An IrO2@NiRuO3 formulation for PEM water electrolysis x Anode catalysts, their preparation methods and applications

Abstract

This invention relates to an IrO2@NiRuO3 formulation for PEM water electrolysis. x This invention relates to an anode catalyst, its preparation method, and its application, belonging to the technical field of catalysts for hydrogen production via water electrolysis. The method involves mixing ruthenium salt, nickel salt, and carbon material in an acid solution, followed by rotary evaporation and drying. The mixture is then successively calcined under a reducing atmosphere and calcined in air, followed by immersion in an acid solution, and finally washed and dried to obtain NiRuO. x Add iridium precursor and NiRuO to the alcohol solvent system x After stirring and impregnation for 1-4 hours, nitrate is added and stirring and impregnation continues for 0.25-1 hour. The solvent is then removed to obtain NiRuO supported on the iridium precursor. x Finally, the anode catalyst is obtained by calcining at 480-520℃ for 10-60 minutes in air, followed by washing and drying. The anode catalyst of this invention achieves high catalytic activity and improved long-term stability under high current density conditions in high-pressure PEM electrolysis.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology for hydrogen production by water electrolysis, and particularly relates to an IrO2@NiRuO catalyst for PEM water electrolysis. x Anode catalysts, their preparation methods, and applications. Background Technology

[0002] The core challenge of proton exchange membrane (PEM) water electrolysis for hydrogen production lies in developing anode catalysts with high activity, high stability, and low noble metal (PGM) content. Existing technologies include constructing Ru@Ir on carbon materials and then forming a RuO2 core and IrO2 shell structure on the carbon support through low-temperature air oxidation, serving as the anode catalyst. However, carbon supports are prone to metal-carbon interface failure in acidic, high-current-density, and / or high-pressure PEM environments, limiting their reliability in practical applications. Existing technologies also report on loading noble metals onto inorganic oxide supports as anode catalysts. For example, using non-noble metal oxides such as TiO2, SnO2, Nb2O5, and ATO as supports, loading IrO2 / RuO2 nanoparticles, and then introducing oxygen vacancies through atmospheric annealing (e.g., ammonia / inert atmosphere annealing) to enhance conductivity. While this approach avoids the carbon support instability problem, it does not integrate the synergistic stabilizing effect of the active core, and the interface optimization between the active phase and the support is still insufficient to cope with harsh high-pressure conditions. Existing anode catalysts are generally limited to PEM electrolysis of water at atmospheric pressure, which limits the application of these catalysts to real high pressures (e.g., ≥30 bar) and high current densities (e.g., ≥1 A / cm²). 2 The durability under operating conditions is highly unstable.

[0003] Therefore, there is an urgent need to provide an IrO2@NiRuO3 formulation for PEM water electrolysis. x Anode catalysts, their preparation methods, and applications, using NiRuO x The synergistic design of core stabilization and IrO2 thin-shell protection reduces the amount of Ir used while meeting the comprehensive requirements of high current density and / or high pressure PEM electrolysis for activity, stability and cost. Summary of the Invention

[0004] To address one or more technical problems existing in the prior art, this invention provides an IrO2@NiRuO2 composite material for PEM water electrolysis. x Anode catalysts, their preparation methods, and applications.

[0005] In a first aspect, the present invention provides IrO2@NiRuO for PEM water electrolysis. x A method for preparing an anode catalyst, the method comprising the following steps: (1) The ruthenium salt, nickel salt and carbon material are mixed evenly in an acid solution, and then rotary evaporated and dried to obtain a precursor mixture; (2) The precursor mixture was successively calcined in a reducing atmosphere and in an air atmosphere, then soaked in an acid solution, and finally washed and dried to obtain the Ni-doped Ru oxide core NiRuO. x ; (3) Add iridium precursor and Ni-doped Ru oxide core NiRuO to the alcohol solvent system x After stirring and impregnation for 1-4 hours, nitrate is added and stirring and impregnation continues for 0.25-1 hour. Then, the solvent is removed to obtain NiRuO supported on the iridium precursor. x ; (4) NiRuO loaded with iridium precursor x IrO2@NiRuO2 for PEM water electrolysis was prepared by calcining at 480-520℃ for 10-60 min in air atmosphere, followed by washing and drying. x Anode catalyst.

[0006] Preferably, in step (1): the ruthenium salt is a water-soluble ruthenium salt, which is one or more of hydrated ruthenium chloride and ruthenium nitrate; the nickel salt is a water-soluble nickel salt, which is one or more of hydrated nickel chloride, nickel nitrate, and nickel acetate; the carbon material is a low-dimensional carbon nanomaterial, which is one or more of carbon black, graphene, and carbon nanotubes; the concentration of the acid solution is 0.2~2 mol / L; the acid solution is one or more of hydrochloric acid solution, nitric acid solution, and acetic acid solution; the molar ratio of nickel in the nickel salt to ruthenium in the ruthenium salt is 1:(2~4); and / or the ratio of the sum of the mass of the ruthenium salt and the nickel salt to the mass of the carbon material is 1:(0.1~3).

[0007] Preferably, in step (2): the reducing atmosphere is a mixture of hydrogen and an inert gas, wherein the volume fraction of hydrogen in the mixture is 1~10 vol%; and / or calcined at 800~950°C for 0.5~4 h in a reducing atmosphere.

[0008] Preferably, in step (2): calcination is carried out at 400~500℃ for 1~4h in an air atmosphere.

[0009] Preferably, in step (2): the concentration of the acid solution used in the acid solution soaking treatment is 0.2~2 mol / L; the acid solution used in the acid solution soaking treatment is one or more of hydrochloric acid solution, nitric acid solution, sulfuric acid solution, and acetic acid solution; and / or the acid solution soaking treatment is soaking at 15~80℃ for 4~24h.

[0010] Preferably, in step (3): the alcohol solvent system comprises 0.5-30% water and 70-99.5% alcohol solvent by volume percentage, wherein the alcohol solvent is one or more of isopropanol, ethanol, and methanol; the iridium precursor is one or more of chloroiridium acid, iridium nitrate, and iridium acetylacetonate; and / or the nitrate is one or more of sodium nitrate, potassium nitrate, and ammonium nitrate.

