An iridium-based anode catalyst for PEM electrolysis of water and a preparation method and application thereof

Abstract

The application discloses an iridium-based PEM water electrolysis anode catalyst and a preparation method and application thereof, and belongs to the technical field of functional material preparation and electrocatalysis. The application takes a three-dimensional porous PdRu alloy substrate as an inner core carrier, and loads an amorphous PtIr nanolayer as an active shell on the surface of the three-dimensional porous PdRu alloy substrate, uses disordered atomic arrangement to expose high-density active sites, and simultaneously reduces the dependence on noble metals and improves the fluctuation adaptability. The core-shell structure greatly reduces the material cost through structural design, and the three-dimensional porous structure promotes water molecule penetration and bubble detachment, effectively alleviates concentration polarization; the amorphous interface defects provide high-activity reaction sites, and the oxygen evolution reaction kinetics is significantly enhanced. The application simultaneously solves the two industrial pain points of 'high catalyst cost' and 'poor coupling adaptability of renewable energy' through structural innovation, provides technical support for a renewable energy-PEM water electrolysis integrated system, and promotes the large-scale application of green hydrogen and the energy transformation process.

Description

Technical Field

[0001] This invention belongs to the field of functional material preparation and electrocatalysis technology, specifically relating to an iridium-based PEM water electrolysis anode catalyst, its preparation method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Proton exchange membrane (PEM) water electrolysis for hydrogen production is a key technology for achieving zero-carbon emission green hydrogen production, which is crucial for promoting the low-carbon transformation of the energy structure and addressing climate change. Its synergistic integration with intermittent renewable energy sources such as wind and solar power can construct a closed-loop system for clean energy production and consumption. However, PEM water electrolysis is highly dependent on high-cost Ir-based catalysts. Furthermore, the intermittent power supply from renewable energy sources requires the catalyst and catalyst layer to frequently withstand rapidly changing fluctuating currents, which is a significant challenge for the current commercial application of PEM water electrolysis.

[0004] Under dynamic operating conditions, fluctuating currents severely disturb the gas-liquid interface on the electrode surface, limiting the effective diffusion of water molecules to active sites (responder transport is restricted). Simultaneously, the rapidly generated bubbles are difficult to desorb quickly, easily becoming trapped and blocking electrode pore channels, significantly increasing polarization resistance (exacerbating product retention). Existing water electrolysis anode catalysts, when the loading is reduced, result in a non-uniform electrode that leads to poor contact with the porous transport layer, thereby increasing "dead zones" in the catalyst layer. Furthermore, the high-density oxide-oxide interfaces formed between catalyst particles in traditional catalyst layers are unable to effectively cope with the enhanced mass transfer challenges under the aforementioned dynamic operating conditions, leading to performance degradation and increased energy consumption in water electrolysis. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an iridium-based PEM anode catalyst for water electrolysis, its preparation method, and its application. The iridium-based PEM anode catalyst provided by the present invention significantly reduces material costs through structural design, while the three-dimensional porous structure promotes water molecule penetration and bubble desorption, effectively alleviating concentration polarization; the amorphous interface defects provide highly active reaction sites, which significantly enhances the oxygen evolution reaction kinetics.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides an iridium-based PEM water electrolysis anode catalyst comprising a three-dimensional porous PdRu alloy matrix and an amorphous PtIr supported on the surface of the three-dimensional porous PdRu alloy matrix.

[0008] In some embodiments of the present invention, the loading of the amorphous PtIr is 15%-20%.

[0009] A second aspect of the present invention provides a method for preparing the above-mentioned iridium-based PEM water electrolysis anode catalyst, comprising:

[0010] Palladium and ruthenium salts were added to water, heated, and stirred. Sodium borohydride was added, and after the reaction, the mixture was allowed to stand. Then, iridium, platinum, oleylamine, and sodium citrate dihydrate were added, mixed, and transferred to a reaction vessel for heating and reaction to obtain an iridium-based PEM water electrolysis anode catalyst.

[0011] In some embodiments of the present invention, the palladium salt includes, but is not limited to, any one or more of potassium chloropalladium, ammonium chloropalladium, and sodium chloropalladium;

[0012] The ruthenium salt includes ruthenium chloride trihydrate;

[0013] The iridium salt includes any one or more of chloroiridium hexahydrate, ammonium chloroiridium hexahydrate, and sodium chloroiridium hexahydrate;

[0014] The platinum salt includes any one or more of chloroplatinic acid hexahydrate, ammonium chloroplatinic acid hexahydrate, and potassium chloroplatinic acid hexahydrate.

