PEM water electrolysis catalyst, PEM water electrolysis oxygen desorption electrode and preparation method and application of PEM water electrolysis catalyst and PEM water electrolysis oxygen desorption electrode

Abstract

The invention relates to the technical field of hydrogen production through water electrolysis, in particular to a PEM water electrolysis catalyst, a PEM water electrolysis oxygen desorption electrode and a preparation method and application of the PEM water electrolysis catalyst and the PEM water electrolysis oxygen desorption electrode. The catalyst provided by the invention comprises an amorphous MnO2 carrier and IrO2, wherein the IrO2 is uniformly dispersed in the amorphous MnO2 carrier in the form of crystal particles. According to the catalyst, the amorphous MnO2 carrier is adopted to load IrO2, the Ir loading capacity is effectively reduced, meanwhile, the Ir6 + content is increased, and the catalyst shows extremely high OER activity and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production by electrolysis of water, and in particular to a PEM water electrolysis catalyst, a PEM water electrolysis oxygen-decomposing electrode, and a preparation method and application thereof. Background Art

[0002] Renewable energy-driven water electrolysis for hydrogen production is a highly promising method for renewable energy storage. Proton exchange membrane (PEM) water electrolysis, with its advantages of high current density, high voltage efficiency, and rapid response to load changes, has gained widespread recognition. However, the commercial application of hydrogen production in PEM water electrolyzers still faces challenges, such as high overpotential for the oxygen evolution reaction (OER) on the anode side, resulting in high hydrogen production costs and high power consumption. The use of high-performance catalysts can effectively improve the efficiency of hydrogen production through electrolysis. Currently, high-performance catalysts are mostly made of precious metal materials, such as Pt / C and IrO2, but their scarcity and high cost mean that their large-scale application still faces numerous challenges.

[0003] Improving atomic utilization by dispersing IrO2 through carrier materials is an effective way to reduce Ir loading and enhance OER activity. For example, the patent document with publication number CN119593011A discloses an iridium-cobalt oxide nanoparticle, its preparation method and application. The Co3O4 composite IrO2 catalyst uses 0.5 M H2SO4 as electrolyte at 10 mA cm -2 It can operate stably for 2 h at a low current density, but its commercial application still faces the key problems of insufficient activity and stability. Summary of the Invention

[0004] The present invention provides a low iridium loading PEM water electrolysis OER catalyst rich in hexavalent iridium, a PEM water electrolysis oxygen separation electrode and its preparation method and application, in order to solve the problem of insufficient activity and stability of current low iridium loading catalysts. The present invention provides an amorphous MnO2 material loaded IrO2 catalyst, which reduces the Ir loading while increasing the Ir 6+ The catalyst exhibited extremely high OER activity and stability.

[0005] According to a first aspect of the present invention, the present invention provides a hexavalent iridium-rich low iridium loading PEM water electrolysis OER catalyst, comprising an amorphous MnO2 carrier and IrO2, wherein the IrO2 is uniformly dispersed on the amorphous MnO2 carrier in the form of crystalline particles.

[0006] In the catalyst of the present invention, since the work function of the amorphous MnO2 carrier is larger than that of IrO2, electrons will overflow from IrO2 through the interface into the amorphous MnO2, which significantly increases the valence of Ir and increases the proportion of hexavalent iridium, thereby improving the intrinsic OER activity and stability of the catalyst. The content of planar oxygen in the amorphous MnO2 carrier is greatly increased, which is beneficial to inhibit the dissolution of manganese ions and oxygen, making the carrier MnO2 have a high OER activity at a large industrial current density (500 mA cm -2 ) still has high stability under the condition of

[0007] Furthermore, the iridium loading in the catalyst is 0.039-0.136 mg cm -2 , Ir in the catalyst 6+ The atomic percentage of Ir in the whole catalyst is 31%~37.5%. Within this loading and content range, the activity and stability of the catalyst are significantly improved. The lower iridium loading achieves cost reduction, while the higher Ir 6+ The content enhances the intrinsic OER activity of the catalyst, enabling the catalyst to achieve efficient oxygen evolution reaction at a lower overpotential, thereby improving the efficiency of hydrogen production by water electrolysis.