[0011] Preferably, in step (3): the molar ratio of the nitrate to the iridium contained in the iridium precursor is (20~300):1; and / or in the addition of a Ni-doped Ru oxide core NiRuO x Subsequently, the Ni-doped Ru oxide core NiRuO x The concentration in alcohol solvent systems is 2~50 mg / mL.

[0012] Preferably, in step (4): the temperature is increased to 480-520°C at a heating rate of 3-10°C / min; and / or the IrO2@NiRuO x The iridium content in the anode catalyst is 20-70% by mass.

[0013] In a second aspect, the present invention provides IrO2@NiRuO for PEM water electrolysis. x Anode catalyst, the IrO2@NiRuO x The anode catalyst was prepared using the preparation method described in the first aspect of this invention; the IrO2@NiRuO x The anode catalyst contains a Ni-doped Ru oxide core, NiRuO. x and NiRuO coated in Ni-doped Ru oxide core x The surface has an IrO2 shell layer, the thickness of which is 0.5~10nm.

[0014] In a third aspect, the present invention provides an IrO2@NiRuO3 for PEM water electrolysis. x Application of anode catalyst in high-pressure PEM water electrolysis for hydrogen production, wherein IrO2@NiRuO x The anode catalyst is prepared using the method described in the first aspect of this invention; the pressure of the high-pressure PEM electrolysis for hydrogen production is ≥30 bar, and the current density is ≥1 A / cm². 2 .

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: (1) In this invention, ruthenium salt (Ru salt), nickel salt (Ni salt) and carbon material are formulated into an acidic dispersion, which is then subjected to high-temperature treatment in a reducing atmosphere, medium-temperature oxidation in air atmosphere and acid immersion treatment in sequence to obtain highly dispersed NiRuO. xCore powder; subsequently, an impregnation solution containing Ir precursor and nitrate was prepared in an alcohol solvent system, and the iridium precursor (Ir precursor) was loaded onto NiRuO through liquid phase loading. x Uniform adsorption on the core surface, followed by short-term calcination (10-60 min) in air at 480-520℃, achieves controlled decomposition and in-situ transformation of the Ir precursor (nitrate acts as an oxidizing agent to promote the conversion of the Ir precursor to IrO2), thereby achieving the controlled decomposition and in-situ transformation of the NiRuO2 precursor. x A uniform, continuous, and dense IrO2 shell of uniform thickness was formed on the core surface; the IrO2@NiRuO2 obtained in this invention x The anode catalyst contains a dense and uniform IrO2 shell, without thick-shell aggregation or grain coarsening. Furthermore, the IrO2@NiRuO x The anode catalyst contains no carbon residue. This invention optimizes the shell continuity to obtain the IrO2@NiRuO2 catalyst. x The anode catalyst achieves high catalytic activity and long-term stability under high current density in high-pressure PEM electrolysis conditions (≥30 bar), improving lifetime and PGM utilization (Ir atom utilization) under high-pressure / high-current conditions, reducing Ir usage, hydrogen production costs, and energy consumption. The IrO2@NiRuO2 catalyst prepared in this invention... x The anode catalyst can achieve stability and low voltage decay under acidic high current density and high-voltage PEM conditions with low Ir dosage, effectively improving activity, lifetime and precious metal utilization.

[0016] (2) The preparation method of this invention has significant advantages in terms of process efficiency and scalability. The nitrate-assisted impregnation process effectively improves the decomposition and spreading uniformity of the Ir precursor. The shell formation by short-time calcination (10-60 min) in air at 480-520℃ not only shortens the process time and inhibits excessive thickness of the IrO2 shell layer and grain coarsening, but also facilitates large-scale production. Moreover, the entire process does not require ammonia gas pore-forming or long-term high-temperature treatment, avoiding the negative impacts of active site coverage or structural damage that may be caused by ammonia treatment. While simplifying the process, it also has higher safety and lower energy consumption. These characteristics together ensure high consistency of the preparation batches and clear parameter windows, laying a solid foundation for industrial application. In terms of environmental and cost benefits, the method of this invention significantly improves electrocatalytic performance while significantly reducing the amount of precious metal iridium (Ir), reducing dependence on noble metals. The prepared IrO2@NiRuO x Anode catalysts can reduce the overall operating voltage and system energy consumption, thereby reducing the energy consumption per unit of hydrogen production. At the same time, because they use carbon-free carriers and can inhibit metal leaching, they avoid the risk of secondary pollution from carbon corrosion byproducts and leached metal ions, demonstrating excellent environmental friendliness. Attached Figure Description

