Proton exchange membrane water electrolysis membrane electrode and preparation method therefor

Abstract

A proton exchange membrane water electrolysis membrane electrode, comprising a proton exchange membrane, an anode catalyst layer, and a cathode catalyst layer, wherein the anode catalyst layer comprises an anode catalyst and a proton-conducting ionomer, the Ir content is 0.02-2.0 mg / cm2, a mass ratio of the proton-conducting ionomer to the anode catalyst is 1:2-1:10, and the anode catalyst is a ruthenium-iridium-terbium nanocatalyst. The membrane electrode and the preparation method therefor provided by the present invention result in catalyst layers with a uniform distribution of noble metals, and the catalyst layers of the membrane electrode exhibit a uniform, consistent microstructure with good continuity, which is beneficial to improving water electrolysis activity and stability in catalyst layers of membrane electrodes.

Description

A proton exchange membrane electrolysis water membrane electrode and its preparation method

[0001] Cross-reference information

[0002] This application claims priority to Chinese Patent Application No. 202411537606.9, filed on October 30, 2024, entitled "A Proton Exchange Membrane Electrode for Water Electrolysis and Its Preparation Method", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of proton exchange membrane electrolysis for hydrogen production, and more specifically, to a proton exchange membrane electrolysis electrode and its preparation method. Background Technology

[0004] Proton exchange membrane electrolysis (PEMWE) is a technology that directly uses electricity to decompose water molecules into hydrogen and oxygen. It has advantages such as high energy conversion efficiency, rapid low-temperature start-up, and flexible operation. It is considered an advanced hydrogen production technology that can match the volatility of renewable energy power generation and is currently in the early stages of commercialization.

[0005] The fuel cell stack is a key component of PEMWE (Proton Exchange Membrane Evolution), comprising components such as the membrane electrode, diffusion layer (also called current collector), and electrodes. The membrane electrode consists of an anode catalyst, a proton exchange membrane, and a cathode catalyst. Currently, the high noble metal loading and high cost of the membrane electrode catalyst layer are key factors hindering the further commercialization of PEMWE. Commercial membrane electrodes typically use iridium black or iridium oxide as the anode oxygen evolution catalyst, which suffers from limited improvement in activity due to the high mass-to-weight ratio of noble metals. Therefore, in practical applications, the anode noble metal loading is greater than 2 mg / cm³. 2 Studies have shown that RuO2, which has a lower cost, has better electrocatalytic oxygen evolution activity than IrO2, and is expected to reduce the noble metal loading in membrane electrodes. However, RuO2 will be converted into soluble RuO4 or H2RuO5 under conditions such as high oxidation potential, low pH, and high oxygen concentration, and its stability urgently needs to be improved.

[0006] Traditional fabrication processes for membrane electrode assemblies (MEAs) include catalyst-coated membrane (CCM) and catalyst-coated substrate (CCS). The CCM method involves directly coating the catalyst onto the proton exchange membrane using methods such as blade coating, spraying, or transfer printing, forming a three-layer structure of catalyst-proton exchange membrane-catalyst. The CCS method involves loading the catalyst onto a gas diffusion layer and then hot-pressing it with the proton exchange membrane to form the MEA assembly. The CCM process not only improves catalyst utilization but also enhances the bonding force between the catalyst and the proton exchange membrane, reducing interfacial resistance and thus achieving higher current densities. Therefore, the CCM method is currently more widely used.

[0007] CN110745881A discloses calcium-doped yttrium ruthenium ruthenium, its preparation method, and its application in electrochemical devices. This calcium-doped yttrium ruthenium ruthenium exhibits a hole-doping effect during oxygen catalysis, increasing the surface oxygen vacancy concentration and thus providing more active sites for the oxygen evolution reaction. Furthermore, the divalent Ca²⁺... 2+ Replacement of trivalent Y 3+ Inducing Ru 5+ The generation of oxygen promotes the oxygen evolution reaction.

[0008] CN114836767A discloses a technical solution that uses a proton-electron conductor as the main component of a catalyst slurry. The proton-electron conductor increases the sites for proton transport in the water electrolysis hydrogen production reaction, accelerating the transport of protons and electrons, thereby improving the performance of the catalyst layer while reducing the amount of catalyst used. The drawback of this technology is that it cannot solve the problem of uniform distribution of noble metals in the catalyst layer, resulting in a high noble metal loading in the membrane electrode.

[0009] CN102088092B discloses a technical solution for preparing a three-dimensional network structure catalyst layer using a temperature-controlled ultrasonic spraying process, which can increase the number of exposed active sites on the catalyst. However, this technology has drawbacks compared to the present invention: the resulting catalyst layer has poor uniformity in thickness, and local hot spots are easily formed during long-term water electrolysis, posing risks of proton exchange membrane perforation and hydrogen-oxygen crosstalk. Summary of the Invention

[0010] To address the aforementioned technical problems, the present invention aims to provide a proton exchange membrane electrolysis water electrode that, by employing ruthenium-iridium-terbium nanocatalysts as the anode catalyst, achieves excellent catalytic activity and stability in water electrolysis.

[0011] To achieve the above objectives, the present invention first provides a proton exchange membrane electrolysis water membrane electrode, wherein the proton exchange membrane electrolysis water membrane electrode includes a proton exchange membrane, an anode catalyst layer and a cathode catalyst layer;

[0012] The anode catalyst layer contains an anode catalyst and an ionomer-based electronic conductor; the Ir content, based on the area of ​​the anode catalyst layer, is 0.02-2.0 mg / cm². 2 The mass ratio of the ionomer to the anode catalyst is 1:2 to 1:10.

[0013] The anode catalyst is a ruthenium-iridium-terbium nanocatalyst with the molecular formula Tb₂Ru. x Ir 2-x O7, where 0 <x<2。

[0014] According to a specific embodiment of the present invention, preferably, the content of the anode catalyst, based on the area of ​​the anode catalyst layer, is 0.05-17.34 mg / cm². 2 According to a specific embodiment of the present invention, preferably, the cathode catalyst layer contains a cathode catalyst and an ionomer-based quantum conductor;

[0015] The cathode catalyst is a Pt / C catalyst; the Pt content, based on the area of ​​the cathode catalyst layer, is 0.05-0.4 mg / cm². 2 The Pt element content in the Pt / C catalyst is 5-40%, and the mass ratio of the ionomer conductor to the cathode catalyst is 1:2-1:10.

[0016] According to a specific embodiment of the present invention, preferably, the content of the Pt / C catalyst, based on the area of ​​the cathode catalyst layer, is 0.1-1.0 mg / cm². 2 .

[0017] According to a specific embodiment of the present invention, preferably, the cathode catalyst layer is a porous structure composed of a cathode catalyst and an ionomer-based quantum conductor, the catalyst of the cathode catalyst layer is a Pt / C catalyst, and the catalyst content of the cathode catalyst layer is 0.2-1.0 mg / cm³. 2 Pt content 0.10-0.20 mg / cm³ 2 Specifically, the Pt content in the Pt / C catalyst can be 10-40 wt%.

[0018] According to a specific embodiment of the present invention, preferably, the content of the anode catalyst, based on the area of ​​the anode catalyst layer, is 0.05-17.34 mg / cm². 2 More preferably 2.0-3.0 mg / cm³ 2 .

[0019] According to a specific embodiment of the present invention, preferably, the Ir content is 0.2-1.0 mg / cm² based on the area of ​​the anode catalyst layer. 2 .

[0020] According to a specific embodiment of the present invention, preferably, in the anode catalyst layer, the mass ratio of the ionomerized electron conductor to the anode catalyst is 1:2-1:5.

[0021] According to a specific embodiment of the present invention, the ruthenium-iridium-terbium nanocatalyst used in the above-mentioned proton exchange membrane electrolysis water membrane electrode has an A2B2O7 structure, i.e., a pyrochlore structure. Preferably, in the molecular formula of the ruthenium-iridium-terbium nanocatalyst, 0.05≤x≤1.95; more preferably, 0.4≤x≤1.6. The catalyst used in the present invention is ruthenium-based pyrochlore, a mixed metal oxide. Compared with rutile-type RuO2 and perovskite-type ruthenium-based oxides, it has a more stable band structure, exhibits higher oxygen evolution reaction (OER) activity and stability under harsh working environments of high voltage and strong acidity, and can significantly reduce the content of the noble metal Ru.