[0008] The crystal particle diameter of the IrO2 is 5-10 nm.

[0009] According to a second aspect of the present invention, the present invention further provides a PEM water electrolysis oxygen evolution electrode, comprising the above-mentioned catalyst, wherein the oxygen evolution electrode further comprises titanium felt.

[0010] According to the third aspect of the present invention, the present invention uses titanium felt as a substrate and the above-mentioned catalyst as an oxygen evolution catalyst to form an oxygen evolution electrode, and provides a method for preparing the above-mentioned hexavalent iridium-rich low iridium loading PEM water electrolysis oxygen evolution electrode, comprising the following steps: Step S1: pre-treating the titanium felt; Step S2: preparing a MnO2 carrier by electrodeposition in a three-electrode system; the specific steps are: using pretreated titanium felt as a working electrode, a carbon rod as a counter electrode, an Ag / AgCl electrode as a reference electrode, and Mn(CH3COO)2 and CH3COONa as a deposition solution, using constant pressure deposition to obtain a MnO2 precursor; calcining the MnO2 precursor at a high temperature to obtain a MnO2 material; Step S3: dissolving chloroiridic acid in an organic solvent to obtain a chloroiridic acid solution, and immersing the MnO2 material in the chloroiridic acid solution; and calcining the impregnated material.

[0011] The preparation method of the present invention includes key steps such as titanium felt pretreatment, MnO2 carrier synthesis and IrO2 loading. Through specific preparation steps and process conditions, the structural design of amorphous MnO2 carrier and uniformly dispersed IrO2 crystal particles can be achieved, thereby giving full play to the advantages of the catalyst.

[0012] Appropriate immersion temperature and time help avoid localized concentrations that are too high or too low, making the catalyst's composition and structure more uniform, thereby improving the catalyst's activity and stability, leading to better performance in the OER reaction. Furthermore, in step S3, the immersion temperature is 60-80°C, and the immersion time is 1-3 hours.

[0013] By optimizing the impregnation temperature and time, it can be ensured that the MnO2 material is fully impregnated in the chloroiridic acid solution, so that the chloroiridic acid is uniformly adsorbed on the surface of the MnO2 carrier.

[0014] Appropriate calcination conditions can ensure that the active sites of the catalyst are fully exposed, while avoiding excessive sintering that leads to a reduction in active sites or structural damage, ensuring that the catalyst has high OER activity and stability. Furthermore, the calcination temperature in step S3 is 400-500 °C, the calcination time is 2-4 h, and the heating rate is 2-5 °C min -1 .

[0015] Furthermore, in the chloroiridic acid solution, 1 to 5 μl of chloroiridic acid is dissolved in each milliliter of organic solvent.

[0016] Furthermore, the organic solvent is selected from one or more of methanol, ethanol and propanol.

[0017] By controlling the concentration of the chloroiridic acid solution and the type of organic solvent, the composition and structure of the catalyst can be further adjusted to optimize the interaction between the MnO2 support and IrO2, thereby achieving the formation of an amorphous MnO2 support and uniform loading of IrO2, and optimizing its performance.

[0018] Furthermore, in step S2, in the electrodeposition method, a voltage of 4 to 6.0 V is applied to the working electrode, and the deposition time is 150 to 450 s; the high-temperature calcination temperature is 400 to 500 °C, the time is 2 to 4 h, and the heating rate is 2 to 5 °C min -1 Optimizing voltage and deposition time ensures uniform deposition and sufficient formation of the MnO2 precursor, avoiding problems such as uneven or excessively thick deposition. Optimizing high-temperature calcination conditions helps remove organic impurities, resulting in a MnO2 support with high crystallinity and stability, thereby improving the overall performance of the catalyst.

[0019] Furthermore, the concentration of Mn(CH3COO)2 is 0.1~0.3 mol L -1 The concentration of CH3COONa is 0.1~0.5 mol L -1 By precisely controlling the concentration of the deposition solution, the composition and structure of the MnO2 support can be adjusted to further optimize its performance.