[0017] Figure 1 This is the IrO2@NiRuO2 prepared in Example 1 of the present invention for PEM water electrolysis. x TEM image of the anode catalyst. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] In a first aspect, the present invention provides IrO2@NiRuO for PEM water electrolysis. x Anode catalyst (abbreviated as IrO2@NiRuO) x A method for preparing an anode catalyst, the method comprising the following steps: (1) The ruthenium salt, nickel salt and carbon material are mixed evenly in an acid solution, and then the mixture is obtained by rotary evaporation and drying. The present invention does not make specific limitations on the rotary evaporation and drying. Those skilled in the art can choose conventionally. In the present invention, the rotary evaporation can be concentrated to a paste or to remove most of the solvent (e.g., remove the solvent to a solid content of 30-90%) under reduced pressure at 40-80°C. The drying can be dried to constant weight at 60-120°C. In the present invention, step (1) is, for example, dissolving the ruthenium salt and nickel salt in an acid solution, then adding the carbon material and sonicating for 0.5-4 hours, and then stirring at 400-800 r / min for 6-24 hours to mix evenly. The ratio of the sum of the mass of the ruthenium salt, nickel salt and the carbon material to the amount of the acid solution is, for example, 1 g: (50-500) mL. (2) The precursor mixture was successively calcined in a reducing atmosphere and in an air atmosphere, then soaked in an acid solution, and finally washed and dried to obtain the Ni-doped Ru oxide core NiRuO. x (abbreviated as NiRuO) x This invention constructs a Ni-doped Ru oxide core, NiRuO. x This can improve lattice stability and resistance to dissolution; in this invention, when treated with acid solution immersion, the ratio of the precursor mixture to the acid solution is, for example, 1 g: (50~500) mL; in this invention, the Ni-doped Ru oxide core is NiRuO x In this context, 'x' represents the non-stoichiometric oxygen content, and the Ni-doped Ru oxide core is NiRuO.x You can also use Ru 1-a Ni a O 2-δ This indicates that 'a' represents the mole fraction of Ni doping, δ ranges from 0 to 0.5, and the non-stoichiometric oxygen content x = 1.5 to 2.0, i.e., in NiRuO x In this invention, x takes the value of 1.5 to 2.0, and x can be obtained by characterization and / or ICP, etc.; In this invention, the washing can be carried out by washing with deionized water until neutral, and then drying at 60 to 120°C to constant weight; In this invention, in step (2), after calcination in a reducing atmosphere, it is first cooled to room temperature in an inert atmosphere (nitrogen and / or argon atmosphere), and then calcined in an air atmosphere; (3) Add iridium precursor and Ni-doped Ru oxide core NiRuO to the alcohol solvent system x After stirring and impregnating for 1–4 h (e.g., 1, 1.5, 2, 2.5, 3, 3.5, or 4 h), nitrate is added and stirring and impregnation continues for 0.25–1 h (e.g., 0.25, 0.5, or 1 h). Then the solvent is removed to obtain NiRuO supported on the iridium precursor. x The present invention does not specify the stirring speed for stirring and impregnation. Those skilled in the art can choose conventionally, for example, 400~800 r / min. In the present invention, the solvent removal method is, for example, to concentrate to a paste or near-dry state by means of water bath at 80~95℃ and / or rotary evaporation at 40~80℃, and then dry to constant weight at 60~120℃. In step (3) of the present invention, if wall-mounted crystal salts appear during stirring and impregnation, a small amount of alcohol solvent system can be added to rinse and / or disperse the wall-mounted crystal salts so that the attached wall-mounted crystal salts can re-enter the slurry system. (4) NiRuO loaded with iridium precursor x The product is calcined in air at 480–520°C (e.g., 480°C, 490°C, 500°C, 510°C, or 520°C) for 10–60 min (e.g., 10, 20, 30, 40, 50, or 60 min), followed by washing and drying to obtain IrO2@NiRuO for PEM water electrolysis. x Anode catalyst; the IrO2@NiRuO x The anode catalyst contains NiRuO x The kernel and the covering in NiRuO x The IrO2 outer shell layer on the core surface, namely the IrO2@NiRuO x The anode catalyst is NiRuO x A core-shell composite structure consisting of a core and an IrO2 outer shell.

[0020] The IrO2@NiRuO prepared by this inventionx The stability of the anode catalyst in acidic, high-current-density, and high-pressure PEM water electrolysis is significantly improved. NiRuO x Ni doping in the core stabilizes the Ru oxide lattice, inhibiting excessive oxidation and dissolution of ruthenium (Ru). A thin IrO2 outer shell provides chemical / electrochemical protection under acidic and high-potential conditions, mitigating core loss and phase reconstruction. In stack / electrolyte durability tests, it performs well at high current densities (≥1 A / cm²). 2 Under harsh conditions such as high pressure (≥30 bar), this IrO2@NiRuO x The anode catalyst exhibits both a significantly reduced voltage ramp-up rate and a significantly extended lifetime; the IrO2@NiRuO prepared in this invention... x The anode catalyst constructs a thin and continuous IrO2 shell layer, precisely positioning the noble metal Ir at the reaction interface, effectively avoiding the "bulk phase idleness" of Ir in a thick IrO2 shell layer. Simultaneously, short-time calcination (10-60 min) in air at 480-520℃ effectively inhibits IrO2 grain growth, thereby exposing more high-specific-surface-area active sites. The synergistic effect of "interface positioning" and "high active site density" in this invention improves the effective activity and protective effect per unit of Ir, significantly enhancing the utilization rate of the noble metal Ir. This allows for a reduction in the total Ir usage while achieving equivalent or better performance, improving PGM utilization (Ir atomic utilization) and ultimately reducing PGM cost (reduced unit hydrogen production cost). The IrO2@NiRuO2 prepared by this invention... x The anolyte catalyst, by constructing a thin and continuous IrO2 shell structure, effectively reduces the ion and electron penetration paths and decreases the interfacial / bulk resistance. The core provides high intrinsic active sites, while the shell provides a stable active surface, resulting in lower overpotential or stack voltage at the same current density and thus reducing overall energy consumption. The IrO2@NiRuO2 catalyst prepared in this invention... x The anode catalyst, by constructing a thin and dense IrO2 outer shell structure, exhibits significantly improved interfacial mechanical / chemical robustness due to its more uniform stress distribution and fewer grain boundary defects compared to a thicker shell. This allows it to better adapt to high pressure differentials and load fluctuations. Furthermore, the IrO2@NiRuO2 structure... x The anode catalyst has no residual carbon support (carbon only serves as a precursor template and can be completely removed during air calcination), fundamentally eliminating the risk of carbon corrosion under acidic, high current density, and / or high potential environments. This structural characteristic makes the IrO2@NiRuO prepared in this invention... x Anode catalyst under high pressure (≥30 bar) / high current density (≥1 A / cm) 2 Under dynamic loading conditions, it can maintain a lower activity decay rate and noble metal dissolution rate.

[0021] The IrO2@NiRuO3 used in PEM water electrolysis in this invention x Anode catalyst, via NiRuO x The ternary synergistic structure design of core stabilization and IrO2 thin-shell protection reduces the amount of Ir used while meeting the comprehensive requirements of high-pressure PEM electrolysis for activity, stability and cost. This invention achieves a thin and continuous IrO2 outer shell layer through nitrate-assisted impregnation and short-time air calcination. The use of an alcohol solvent system and nitrate additives to assist impregnation can promote uniform shell formation and interfacial bonding, inhibit IrO2 particle growth. Furthermore, this invention finds that in step (3), an alcohol solvent system containing an iridium precursor is first used to impregnate NiRuO2. x A stepwise impregnation method, which involves pre-impregnation (e.g., 1–4 h), followed by the addition of nitrate and continued impregnation (e.g., 0.25–1 h), is more beneficial for the formation of iridium species on NiRuO compared to an impregnation method that adds the iridium precursor and nitrate simultaneously. x The uniform distribution and anchoring of iridium species on the surface and in the pores facilitates the formation of a thinner, continuous, and more uniform IrO2 outer shell during subsequent short-time air calcination, reducing the probability of discrete particle accumulation, localized thick shells, or discontinuous shell layers. The stepwise impregnation method of this invention improves the effective contact and anchoring of iridium species through time-series control, thereby contributing to the uniformity and controllability of subsequent shell formation. Furthermore, this invention utilizes NiRuO2 loaded with iridium precursors… x The formation process of the IrO2 outer shell layer is controllably regulated by calcining at 480–520 °C for 10–60 min in air atmosphere. This temperature range promotes the oxidation / crystallization of iridium species, while short calcination helps limit IrO2 grain growth and sintering coarsening, thus obtaining a thin IrO2 outer shell layer. If the calcination temperature in air atmosphere is too high or the time is too long, it is more likely to cause IrO2 grain coarsening and agglomeration. The IrO2@NiRuO2 prepared by this invention... x The anode catalyst is suitable for high-pressure / high-current PEM water electrolysis conditions, which helps to reduce voltage decay and extend life. It can achieve better overall pile performance under low Ir loading, improve PGM utilization and reduce costs.

