background Technology
[0002] Proton exchange membrane water electrolysis (PEMWE) is a green and efficient hydrogen production technology. It boasts high efficiency, a compact equipment structure, and the ability to be efficiently coupled with fluctuating renewable energy sources (such as photovoltaic and wind power), making it widely considered a key pathway for green hydrogen production. However, due to the slow kinetics of the oxygen evolution reaction on the anode side, it requires acidic and high-voltage conditions, currently only iridium-based materials can meet these requirements. The membrane electrode assembly (MEA) is the core component of the electrolyzer. Its structure typically involves directly coating the catalyst onto both sides of the proton exchange membrane, forming a catalyst-coated membrane (CCM) structure. However, this structure requires a high loading of iridium catalyst, generally reaching 1 mg / cm³. 2If the iridium loading is reduced, the structure of the catalyst layer will change. When the iridium loading is too low, it is difficult for the catalyst layer to form a uniform and continuous conductive network, forming catalyst "islands" that hinder electron conduction and thus accelerate catalyst failure. Furthermore, when the electrolyzer operates at high current density, a large number of bubbles are generated inside the catalyst layer. However, due to the compact structure and low porosity of the catalyst layer, these bubbles are difficult to remove in time, leading to an increase in mass transfer overpotential and reduced performance. A large number of bubbles can also erode the catalyst, causing changes in the physical structure of the catalyst layer and affecting its activity. Additionally, when using a CCM-type structure, the titanium felt used as the porous transport layer of the anode generally needs to be platinum-plated to prevent oxidation under long-term operating conditions, which would increase the contact resistance of the membrane electrode. Catalyst-coated substrates (CCS) are another electrode structure where the catalyst is grown directly in situ on a titanium substrate, effectively solving the problems faced by CCM. The three-dimensional porous structure of the self-supporting substrate provides ideal anchoring points for the catalyst, improving the long-term durability of the electrode. Secondly, the CCS structure eliminates the need for a binder, allowing the active sites of the catalyst to be fully exposed, thus improving catalytic activity while reducing catalyst loading. Currently, there are reports of directly coating the surface of titanium felt with iridium oxide as a porous oxygen evolution transport electrode (Cho J, Kim KS, Kim S, et al. Substrate‐Driven Catalyst Reducibility for Oxygen Evolution and Its Effect on the Operation of Proton Exchange Membrane Water Electrolyzers[J]. SmallStructures, 2024, 5(1).). However, it is difficult to uniformly coat the entire titanium felt fiber with only iridium oxide at low loadings, which can lead to oxidation of the underlying titanium metal during long-term operation, affecting activity and stability. Therefore, developing a porous transport electrode that can uniformly coat the substrate and has excellent stability aligns with current technological trends. Summary of the Invention
[0003] In view of the above-mentioned problems existing in the prior art, the first technical problem to be solved by the present invention is to provide an IrSnOx / Ti porous transport electrode; the second technical problem to be solved by the present invention is to provide a method for preparing the IrSnOx / Ti porous transport electrode; and the third technical problem to be solved by the present invention is to provide the application of the IrSnOx / Ti porous transport electrode as an OER catalyst in acidic solution in the electrolysis of water to produce hydrogen.
[0004] To address the above problems, the present invention provides the following technical solution: In a first aspect, there is an IrSnOx / Ti porous transport electrode, comprising a titanium substrate and an IrSnOx layer grown in situ on the titanium substrate, wherein the IrSnOx layer uniformly coats the titanium substrate and the molar ratio of Ir to Sn in the IrSnOx layer is 1:1-10.
[0005] In one embodiment of this application, the porosity of the titanium matrix is 50%-70%.
[0006] In one embodiment of this application, the thickness of the IrSnOx layer is 0.4-0.8 micrometers.
[0007] In one embodiment of this application, the Sn loading in the IrSnOx / Ti porous transport electrode is 0.3 mg / cm³. 2 -2mg / cm 2 The Ir loading was 0.2 mg / cm³. 2 .
[0008] In one embodiment of this application, the titanium matrix is selected from titanium felt, titanium foam, titanium foil, titanium mesh, and porous titanium sheet.
[0009] Secondly, a method for preparing an IrSnOx / Ti porous transport electrode includes the following steps: S1. The surface of the titanium felt is pretreated by pickling, then rinsed with deionized water and anhydrous ethanol in sequence, and then dried. S2. Using titanium felt as the cathode and platinum sheet electrode as the anode, constant current tin deposition is performed in a tin electrodeposition solution until the tin loading is 0.3 mg / cm³. 2 -2mg / cm 2 Sn / Ti electrode was obtained, rinsed with deionized water, and dried; S3. In a three-electrode system, using Sn / Ti as the working electrode, and a saturated calomel electrode and a platinum sheet electrode as the reference and counter electrodes, constant-voltage electrodeposition of amorphous iridium oxide is performed in the iridium oxide electrodeposition solution until the iridium loading is 0.2 mg / cm³. 2 IrSn / Ti electrodes were obtained; S4. Heat-treat the IrSn / Ti electrode at 200-500℃ for 0.5-5h to obtain the IrSnOx / Ti porous transport electrode.