[0022] According to a specific embodiment of the present invention, preferably, the ruthenium-iridium-terbium nanocatalyst is Tb₂Ru. 1.95 Ir 0.05 O7、Tb2Ru 1.90 Ir 0.10 O7、Tb2Ru 1.85 Ir 0.15 O7、Tb2Ru 1.80 Ir 0.20 O7、Tb2Ru 1.75 Ir 0.25 O7、Tb2Ru 1.70 Ir 0.30 O7、Tb2Ru 1.65 Ir 0.35 O7、Tb2Ru 1.60 Ir 0.40 O7、Tb2Ru 1.55 Ir 0.45 O7、Tb2Ru 1.50 Ir 0.50 O7、Tb2Ru 1.45 Ir 0.55 O7、Tb2Ru 1.40 Ir 0.60 O7、Tb2Ru 1.35 Ir 0.65 O7、Tb2Ru 1.30 Ir 0.70 O7、Tb2Ru 1.25 Ir 0.75 O7、Tb2Ru 1.20 Ir 0.80 O7、Tb2Ru 1.15 Ir 0.85 O7、Tb2Ru1.10 Ir 0.90 O7、Tb2Ru 1.05 Ir 0.95 O7、Tb2Ru 1.00 Ir 1.00 O7、Tb2Ru 0.95 Ir 1.05 O7、Tb2Ru 0.90 Ir 1.10 O7、Tb2Ru 0.85 Ir 1.15 O7、Tb2Ru 0.80 Ir 1.20 O7、Tb2Ru 0.75 Ir 1.25 O7、Tb2Ru 0.70 Ir 1.30 O7、Tb2Ru 0.65 Ir 1.35 O7、Tb2Ru 0.60 Ir 1.40 O7、Tb2Ru 0.55 Ir 1.45 O7、Tb2Ru 0.50 Ir 1.50 O7、Tb2Ru 0.45 Ir 1.55 O7、Tb2Ru 0.40 Ir 1.60 O7、Tb2Ru 0.35 Ir 1.65 O7、Tb2Ru 0.30 Ir 1.70 O7、Tb2Ru 0.25 Ir 1.75 O7、Tb2Ru 0.20 Ir 1.80 O7、Tb2Ru 0.15 Ir 1.85 O7、Tb2Ru 0.10 Ir 1.90 O7、Tb2Ru 0.05 Ir 1.95 At least one of O7.

[0023] According to a specific embodiment of the present invention, preferably, the ruthenium-iridium-terbium nanocatalyst is particulate with a particle size of 40-180 nm, more preferably, with a particle size of 60-80 nm. The ruthenium-iridium-terbium nanocatalyst with a particle size within the above range can have a higher specific surface area and exhibit better oxygen evolution reaction (OER) catalytic activity.

[0024] According to a specific embodiment of the present invention, the preparation method of the above-mentioned ruthenium-iridium-terbium nanocatalyst includes the following steps:

[0025] (1) Provide a mixed solution containing ruthenium ions, terbium ions and iridium ions;

[0026] (2) Add water-soluble organic matter as a metal ion complex to the mixed solution and dry it to obtain a gel precursor;

[0027] (3) The gel precursor was pulverized and calcined in an oxygen-containing atmosphere to obtain ruthenium-iridium-terbium nanocatalyst.

[0028] According to a specific embodiment of the present invention, preferably, in the above preparation method, in the mixed solution of step (1), the molar ratio of ruthenium ions, terbium ions and iridium ions is the same as that of the Tb2Ru x Ir 2-x The molar ratios of Ru, Tb, and Ir in O7 are the same. In step (1), deionized water can be used as the solvent for the mixed solution.

[0029] According to a specific embodiment of the present invention, preferably, in the above preparation method, the concentration of ruthenium ions in the mixed solution is 0.001-0.1 mol / L, the concentration of terbium ions is 0.001-0.1 mol / L, and the concentration of iridium ions is 0.001-0.1 mol / L, based on the volume of the mixed solution. More preferably, the concentration of ruthenium ions in the mixed solution is 0.01-0.05 mol / L, the concentration of terbium ions is 0.01-0.05 mol / L, and the concentration of iridium ions is 0.005-0.02 mol / L.

[0030] According to a specific embodiment of the present invention, preferably, in the above preparation method, the water-soluble organic compound is selected from one or more combinations of citric acid, glycine, malic acid, and ethylenediaminetetraacetic acid. In the preparation of the gel precursor of the present invention, only one water-soluble organic compound is needed as a metal ion complex, without the need to add alcohols.

[0031] According to a specific embodiment of the present invention, preferably, in the above preparation method, the molar ratio of the water-soluble organic matter to the metal ions (i.e., the sum of ruthenium ions, terbium ions, and iridium ions) is 1:1 to 1:4.

[0032] According to a specific embodiment of the present invention, preferably, in the above preparation method, the drying temperature is 70℃-90℃, more preferably 80℃. In the process of preparing the gel precursor, the various raw materials only need to be mixed in water and dried at a low temperature, without the need for a long heating reaction process. Therefore, this process of the present invention is relatively simple and low in cost.

[0033] According to a specific embodiment of the present invention, preferably, in the above preparation method, the calcination temperature is 700-1100℃ and the holding time is 1-12 hours.

[0034] According to a specific embodiment of the present invention, preferably, in the above preparation method, the ruthenium ions are provided by one or more combinations of ruthenium nitrate, ruthenium acetate, and ruthenium trichloride; the terbium ions are provided by one or more combinations of terbium chloride, terbium nitrate, and terbium acetate; and the iridium ions are provided by iridium chloride and / or iridium tetrachloride.

[0035] The structure and properties of the catalyst layer have a significant impact on the activation polarization, concentration polarization, and ohmic polarization of electrochemical reactions. The catalyst in the catalyst layer is one of the key factors affecting activation polarization. In the ruthenium-iridium-terbium catalyst used in this invention, the terbium ion has a unique outermost 4f electron configuration (4f... 8 Half-filled or fully-filled orbitals are relatively stable and difficult to lose further electrons, while terbium ions, which can reach a half-filled state by losing just one electron, easily transition to an electron-deficient state (4f). 7 Due to the Tb-O-Ru double exchange in pyrochlore, more electrons can be induced from ruthenium ions to terbium ions, thereby inducing more highly active pentavalent ruthenium sites. Furthermore, the ruthenium-iridium-terbium catalyst used in this invention employs Ir... 4+ Replace some of the Ru in the pyrochlore-structured Tb2Ru2O7 4+ Compared to Tb₂Ru₂O₇, the ruthenium-iridium-terbium catalyst of this invention forms a [IrO₆]-[RuO₆] network structure. Electrons at ruthenium sites can be transferred to iridium sites via oxygen. This double exchange interaction constructs a spin-polarized charge transport channel, optimizes the spin distribution of d-orbital electrons in Ru and Ir, shortens the Ru-O bond length, effectively weakens the octahedral distortion caused by the Jameer-Taylor effect, and achieves the construction of a stable [IrO₆]-[RuO₆] framework. This alleviates the Jameer-Taylor distortion of the [RuO₆] unit in pyrochlore, thereby making the active sites of the ruthenium-iridium-terbium catalyst more stable in the OER process, obtaining a more ideal octahedral stable framework structure, improving the intrinsic activity and stability of the catalyst, and thus promoting the oxygen evolution reaction.