[0015] The molar ratio of palladium salt, ruthenium salt, sodium borohydride, iridium salt, platinum salt, oleylamine and sodium citrate dihydrate is (2-3.1):(0.3-1.2):(20-35):(0.3-1.5):(0.09-0.3):(35-60):(0.1-0.6).

[0016] In some embodiments of the present invention, the palladium salt and ruthenium salt are added to water, heated to 50-70°C and stirred for 1.5-2.5 h.

[0017] In some embodiments of the present invention, the heating reaction is carried out at 150-170°C for 1.5-2.5 h.

[0018] In some embodiments of the present invention, the preparation method further includes: after the heating reaction is completed, cooling to room temperature, solid-liquid separation to collect the product, washing, drying, and obtaining an iridium-based PEM water electrolysis anode catalyst.

[0019] A third aspect of the present invention provides the application of the above-described iridium-based PEM anode catalyst for water electrolysis or the iridium-based PEM anode catalyst prepared by the above-described preparation method in the oxygen evolution reaction of water electrolysis.

[0020] In a fourth aspect, the present invention provides a membrane electrode comprising the iridium-based PEM water electrolysis anode catalyst described above or the iridium-based PEM water electrolysis anode catalyst prepared by the above preparation method.

[0021] A fifth aspect of the present invention provides a PEM device comprising the membrane electrode described above.

[0022] The beneficial effects of this invention are as follows:

[0023] This invention provides an iridium-based PEM anode catalyst for water electrolysis. Through the synergistic construction of a three-dimensional porous PdRu alloy matrix and an amorphous PtIr layer on the surface, it achieves a breakthrough improvement in mass transfer efficiency and intrinsic activity under fluctuating current dynamic conditions. Specifically, the three-dimensional interconnected pore structure significantly promotes the bulk diffusion of water molecules and the rapid desorption of oxygen bubbles, while the high-density coordination defects of the amorphous PtIr nanolayer provide abundant unsaturated active sites, resulting in catalytic activity superior to commercial IrO2 catalysts. Rotating disk testing results show that at 10 mA cm⁻¹… -2 The potential at the current density was 1.50 V, significantly lower than that of the commercial IrO2 catalyst (1.58 V) by 80 mV, demonstrating good oxygen evolution reaction (OER) activity. Membrane electrodes were prepared using PdRu@PtIr and commercial IrO2 as anolyte catalysts, respectively, and assembled into a PEM electrolyzer (Ir loading 0.8 mg cm⁻¹). -2 PEM electrolysis results showed that PdRu@PtIr at 60℃ and 1.5 A cm⁻¹ -2 The voltage was 1.797 V, lower than that of commercial IrO2 (1.907 V). Meanwhile, the strong interfacial coupling between the amorphous shell and the porous support suppressed particle exfoliation during high-potential cycling. After 5000 h of testing, the catalyst's voltage decreased from 1.795 V to 1.810 V (decay rate = 3 μV / h), demonstrating good stability.

[0024] This invention also provides a method for preparing an iridium-based PEM anode catalyst for water electrolysis. First, a three-dimensional porous PdRu alloy matrix is ​​prepared using a sodium borohydride reduction method. This synthesis method is convenient and suitable for large-scale catalyst preparation. Further, an amorphous PtIr layer is loaded onto the surface of the three-dimensional porous PdRu alloy matrix using a liquid-phase reduction process, forming a core-shell structure (PdRu@PtIr). The three-dimensional porous PdRu alloy matrix optimizes mass transfer and electron transport of the catalyst through its high specific surface area and conductivity. The amorphous PtIr nanolayer acts as an active shell, exposing high-density active sites through disordered atomic arrangement, simultaneously reducing noble metal dependence and improving volatility adaptability. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0026] Figure 1 This is a scanning electron microscope (SEM) image of PdRu in Embodiment 1 of the present invention.

[0027] Figure 2 This is a high-resolution transmission electron microscope (HRTEM) image of PdRu in Embodiment 1 of the present invention.

[0028] Figure 3 This is a transmission electron microscope image of PdRu@PtIr in Embodiment 1 of the present invention.

[0029] Figure 4 This is a high-resolution transmission electron microscope (HRTEM) image of PdRu@PtIr in Embodiment 1 of the present invention.