[0022] According to some preferred embodiments, in step (1): the ruthenium salt is a water-soluble ruthenium salt, which is one or more of hydrated ruthenium chloride (hydrated ruthenium trichloride) and ruthenium nitrate, preferably hydrated ruthenium chloride; the nickel salt is a water-soluble nickel salt, which is one or more of hydrated nickel chloride (nickel chloride hydrate), nickel nitrate, and nickel acetate, preferably hydrated nickel chloride; the carbon material is a low-dimensional carbon nanomaterial, which is one or more of carbon black, graphene, and carbon nanotubes; the present invention does not specify the carbon black, graphene, or carbon nanotubes. The carbon material is limited in size and can be conventionally selected by those skilled in the art; for example, the carbon black can be Vulcan carbon black, BP2000 carbon black, etc. In this invention, the carbon material is only used as a pre-dispersion template and can be removed during the air calcination stage. The concentration of the acid solution is 0.2~2 mol / L (e.g., 0.2, 0.5, 0.8, 1, 1.2, 1.5 mol / L or 2 mol / L). The acid solution is one or more of hydrochloric acid solution, nitric acid solution, and acetic acid solution. The molar ratio of nickel in the nickel salt to ruthenium in the ruthenium salt is 1:(2~). 4) (e.g., 1:2, 1:2.5, 1:3, 1:3.5 or 1:4), preferably 1:(2.5~3.5); In this invention, it is preferred that the molar ratio of nickel in the nickel salt to ruthenium in the ruthenium salt is 1:(2~4). This invention has found that the Ni:Ru molar ratio within the above range is more conducive to balancing activity and stability under acidic OER / PEM conditions; when the nickel content deviates from this range, the catalyst performance often tends to deteriorate; this invention has found that the electrocatalytic activity and stability of the Ni-doped Ru oxide core are highly dependent on the Ni content. It exhibits a clear dependence, and within a certain doping range, durability can be improved through methods such as stabilizing lattice oxygen / inhibiting Ru dissolution; however, when nickel doping is too high or too low, it may lead to adverse changes in phase structure / defect state / conductive network and active site exposure, thereby causing decreased activity or insufficient stability; and / or the ratio of the sum of the mass of the ruthenium salt and the nickel salt to the mass of the carbon material is 1:(0.1~3) (e.g., 1:0.1, 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5 or 1:3), preferably 1:(0.1~2).

[0023] According to some preferred embodiments, in step (2): the reducing atmosphere is a mixture of hydrogen and an inert gas (e.g., nitrogen and / or argon), wherein the mixture contains hydrogen at a volume fraction of 1 to 10 vol% (e.g., 1 vol%, 2 vol%, 3 vol%, 4 vol%, 5 vol%, 6 vol%, 7 vol%, 8 vol%, 9 vol%, or 10 vol%); and / or calcined at 800 to 950°C (e.g., 800°C, 850°C, 900°C, or 950°C) for 0.5 to 4 hours (e.g., 0.5, 1, 1.5, 2, 2.5, 3, 3.5, or 4 hours) in a reducing atmosphere.

[0024] According to some preferred embodiments, in step (2): calcination is carried out in an air atmosphere at 400~500°C (e.g. 400°C, 450°C or 500°C) for 1~4 hours (e.g. 1, 1.5, 2, 2.5, 3, 3.5 or 4 hours).

[0025] According to some preferred embodiments, in step (2): the concentration of the acid solution used in the acid solution immersion treatment is 0.2~2 mol / L (e.g., 0.2, 0.5, 0.8, 1, 1.2, 1.5 or 2 mol / L); the acid solution used in the acid solution immersion treatment is one or more of hydrochloric acid solution, nitric acid solution, sulfuric acid solution, and acetic acid solution; and / or the acid solution immersion treatment is performed at 15~80℃ (e.g., 15℃, 20℃, 25℃, 30℃, 35, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃) for 4~24h (e.g., 4, 6, 8, 10, 12, 15, 18, 20, 22 or 24h); in this invention, the acid solution immersion treatment can be used to remove unstable sites and impurity ions, and the control of the concentration of the acid solution and the acid solution immersion treatment time is beneficial to ensure that the removal target is achieved without damaging NiRuO. x The structure of the kernel.

[0026] According to some preferred embodiments, in step (3): the alcohol solvent system comprises 0.5-30% water and 70-99.5% alcohol solvent by volume percentage, wherein the alcohol solvent is one or more of isopropanol, ethanol, and methanol; in this invention, a small amount of low-boiling-point ketone solvent (e.g., acetone) may also be added to the alcohol solvent system; the iridium precursor is one or more of chloroiridium acid, iridium nitrate, and iridium acetylacetonate, preferably chloroiridium acid or its hydrate (chloroiridium acid hydrate); and / or the nitrate is one or more of sodium nitrate, potassium nitrate, and ammonium nitrate.

[0027] According to some preferred embodiments, in step (3): the molar ratio of the nitrate to the iridium contained in the iridium precursor is (20~300):1 (e.g. 20:1, 50:1, 100:1, 150:1, 200:1, 250:1 or 300:1); and / or in the addition of a Ni-doped Ru oxide core NiRuO x Subsequently, the Ni-doped Ru oxide core NiRuO x The concentration in the alcohol solvent system is 2~50 mg / mL (e.g., 2, 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50 mg / mL), in other words, the NiRuO x The ratio of the amount of [agent] added to the amount of the alcohol solvent system is (2~50) mg: 1 mL.