[0036] The present invention also provides a method for preparing the above-mentioned proton exchange membrane electrolysis water membrane electrode, which includes the following steps:

[0037] S1: Preparation of anode catalyst slurry;

[0038] S2: An anode catalyst layer is prepared on one side of the proton exchange membrane using the anode catalyst slurry;

[0039] S3: Preparation of cathode catalyst slurry;

[0040] S4: Prepare a cathode catalyst layer on the other side of the proton exchange membrane using the cathode catalyst slurry;

[0041] S5: The proton exchange membrane, on which the anode catalytic layer and the cathode catalytic layer are formed on both sides respectively, is hot-pressed to obtain the proton exchange membrane water electrolysis membrane electrode.

[0042] According to a specific embodiment of the present invention, preferably, step S1, preparing the anode catalyst slurry, includes the following steps:

[0043] S11: Place water (deionized water) in the inner cavity of the jacketed container, connect ice water to the outer cavity of the jacketed container for circulating cooling, and stir in the inner cavity of the jacketed container.

[0044] S12: Add the ionomer and liquid alcohol to the inner cavity of the jacketed container in sequence, and disperse them using a dispersion device to obtain a dispersion.

[0045] S13: The anode catalyst is added to the dispersion in multiple portions and dispersed using a dispersion device to obtain the anode catalyst slurry.

[0046] According to a specific embodiment of the present invention, preferably, in the process of preparing the anode catalyst slurry, the dispersion or stirring is achieved by a high-speed shear mill, an ultrasonic crusher, an ultrasonic cell pulverizer, a high-pressure homogenizer, or a high-energy ball mill with cooling function. More preferably, the high-speed shear mill rotates at 2000-5000 rpm, the ultrasonic crusher has a power of 600-1000 W, the ultrasonic cell pulverizer has a power of 600-1000 W, the high-energy ball mill rotates at 1000-2500 rpm, and the high-pressure homogenizer has a dispersion pressure of 15000 psi-17000 psi.

[0047] According to a specific embodiment of the present invention, preferably, in step S12, the dispersion time is 0.5-1h.

[0048] According to a specific embodiment of the present invention, preferably, in step S13, the dispersion time is 1-2 hours.

[0049] According to a specific embodiment of the present invention, preferably, based on the mass of the anode catalyst slurry as 100%, the amount of the anode catalyst is 1-30 wt%, and the amount of the ionomerized quantum conductor is 0.75-3%.

[0050] According to a specific embodiment of the present invention, preferably, the ionomer is a perfluorosulfonic acid resin solution, the concentration of the perfluorosulfonic acid resin solution is 5-20 wt%, and the perfluorosulfonic acid resin is selected from one or more of DuPont Nafion resin, Solvay D79 series resin, Asahi Glass IC100 resin and Asahi Glass IC154 resin.

[0051] According to a specific embodiment of the present invention, preferably, the liquid alcohol is selected from one or more combinations of ethanol, propanol, butanol, ethylene glycol, ethoxyethanol, and methoxyethanol.

[0052] According to a specific embodiment of the present invention, preferably, the volume ratio of water to liquid alcohol is 1:1 to 1:8. The water can be deionized water. In the anode catalyst slurry of the present invention, different water-to-alcohol ratios result in different solvent properties, including boiling point, viscosity, rheology, surface tension, and dielectric constant. These properties affect the dispersion state of the catalyst particles and ionomers, thereby affecting the dispersibility, stability, and final catalyst layer performance of the catalyst slurry itself.

[0053] According to a specific embodiment of the present invention, preferably, step S2, which involves preparing the anode catalyst layer using the anode catalyst slurry, includes the following steps:

[0054] The anode catalyst slurry is sprayed or coated onto the surface of the proton exchange membrane to obtain the anode catalyst layer.

[0055] According to a specific embodiment of the present invention, preferably, the spraying is achieved by ultrasonic spraying. The specific steps, operations, and parameters of ultrasonic spraying can be selected and controlled in a conventional manner as needed.

[0056] According to a specific embodiment of the present invention, preferably, the coating is achieved by slit coating with heat transfer printing. The specific steps, operations, and parameters of slit coating with heat transfer printing can be selected and controlled in a conventional manner as needed.

[0057] According to a specific embodiment of the present invention, preferably, the proton exchange membrane is located on a substrate, and more preferably, the temperature of the substrate is 80-90°C.

[0058] According to a specific embodiment of the present invention, preferably, the flow rate of the sprayed anode catalyst slurry is 0.2-2 mL / min.

[0059] According to a specific embodiment of the present invention, preferably, the preparation of the cathode catalyst slurry in step S3 includes the following steps:

[0060] S31: Place deionized water into the inner cavity of the jacketed container, connect ice water to the outer cavity of the jacketed container for circulating cooling, and stir in the inner cavity of the jacketed container.

[0061] S32: In the inner cavity of the jacketed container, add the ionic polymer solution and liquid alcohol in sequence to disperse them and obtain a dispersion.

[0062] S33: The cathode catalyst is added to the dispersion in multiple portions for further dispersion to obtain a cathode catalyst slurry.

[0063] According to a specific embodiment of the present invention, preferably, in the process of preparing the cathode catalyst slurry, the dispersion or stirring can be achieved by a high-speed shear mill, an ultrasonic crusher, an ultrasonic cell pulverizer, a high-pressure homogenizer, or a high-energy ball mill with cooling function. More preferably, the high-speed shear mill rotates at 2000-5000 rpm, the ultrasonic crusher has a power of 300-400W, the ultrasonic cell pulverizer has a power of 300-400W, the high-energy ball mill rotates at 1000-2500 rpm, and the high-pressure homogenizer has a dispersion pressure of 15000psi-17000psi.

[0064] According to a specific embodiment of the present invention, preferably, in step S32, the dispersion time is 0.5-1h.

[0065] According to a specific embodiment of the present invention, preferably, in step S33, the dispersion time is 0.5-1h.

[0066] According to a specific embodiment of the present invention, preferably, step S4 includes the following steps:

[0067] S41: Spray or coat the cathode catalyst slurry onto the other side of the proton exchange membrane that has been coated with the anode catalyst layer to obtain the cathode catalyst layer.

[0068] According to a specific embodiment of the present invention, preferably, in steps S2 and S41, the spraying includes a method of directly spraying onto the surface of the proton exchange membrane, and a method of spraying onto the surface of the transfer membrane and then transferring onto the surface of the proton exchange membrane.

[0069] According to a specific embodiment of the present invention, preferably, in steps S2 and S41, the coating includes a method of directly coating onto the surface of the proton exchange membrane, and a method of coating onto the surface of the transfer membrane and then transferring onto the surface of the proton exchange membrane.

[0070] According to a specific embodiment of the present invention, preferably, in step S41, the spraying is achieved by ultrasonic spraying, and the coating is achieved by slit coating with heat transfer. The specific steps, operations, and parameters of ultrasonic spraying can be selected and controlled in a conventional manner as needed.

[0071] According to a specific embodiment of the present invention, preferably, the coating is achieved by slit coating with heat transfer printing. The specific steps, operations, and parameters of slit coating with heat transfer printing can be selected and controlled in a conventional manner as needed.

[0072] According to a specific embodiment of the present invention, preferably, in step S5, the proton exchange membrane coated with the anode catalyst layer and the cathode catalyst layer is hot-pressed, wherein the hot-pressing temperature is 120℃-140℃ and the pressure is 3MPa-15MPa.

[0073] The proton exchange membrane electrolysis water membrane electrode of this invention uses an anode catalyst slurry with uniform catalyst dispersion and suitable overall slurry viscosity. This avoids problems such as catalyst sedimentation and agglomeration, and prevents the risk of subsequent membrane electrode catalyst layer cracking and detachment, which would affect catalytic performance. At the same time, by adjusting the slurry formulation and preparation method during the slurry preparation process, the activity and stability of the ruthenium-iridium-terbium catalyst in the slurry are maintained to the maximum extent, further improving the membrane electrode performance. In addition, it exhibits higher oxygen evolution reaction (OER) activity and stability under harsh working environments of high voltage and strong acidity, and significantly reduces the content of noble metals Ru and Ir, thus preparing a high-performance PEMWE membrane electrode with low noble metal content, thereby reducing the technical cost of PEMWE.