[0030] Figure 5 This is a scan of the elemental surface distribution of PdRu@PtIr in Embodiment 1 of the present invention.

[0031] Figure 6 This is a comparison of the rotating disk test results of PdRu@PtIr and IrO2 in Embodiment 1 of the present invention.

[0032] Figure 7 This is a comparison of the PEM electrolysis polarization curves of PdRu@PtIr and IrO2 in Example 1 of the present invention.

[0033] Figure 8 This is a long-term stability test of PdRu@PtIr PEM electrolysis water in Example 1 of the present invention.

[0034] Figure 9 This is a test of the PEM electrolysis input current adjustment of PdRu@PtIr in Embodiment 1 of the present invention. Detailed Implementation

[0035] This invention provides an iridium-based PEM anode catalyst for water electrolysis, its preparation method, and its application. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and fall within the scope of this invention. The method and application of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the method and application described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0036] The present invention provides an iridium-based PEM water electrolysis anode catalyst, comprising a three-dimensional porous PdRu alloy matrix and an amorphous PtIr supported on the surface of the three-dimensional porous PdRu alloy matrix.

[0037] To address the challenges of mass transfer, such as limited reactant transport and increased product retention, faced by traditional water electrolysis anode catalysts under dynamic operating conditions, this invention provides an iridium-based PEM water electrolysis anode catalyst. This catalyst uses a three-dimensional porous PdRu alloy substrate as its core support, with an amorphous PtIr nanolayer loaded on its surface as the active shell. It optimizes mass and electron transport through high specific surface area and conductivity, exposes high-density active sites using disordered atomic arrangement, and simultaneously reduces dependence on precious metals and improves adaptability to fluctuations. This core-shell structure significantly reduces material costs through structural design, while the three-dimensional porous structure promotes water molecule permeation and bubble desorption, effectively mitigating concentration polarization; the amorphous interface defects provide highly active reaction sites, significantly enhancing the oxygen evolution reaction kinetics. This catalyst design, through structural innovation, simultaneously solves two major industry pain points: high catalyst cost and poor adaptability to renewable energy coupling, providing technical support for renewable energy-PEM water electrolysis integrated systems and promoting the large-scale application of green hydrogen and the energy transition process.

[0038] In this invention, the loading of the amorphous PtIr is 15%-20%.

[0039] In this invention, the loading of amorphous PtIr is limited to 15%-20%. Within this range, while ensuring structural stability and unobstructed pores, the density of amorphous interface defects (high-activity sites) can be maximized, achieving a synergistic improvement in reaction kinetics and mass transfer efficiency. If the loading is too low, the density of active sites will be insufficient, failing to fully utilize the high catalytic activity advantage of amorphous materials. Furthermore, ultrathin coatings may lead to structural discontinuities, making local structural collapse or dissolution more likely under dynamic conditions. If the loading is too high, an excessively thick nanolayer may block the pore channels of the three-dimensional porous PdRu alloy matrix (undermining the core structural advantages), hindering water molecule diffusion and bubble desorption; simultaneously, the densification tendency will reduce the proportion of amorphous-specific defect sites.

[0040] As is understood, the term loading refers to the amount of active component (i.e., amorphous PtIr) loaded on a unit mass or unit volume of catalyst. The loading is expressed as a mass percentage. For example, in this invention, the loading of amorphous PtIr is 15%-20% (mass percentage). That is, 10 g of iridium-based PEM water electrolysis anode catalyst contains 1.5-2 g of amorphous PtIr, and the corresponding loading is (1.5-2) ÷ 10 = 15%-20%.

[0041] This invention also provides a method for preparing the above-mentioned iridium-based PEM water electrolysis anode catalyst, comprising:

[0042] Palladium and ruthenium salts were added to water, heated, and stirred. Sodium borohydride was added, and after the reaction, the mixture was allowed to stand. Then, iridium, platinum, oleylamine, and sodium citrate dihydrate were added, mixed, and transferred to a reaction vessel for heating and reaction to obtain an iridium-based PEM water electrolysis anode catalyst.