[0020] Furthermore, in step S1, the titanium felt is pretreated by ultrasonically cleaning the titanium felt in a degreaser and a cleaning agent for 30 to 60 minutes, followed by drying at 60 to 80°C. Preferably, the degreaser is acetone, and the cleaning agents are ethanol and deionized water. By optimizing the titanium felt pretreatment, impurities and oil stains on the titanium felt surface can be effectively removed, improving the surface cleanliness and activity of the titanium felt, thereby ensuring that the MnO2 carrier can be uniformly deposited on the titanium felt surface during subsequent electrodeposition, thereby improving the quality of catalyst preparation. The thoroughly pretreated titanium felt surface is cleaner and smoother, which helps enhance the adhesion between the MnO2 carrier and the titanium felt, preventing the carrier from falling off during use, thereby improving the stability and service life of the catalyst.

[0021] Furthermore, the thickness of the titanium felt is 0.2-0.6 mm.

[0022] According to a fourth aspect of the present invention, the present invention also provides the use of the above-mentioned PEM water electrolysis catalyst in a proton exchange membrane water electrolysis oxygen separation reaction.

[0023] In response to the problems of high OER overpotential on the anode side, high hydrogen production cost, and high power consumption in existing PEM water electrolyzers, this catalyst can effectively reduce the OER overpotential and improve the efficiency of electrolytic hydrogen production, thereby providing strong technical support for the development of proton exchange membrane water electrolysis technology and promoting the commercial application of water electrolysis hydrogen production technology driven by renewable energy.

[0024] According to a fifth aspect of the present invention, the present invention further provides a PEM water electrolysis cell, which uses the above-mentioned PEM water electrolysis catalyst as the anode and constructs the cathode catalyst layer with a Pt / C catalyst.

[0025] The application of the catalyst of the present invention at the anode can significantly reduce the OER overpotential and improve the efficiency of the anode reaction, thereby improving the electrolysis efficiency and energy conversion efficiency of the entire electrolyzer, reducing hydrogen production costs and energy consumption, and making it more competitive in large-scale water electrolysis hydrogen production applications. Combining this catalyst with existing Pt / C catalysts achieves an optimized configuration of anode and cathode catalysts, promotes the integration and innovation of water electrolysis hydrogen production technology, provides more comprehensive technical support for the commercial application of proton exchange membrane water electrolyzers, and promotes the development of renewable energy hydrogen production technology.

[0026] Furthermore, the method for constructing the cathode catalyst layer is as follows: a Pt / C catalyst is dispersed in an isopropanol and Nafion solution, and then the solution containing the Pt / C catalyst is coated on the proton exchange membrane by spraying.

[0027] Preferably, the proton exchange membrane is a Nafion 115 or Nafion 121 membrane.

[0028] Preferably, the mass ratio of the Pt / C catalyst, the Nafion solution, and the isopropanol is 1:(0.2-0.4):(70-90). By rationally selecting and proportioning the materials for the cathode catalyst layer, the cathode reaction can be efficiently carried out. This, in conjunction with the anode catalyst, improves the electrolysis efficiency, stability, and service life of the entire electrolyzer, maintaining good performance over long periods of operation and reducing maintenance costs.

[0029] Furthermore, the cathode is prepared by hot pressing at a temperature of 130-150°C, a pressure of 0.2-1.5 MPa, and a time of 1-3 min.

[0030] Beneficial effects of the present invention: The present invention provides a low iridium loading PEM water electrolysis OER catalyst rich in hexavalent iridium using an amorphous MnO2 carrier loaded with IrO2 strategy, which effectively reduces the Ir loading and improves the Ir 6+ The catalyst exhibits extremely high OER activity and stability. Compared with the commercially used IrO2 catalyst, its mass specific activity is improved by about 10 times at a potential of 1.53 V vs. RHE, showing good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 XRD patterns of the electrodes of Comparative Example 1, Comparative Example 2 and Example 1 provided by the present invention; wherein (a) is Comparative Example 1, (b) is Comparative Example 2, and (c) is Example 1.