[0074] The membrane electrode catalytic layer, a porous layer mainly composed of electrocatalysts and ionomers acting as electron conductors, is the core site for electrocatalytic reactions involving multiphase mass transport and energy conversion. The structure and characteristics of the catalytic layer significantly influence the activation polarization, ohmic polarization, and concentration polarization of the electrochemical reaction. The amount and distribution of ionomers, which function as proton conductors and binders, have a substantial impact on electrolysis performance. Insufficient ionomers lead to decreased proton conductivity, while excessive ionomers occupy too much volume, reducing pore permeability, increasing oxygen transport resistance, and even causing oxygen accumulation and microbubbles that tear the catalytic layer, resulting in localized peeling and reduced durability after long-term operation. Conversely, excessive ionomers decrease conductivity within the catalytic layer and increase the contact resistance between the catalytic layer and the diffusion layer. Therefore, the design and development of the catalytic layer require comprehensive consideration of the three-phase reactions involving protons, electrons, and mass transport, as well as the compatibility, suitability, and durability of various materials.

[0075] The membrane electrode and its preparation method provided by this invention can obtain a catalyst layer with uniform distribution of noble metals. The microstructure of the membrane electrode catalyst layer is uniform, consistent, and continuous, which is conducive to the exposure of active centers. While reducing the amount of noble metals used, it improves the electrolytic activity and stability of the membrane electrode catalyst layer. In addition, this invention maximizes the construction of the three-phase interface by adjusting the composition of the catalyst layer and the membrane electrode preparation method, improves the contact between the catalyst layer and the membrane electrode interface, increases the mass transfer and charge transport of the catalyst layer, helps maintain the activity and stability of the ruthenium-iridium-terbium catalyst, and improves the performance of the membrane electrode. Attached Figure Description

[0076] Figure 1 shows the XRD diffraction patterns of the ruthenium-iridium-terbium catalysts prepared in Examples 1-3 and the Tb2Ru2O7 and Tb2Ir2O7 prepared in Comparative Examples 1-2.

[0077] Figure 2 shows the SEM images of the ruthenium-iridium-terbium catalysts prepared in Examples 1-3 and the Tb2Ru2O7 and Tb2Ir2O7 prepared in Comparative Examples 1-2.

[0078] Figure 3 shows the particle size distribution statistics of the ruthenium-iridium-terbium catalysts prepared in Examples 1-3 and the Tb2Ru2O7 and Tb2Ir2O7 in Comparative Examples 1-2.

[0079] Figure 4 shows the polarization curves of the ruthenium-iridium-terbium catalysts prepared in Examples 1-3 and the catalysts in Comparative Examples 1-4 in 0.5M sulfuric acid solution.

[0080] Figure 5 shows the ruthenium-iridium-terbium catalysts prepared in Examples 1-3 and the catalysts in Comparative Examples 1-4 in 0.5M sulfuric acid solution at 10 mA / cm². 2 Chronopotential curves at current density.

[0081] Figure 6 is an optical microscope image of the anode catalyst layer prepared in Example 7.

[0082] Figure 7 is an optical microscope image of the anode catalyst layer prepared in Comparative Example 10. Detailed Implementation

[0083] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0084] The raw materials involved in the examples are as follows:

[0085] Deionized water: homemade, 18.2MΩ

[0086] Anode catalyst: Self-made ruthenium-iridium-terbium catalyst Tb2Ru 0.4 Ir 1.6 O7、Tb2Ru 1.0 Ir 1.0 O7、Tb2Ru 1.6 Ir 0.4 O7; Tb2Ru2O7, Tb2Ir2O7 catalysts.

[0087] Cathode catalysts: 10 wt% Pt / C catalyst (Pt content 10%), 20 wt% Pt / C catalyst (Pt content 20%), 40 wt% Pt / C catalyst (Pt content 40%).

[0088] Proton exchange membrane: DuPont N117 type proton exchange membrane.

[0089] Ionomers: Perfluorosulfonic acid resin solution (5% content, Chemours), Perfluorosulfonic acid resin solution (20% content, Chemours).

[0090] Equipment: Multi-channel PEM water electrolysis membrane electrode test stand, handheld X-ray fluorescence spectrometer.

[0091] Example 1

[0092] This embodiment provides a PEM electrolysis water anode catalyst slurry I, which, by mass percentage, comprises: 1.5% Tb2Ru 1.6 Ir 0.4 O7, 15% perfluorosulfonic acid resin solution (mass concentration of 5%) and 83.5% solvent; wherein the perfluorosulfonic acid resin is a commercial resin with an ion exchange equivalent of 1000, and the solvent is a mixture of deionized water and isopropanol in a volume ratio of 1:1.

[0093] The preparation process of this slurry I includes the following steps:

[0094] S1: Take 46.8g of deionized water and place it in the inner cavity of the jacketed container. Introduce ice water in the jacket layer for circulating cooling. Stir the inner cavity of the jacketed container using an ultrasonic cell disruptor.

[0095] S2: In the inner cavity of the jacketed container, add 15.0g of perfluorosulfonic acid resin solution and 36.7g of isopropanol in sequence, and disperse them rapidly using an ultrasonic cell disruptor with a power of 900W for 0.5 hours to obtain a dispersed solvent.

[0096] S3: Add 1.5g Tb2Ru 1.6 Ir 0.4 The O7 catalyst was added to the dispersed solvent of S2 in two batches and then rapidly dispersed using an ultrasonic cell disruptor at a power of 900W for 1 hour to obtain anode catalyst slurry I.

[0097] The ruthenium-iridium-terbium nanocatalyst used in this embodiment is Tb2Ru. 1.6 Ir 0.4 O7, with a pyrochlore structure and a particle size between 40-180 nm, is prepared by the following specific steps:

[0098] (1) Dissolve 0.84g of citric acid in 20mL of deionized water, add 0.173g of terbium chloride, 0.083g of ruthenium nitrate and 0.015g of iridium chloride, and sonicate to dissolve evenly to obtain a mixed solution;

[0099] (2) The above mixed solution was placed in an oven at 80°C and dried and aged to obtain a fluffy dry gel. The dry gel was ball-milled to obtain gel powder.

[0100] (3) The above gel powder was heated in a muffle furnace at 1000℃ for 4 hours to obtain the powder product Tb2Ru. 1.6 Ir 0.4 O7.

[0101] Example 2

[0102] This embodiment provides a PEM electrolysis water anode catalyst slurry II, which, by mass percentage, comprises: 10% Tb2Ru 1.0 Ir 1.0 O7, 10% perfluorosulfonic acid resin solution (mass concentration of 20%) and 80% solvent; wherein the perfluorosulfonic acid resin is a commercial resin with an ion exchange equivalent of 1000, and the solvent is a mixture of deionized water and isopropanol in a volume ratio of 1:2.

[0103] The preparation process of slurry II includes the following steps:

[0104] S1: Take 31.1g of deionized water and place it in the inner cavity of the jacketed container. Introduce ice water in the jacket layer for circulating cooling. Stir the inner cavity of the jacketed container using an ultrasonic cell disruptor.

[0105] S2: Add 10.0g of perfluorosulfonic acid resin solution and 48.9g of isopropanol sequentially into the inner cavity of the jacketed container, and disperse them rapidly using an ultrasonic cell disruptor at a power of 900W for 0.5 hours to obtain a dispersed solvent.

[0106] S3: Add 10g of Tb2Ru anode catalyst 1.0 Ir 1.0 The O7 catalyst was added to the dispersed solvent in S2 in two batches and then dispersed rapidly using an ultrasonic cell disruptor at a power of 900W for 1 hour to obtain anode catalyst slurry II.

[0107] The ruthenium-iridium-terbium nanocatalyst used in this embodiment is Tb2Ru. 1.0 Ir 1.0 O7, with a pyrochlore structure and a particle size between 40-160 nm, is prepared by the following specific steps:

[0108] (1) Dissolve 0.48g glycine in 20mL deionized water, add 0.055g iridium tetrachloride, 0.073g ruthenium acetate and 0.173g terbium chloride, and sonicate to dissolve evenly to obtain a mixed solution;

[0109] (2) The above mixed solution was placed in an oven at 80°C and dried and aged to obtain a fluffy dry gel. The dry gel was ball-milled to obtain gel powder.