[0043] This invention first prepares a three-dimensional porous PdRu alloy matrix using a sodium borohydride reduction method. This synthesis method is convenient and suitable for large-scale catalyst preparation. Further, an amorphous PtIr layer is loaded onto the surface of the three-dimensional porous PdRu alloy matrix using a liquid-phase reduction process, forming a core-shell structure (PdRu@PtIr). The three-dimensional porous PdRu alloy matrix optimizes mass transfer and electron transport of the catalyst through its high specific surface area and conductivity. The amorphous PtIr nanolayer acts as an active shell, exposing high-density active sites through disordered atomic arrangement, simultaneously reducing noble metal dependence and improving volatility adaptability.

[0044] In this invention, the palladium salt includes, but is not limited to, any one or more of potassium chloropalladium, ammonium chloropalladium, and sodium chloropalladium;

[0045] The ruthenium salt includes ruthenium chloride trihydrate;

[0046] The iridium salt includes any one or more of chloroiridium hexahydrate, ammonium chloroiridium hexahydrate, and sodium chloroiridium hexahydrate;

[0047] The platinum salt includes any one or more of chloroplatinic acid hexahydrate, ammonium chloroplatinic acid hexahydrate, and potassium chloroplatinic acid hexahydrate.

[0048] The molar ratio of palladium salt, ruthenium salt, sodium borohydride, iridium salt, platinum salt, oleylamine and sodium citrate dihydrate is (2-3.1):(0.3-1.2):(20-35):(0.3-1.5):(0.09-0.3):(35-60):(0.1-0.6).

[0049] The ratio of palladium to ruthenium salts directly determines the atomic composition of the three-dimensional porous PdRu alloy matrix, affecting its electronic structure and the stability of its three-dimensional pores. Within this range, a stable three-dimensional porous PdRu alloy support (palladium / ruthenium ratio, sodium borohydride dosage) can be ensured, avoiding pore collapse or particle coarsening. Deviations from this ratio will lead to pore collapse or decreased conductivity in the catalyst. Sodium borohydride, as a strong reducing agent, requires precise matching of its dosage to the total amount of metal ions. Too low a dosage will result in incomplete reduction of metal ions. Too high a dosage will lead to over-reduction, causing coarsening of alloy particles and damaging the three-dimensional porous structure. The above-mentioned range allows for precise control of the core structure, improving the catalyst's activity and stability.

[0050] By controlling the platinum / iridium ratio, oleylamine, and sodium citrate dihydrate dosage, a uniform, amorphous coating of the entire PtIr active shell was achieved, maximizing the interfacial defect density and preventing pore blockage. The atomic ratio of Pt to Ir in the amorphous PtIr shell significantly affects the intrinsic activity of the catalyst. A Pt:Ir ratio within this range can effectively increase the valence state of Ir during the reaction, thereby enhancing the catalytic activity of the catalyst.

[0051] Oleylamine forms micelles at specific concentrations, reducing and guiding the uniform amorphous deposition of PtIr (deviations from the ratio will result in PtIr particle agglomerates). Sodium citrate dihydrate adsorbs onto the surface of the nanocatalyst through its functional groups, preventing agglomeration and influencing the final state of the nanolayer. This invention, by limiting the amount of each raw material, balances the contradictions between strong reduction and amorphous nucleation kinetics, and between protecting pores and ensuring sufficient coating. It specifically solves the dual mass transfer challenges of limited reactant transport (concentration polarization) and product retention (bubble blockage) under dynamic operating conditions (fluctuating current), ensuring the high performance and long lifespan of the catalyst under harsh conditions.

[0052] In this invention, the palladium salt is potassium chloropalladium, the ruthenium salt is ruthenium chloride trihydrate, the iridium salt is chloroiridium hexahydrate, and the platinum salt is chloroplatinic acid hexahydrate;

[0053] The molar ratio of potassium chloropalladiumate, ruthenium chloride trihydrate, sodium borohydride, chloroiridium hexahydrate, chloroplatinic acid hexahydrate, oleylamine, and sodium citrate dihydrate is (2.5-2.6):(0.8-0.9):(26-27):(0.9-1.0):(0.2-0.3):(55-57):(0.3-0.4). Within this range, the resulting catalyst exhibits optimal performance.

[0054] In this invention, palladium salt and ruthenium salt are added to water, heated to 50-70°C and stirred for 1.5-2.5 h.

[0055] This invention improves the stability of nanostructures by controlling the heating temperature. This temperature range ensures the complete hydrolysis of palladium and ruthenium salts, and the strong reducing properties of sodium borohydride accelerate the formation of atomic-level alloy clusters, avoiding the formation of amorphous oxide impurities.