[0033] Figure 2 These are the Raman graphs of the electrodes of Comparative Example 1, Comparative Example 2 and Example 1 provided by the present invention.

[0034] Figure 3 This is a TEM image of the electrode of Example 1 provided by the present invention.

[0035] Figure 4 These are XPS graphs of the electrodes of Comparative Example 2 and Examples 1-3 provided by the present invention.

[0036] Figure 5 The OER performance diagrams of the electrodes of Comparative Example 1, Comparative Example 2 and Examples 1-3 provided by the present invention; wherein (a) is a polarization curve diagram; (b) is a 500 mA cm -2 Chronopotentiometry curves at different current densities.

[0037] Figure 6 The OER polarization curves of the electrodes of Example 1 and Comparative Example 3 provided by the present invention are shown.

[0038] Figure 7 The performance test diagrams of the PEM water electrolyzer of the electrodes of Example 1 and Comparative Example 2 provided by the present invention; wherein (a) is a polarization curve diagram; (b) is a 2 A cm -2 Chronopotentiometry curves at different current densities. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0040] Example 1 This embodiment provides a method for preparing a PEM water electrolysis oxygen electrode, comprising the following steps: Step S1: The titanium felt was ultrasonically cleaned in acetone, ethanol, and deionized water for 30 min in sequence to remove residual chemicals, and then dried at 60 °C for use.

[0041] Step S2: Electrodeposition was performed in a three-electrode system using an electrochemical workstation, with the treated titanium felt as the working electrode, the carbon rod as the counter electrode, and the Ag / AgCl electrode (in saturated KCl solution) as the reference electrode. 0.1 M Mn(CH3COO)2 and 0.2 M CH3COONa were used as the deposition solution. The electrodeposition was performed at a voltage of 5.0 V (vs. the Ag / AgCl electrode) for 300 s. After electrodeposition, the MnO2 sample was incubated in air at 5 °C min -1 The material was calcined at 450 °C for 3 h at a heating rate of 100 nm to obtain MnO2 material.

[0042] Step S3: Dissolve 15 μl of chloroiridic acid in 5 ml of methanol to obtain a chloroiridic acid solution, and then immerse the prepared MnO2 material in the chloroiridic acid solution at 70°C for 3 h. Then transfer the sample to a muffle furnace and immerse it in air at 5°C min -1 The electrode was heated to 450 °C and calcined for 3 h. The Ir loading in the obtained electrode was 0.109 mg cm -2 , where Ir 6 + It accounts for 37.5% of the total Ir content.

[0043] Example 2 This embodiment provides a method for preparing a PEM water electrolysis oxygen electrode, comprising the following steps: Step S1: The titanium felt was ultrasonically cleaned in acetone, ethanol, and deionized water for 30 min in sequence to remove residual chemicals, and then dried at 60 °C for use.

[0044] Step S2: Electrodeposition was performed in a three-electrode system using an electrochemical workstation, with the treated titanium felt as the working electrode, the carbon rod as the counter electrode, and the Ag / AgCl electrode (in saturated KCl solution) as the reference electrode. 0.1 M Mn(CH3COO)2 and 0.2 M CH3COONa were used as the deposition solution. The electrodeposition was performed at a voltage of 5.0 V (vs. the Ag / AgCl electrode) for 300 s. After electrodeposition, the MnO2 sample was incubated in air at 5 °C min -1 The material was calcined at 450 °C for 3 h at a heating rate of 100 nm to obtain MnO2 material.

[0045] Step S3: Dissolve 5 μl of chloroiridic acid in 5 ml of methanol to obtain a chloroiridic acid solution, and then immerse the prepared MnO2 material in the chloroiridic acid solution at 70 °C for 3 h. Then transfer the sample to a muffle furnace and immerse it in air at 5 °C min -1 The electrode was heated to 450 °C and calcined for 3 h. The Ir loading in the obtained electrode was 0.039 mg cm -2 , where Ir 6+ It accounts for 33.5% of the total Ir content.