[0110] (3) The above gel powder was heated in a muffle furnace at 1000℃ for 4 hours to obtain the powder product Tb2Ru. 1.0 Ir 1.0 O7.

[0111] Example 3

[0112] This embodiment provides a PEM electrolysis water anode catalyst slurry III, wherein, by mass percentage, the composition of slurry III includes: 30% Tb2Ru 0.4 Ir 1.6 O7, 15% perfluorosulfonic acid resin solution (mass concentration of 20%) and 55% solvent; wherein, the perfluorosulfonic acid resin is a commercial resin with an ion exchange equivalent of about 1000, and the solvent is a mixture of deionized water and isopropanol in a volume ratio of 1:2.

[0113] The preparation process of this slurry III includes the following steps:

[0114] S1: Take 21.4g of deionized water and place it in the inner cavity of the jacketed container. Introduce ice water into the jacket layer for circulating cooling. Stir the contents of the inner cavity of the jacketed container using a high-speed shearing machine.

[0115] S2: Add 15.0g of perfluorosulfonic acid resin solution and 33.6g of isopropanol sequentially into the inner cavity of the jacketed container, and disperse them rapidly using an ultrasonic cell disruptor at a power of 900W for 0.5 hours to obtain a dispersed solvent.

[0116] S3: Add 30g of Tb2Ru anode catalyst 0.4 Ir 1.6 The O7 catalyst was added to the dispersed solvent in S2 in three parts, and then rapidly dispersed using a high-speed shear mill at 2000 rpm for 1.5 hours to obtain anode catalyst slurry III.

[0117] The ruthenium-iridium-terbium nanocatalyst used in this embodiment is Tb2Ru. 0.4 Ir 1.6 O7, with a pyrochlore structure and a particle size between 40-140 nm, is prepared by the following specific steps:

[0118] (1) Dissolve 0.48g glycine in 20mL deionized water, add 0.088g iridium tetrachloride, 0.041g ruthenium trichloride and 0.173g terbium chloride, and sonicate to dissolve evenly to obtain a mixed solution;

[0119] (2) The above mixed solution was placed in an oven at 80°C and dried and aged to obtain a fluffy dry gel. The dry gel was ball-milled to obtain gel powder.

[0120] (3) The above gel powder was heated in a muffle furnace at 1000℃ for 4 hours to obtain the powder product Tb2Ru. 0.4 Ir 1.6 O7.

[0121] Comparative Example 1

[0122] This comparative example provides an anode catalyst slurry D1, wherein, except for the selection of the catalyst, the composition and preparation method of the slurry are the same as those in Example 1.

[0123] The catalyst used in this comparative example is a ruthenium-terbium catalyst (without iridium doping), with the molecular formula Tb2Ru2O7. This Tb2Ru2O7 catalyst has a pyrochlore structure and is a catalyst without iridium substitution, with a particle size between 40-180 nm.

[0124] The preparation steps of this ruthenium-terbium catalyst are as follows:

[0125] (1) Dissolve 0.84g of citric acid in 20mL of deionized water, add 0.103g of ruthenium trichloride and 0.173g of terbium chloride, and sonicate to dissolve evenly to obtain a mixed solution;

[0126] (2) The above mixed solution was placed in an oven at 80°C and dried and aged to obtain a fluffy dry gel. The dry gel was ball-milled to obtain gel powder.

[0127] (3) The above gel powder was heated in a muffle furnace at 1100℃ for 2 hours to obtain the powder product Tb2Ru2O7.

[0128] Comparative Example 2

[0129] This comparative example provides an anode catalyst slurry D2, wherein, except for the selection of the catalyst, the composition and preparation method of the slurry are the same as those in Example 2.

[0130] The catalyst used in this comparative example is Tb2Ir2O7 (ruthenium-free) catalyst, which has a pyrochlore structure and a particle size between 40-140 nm.

[0131] The preparation steps of this Tb₂Ir₂O₇ catalyst are as follows:

[0132] (1) Dissolve 0.84g of citric acid in 20mL of deionized water, add 0.11g of iridium tetrachloride and 0.173g of terbium chloride, and sonicate to dissolve evenly to obtain a mixed solution;

[0133] (2) The above mixed solution was placed in an oven at 80°C and dried and aged to obtain a fluffy dry gel. The dry gel was ball-milled to obtain gel powder.

[0134] (3) The above gel powder was heated in a muffle furnace at 1100℃ for 6 hours to obtain the powder product Tb2Ir2O7.

[0135] Comparative Example 3

[0136] This comparative example provides a slurry D3, in which a commercially available IrO2 catalyst was used, purchased from Alfaisa (China) Chemical Co., Ltd., CAS No. 12030-49-8, with a purity of 99.99%. Except for the choice of catalyst, the composition and preparation method of the slurry are the same as in Example 2.

[0137] Comparative Example 4

[0138] This comparative example provides a slurry D4, in which the catalyst used is a commercial RuO2 catalyst purchased from Alfaisa (China) Chemical Co., Ltd., CAS No. 12036-10-1, with a purity of 99.95%. Except for the choice of catalyst, the composition and preparation method of the slurry are the same as in Example 1.

[0139] Example 4

[0140] This embodiment provides a cathode catalyst slurry I, the preparation method of which is as follows:

[0141] Cathode catalyst: 10 wt% Pt / C was used as the cathode catalyst.

[0142] Preparation of cathode catalyst slurry I: Except for the selection of catalyst and the ultrasonic power of 300W, the composition and preparation method of the slurry are the same as in Example 1.

[0143] Example 5

[0144] This embodiment provides a PEM electrolysis water cathode catalyst slurry II, which, by mass percentage, comprises: 1.5% 20wt% Pt / C, 9% perfluorosulfonic acid resin solution (mass concentration of 5%), and 89.5% solvent; wherein the perfluorosulfonic acid resin is a commercial resin with an ion exchange equivalent of 1000, and the solvent is a mixture of deionized water and isopropanol in a volume ratio of 1:1.

[0145] The preparation process of this slurry II includes the following steps:

[0146] S1: Take 50.1g of deionized water and place it in the inner cavity of the jacketed container. Introduce ice water in the jacket layer for circulating cooling. Stir the inner cavity of the jacketed container using an ultrasonic cell disruptor.

[0147] S2: In the inner cavity of the jacketed container, add 9.0g of perfluorosulfonic acid resin solution and 39.4g of isopropanol in sequence, and disperse them rapidly using an ultrasonic cell disruptor at a power of 350W for 0.5 hours to obtain a dispersed solvent.

[0148] S3: Add 1.5g of 20wt% Pt / C catalyst to the dispersed solvent of S2 in two portions, and continue to disperse rapidly using an ultrasonic cell disruptor at a power of 350W for 1 hour to obtain cathode catalyst slurry II.

[0149] Example 6

[0150] This embodiment provides a PEM electrolysis water cathode catalyst slurry III, which, by mass percentage, comprises: 1% 40wt% Pt / C, 0.5% perfluorosulfonic acid resin solution (mass concentration of 20%), and 98.5% solvent; wherein the perfluorosulfonic acid resin is a commercial resin with an ion exchange equivalent of 1000, and the solvent is a mixture of deionized water and isopropanol in a volume ratio of 1:2.

[0151] The preparation process of this slurry III includes the following steps:

[0152] S1: Take 38.3g of deionized water and place it in the inner cavity of the jacketed container. Introduce ice water in the jacket layer for circulating cooling. Stir the inner cavity of the jacketed container using an ultrasonic cell disruptor.

[0153] S2: Add 0.5g of perfluorosulfonic acid resin solution and 60.2g of isopropanol sequentially into the inner cavity of the jacketed container, and disperse them rapidly using an ultrasonic cell disruptor at a power of 400W for 0.5 hours to obtain a dispersed solvent.