[0010] In one embodiment of this application, in step S1, the mass fraction of the pickling solution is 3-8 wt.%.
[0011] In one embodiment of this application, in step S1, the pickling solution is selected from acetic acid and oxalic acid.
[0012] In one embodiment of this application, in step S1, the temperature of the pickling pretreatment is 80-100°C.
[0013] In one embodiment of this application, the pickling pretreatment time in step S1 is 20-40 minutes.
[0014] In one embodiment of this application, in step S2, the tin electrodeposition solution is a mixture of tin precursor, complexing agent and urea.
[0015] In one embodiment of this application, in step S2, the molar ratio of tin precursor, complexing agent and urea is 0.05:1:1.
[0016] In one embodiment of this application, in step S2, the current density is 3-8 mg / cm³. 2 .
[0017] In one embodiment of this application, the tin deposition time in step S2 is 5-120 min.
[0018] In one embodiment of this application, in step S2, the tin precursor is selected from one of stannous chloride hydrate, stannous chloride hydrate, stannous sulfate, stannous acetate, and stannous oxalate.
[0019] In one embodiment of this application, in step S2, the complexing agent is selected from sodium citrate, citric acid, and tartaric acid.
[0020] In one embodiment of this application, in step S3, the iridium source is dissolved in oxalic acid, the pH value is adjusted to 9-11, and the solution is placed in a water bath to obtain an iridium oxide precipitate.
[0021] In one embodiment of this application, in step S3, the iridium source is selected from one of IrCl3, K2IrCl6, K3IrCl6, IrCl4, and H2IrCl6.
[0022] In one embodiment of this application, in step S3, the molar ratio of iridium source to oxalic acid is 1:5.
[0023] In one embodiment of this application, in step S3, the molar concentration of the iridium source is 10 mmol / L.
[0024] In one embodiment of this application, in step S3, the temperature of the water bath is 30-50°C.
[0025] In one embodiment of this application, the water bath time in step S3 is 12-36 hours.
[0026] In one embodiment of this application, the voltage range in step S3 is 0.5-1V.
[0027] Thirdly, this application provides the application of IrSnOx / Ti porous transport electrode as an OER catalyst in acidic solution for hydrogen production by water electrolysis.
[0028] Compared with the prior art, the present invention has the following beneficial effects: (1) The IrSnOx / Ti porous transport electrode provided in this application uses tin oxide as the framework and carrier of iridium oxide, which can effectively reduce the amount of precious metals used in the membrane electrode and reduce the cost. (2) The IrSnOx / Ti porous transport electrode provided in this application is based on three-dimensional porous titanium felt, which can provide sufficient water vapor transport channels and enhance material transport when operating at high current density; (3) The IrSnOx / Ti porous transport electrode provided in this application has an IrSnOx layer grown in situ on the substrate, with good dispersion of active component particles, which can fully expose active sites, uniformly coat the titanium felt, and improve the long-term operational stability of the titanium felt. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1 The Ir1Sn5O prepared in Example 1 of this invention x Scanning electron microscope image of the / Ti electrode, with the scale bar at 50 μm; Figure 2 Linear sweep voltammetry curves of the electrodes prepared in Examples 1-3 and Comparative Example 1 in a three-electrode system. Detailed Implementation
[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Example 1
[0032] First, prepare an oxalic acid aqueous solution with a mass fraction of 5 wt.%. Place the titanium felt in the oxalic acid solution and keep it at 90°C for 30 minutes. After that, let it cool naturally. Then, rinse it with deionized water and anhydrous ethanol in sequence, and place it in a vacuum oven to dry. A tin deposition solution was prepared, containing 0.05 mmol / L stannous chloride dihydrate, 0.1 mmol / L sodium citrate, and 0.1 mmol / L urea. After thorough mixing, tin was deposited using a titanium felt as the anode and a platinum sheet electrode as the cathode, employing a potentiostat with an applied voltage of 5 mA / cm². 2 The cathode current was applied for 30 minutes to obtain a Sn / Ti electrode. After the process, the electrode was rinsed with deionized water and then vacuum dried. The tin loading was determined to be approximately 1.0 mg / cm³ by gravimetric analysis. 2 ; An iridium oxide deposition solution of 10 mmol / L iridium trichloride and 50 mmol / L oxalic acid was prepared. The pH was adjusted to 10.5 using potassium carbonate. Chronoamperometry deposition was performed in a three-electrode system using a Sn / Ti electrode as the working electrode and a saturated calomel electrode and a platinum sheet electrode as the counter electrodes. A constant potential of 0.7 V was applied for 10 min, yielding a concentration of 0.2 mg / cm³. 2 The iridium loading was adjusted to obtain an Ir1Sn5 / Ti electrode. The Ir1Sn5 / Ti electrode was then rinsed with deionized water and dried. Ir1Sn5 / Ti was placed in a muffle furnace and heat-treated at 300℃ for 1 hour to obtain Ir1Sn5O. x The electrode was used as a / Ti electrode, and then the acidic OER performance of the three-electrode system was tested. The electrolyte was 0.5 M sulfuric acid. Before the linear sweep voltammetry (LSV) test, 20 cycles of cyclic voltammetry were performed in the range of 0-1.2 V (vs SCE) to activate the electrode. Then, the linear sweep voltammetry test was performed in the range of 0.9-1.5 V (vs SCE) at a scan rate of 5 mV / s.