[0046] Example 3 This embodiment provides a method for preparing a PEM water electrolysis oxygen electrode, comprising the following steps: Step S1: The titanium felt was ultrasonically cleaned in acetone, ethanol, and deionized water for 30 min in sequence to remove residual chemicals, and then dried at 60 °C for use.

[0047] Step S2: Electrodeposition was performed in a three-electrode system using an electrochemical workstation, with the treated titanium felt as the working electrode, the carbon rod as the counter electrode, and the Ag / AgCl electrode (in saturated KCl solution) as the reference electrode. 0.1 M Mn(CH3COO)2 and 0.2 M CH3COONa were used as the deposition solution. The electrodeposition was performed at a voltage of 5.0 V (vs. the Ag / AgCl electrode) for 300 s. After electrodeposition, the MnO2 sample was incubated in air at 5 °C min -1 The material was calcined at 450 °C for 3 h at a heating rate of 100 nm to obtain MnO2 material.

[0048] Step S3: Dissolve 25 μl of chloroiridic acid in 5 ml of methanol to obtain a chloroiridic acid solution, and then immerse the prepared MnO2 material in the chloroiridic acid solution at 70 °C for 3 h. Then transfer the sample to a muffle furnace and immerse it in air at 5 °C min -1 The electrode was heated to 450 °C and calcined for 3 h, and the Ir loading in the obtained electrode was 0.136 mg cm -2 , where Ir 6+ It accounts for 31.3% of the total Ir content.

[0049] Comparative Example 1 This comparative example provides a MnO2 sample, which is prepared according to steps S1 and S2 of Example 1.

[0050] Comparative Example 2 This comparative example provides an IrO2 sample. The preparation method of this IrO2 sample differs from that of Example 1 only in that: Step S2 is not included. Instead, the Ti felt obtained in Step S1 is directly immersed in 15 μl of chloroiridic acid and 5 ml of methanol solution. Then, the method of Step S3 is followed to obtain the final IrO2 sample with an Ir loading of 0.107 mg cm -2 , where Ir 6+ It accounts for 19.6% of the total Ir content.

[0051] Comparative Example 3 This comparative example provides a method for preparing a PEM water electrolysis oxygen electrode, comprising the following steps: Step S1: The titanium felt was ultrasonically cleaned in acetone, ethanol, and deionized water for 30 min in sequence to remove residual chemicals, and then dried at 60 °C for use.

[0052] Step S2: Electrodeposition was performed in a three-electrode system using an electrochemical workstation, with the treated titanium felt as the working electrode, the carbon rod as the counter electrode, the Ag / AgCl electrode (in saturated KCl solution) as the reference electrode, 0.1 M Mn(CH3COO)2 and 0.2 M CH3COONa as the deposition solution, and a voltage of 5.0 V (relative to the Ag / AgCl electrode) for 300 s.

[0053] Step S3: Dissolve 15 μl of chloroiridic acid in 5 ml of methanol to obtain a chloroiridic acid solution, and then immerse the prepared MnO2 material in the chloroiridic acid solution at 70 °C for 3 h. Then transfer the sample to a muffle furnace and immerse it in air at 5 °C min -1 The electrode was heated to 450 °C and calcined for 3 h. The Ir loading in the obtained electrode was 0.114 mg cm -2 .

[0054] According to XRD test, it can be seen that (such as Figure 1 As shown in Figure 3 ), the MnO2 sample (JCPDS 44-0141) and the IrO2 (JCPDS 43-1019) sample have distinct corresponding peaks, indicating that both MnO2 and IrO2 are tetragonal. In Example 1 of the present invention, there are no distinct peaks corresponding to MnO2, and only peaks corresponding to IrO2 (JCPDS 43-1019), indicating that the carrier MnO2 has transformed into an amorphous phase.