[0154] S3: Add 1.0g of 40wt% Pt / C catalyst to the dispersed solvent in S2 in two portions, and continue to disperse rapidly using an ultrasonic cell disruptor at 400W for 1 hour to obtain cathode catalyst slurry III.

[0155] Example 7

[0156] This embodiment provides a membrane electrode CCM1, the preparation method of which is as follows:

[0157] Anode catalyst slurry I was coated onto the surface of N117 membrane (proton exchange membrane) using ultrasonic spraying, with the heating plate temperature at 90°C and the spraying speed at 1.3 mL / min.

[0158] The iridium content on the anode side was determined to be 0.23 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the anode catalyst loading is 2.0 mg / cm³.2 The coated anode side is obtained.

[0159] The cathode catalyst slurry II was sprayed onto the other side of the N117 membrane using ultrasonic spraying, with the heating plate temperature at 80°C and the spraying speed at 2.0 mL / min.

[0160] The platinum content on the cathode side was determined to be 0.20 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the cathode catalyst loading is 1.0 mg / cm³. 2 The coated cathode side is obtained.

[0161] Finally, the proton exchange membrane after hot-pressing the cathode and anode catalyst layers at 120℃ and 5MPa for 5 minutes was used to obtain the membrane electrode CCM1.

[0162] Example 8

[0163] This embodiment provides a membrane electrode CCM2, the preparation method of which is as follows:

[0164] The anode catalyst slurry II was coated onto the PTFE membrane (transfer membrane) using a slot coater, dried at 80°C, and then transferred to the surface of the N117 membrane by hot pressing.

[0165] The iridium content on the anode side was determined to be 0.80 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the anode catalyst loading is 3.0 mg / cm³. 2 The coated anode side is obtained.

[0166] The cathode catalyst slurry III was sprayed onto the other side of the N117 membrane using ultrasonic spraying, with the heating plate temperature at 85°C and the spraying speed at 2.0 mL / min.

[0167] The platinum content on the cathode side was determined to be 0.15 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the cathode catalyst loading is 0.375 mg / cm³. 2 The coated cathode side is obtained.

[0168] Finally, the proton exchange membrane after hot-pressing the cathode and anode catalyst layers at 140℃ and 10MPa for 2 minutes was obtained as membrane electrode CCM2.

[0169] Example 9

[0170] This embodiment provides a membrane electrode CCM3, the preparation method of which is as follows:

[0171] The anode catalyst slurry III was coated onto the PTFE membrane (transfer membrane) using a slot coater, dried at 85°C, and then transferred to the surface of the N117 membrane by hot pressing.

[0172] The iridium content on the anode side was determined to be 0.99 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the anode catalyst loading is 2.5 mg / cm³. 2 The coated anode side is obtained.

[0173] The cathode catalyst slurry I was sprayed onto the other side of the N117 membrane using ultrasonic spraying, with the heating plate temperature at 90°C and the spraying speed at 1.0 mL / min.

[0174] The platinum content on the cathode side was determined to be 0.10 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the cathode catalyst loading is 1.0 mg / cm³. 2 The coated cathode side is obtained.

[0175] Finally, the proton exchange membrane after hot-pressing the cathode and anode catalyst layers at 130℃ and 15MPa for 1 min was obtained as membrane electrode CCM3.

[0176] Example 10

[0177] This embodiment provides a membrane electrode CCM4, the preparation method of which is as follows:

[0178] The anode catalyst slurry I was coated onto the surface of the N117 membrane (proton exchange membrane) using ultrasonic spraying, with the heating plate temperature at 90°C and the spraying speed at 2.0 mL / min.

[0179] The iridium content on the anode side was determined to be 1.99 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the anode catalyst loading is 17.34 mg / cm³. 2 The coated anode side is obtained.

[0180] The cathode catalyst slurry III was sprayed onto the other side of the N117 membrane using ultrasonic spraying, with the heating plate temperature at 90°C and the spraying speed at 2.0 mL / min.

[0181] The platinum content on the cathode side was determined to be 0.40 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the cathode catalyst loading is 1.0 mg / cm³. 2 The coated cathode side is obtained.

[0182] Finally, the proton exchange membrane after hot-pressing the cathode and anode catalyst layers at 120℃ and 7MPa for 4 minutes was used to obtain the membrane electrode CCM4.

[0183] Example 11

[0184] This embodiment provides a membrane electrode CCM5, the preparation method of which is as follows:

[0185] The anode catalyst slurry III was coated onto the PTFE membrane (transfer membrane) using a slot coater, dried at 80°C, and then transferred to the surface of the N117 membrane by hot pressing.

[0186] The iridium content on the anode side was determined to be 0.02 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the anode catalyst loading is 0.05 mg / cm³. 2 The coated anode side is obtained.

[0187] The cathode catalyst slurry III was sprayed onto the other side of the N117 membrane using ultrasonic spraying, with the heating plate temperature at 85°C and the spraying speed at 0.5 mL / min.

[0188] The platinum content on the cathode side was determined to be 0.04 mg / cm³ using a handheld X-ray fluorescence spectrometer. 2 That is, the cathode catalyst loading is 0.10 mg / cm³. 2 The coated cathode side is obtained.

[0189] Finally, the proton exchange membrane after hot-pressing the cathode and anode catalyst layers at 120℃ and 3MPa for 2 minutes was obtained to obtain the membrane electrode CCM5.

[0190] Comparative Example 5

[0191] This comparative example provides a membrane electrode D1, wherein, except that the anode slurry uses anode catalyst slurry D1, the composition and preparation method of the membrane electrode are the same as in Example 7.

[0192] Comparative Example 6

[0193] This comparative example provides a membrane electrode D2, wherein, except that the anode slurry uses anode catalyst slurry D2, the composition and preparation method of the membrane electrode are the same as those in Example 8.

[0194] Comparative Example 7

[0195] This comparative example provides a membrane electrode D3, wherein, except that the anode slurry uses anode catalyst slurry D3, the composition and preparation method of the membrane electrode are the same as those in Example 8.

[0196] Comparative Example 8

[0197] This comparative example provides a membrane electrode D4, wherein, except that the anode slurry uses anode catalyst slurry D4, the composition and preparation method of the membrane electrode are the same as in Example 7.

[0198] Comparative Example 9

[0199] This comparative example provides an anode catalyst slurry D5 and a membrane electrode D5. In the preparation of the anode catalyst slurry D5, a perfluorosulfonic acid resin solution diluted to 0.5% is used. The composition and preparation method of the remaining slurries are the same as in Example 1.

[0200] The anode slurry of membrane electrode D5 uses anode catalyst slurry D5. The composition and preparation method of the remaining membrane electrode components are the same as in Example 7, that is, the mass ratio of ionomer catenary to anode catalyst in the anode catalyst layer of membrane electrode D5 is 0.05.

[0201] Comparative Example 10

[0202] This comparative example provides a membrane electrode D6, wherein, except that the hot-pressing temperature is set to room temperature, the composition and preparation method of the membrane electrode are the same as those in Example 7.

[0203] To better illustrate the advantages of the technical solution of the present invention, corresponding performance tests were conducted on the materials of Examples 1-3 and Comparative Examples 1-4:

[0204] (1) XRD characterization

[0205] The self-made catalyst materials from Examples 1-3 and Comparative Examples 1-2, which were not commercially sourced, were characterized by X-ray powder diffraction, and the results are shown in Figure 1. As can be seen from Figure 1, the Ir-substituted Ru ruthenium-iridium-terbium catalysts of Examples 1-3 and the undoped Tb₂Ru₂O₇ and Tb₂Ir₂O₇ catalysts of Comparative Examples 1-2 have similar characteristic peaks. However, the diffraction peaks of the examples are slightly shifted to lower angles, indicating that iridium doping causes a slight lattice expansion.