[0028] According to some preferred embodiments, in step (4): the temperature is increased to 480-520°C (e.g., 480°C, 490°C, 500°C, 510°C, or 520°C) at a heating rate of 3-10°C / min (e.g., 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, or 10°C / min); in this invention, it is preferable to perform short-time air calcination at a controlled heating rate of 3-10°C / min to 480-520°C in step (4), which is beneficial to obtain an IrO2 shell layer with a thickness of 0.5-10 nm; and / or the IrO2@NiRuO x The anolyte catalyst contains 20-70% iridium by mass (e.g., 20%, 30%, 40%, 50%, 60%, or 70%), preferably 30-60% (e.g., 30%, 40%, 50%, or 60%). The amount of iridium precursor used in step (3) of this invention is preferably such that the IrO2@NiRuO x The iridium content in the anode catalyst is 20-70% by mass.

[0029] In this invention, it is preferred to control the molar ratio of nitrate to iridium precursor to be (20~300):1, before adding NiRuO. x Afterwards, NiRuO x The concentration in the alcohol solvent system is 2~50 mg / mL and IrO2@NiRuO x The iridium mass fraction in the catalyst is 20-70%, which ensures that IrO2 is uniformly coated on NiRuO. x An optimized outer shell layer with a thickness of 0.5~10 nm is formed on the carrier surface. This invention reveals that a sufficient excess of nitrate is necessary to create a molten salt environment / oxidative conversion environment. Furthermore, the molar ratio of nitrate to iridium precursor and the NiRuO... xThe optimal parameters for Ir concentration and Ir mass fraction in the alcohol system are determined by their interaction. If these parameters are inappropriate, the deposition and oxidation-transformation of Ir species can easily become unbalanced, leading to uneven IrO2 shell coating or grain coarsening. These parameters work synergistically to regulate the deposition of IrO2 in NiRuO2. x Uniform coating of the carrier surface ensures the formation of a continuous thin-shell structure with a thickness of 0.5~10nm, balancing the thickness of the shell layer with catalytic performance, and ensuring high activity and stability of the core-shell structure. If the IrO2 shell layer is too thin, locally exposed, or has local discrete particle accumulation, it will lead to poor stability and easy corrosion in acidic electrolysis environment. An excessively thick IrO2 shell layer is not only more prone to particle sintering during high-temperature calcination, further reducing the active surface area, but also increases charge transport resistance, ultimately reducing catalytic efficiency.

[0030] In a second aspect, the present invention provides IrO2@NiRuO for PEM water electrolysis. x Anode catalyst, the IrO2@NiRuO x The anode catalyst was prepared using the preparation method described in the first aspect of this invention; the IrO2@NiRuO x The anode catalyst contains a Ni-doped Ru oxide core, NiRuO. x and the NiRuO core coated thereon x The surface has an IrO2 shell layer, the thickness of which is 0.5~10nm (e.g. 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10nm), preferably 2~8nm (e.g. 2, 3, 4, 5, 6, 7 or 8nm).

[0031] In a third aspect, the present invention provides an IrO2@NiRuO3 for PEM water electrolysis. x Application of anode catalyst in high-pressure PEM water electrolysis for hydrogen production, wherein IrO2@NiRuO x The anode catalyst is prepared using the method described in the first aspect of this invention; the pressure of the high-pressure PEM electrolysis for hydrogen production is ≥30 bar, and the current density is ≥1 A / cm². 2 .

[0032] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments. The present invention may have many other embodiments, and those skilled in the art can make various corresponding changes and modifications based on the present invention without departing from its spirit and essence. However, all such corresponding changes and modifications should fall within the scope of protection of the appended claims. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials, reagents, etc., used in the following embodiments can be obtained commercially or prepared by existing methods.

[0033] Example 1 S1: Dissolve 0.172 g of hydrated ruthenium chloride (RuCl3·xH2O) and 0.0656 g of hydrated nickel chloride (NiCl2·6H2O) in 150 mL of 1 mol / L hydrochloric acid solution, add 0.40 g of Vulcan carbon black, sonicate for 2 h, and stir for 18 h; then concentrate by rotary evaporation to a paste and dry at 80 °C to constant weight to obtain a precursor mixture.

[0034] S2: The precursor mixture was first calcined at 900℃ for 2 hours under a reducing atmosphere, then cooled to room temperature under an argon atmosphere, and then calcined at 450℃ for 3 hours under an air atmosphere. It was then soaked in a 1 mol / L hydrochloric acid solution at room temperature (25℃) for 12 hours, washed with deionized water by centrifugation until neutral, and finally dried at 80℃ to constant weight to obtain the Ni-doped Ru oxide core NiRuO. x The reducing atmosphere is a mixture of hydrogen and argon, wherein the volume fraction of hydrogen in the mixture is 5 vol%; the ratio of the precursor mixture to the hydrochloric acid solution is 1 g: 150 mL; the heating rate to 900 °C under the reducing atmosphere and the heating rate to 450 °C under air atmosphere are both 5 °C / min.

[0035] S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 80 mg of NiRuO. x The mixture was stirred and impregnated for 2 hours, then 6.0 g of sodium nitrate (NaNO3) was added, and stirring and impregnation continued for 30 minutes. During the stirring and impregnation process, if adhering salt crystals appeared on the walls, a small amount of alcohol solvent system could be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, the mixture was evaporated to a paste state in a 90°C water bath, and then dried to constant weight at 80°C to obtain NiRuO4 loaded with the iridium precursor. x The alcohol solvent system is composed of isopropanol and water in a volume ratio of 9:1.

[0036] S4: NiRuO loaded with iridium precursor x The product was calcined at 500℃ (heating rate of 5℃ / min) in air for 30 min, cooled to room temperature, washed with deionized water by suction filtration, and finally dried at 80℃ to constant weight to obtain IrO2@NiRuO for PEM water electrolysis. x Anode catalyst.

[0037] The IrO2@NiRuO2 prepared in this embodiment for PEM water electrolysis was measured. x The iridium content of the anode catalyst is 48.5 wt%, and the thickness of the IrO2 shell layer is 4~5 nm.