[0055] like Figure 2 As shown, IrO2 is at about 551cm -1 and 732cm -1 There are two strong bands at the g 、A 1g and B 2g Vibration Mode (A 1g and B 2g The Raman peak of MnO2 is at about 572 cm -1 and 630cm -1 There are two strong bands at 180cm, which are attributed to the Mn-O stretching vibration in the MnO6 octahedral layer. -1 The low-frequency band at 275 cm is attributed to the external vibration generated by the translational motion of the MnO6 octahedron. -1 and 477cm -1 The peak at is a characteristic spectral feature of the MnO2 phase. Weak peaks corresponding to Ir-O vibrations can also be found in Example 1 of the present invention. However, the Raman bands corresponding to MnO2 are all blue-shifted, and the peak intensity is significantly reduced, indicating that the long-range and short-range order of the Mn-O bond are significantly reduced, and the carrier MnO2 is amorphous.

[0056] High-resolution TEM image of Example 1 ( Figure 3 As shown in the figure, there are no obvious lattice fringes on the carrier, indicating that the carrier MnO2 is amorphous. The lattice fringes spacing in the figure is 3.18 Å and 2.25 Å, corresponding to the (110) and (200) crystal planes of IrO2 respectively. Figure 3 The results also show that the crystal particle diameter of IrO2 is 5~10 nm.

[0057] Figure 4 The XPS graphs show that compared with IrO2, Ir 6+ The content of Ir increases significantly. From Examples 1-3, as the amount of chloroiridic acid increases, 6+ The atomic percentage of IrO2 first increases and then decreases. This is mainly attributed to the charge transfer interface formed between IrO2 and amorphous MnO2. As the IrO2 loading increases, the charge transfer between the interface of the carrier amorphous MnO2 and IrO2 in the series of catalytic electrodes is insufficient, resulting in the formation of IrO2. 6+ The atomic percentage of Ir in the catalytic electrode of Example 1 decreased. 6+ The atomic percentage of is the largest, which is beneficial to enhance the activity and stability of the Ir site, such as Figure 4 shown.

[0058] The OER activity of the prepared catalytic electrode was tested using a three-electrode system. The prepared catalytic electrode, Pt wire, and Ag / AgCl electrode (saturated KCl solution) were used as the working electrode, counter electrode, and reference electrode, respectively. Electrochemical performance was tested in an O2-saturated 0.5 M H2SO4 electrolyte. Cyclic voltammetry was used to test the electrochemical performance of the prepared catalytic electrode. The test voltage range was 0.8-2.1 V (vs. Ag / AgCl saturated KCl solution) at a scan rate of 2 mV s. -1 The OER stability of the catalytic electrode was tested by chronopotentiometry at a current density of 500 mA cm -2 .

[0059] In 0.5 M H2SO4 electrolyte, the electrode of Example 1 only needs 216 mV overpotential to reach 10 mAcm -2 , which is significantly better than Comparative Example 1 and Comparative Example 2. At the same time, the stability test shows that at 500 mA cm -2 Under the current density, the comparative example 2 lost its activity in less than 50 hours of operation, but maintained excellent performance after 500 hours of continuous operation. Figure 5 shown.

[0060] like Figure 6As shown in the figure, the OER activity of Example 1 of the present invention is better than that of Comparative Example 3, which shows that compared with Comparative Example 3, after the amorphous MnO2 is prepared by electrodeposition, it is directly impregnated and loaded with IrO2. The method of the present invention, which is followed by calcination after electrodeposition and then impregnation and calcination, can form a charge transfer interface between IrO2 and amorphous MnO2, so that Ir 6+ The atomic percentage of isocyanate is significantly increased, so the catalyst exhibits excellent OER activity and stability.

[0061] A HER catalyst layer was constructed using commercial Pt / C as the HER catalyst. Pt / C (40%) was dispersed in an isopropanol and Nafion solution, ensuring a mass ratio of Pt / C, isopropanol, and Nafion of 1:0.3:80. The Pt / C catalyst was then spray-coated onto a Nafion 115 proton exchange membrane (Pt loading of 0.4 mg cm). -2 ).

[0062] The membrane electrode was constructed by hot-pressing hydrophobic carbon paper and Pt / C-sprayed Nafion 115 membrane at 140°C, 1 MPa, and 2 min.