[0206] (2) SEM characterization

[0207] The catalyst materials used in Examples 1-3 and Comparative Examples 1-2 were subjected to scanning electron microscopy (SEM) tests, and the results are shown in Figure 2. Figure 2 shows that the Ir-substituted Ru ruthenium-iridium-terbium catalysts of Examples 1-3, the undoped Tb₂Ru₂O₇ catalysts of Comparative Examples 1-2, and the Tb₂Ir₂O₇ catalysts have similar particle sizes, mostly between 40-180 nm. Figure 3 shows the particle size distribution of the ruthenium-iridium-terbium catalysts used in Examples 1-3 and the catalysts used in Comparative Examples 1-2. Figure 3 shows that the particle size of the catalysts in Examples 1-3 tends to decrease after Ir doping substitution, indicating that doping substitution plays a role in refining the grain size.

[0208] (3) Electrochemical testing

[0209] Three-electrode testing is performed in an acidic solution, following these steps:

[0210] Take 4 mg of each of the catalyst materials used in Examples 1-3 and Comparative Examples 1-4, mix them with 1 mg of acetylene black, dissolve them in 0.5 mL of ethanol, and ultrasonically disperse them for 30 min respectively.

[0211] Add 20 μL of 5 wt% Nafion solution to each electrode and continue dispersing for 30 min. Take 5 μL and coat it onto a glassy carbon electrode with a diameter of 4 mm. Let it air dry to obtain the electrode.

[0212] Using the aforementioned electrode as the working electrode, the standard hydrogen electrode as the reference electrode, and the shape-stable anode as the counter electrode (shape-stable anode refers to the coated titanium anode, commonly known as the size-stable anode, abbreviated as DSA), a three-electrode electrochemical system was formed, and its electrochemical performance was tested in 0.5M H2SO4 solution. The voltage scan range of the polarization curve was 1.1–1.6 V, and the scan rate was 10 mV / s. The results are shown in Figure 4, and the overpotential results are shown in Table 1 below.

[0213] The working electrode is at 10 mA / cm 2 The current density was continuously operated in a three-electrode electrolytic cell, and the voltage change curve over time was recorded. The results are shown in Figure 5.

[0214] Table 1

[0215] As can be seen from the overpotential data shown in Table 1, the catalysts used in the examples have high oxygen evolution activity. The catalysts of Examples 1-3 and Comparative Example 1 all have better oxygen evolution reaction catalytic activity than the commercial catalysts of Comparative Examples 3-4, proving that the catalysts and their preparation methods provided in the examples are advanced.

[0216] As can be seen from Figure 4 and Table 1, at a potential of 1.5V relative to the standard hydrogen electrode potential, the electrode current density corresponding to Example 1 is higher than that corresponding to Comparative Examples 1-2, and much higher than that of Comparative Examples 3-4.

[0217] As can be seen from Figure 5 and Table 1, during the constant current electrolysis process of more than 30 hours, the electrode voltage of the catalyst in Example 1 did not change significantly, while the electrode made of Tb2Ru2O7 in Comparative Example 1 showed a significant performance degradation after 10 hours of electrolysis. This indicates that the ruthenium-iridium-terbium catalyst provided by the present invention can significantly improve the intrinsic stability in the acidic oxygen evolution reaction.

[0218] Therefore, the oxygen evolution reaction catalyst provided in the embodiments of the present invention has the characteristics of high catalytic activity and good stability, and its preparation method is simple and easy to repeat.

[0219] (4) Characterization and testing of membrane electrodes:

[0220] After the catalyst slurry was coated onto the proton exchange membrane, the content and range of noble metals in the catalyst layer were determined using a handheld X-ray fluorescence spectrometer. The iridium content and range results on the anode side are shown in Table 2.

[0221] Table 2

[0222] As shown in Table 2, the iridium content range on the anode side is relatively large when the mass ratio of the ionomer subconductor to the anode catalyst is less than 0.1, indicating uneven iridium distribution in the anode catalyst layer. However, in the membrane electrode obtained in the embodiments of the present invention, the iridium content range on the anode side is significantly reduced. This demonstrates that the mass ratio of the ionomer subconductor to the anode catalyst used in the membrane electrode preparation process of the present invention is beneficial for obtaining a uniform slurry, thereby ensuring the compositional uniformity of the membrane electrode catalyst layer, maximizing the construction of the three-phase interface, increasing mass transfer and charge transport in the catalyst layer, helping to maintain the activity and stability of the ruthenium-iridium-terbium catalyst, and improving the performance of the membrane electrode.

[0223] The morphology of the anode catalyst layer of the prepared membrane electrode was characterized using an optical microscope. Figures 6 and 7 are optical microscope images of the anode catalyst layers prepared in Example 7 and Comparative Example 10, respectively. As can be seen from Figure 6, the anode catalyst layer of the membrane electrode obtained by hot pressing has good continuity and a uniform and consistent morphology. The membrane electrode with simple pressurization has poor contact between the anode catalyst layer and the proton exchange membrane, and partial detachment occurs. This proves that the hot pressing process used in the membrane electrode preparation process of this invention helps to improve the contact between the catalyst layer and the proton exchange membrane, which is beneficial to improving the electrolytic activity and stability of the catalyst layer.

[0224] The membrane electrodes prepared in Examples 7-10 and Comparative Examples 5-8 were installed in the fixture of the membrane electrode test stage for testing at a constant current density of 2 A / cm². 2 The tank pressure was monitored over time under the specified conditions, and the state of the catalyst layer on the membrane electrode surface was observed after 500 hours of testing. The membrane electrode test data are shown in Table 3.

[0225] Table 3

[0226] As shown in Table 3, the test results of Examples 7-10 are superior to those of Comparative Examples 5-8. The membrane electrodes of Examples 7-10 exhibit high water electrolysis activity and good stability during the test time, with no catalyst detachment observed. Comparative Example 5 uses Tb₂Ru₂O₇ as the catalyst material in the anode catalyst layer. Although it has high initial activity, its stability is poor, and the voltage increases significantly within 50 hours. Partial detachment of the anode catalyst occurs during the test time, directly affecting the oxygen evolution activity. The catalyst layers of Comparative Examples 6-8 are uniform, but their oxygen evolution activity and stability are inferior to those of the Examples. The above results indicate that the PEM water electrolysis membrane electrode and its preparation process of the present invention can fully demonstrate the water electrolysis performance of the catalyst. That is, by adjusting the composition and structure of the catalyst layer, fully exposing the active centers, constructing sufficient three-phase interfaces, maintaining the activity and stability of the ruthenium-iridium-terbium catalyst, and improving the membrane electrode performance.

[0227] The above embodiments illustrate and describe the main features and advantages of the present invention in detail. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A proton exchange membrane electrolysis water electrode, wherein, The proton exchange membrane electrolysis water electrode includes a proton exchange membrane, an anode catalyst layer, and a cathode catalyst layer; The anode catalyst layer contains an anode catalyst and an ionomer-based quantum conductor; The anode catalyst is a ruthenium-iridium-terbium nanocatalyst with the molecular formula Tb₂Ru. x Ir 2-x O7, where 0 <x<2; The iridium content, based on the area of ​​the anode catalyst layer, is 0.02-2.0 mg / cm². 2 The mass ratio of the ionomer to the anode catalyst is 1:2 to 1:

10.

2. The proton exchange membrane electrolysis water membrane electrode according to claim 1, wherein, Based on the area of ​​the anode catalyst layer, the content of the anode catalyst is 0.05-17.34 mg / cm². 2 .

3. The proton exchange membrane electrolysis water membrane electrode according to claim 1, wherein, The cathode catalyst layer contains a cathode catalyst and an ionomer-based quantum conductor; The cathode catalyst is a Pt / C catalyst; the Pt content, based on the area of ​​the cathode catalyst layer, is 0.05-0.4 mg / cm². 2 The Pt element content in the Pt / C catalyst is 5-40%, and the mass ratio of the ionomer conductor to the cathode catalyst is 1:2-1:

10.

4. The proton exchange membrane electrolysis water membrane electrode according to claim 3, wherein, Based on the area of ​​the cathode catalyst layer, the content of the Pt / C catalyst is 0.1-1.0 mg / cm². 2 .