[0038] The IrO2@NiRuO2 prepared for PEM water electrolysis in Example 1 of this invention x TEM image of the anode catalyst, as shown Figure 1 As shown; by Figure 1 It can be seen that the IrO2@NiRuO x The anolyte catalyst contains a uniform and thin IrO2 shell layer, which is a continuous thin-shell structure.

[0039] Example 2 S1: Same as step S1 in Example 1.

[0040] S2: The precursor mixture was first calcined at 850℃ for 1 h under a reducing atmosphere, then cooled to room temperature under an argon atmosphere, and then calcined at 400℃ for 2 h under an air atmosphere. It was then soaked in a 1 mol / L hydrochloric acid solution at room temperature (25℃) for 12 h, washed with deionized water by centrifugation until neutral, and finally dried at 80℃ to constant weight to obtain the Ni-doped Ru oxide core NiRuO. x The reducing atmosphere is a mixture of hydrogen and argon, wherein the volume fraction of hydrogen in the mixture is 3 vol%; the ratio of the precursor mixture to the hydrochloric acid solution is 1 g: 150 mL; the heating rate to 850 °C under the reducing atmosphere and the heating rate to 400 °C under air atmosphere are both 3 °C / min.

[0041] S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 80 mg of NiRuO. x The mixture was stirred and impregnated for 1.5 hours, then sodium nitrate (NaNO3) was added, and stirring and impregnation continued for 15 minutes. During the stirring and impregnation process, if adhering salt crystals appeared on the walls, a small amount of alcohol solvent system could be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, the mixture was evaporated to a paste state in a 90°C water bath, and then dried to constant weight at 80°C to obtain NiRuO4 loaded with the iridium precursor.x The alcohol solvent system is composed of an alcohol solvent and water in a volume ratio of 9:1, and the alcohol solvent is composed of isopropanol and ethanol in a volume ratio of 1:1. The amount of sodium nitrate used is such that the molar ratio of sodium nitrate to iridium contained in the chloroiridium acid hydrate is 20:1.

[0042] S4: NiRuO loaded with iridium precursor x The product was calcined at 490℃ (heating rate of 3℃ / min) in air for 20 min, cooled to room temperature, washed with deionized water, and finally dried at 80℃ to constant weight to obtain IrO2@NiRuO for PEM water electrolysis. x Anode catalyst.

[0043] The IrO2@NiRuO2 prepared in this embodiment for PEM water electrolysis was measured. x The IrO2 outer shell layer contained in the anode catalyst has a thickness of 2~3 nm.

[0044] Example 3 S1: Same as step S1 in Example 1.

[0045] S2: The precursor mixture was first calcined at 950℃ for 4 hours under a reducing atmosphere, then cooled to room temperature under an argon atmosphere, and then calcined at 500℃ for 4 hours under an air atmosphere. It was then soaked in a 1 mol / L hydrochloric acid solution at room temperature (25℃) for 12 hours, washed with deionized water by centrifugation until neutral, and finally dried at 80℃ to constant weight to obtain the Ni-doped Ru oxide core NiRuO. x The reducing atmosphere is a mixture of hydrogen and argon, wherein the volume fraction of hydrogen in the mixture is 10 vol%; the ratio of the precursor mixture to the hydrochloric acid solution is 1 g: 150 mL; the heating rate to 950 °C under the reducing atmosphere and the heating rate to 500 °C under air atmosphere are both 10 °C / min.

[0046] S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 80 mg of NiRuO. x The mixture was stirred and impregnated for 4 hours, then sodium nitrate (NaNO3) was added, and stirring and impregnation continued for another hour. During the stirring and impregnation process, if adhering salt crystals appeared on the walls, a small amount of alcohol solvent system could be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, the mixture was evaporated to a paste-like consistency in a 90°C water bath, and then dried to a constant weight at 80°C to obtain NiRuO4 loaded with the iridium precursor. xThe alcohol solvent system is composed of isopropanol and water in a volume ratio of 9:1, and the amount of sodium nitrate is such that the molar ratio of sodium nitrate to iridium contained in the chloroiridium acid hydrate is 300:1.

[0047] S4: NiRuO loaded with iridium precursor x The product was calcined at 520℃ (heating rate of 10℃ / min) in air for 60 min, cooled to room temperature, washed with deionized water, and finally dried at 80℃ to constant weight to obtain IrO2@NiRuO for PEM water electrolysis. x Anode catalyst.

[0048] The IrO2@NiRuO2 prepared in this embodiment for PEM water electrolysis was measured. x The IrO2 outer shell layer contained in the anode catalyst has a thickness of 6~8 nm.

[0049] Example 4 S1: Same as step S1 in Example 1.

[0050] S2: Same as step S2 in Example 1.

[0051] S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 80 mg of NiRuO. x After stirring and impregnation for 2 hours, 6g of potassium nitrate (KNO3) was added, and stirring and impregnation continued for 30 minutes. During the stirring and impregnation process, if adhering salt crystals appeared on the wall, a small amount of alcohol solvent system could be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, the mixture was evaporated to a paste state in a 90℃ water bath, and then dried to constant weight in a vacuum oven at 80℃ to obtain NiRuO supported on the iridium precursor. x The alcohol solvent system is composed of methanol and water in a volume ratio of 9:1.

[0052] S4: NiRuO loaded with iridium precursor x The product was calcined at 480℃ (heating rate of 3℃ / min) in air for 40 min, cooled to room temperature, washed with deionized water, and finally dried at 80℃ to constant weight to obtain IrO2@NiRuO for PEM water electrolysis. x Anode catalyst.

[0053] The IrO2@NiRuO2 prepared in this embodiment for PEM water electrolysis was measured. x The IrO2 outer shell layer contained in the anode catalyst has a thickness of 3~5 nm.

[0054] Example 5 Example 5 is basically the same as Example 1, except that: S1: Dissolve 0.172 g of hydrated ruthenium chloride (RuCl3·xH2O) and hydrated nickel chloride (NiCl2·6H2O) in 150 mL of 1 mol / L hydrochloric acid solution, add 0.40 g of Vulcan carbon black, sonicate for 2 h, and stir for 18 h; then concentrate by rotary evaporation to a paste and dry at 80 °C to constant weight to obtain a precursor mixture; wherein, the amount of hydrated nickel chloride is such that the molar ratio of nickel in the hydrated nickel chloride to ruthenium in the hydrated ruthenium chloride is 1:1.