[0056] This invention regulates the nanoscale ordering and pore evolution of alloy cores by controlling the stirring time. This time range ensures that metal ions complete diffusion-nucleation-directional growth, forming a through-type three-dimensional porous network.

[0057] In this invention, the heating reaction is carried out at 150-170°C for 1.5-2.5 h.

[0058] This invention guides the formation of amorphous structures by limiting the heating temperature. Within this temperature range, oleylamine forms a dynamic micelle template, forcing the disordered deposition of platinum / iridium atoms and inhibiting the Ostwald ripening of noble metals, thus preventing the transformation from amorphous to crystalline. Furthermore, this temperature range readily induces the formation of high-density twin boundaries / vacancy clusters, optimizing Pt / Ir electronic coupling, enhancing the intrinsic activity of the oxygen evolution reaction (OER), and accelerating reaction kinetics.

[0059] This invention ensures that oleamide micelles fully penetrate the three-dimensional pores by limiting the reaction time, thereby completing the amorphous / carrier interface alloying.

[0060] This invention achieves a balance between the highly active amorphous state and structural stability of the catalyst, as well as a balance between full pore coverage and pore unobstructed flow, by synergistically constructing a "highly active amorphous shell" and a "smooth three-dimensional mass transfer channel" under limited reaction temperature and time.

[0061] In this invention, the preparation method further includes: after the heating reaction is completed, cooling to room temperature, solid-liquid separation to collect the product, washing, drying, and obtaining an iridium-based PEM water electrolysis anode catalyst.

[0062] The present invention also provides the application of the above-mentioned iridium-based PEM anode catalyst for water electrolysis or the iridium-based PEM anode catalyst prepared by the above-mentioned preparation method in the oxygen evolution reaction of water electrolysis.

[0063] The present invention also provides a membrane electrode comprising the above-described iridium-based PEM water electrolysis anode catalyst or the iridium-based PEM water electrolysis anode catalyst prepared by the above-described preparation method.

[0064] The present invention also provides a PEM device, including the above-described membrane electrode.

[0065] This invention innovatively designs a three-dimensional porous PdRu alloy substrate as the core carrier, and loads an amorphous PtIr nanolayer on its surface as the active shell. The high specific surface area and conductivity of the core carrier optimize mass transfer and electron transport, while the disordered atomic arrangement of the active shell exposes high-density active sites, simultaneously reducing dependence on precious metals and improving volatility adaptability. This core-shell structure significantly reduces material costs, while the three-dimensional porous structure promotes water molecule permeation and bubble desorption, effectively mitigating concentration polarization; the amorphous interface defects provide highly active reaction sites, significantly enhancing the oxygen evolution reaction kinetics. This catalyst design, through structural innovation, simultaneously addresses two major industry pain points: high cost of precious metals and poor adaptability to renewable energy coupling, providing technical support for renewable energy-PEM water electrolysis integrated systems and promoting the large-scale application of green hydrogen and the energy transition process.

[0066] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0067] Example 1

[0068] An iridium-based PEM anode catalyst for water electrolysis is prepared as follows:

[0069] 1 g potassium chloropalladium and 0.23 g ruthenium chloride trihydrate were added to 100 mL of water, heated to 60 °C, and magnetically stirred for 2 h. Next, 1 g sodium borohydride was added, and after reacting for half an hour, the mixture was allowed to stand overnight to obtain a three-dimensional porous PdRu alloy substrate. Then, 0.47 g chloroiridium hexahydrate, 0.13 g chloroplatinic acid hexahydrate, 15 g oleylamine, and 0.1 g sodium citrate dihydrate were added to the solution, and the mixture was magnetically stirred for 2 h. After thorough mixing, the mixture was transferred to a reaction vessel, heated to 160 °C, and held for 2 h. Heating was then stopped, and the mixture was cooled to room temperature. The product was collected by centrifugation and washed twice with deionized water and ethanol, respectively. The product was then dried in a vacuum oven to obtain an iridium-based PEM water electrolysis anode catalyst, named PdRu@PtIr.

[0070] Figure 1 This is a SEM image of the three-dimensional porous PdRu alloy matrix prepared by the sodium borohydride reduction method in this embodiment. The three-dimensional porous structure can effectively enhance the mass transfer between reactants and products while ensuring conductivity.