5. The proton exchange membrane electrolysis water membrane electrode according to claim 1, wherein, The content of the anode catalyst is 2.0-3.0 mg / cm², based on the area of ​​the anode catalyst layer. 2 .

6. The proton exchange membrane electrolysis water membrane electrode according to claim 1, wherein, Based on the area of ​​the anode catalyst layer, the Ir content is 0.2-1.0 mg / cm². 2 .

7. The proton exchange membrane electrolysis water membrane electrode according to claim 1, wherein, In the anode catalyst layer, the mass ratio of the ionomerized electron conductor to the anode catalyst is 1:2 to 1:

5.

8. The proton exchange membrane electrolysis water membrane electrode according to claim 1, wherein, In the molecular formula of the ruthenium-iridium-terbium nanocatalyst, 0.05 ≤ x ≤ 1.

95.

9. The proton exchange membrane electrolysis water membrane electrode according to claim 8, wherein, The ruthenium-iridium-terbium nanocatalyst is Tb2Ru 1.95 Ir 0.05 O7, Tb2Ru 1.90 Ir 0.10 O7, Tb2Ru 1.85 Ir 0.15 O7, Tb2Ru 1.80 Ir 0.20 O7, Tb2Ru 1.75 Ir 0.25 O7, Tb2Ru 1.70 Ir 0.30 O7, Tb2Ru 1.65 Ir 0.35 O7, Tb2Ru 1.60 Ir 0.40 ]>O7, Tb2Ru 1.55 Ir 0.45 O7, Tb2Ru 1.50 Ir 0.50 O7, Tb2Ru 1.45 Ir 0.55 O7, Tb2Ru 1.40 Ir 0.60 O7, Tb2Ru 1.35 Ir 0.65 O7, Tb2Ru 1.30 Ir 0.70 O7, Tb2Ru 1.25 Ir 0.75 O7, Tb2Ru 1.20 Ir 0.80 O7, Tb2Ru 1.15 Ir 0.85 O7, Tb2Ru 1.10 Ir 0.90 O7, Tb2Ru 1.05 Ir 0.95 O7, Tb2Ru 1.00 Ir 1.00 O7, Tb2Ru 0.95 Ir 1.05 O7, Tb2Ru 0.90 Ir 1.10 O7, Tb2Ru 0.85 Ir 1.15 O7, Tb2Ru 0.80 Ir 1.20 O7, Tb2Ru 0.75 Ir 1.25 O7, Tb2Ru 0.70 Ir 1.30 O7, Tb2Ru 0.65 Ir 1.35 O7, Tb2Ru 0.60 Ir 1.40 O7, Tb2Ru 0.55 Ir 1.45 O7, Tb2Ru 0.50 Ir 1.50 O7, Tb2Ru 0.45 Ir 1.55 O7, Tb2Ru 0.40 Ir 1.60 O7, Tb2Ru 0.35 Ir 1.65 O7, Tb2Ru 0.30 Ir 1.70 O7, Tb2Ru 0.25 Ir 1.75 O7, Tb2Ru 0.20 Ir 1.80 O7, Tb2Ru 0.15 Ir 1.85 O7, Tb2Ru 0.10 Ir 1.90 O7, Tb2Ru 0.05 Ir 1.95 O7 medium size.

10. The proton exchange membrane electrolysis water membrane electrode according to claim 8, wherein, In the molecular formula of the ruthenium-iridium-terbium nanocatalyst, 0.4 ≤ x ≤ 1.

6.

11. The proton exchange membrane electrolysis water membrane electrode according to claim 8, wherein, The ruthenium-iridium-terbium catalyst is in particulate form with a particle size of 40-180 nm.

12. A method for preparing a proton exchange membrane electrolysis water membrane electrode according to any one of claims 1-11, comprising the following steps: S1: Preparation of anode catalyst slurry; S2: An anode catalyst layer is prepared on one side of the proton exchange membrane using the anode catalyst slurry; S3: Preparation of cathode catalyst slurry; S4: Prepare a cathode catalyst layer on the other side of the proton exchange membrane using the cathode catalyst slurry; S5: The proton exchange membrane, on which the cathode catalytic layer and the anode catalytic layer are formed on both sides respectively, is hot-pressed to obtain the proton exchange membrane water electrolysis membrane electrode.

13. The preparation method according to claim 12, wherein, Step S1 includes the following steps: S11: Place water in the inner cavity of the jacketed container, connect ice water to the outer cavity of the jacketed container for circulating cooling, and stir in the inner cavity of the jacketed container. S12: Add ionic polymer and liquid alcohol to the inner cavity of the jacketed container in sequence for dispersion to obtain a dispersion. S13: The ruthenium-iridium-terbium nanocatalyst is added to the dispersion in multiple batches for further dispersion to obtain the anode catalyst slurry.

14. The preparation method according to claim 13, wherein, The dispersion or stirring is achieved by a high-speed shearing machine, ultrasonic crusher, ultrasonic cell pulverizer, high-pressure homogenizer, or high-energy ball mill with cooling function; The high-speed shearing machine has a rotation speed of 2000-5000 rpm, the ultrasonic crusher has a power of 600-1000W, the ultrasonic cell pulverizer has a power of 600-1000W, the high-energy ball mill has a rotation speed of 1000-2500 rpm, and the high-pressure homogenizer has a dispersion pressure of 15000psi-17000psi.

15. The preparation method according to claim 13, wherein, In step S12, the dispersion time is 0.5-1h; in step S13, the dispersion time is 1-2h.

16. The preparation method according to claim 13, wherein, Based on the mass of the anode catalyst slurry as 100%, the amount of the anode catalyst is 1-30 wt%, and the amount of the ionomerized electronic conductor is 0.75-3%.

17. The preparation method according to claim 13, wherein, The ionomer is a perfluorosulfonic acid resin solution with a concentration of 5-20 wt%. The perfluorosulfonic acid resin is selected from one or more of DuPont Nafion resin, Solvay D79 series resin, Asahi Glass IC100 resin and Asahi Glass IC154 resin. The liquid alcohol is selected from one or more of ethanol, propanol, butanol, ethylene glycol, ethoxyethanol and methoxyethanol; The volume ratio of water to liquid alcohol is 1:1 to 1:

8.

18. The preparation method according to claim 12, wherein, S2 includes the following steps: The anode catalyst slurry is sprayed or coated onto the surface of the proton exchange membrane to obtain the anode catalyst layer.

19. The preparation method according to claim 12, wherein, S3 includes the following steps: S31: Water is placed in the inner cavity of the jacketed container, ice water is connected to the outer cavity of the jacketed container for circulating cooling, and stirring is carried out in the inner cavity of the jacketed container. S32: Add ionic polymer and liquid alcohol to the inner cavity of the jacketed container in sequence for dispersion to obtain a dispersion; S33: The cathode catalyst is added to the dispersion in multiple portions for further dispersion to obtain the cathode catalyst slurry.

20. The preparation method according to claim 19, wherein, The dispersion or stirring is achieved by a high-speed shearing machine, ultrasonic crusher, ultrasonic cell pulverizer, high-pressure homogenizer, or high-energy ball mill with cooling function; The high-speed shearing machine has a rotation speed of 2000-5000 rpm, the ultrasonic crusher has a power of 300-400W, the ultrasonic cell pulverizer has a power of 300-400W, the high-energy ball mill has a rotation speed of 1000-2500 rpm, and the high-pressure homogenizer has a dispersion pressure of 15000psi-17000psi.

21. The preparation method according to claim 19, wherein, In step S32, the dispersion time is 0.5-1h; in step S33, the dispersion time is 0.5-1h.

22. The method according to claim 12, wherein, S4 includes the following steps: S41: Spray or coat the cathode catalyst slurry onto the other side of the proton exchange membrane that has been coated with the anode catalyst layer to obtain the cathode catalyst layer.

23. The method according to claim 12, wherein, The hot pressing temperature is 120℃-140℃, and the pressure is 3MPa-15MPa.

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