[0055] Example 6 Example 6 is basically the same as Example 1, except that: S1: Dissolve 0.172 g of hydrated ruthenium chloride (RuCl3·xH2O) and hydrated nickel chloride (NiCl2·6H2O) in 150 mL of 1 mol / L hydrochloric acid solution, add 0.40 g of Vulcan carbon black, sonicate for 2 h, and stir for 18 h; then concentrate by rotary evaporation to a paste and dry at 80 °C to constant weight to obtain a precursor mixture; wherein, the amount of hydrated nickel chloride is such that the molar ratio of nickel in the hydrated nickel chloride to ruthenium in the hydrated ruthenium chloride is 1:6.

[0056] Example 7 Example 7 is basically the same as Example 1, except that: S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 3.8 mg of NiRuO. x The mixture was stirred and impregnated for 2 hours, then sodium nitrate (NaNO3) was added, and stirring and impregnation continued for 30 minutes. During the stirring and impregnation process, if adhering salt crystals appeared on the walls, a small amount of alcohol solvent system could be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, the mixture was evaporated to a paste state in a 90°C water bath, and then dried to a constant weight at 80°C to obtain NiRuO4 loaded with the iridium precursor. x The alcohol solvent system is composed of isopropanol and water in a volume ratio of 9:1, and the amount of sodium nitrate used is such that the molar ratio of sodium nitrate to iridium contained in the chloroiridium acid hydrate is 5:1.

[0057] This embodiment is due to NiRuO x If the dosage is too low or there are insufficient anchoring points on the substrate surface, Ir species are prone to free nucleation and aggregation during subsequent desolventizing / calcination processes. This results in IrO2 existing as discrete particles and discontinuous thin layers, manifested as local shell loss (exposed) or extremely thin layers, accompanied by IrO2 particle accumulation.

[0058] Example 8 Example 8 is basically the same as Example 1, except that: S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 228 mg of NiRuO. x The mixture was stirred and impregnated for 2 hours, then sodium nitrate (NaNO3) was added, and stirring and impregnation continued for 30 minutes. During the stirring and impregnation process, if adhering salt crystals appeared on the walls, a small amount of alcohol solvent system could be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, the mixture was evaporated to a paste state in a 90°C water bath, and then dried to a constant weight at 80°C to obtain NiRuO4 loaded with the iridium precursor. x The alcohol solvent system is composed of isopropanol and water in a volume ratio of 9:1, and the amount of sodium nitrate used is such that the molar ratio of sodium nitrate to iridium contained in the chloroiridium acid hydrate is 350:1.

[0059] In this embodiment, due to the Ir precursor being relative to NiRuO x The dosage was too low, resulting in an overall IrO2 outer shell that was either too thin or discontinuous, exhibiting island-like / dot-like deposition accompanied by a certain proportion of NiRuO. x The surface is exposed; a small amount of IrO2 particles are visible in some areas, but the overall coating uniformity is insufficient.

[0060] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that it does not include steps S3 and S4, and only steps S1 and S2 are performed to obtain the Ni-doped Ru oxide core NiRuO. x As an anode catalyst for PEM water electrolysis.

[0061] Comparative Example 2 S1: 200 mg of polyvinylpyrrolidone (PVP), 40 mg of ruthenium chloride hydrate (RuCl3·xH2O), and 20 mg of ascorbic acid were added to 14 mL of ethylene glycol and sonicated for 30 minutes until completely dissolved. The solution was then transferred to a pressure-resistant tube and heated to 180 °C for 3 hours to obtain the Ru core. After cooling, the solution was transferred to a three-necked flask and heated under a nitrogen atmosphere, while a solution of ethylene glycol containing dissolved iridium chloride was added dropwise at a uniform rate, maintaining a molar ratio of Ir to Ru of 1:1. The mixture was refluxed to 180 °C and reacted for another 2 hours. After cooling, the product was washed with ethanol and acetone to obtain the intermediate product Ru@Ir.

[0062] S2: Take 20 mg of the intermediate Ru@Ir synthesized in the above steps and uniformly disperse it in 30 mL of ethanol, denoted as solution 1. Disperse 50 mg of carbon black uniformly in 30 mL of ethanol, denoted as solution 2. Then add solution 1 to solution 2 and sonicate for 2 h until the catalyst is uniformly loaded onto the carbon black. Then dry in an 80℃ forced-air drying oven overnight. Finally, grind the obtained product to obtain Ru@Ir / C, and heat it in a muffle furnace to 300℃ at 2℃ / min, holding for 1 h to obtain the final product RuO2@IrO2 / C.

[0063] Comparative Example 3 Chloroiridic acid was dissolved in deionized water to prepare a 0.1 mol / L aqueous solution. Sodium citrate was then added as a stabilizer, with a molar ratio of iridium to sodium citrate of 1:2. The solution was stirred in an 80°C water bath for 2 hours to form a homogeneous sol. The sol was then dried in a 120°C oven for 12 hours to obtain the precursor, which was then heated in a muffle furnace to 450°C at a heating rate of 5°C / min and held for 2 hours. The precursor was then washed with deionized water and filtered to remove soluble Na and Cl residues. Finally, the product was dried to obtain IrO2 powder.

[0064] Comparative Example 4 Comparative Example 4 is basically the same as Example 1, except that: S1: Dissolve 0.172 g of hydrated ruthenium chloride (RuCl3·xH2O) in 150 mL of 1 mol / L hydrochloric acid solution and add 0.40 g of Vulcan carbon black. Sonicate for 2 h and stir for 18 h. Then concentrate by rotary evaporation to a paste and dry at 80 °C to constant weight to obtain a precursor mixture.

[0065] This comparative example yields IrO2@RuO x Anode catalyst.

[0066] Comparative Example 5 Comparative Example 5 is basically the same as Example 1, except that: S3: Dissolve 0.210 g of chloroiridium acid hydrate (H2Cl6Ir·xH2O, Ir content 38wt%) in 3.8 mL of alcohol solvent system and add 80 mg of NiRuO. x After stirring and dispersing for 10 minutes, add 6g of sodium nitrate (NaNO3) and continue stirring and impregnation for 2.5 hours. During the stirring and impregnation process, if adhering salt crystals appear on the wall, a small amount of alcohol solvent system can be added to rinse and / or disperse the adhering salt crystals, allowing them to re-enter the slurry system. Finally, evaporate to a paste state in a 90℃ water bath, and then dry at 80℃ to constant weight to obtain NiRuO supported on the iridium precursor. x The alcohol solvent system is composed of isopropanol and water in a volume ratio of 9:1.