[0033] Figure 1 Ir1Sn5O prepared in Example 1 x The scanning electron microscope image of the / Ti electrode shows that Ir1Sn5O x The catalyst is uniformly coated on the surface of the titanium substrate, which effectively protects the titanium substrate and prevents oxidation of the titanium during long-term operation; the LSV curve of the electrode prepared in Example 1 in the three-electrode system is shown below. Figure 2 As shown, the overpotential of the electrode prepared in Example 1 is much lower than that of the electrode prepared with commercial iridium oxide (Comparative Example 1). Therefore, the performance of the electrode prepared in Example 1 is improved by reducing the Ir loading. Example 2
[0034] First, prepare an oxalic acid aqueous solution with a mass fraction of 5 wt.%. Place the titanium felt in the oxalic acid solution and keep it at 90°C for 30 minutes. After that, let it cool naturally. Then, rinse it with deionized water and anhydrous ethanol in sequence, and place it in a vacuum oven to dry. A tin deposition solution was prepared, containing 0.05 mmol / L stannous chloride dihydrate, 0.1 mmol / L sodium citrate, and 0.1 mmol / L urea. After thorough mixing, tin was deposited using a titanium felt as the anode and a platinum sheet electrode as the cathode, employing a potentiostat with an applied voltage of 5 mA / cm². 2 A Sn / Ti electrode was obtained by applying a cathode current for 10 minutes. After the electrode was dried, it was rinsed with deionized water and then vacuum dried. The tin loading was found to be approximately 0.5 mg / cm³ by gravimetric analysis. 2 ; An iridium oxide deposition solution of 10 mmol / L iridium trichloride and 50 mmol / L oxalic acid was prepared. The pH was adjusted to 10.5 using potassium carbonate. Chronoamperometry deposition was performed in a three-electrode system using a Sn / Ti electrode as the working electrode and a saturated calomel electrode and a platinum sheet electrode as the counter electrodes. A constant potential of 0.7 V was applied for 10 min, yielding a concentration of 0.2 mg / cm³. 2 The iridium loading was used to obtain Ir1Sn 2.5 / Ti electrode, Ir1Sn 2.5 The Ti electrode was rinsed with deionized water and dried. Ir1Sn 2.5 Ti was placed in a muffle furnace and heat-treated at 300°C for 1 hour to obtain Ir1Sn. 2.5 O x The system was tested with a Ti electrode, and then the acidic OER performance of the three-electrode system was tested. Example 3
[0035] First, prepare an oxalic acid aqueous solution with a mass fraction of 5 wt.%. Place the titanium felt in the oxalic acid solution and keep it at 90°C for 30 minutes. After that, let it cool naturally. Then, rinse it with deionized water and anhydrous ethanol in sequence, and place it in a vacuum oven to dry. A tin deposition solution was prepared, containing 0.05 mmol / L stannous chloride dihydrate, 0.1 mmol / L sodium citrate, and 0.1 mmol / L urea. After thorough mixing, tin was deposited using a titanium felt as the anode and a platinum sheet electrode as the cathode, employing a potentiostat with an applied voltage of 5 mA / cm². 2 A Sn / Ti electrode was obtained by applying a cathode current for 60 minutes. After the electrode was dried, it was rinsed with deionized water and then vacuum dried. The tin loading was found to be approximately 2.0 mg / cm³ by gravimetric analysis. 2 ; An iridium oxide deposition solution of 10 mmol / L iridium trichloride and 50 mmol / L oxalic acid was prepared. The pH was adjusted to 10.5 using potassium carbonate. Chronoamperometry deposition was performed in a three-electrode system using a Sn / Ti electrode as the working electrode and a saturated calomel electrode and a platinum sheet electrode as the counter electrodes. A constant potential of 0.7 V was applied for 10 min, yielding a concentration of 0.2 mg / cm³. 2 The iridium loading was used to obtain Ir1Sn10 / Ti electrode, Ir1Sn 10 The Ti electrode was rinsed with deionized water and dried. Ir1Sn 10 Ti was placed in a muffle furnace and heat-treated at 300°C for 1 hour to obtain Ir1Sn. 10 O x The system was tested with a Ti electrode, and then the acidic OER performance of the three-electrode system was tested.