[0071] Figure 2 This is a high-resolution transmission electron microscopy (HRTEM) analysis of the three-dimensional porous PdRu alloy matrix in this embodiment. Figure 2 The lattice spacing is 0.223 nm, which is attributed to the {111} crystal plane of the typical Pd face-centered cubic structure. This size is smaller than that of the {111} crystal plane of Pd, indicating that smaller Ru atoms may have entered the Pd lattice, resulting in lattice contraction.

[0072] In this embodiment, an amorphous PtIr layer is loaded onto a three-dimensional porous PdRu alloy matrix using a liquid-phase reduction process to form a core-shell structure (PdRu@PtIr). Figure 3 This is the TEM image of PdRu@PtIr obtained in this embodiment. Figure 4 This is the HRTEM image of PdRu@PtIr obtained in this embodiment. Figure 3 and Figure 4 This confirms that the present invention can cover the surface of a three-dimensional skeleton (three-dimensional porous PdRu alloy matrix) with a continuous amorphous layer.

[0073] Figure 5 This is a scan of the elemental surface distribution of PdRu@PtIr obtained in this embodiment. Figure 5 The study revealed that the Pt / Ir signal is concentrated in the outer shell, while the Pd / Ru signal is enriched in the core, verifying that the core is a PdRu alloy and that the core-shell configuration was successfully constructed.

[0074] The oxygen evolution reaction (OER) activities of PdRu@PtIr and commercial IrO2 were tested using a rotating disk electrode at room temperature and in 0.5 M H2SO4 electrolyte.

[0075] Figure 6 A comparison of rotating disk test results for PdRu@PtIr and commercial IrO2. Figure 6 It can be seen that PdRu@PtIr at 10 mA cm -2 The potential at the current density is 1.50 V, which is 80 mV lower than that of commercial IrO2 catalysts (1.58 V), demonstrating good OER activity.

[0076] Example 2

[0077] A PEM electrolyzer, the preparation method of which includes the following steps:

[0078] The PdRu@PtIr (anodic catalyst) prepared in Example 1 was mixed with ultrapure water for pre-wetting, and then an alcohol solvent was added and ultrasonically dispersed in an ice-water bath for 120 minutes to form a primary suspension. Next, a Nafion ionomer solution was added and ball milling was performed to enhance the binding between the catalyst and the ionomer to form a homogeneous slurry.

[0079] Based on a continuous liquid supply platform, a high-precision peristaltic pump fluid control system is used to achieve continuous liquid supply with pulsation suppression. Multi-channel and adaptive flow compensation technology is employed to effectively eliminate flow fluctuations caused by tubing elastic deformation. Combined with high-frequency ultrasound, argon-protected atomization, and substrate gradient temperature control, the slurry is sprayed at a rate of 5 mL / min onto a pretreated Nafion 115 proton exchange membrane (500 cm²). 2 On one side, Pt / C is sprayed onto the other side in the same manner for hydrogen evolution at the cathode. The membrane electrode assembly is then laminated with the diffusion layer, and high temperature and pressure are applied in a hot press. Through staged depressurization and pressure holding cooling, the catalyst layer is embedded into the proton exchange membrane to form continuous proton channels, effectively reducing interfacial resistance and improving peel strength. Finally, the membrane electrode assembly is assembled with the bipolar plates to form a PEM electrolyzer.

[0080] Comparative Example 1

[0081] A PEM electrolyzer, differing from Example 2 in that the anode catalyst is replaced with a commercial IrO2 catalyst, while the remaining steps are completely identical to those of Example 2.

[0082] Performance verification:

[0083] In Example 2 and Comparative Example 1, membrane electrodes were prepared using PdRu@PtIr and commercial IrO2 as anolyte catalysts, respectively, and assembled into PEM electrolyzers (Ir loading was 0.8 mg / cm³).2 PEM electrolysis results are as follows Figure 7 As shown. By Figure 7 It can be seen that PdRu@PtIr at 60℃ has an A / cm² value of 1.5A. 2 The voltage was 1.797 V, lower than that of commercial IrO2 (1.907 V). Long-term stability test results are as follows... Figure 8 As shown. By Figure 8 It can be seen that after 5000 hours of 1.5 A / cm 2 After constant current testing, the voltage of PdRu@PtIr decreased from 1.795 V to 1.810 V (attenuation rate = 3 μV / h), demonstrating good stability.