[0063] The electrodes prepared in Example 1 and Comparative Example 2 were used as OER catalytic electrodes to assemble a PEM single water electrolysis cell, which was placed on an electrolysis cell performance test bench to test the performance of the PEM electrolysis cell.

[0064] Performance tests include PEM electrolyzer polarization curve and chronopotentiometry tests, with the preferred test temperature being 80°C min -1 , water flow rate is 10 ml min -1 The polarization curve test range is 1~2.5 V, and the current density of the chronopotentiometry test is 2A cm -2 .

[0065] Compared with Comparative Example 2, the PEM electrolytic cell assembled with the electrodes of Example 1 showed better performance, reaching 3.17 A cm at a voltage of 2.0 V. -2 The current density is 2 A cm -2 There is no obvious attenuation after 700 h of continuous water electrolysis. Figure 7 shown.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A PEM water electrolysis catalyst, characterized in that The invention comprises an amorphous MnO2 carrier and IrO2, wherein the IrO2 is uniformly dispersed on the amorphous MnO2 carrier in the form of crystal particles.

2. The PEM water electrolysis catalyst according to claim 1, characterized in that The iridium loading in the catalyst is 0.039-0.136 mg cm -2 , Ir in the catalyst 6+ The atomic percentage of total Ir is 31%~37.5%; The crystal particle diameter of the IrO2 is 5-10 nm.

3. A PEM water electrolysis oxygen electrode, characterized in that: The catalyst according to claim 1 or 2 is included, and the oxygen evolution electrode further includes titanium felt.

4. The method for preparing the PEM water electrolysis oxygen electrode according to claim 3, characterized in that: The steps include: Step S1: pre-treating the titanium felt; Step S2: using the pretreated titanium felt as a working electrode, a carbon rod as a counter electrode, an Ag / AgCl electrode as a reference electrode, and Mn(CH3COO)2 and CH3COONa as a deposition solution, a MnO2 precursor is obtained by constant pressure deposition; and the MnO2 precursor is calcined at a high temperature to obtain a MnO2 material; Step S3: dissolving chloroiridic acid in an organic solvent to obtain a chloroiridic acid solution, and immersing the MnO2 material in the chloroiridic acid solution; and calcining the impregnated material to obtain the oxygen evolution electrode.

5. The preparation method according to claim 4, characterized in that In step S3, the immersion temperature is 60-80° C., and the immersion time is 1-3 h.

6. The preparation method according to claim 4, characterized in that The calcination temperature in step S3 is 400-500 °C, the calcination time is 2-4 h, and the heating rate is 2-5 °C min -1 ; and / or, in the chloroiridic acid solution, 1 to 5 μl of chloroiridic acid is dissolved in each ml of organic solvent; And / or, the organic solvent is selected from one or more of methanol, ethanol, and propanol.

7. The preparation method according to claim 4, characterized in that In step S2, during the constant voltage deposition, a voltage of 4 to 6.0 V is applied to the working electrode, and the deposition time is 150 to 450 s; The high temperature calcination temperature is 400-500 °C, the time is 2-4 h, and the heating rate is 2-5 °C min -1 ; And / or, the concentration of Mn(CH3COO)2 is 0.1~0.3 mol L -1 The concentration of CH3COONa is 0.1~0.5mol L -1 .

8. The preparation method according to claim 4, characterized in that In step S1, the titanium felt is pretreated by ultrasonically cleaning the titanium felt in a degreasing agent and a cleaning agent for 30 to 60 minutes, and then drying it at 60 to 80° C. Preferably, the degreasing agent is acetone, and the cleaning agent is ethanol and deionized water; And / or, the thickness of the titanium felt is 0.2-0.6 mm.

9. Use of the PEM water electrolysis catalyst according to claim 1 or 2 in proton exchange membrane water electrolysis oxygen separation reaction.

10. A PEM water electrolyzer, characterized in that: The PEM water electrolysis oxygen electrode according to claim 3 is used as the anode.

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