[0036] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that iridium deposition was performed instead of tin deposition. Ir / Ti was placed in a muffle furnace and heat-treated at 300°C for 1 hour to obtain IrO. x The system was tested with a Ti electrode, and then the acidic OER performance of the three-electrode system was tested.
[0037] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.
Claims
1. An IrSnOx / Ti porous transport electrode characterized in that, The IrSnOx / Ti porous transport electrode comprises a titanium substrate and an IrSnOx layer grown in situ on the titanium substrate, the IrSnOx layer uniformly coats the titanium substrate, and the molar ratio of Ir to Sn in the IrSnOx layer is 1:1-10, and the porosity of the titanium substrate is 50%-70%.
2. The IrSnOx / Ti porous transport electrode of claim 1, wherein, The Sn loading in the IrSnOx / Ti porous transport electrode is 0.3 mg / cm 2 - 2 mg / cm 2 , the Ir loading is 0.2 mg / cm 2 ; the titanium substrate is selected from one of a titanium felt, a titanium foam, a titanium foil, a titanium mesh, a titanium porous sheet.
3. The method of making an IrSnOx / Ti porous transport electrode according to any one of claims 1-2, characterized in that, The method comprises the following steps: S1, the surface of the titanium felt is pretreated by pickling, then rinsed with deionized water and anhydrous ethanol in sequence, and dried; S2, constant current tin deposition was carried out in the tin electrodeposition solution to a tin loading of 0.3 mg / cm 2 -2 mg / cm 2 , to obtain a Sn / Ti electrode, which was washed with deionized water and dried; S3, in a three-electrode system, taking Sn / Ti as a working electrode, saturated calomel electrode and platinum sheet electrode as reference electrode and counter electrode, carrying out constant voltage electrodeposition of amorphous iridium oxide to iridium in an iridium oxide electrodeposition solution with a loading of 0.2 mg / cm 2 , to obtain an IrSn / Ti electrode; S4, the IrSn / Ti electrode is heat treated at 200-500℃ for 0.5-5h to obtain an IrSnOx / Ti porous transport electrode.
4. The method of claim 3, wherein the IrSnOx / Ti porous transport electrode is prepared by, In step S1, the mass fraction of the pickling solution is 3-8wt.%; the pickling solution is selected from one of acetic acid and oxalic acid; the pickling pretreatment temperature is 80-100℃; and the pickling pretreatment time is 20-40min.
5. The method of claim 3, wherein the IrSnOx / Ti porous transport electrode is prepared by, In step S2, the tin electrodeposition solution is a mixture of a tin precursor, a complexing agent and urea; and the molar ratio of the tin precursor, the complexing agent and urea is 0.05:0.1:0.
1.
6. The method of claim 3, wherein the IrSnOx / Ti porous transport electrode is prepared by, In step S2, the current density is 3-8 mg / cm 2 ; the time for tin deposition is 5-120 min.
7. The method of claim 5, wherein the IrSnOx / Ti porous transport electrode is prepared by, In step S2, the tin precursor is selected from one of stannous chloride hydrate, tin chloride hydrate, stannous sulfate, tin acetate and tin oxalate; and the complexing agent is selected from one of sodium citrate, citric acid and tartaric acid.
8. The method of claim 3, wherein the IrSnOx / Ti porous transport electrode is prepared by, In step S3, an iridium source is dissolved in oxalic acid, and the pH value is adjusted to 9-11, and then water bathed to obtain an iridium oxide deposition solution; the iridium source is selected from one of IrCl3, K2IrCl6, K3IrCl6, IrCl4 and H2IrCl6; and the molar ratio of the iridium source to oxalic acid is 1:
5.
9. The method of claim 8, wherein the IrSnOx / Ti porous transport electrode is prepared by, In step S3, the water bath temperature is 30-50℃; the water bath time is 12-36h; and the voltage range is 0.5-1V.
10. Application of the IrSnOx / Ti porous transport electrode of any one of claims 1-2 as an OER catalyst for an acidic solution in hydrogen production by electrolysis of water.