[0084] In addition, input current adjustment tests were conducted on the electrolytic cell, such as... Figure 9 As shown, the input current density experienced a change of 1.5 A / cm². 2 (30 minutes) ~0.15 A / cm 2 (30 minutes) ~ 2.25 A / cm 2 (30 minutes) ~1.5 A / cm 2 The voltage changes over 30 minutes, with test voltages of 1.797 V, 1.524 V, 1.926 V, and 1.798 V at each stage, at 1.5 A / cm. 2 The voltage under electrical density did not change significantly, demonstrating good adaptability to fluctuating energy.

[0085] Example 3

[0086] An iridium-based PEM anode catalyst for water electrolysis is prepared as follows:

[0087] 0.8 g potassium chloropalladium and 0.1 g ruthenium chloride trihydrate were added to 100 mL of water, heated to 60 °C, and magnetically stirred for 2 h. Next, 0.8 g sodium borohydride was added, and after reacting for half an hour, the mixture was allowed to stand overnight to obtain a three-dimensional porous PdRu alloy substrate. Then, 0.2 g chloroiridium hexahydrate, 0.05 g chloroplatinic acid hexahydrate, 10 g oleylamine, and 0.05 g sodium citrate dihydrate were added to the solution, and the mixture was magnetically stirred for 2 h. After thorough mixing, the mixture was transferred to a reaction vessel, heated to 160 °C, and held for 2 h. Heating was then stopped, and the mixture was cooled to room temperature. The product was collected by centrifugation and washed twice with deionized water and ethanol, respectively. The product was then dried in a vacuum oven to obtain an iridium-based PEM water electrolysis anode catalyst, named PdRu@PtIr.

[0088] The PdRu@PtIr obtained above can be identified as having a core-shell configuration by TEM images. The three-dimensional porous PdRu alloy matrix supports an amorphous PtIr layer to form a core-shell structure.

[0089] The PdRu@PtIr catalyst obtained in Example 3 was prepared using the method in Example 2 and tested in a PEM electrolyzer. At 60°C, 1.5 A / cm... 2 The voltage is 1.807 V.

[0090] Example 4

[0091] An iridium-based PEM anode catalyst for water electrolysis is prepared as follows:

[0092] 1.2 g potassium chloropalladium and 0.3 g ruthenium chloride trihydrate were added to 100 mL of water, heated to 60 °C, and magnetically stirred for 2 h. Next, 1.2 g sodium borohydride was added, and after reacting for half an hour, the mixture was allowed to stand overnight to obtain a three-dimensional porous PdRu alloy substrate. Then, 0.6 g chloroiridium hexahydrate, 0.15 g chloroplatinic acid hexahydrate, 15 g oleylamine, and 0.15 g sodium citrate dihydrate were added to the solution, and the mixture was magnetically stirred for 2 h. After thorough mixing, the mixture was transferred to a reaction vessel, heated to 160 °C, and held for 2 h. Heating was then stopped, and the mixture was cooled to room temperature. The product was collected by centrifugation and washed twice with deionized water and ethanol, respectively. The product was then dried in a vacuum oven to obtain an iridium-based PEM water electrolysis anode catalyst, named PdRu@PtIr.

[0093] The PdRu@PtIr obtained above can be identified as having a core-shell configuration by TEM images. The three-dimensional porous PdRu alloy matrix supports an amorphous PtIr layer to form a core-shell structure.

[0094] The PdRu@PtIr catalyst obtained in Example 4 was prepared using the method in Example 2 and tested in a PEM electrolyzer. At 60°C, 1.5 A / cm... 2 The voltage is 1.811 V.

[0095] Comparative Example 2

[0096] An iridium-based PEM anode catalyst for water electrolysis differs from that in Example 1 in that the amount of potassium chloropalladate used is 0.5 g and 1.5 g, respectively. The remaining steps are completely consistent with those in Example 1.

[0097] Comparative Example 3

[0098] An iridium-based PEM anode catalyst for water electrolysis differs from Example 1 in that the amount of ruthenium chloride trihydrate used is 0.05 g and 0.5 g, respectively. The remaining steps are completely consistent with those of Example 1.

[0099] Comparative Example 4

[0100] An iridium-based PEM anode catalyst for water electrolysis differs from Example 1 in that the amount of sodium borohydride used is 0.5 g and 1.5 g, respectively. The remaining steps are completely consistent with those of Example 1.

[0101] Comparative Example 5

[0102] An iridium-based PEM anode catalyst for water electrolysis differs from that in Example 1 in that the amount of chloroiridium hexahydrate used is 0.1 g and 0.7 g, respectively. The remaining steps are completely consistent with those in Example 1.

[0103] Comparative Example 6

[0104] An iridium-based PEM anode catalyst for water electrolysis differs from that in Example 1 in that the amount of chloroplatinic acid hexahydrate used is 0.01 g and 0.2 g, respectively. The remaining steps are completely consistent with those in Example 1.

[0105] Comparative Example 7

[0106] An iridium-based PEM anode catalyst for water electrolysis differs from Example 1 in that chloroplatinic acid hexahydrate is not added, while the remaining steps are completely consistent with those of Example 1.

[0107] Comparative Example 8

[0108] An iridium-based PEM anode catalyst for water electrolysis differs from that in Example 1 in that the amount of oleylamine used is 7.5 g and 20 g, respectively. The remaining steps are completely consistent with those in Example 1.

[0109] Comparative Example 9

[0110] An iridium-based PEM anode catalyst for water electrolysis differs from that in Example 1 in that the amount of sodium citrate dihydrate used is 0.01 g and 0.2 g, respectively. The remaining steps are completely consistent with those in Example 1.

[0111] The PdRu@PtIr catalysts obtained in Comparative Examples 2-9 were prepared using the method of Example 2 and tested in a PEM electrolyzer. At 60°C, 1.5 A / cm²... 2 The voltages were all higher than 1.811 V. This indicates that the palladium, ruthenium, iridium, platinum and other raw materials in this invention work together to improve the catalytic activity of the iridium-based PEM water electrolysis anode catalyst.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An iridium-based PEM anode catalyst for water electrolysis, characterized in that, It includes a three-dimensional porous PdRu alloy matrix and an amorphous PtIr loaded on the surface of the three-dimensional porous PdRu alloy matrix.

2. The iridium-based PEM anode catalyst for water electrolysis as described in claim 1, characterized in that, The loading of the amorphous PtIr is 15%-20%.

3. A method for preparing the iridium-based PEM anode catalyst for water electrolysis according to claim 1 or 2, characterized in that, include: Add palladium and ruthenium salts to water, heat and stir; add sodium borohydride, react, and let stand. Then, iridium salt, platinum salt, oleylamine, and sodium citrate dihydrate are added, mixed, and transferred to a reaction vessel for heating and reaction to obtain an iridium-based PEM water electrolysis anode catalyst. The molar ratio of palladium salt, ruthenium salt, sodium borohydride, iridium salt, platinum salt, oleylamine and sodium citrate dihydrate is (2-3.1):(0.3-1.2):(20-35):(0.3-1.5):(0.09-0.3):(35-60):(0.1-0.6).

4. The preparation method according to claim 3, characterized in that, The palladium salt includes any one or more of potassium chloropalladium, ammonium chloropalladium, and sodium chloropalladium. The ruthenium salt includes ruthenium chloride trihydrate; The iridium salt includes any one or more of chloroiridium hexahydrate, ammonium chloroiridium hexahydrate, and sodium chloroiridium hexahydrate; The platinum salt includes any one or more of chloroplatinic acid hexahydrate, ammonium chloroplatinic acid hexahydrate, and potassium chloroplatinic acid hexahydrate.

5. The preparation method according to claim 3, characterized in that, Add palladium and ruthenium salts to water, heat to 50-70℃ and stir for 1.5-2.5 hours.

6. The preparation method according to claim 3, characterized in that, The heating reaction is carried out at 150-170°C for 1.5-2.5 hours.

7. The preparation method according to claim 3, characterized in that, The preparation method further includes: after the heating reaction is completed, cooling to room temperature, solid-liquid separation to collect the product, washing, drying, and obtaining iridium-based PEM water electrolysis anode catalyst.

8. The application of an iridium-based PEM anode catalyst for water electrolysis according to claim 1 or 2, or an iridium-based PEM anode catalyst for water electrolysis prepared by any one of claims 3-7, in the oxygen evolution reaction of water electrolysis.

9. A membrane electrode, characterized in that, Includes the iridium-based PEM water electrolysis anode catalyst as described in claim 1 or 2, or the iridium-based PEM water electrolysis anode catalyst prepared by the preparation method described in any one of claims 3-7.

10. A PEM device, characterized in that, Includes the membrane electrode as described in claim 9.

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