[0067] In this comparative example, nitrate was added early and lacked sufficient pre-anchoring, resulting in discontinuous, granular IrO2 formed during subsequent calcination.

[0068] Comparative Example 6 Comparative Example 6 is basically the same as Example 1, except that: This comparative example also includes step S5: taking the IrO2@NiRuO obtained in step S4... x The anode catalyst was placed in a ceramic boat and annealed at 300℃ (heating rate 5℃ / min) for 1 hour under an ammonia atmosphere.

[0069] The ammonia annealing in this comparative example actually damaged the key structure of the invention, the "thin and continuous IrO2 shell layer," causing the active sites to be covered, which leads to greater voltage attenuation and poorer stability.

[0070] Comparative Example 7 0.4 g of TiO2 and 1.47 g of chloroiridium acid aqueous solution were weighed and dispersed in isopropanol. Then, 22.77 g of sodium nitrate was weighed and placed in the ball mill jar of a planetary ball mill. The mixture was ball-milled for 10 hours, with the mill jar rotating at 600 r / min and the direction reversed every 45 minutes. After mixing, the mixture was completely dried in a vacuum drying oven at 70℃. The crucible containing the catalyst precursor powder was then placed in a muffle furnace at 500℃ and held for 30 minutes, followed by furnace cooling to room temperature. The precursor crystals were then washed with deionized water, filtered under positive pressure, and dried overnight in a vacuum drying oven to obtain the catalyst precursor, denoted as IrO2 / TiO2. The IrO2 / TiO2 was then placed in a ceramic boat and annealed at 300℃ for 1 hour under an ammonia atmosphere to obtain a catalyst containing oxygen vacancies, denoted as OVs-IrO2 / TiO2 catalyst.

[0071] This invention assembles the anode catalysts prepared in various embodiments and comparative examples into an electrolyzer and then conducts performance tests on high-pressure PEM electrolysis of water to produce hydrogen. The electrolyzer assembly method is as follows: during the preparation of the membrane electrode assembly, the anode catalytic ink is first directly sprayed onto one side of the proton exchange membrane (Nafion® N117), controlling the Ir loading to be 0.5 mg / cm³. 2 (Comparative Example 1: Ir-free, with Ru loading controlled at 0.5 mg / cm³) 2 The spraying was performed on a 90°C heated stage, with heating occurring simultaneously. Next, the cathode catalytic ink was sprayed onto the other side of the proton exchange membrane (Nafion® N117), maintaining a Pt loading of 0.5 mg / cm³. 2The spraying process is performed on a 90°C heating platform, with simultaneous heating and spraying. Finally, the sprayed double-sided catalytic ink layer proton exchange membrane is placed in a hot press and pressed at 110°C and 20MPa for 2 minutes to ensure a tight bond between the catalytic ink layer and the proton exchange membrane, forming a complete membrane electrode assembly. The prepared membrane electrode assembly (MEA) is then sequentially assembled with the anode porous mass transfer layer, the cathode porous mass transfer layer, and the PTFE sealing gasket, placed between two titanium bipolar plates with flow channels, ensuring that the anode side (OER side) faces the anode flow channel and the cathode side (HER side) faces the cathode flow channel. The entire structure is then fixed using stainless steel end plates and uniformly tightened with bolts to form a complete electrolytic cell structure. After assembly, connect the water supply pipelines for the anode and cathode and the gas output pipelines to the inlet and outlet of the outermost aluminum alloy end plate, respectively. Maintain the target system pressure through a back pressure valve or pressure control module, and connect the current acquisition wire to perform performance testing. The anode catalytic ink is prepared as follows: the anode catalyst, Nafion solution (concentration of 5wt%), and solvent (the solvent is a mixture of isopropanol and water at a volume ratio of 9:1) are mixed at a mass ratio of 100:30:200 and ultrasonically dispersed for 30 minutes, then stirred for 1 hour to form a uniform anode catalytic ink. The cathode catalytic ink is prepared as follows: the cathode catalyst (commercial Pt / C), Nafion solution (concentration of 5wt%), and solvent (the solvent is a mixture of isopropanol and water at a volume ratio of 9:1) are mixed at a mass ratio of 100:30:200 and ultrasonically dispersed for 30 minutes, then stirred for 1 hour to form a uniform cathode catalytic ink.

[0072] Test method for high-pressure PEM electrolysis of water to produce hydrogen after assembly into an electrolyzer: The assembled electrolytic cell was connected to the high-voltage testing system, and a current of 1 A / cm was applied in constant current mode. 2 The current density was controlled to maintain the electrolytic cell temperature at 80±2℃. Oxygen and hydrogen pressures of 30 bar were maintained on the anode and cathode sides respectively via back pressure control modules, and the initial voltage (V) and initial overpotential (mV) were recorded in real time. The anode-cathode pressure difference ΔP (bar) was monitored using a high-precision pressure sensor. Durability testing was conducted at a constant 1 A / cm². 2 The test was conducted continuously at the current density, and the voltage drift (mV) was recorded for 100h, 500h and 1000h. At the same time, the flow fluctuation rate (%) was monitored. The results are shown in Table 1. During the test, high-purity deionized water was continuously introduced into both the anode and the cathode as the reaction medium.

[0073] Table 1: Performance test results of Examples 1-8 and Comparative Examples 1-7.

[0074]

[0075] Note: In Table 1, ΔP between the anode and cathode represents the average pressure difference during the 1000-hour test; the flow rate fluctuation rate represents the maximum oxygen flow rate fluctuation within 1000 hours. The IrO2@NiRuO2 prepared in this invention... x Anode catalyst under high-pressure PEM water electrolysis conditions (30 bar, 1 A / cm) 2 It exhibits excellent overall performance: low overpotential and low initial voltage, and minimal voltage drift in the 1000-hour constant current durability test, demonstrating good long-term operational stability. Meanwhile, the low average pressure difference (ΔP) between the anode and cathode and the small fluctuation rate of oxygen flow rate during the test indicate / indirectly confirm that the assembled electrolyzer maintains stable pressure and gas output, and smooth gas-liquid transmission and discharge processes during high-pressure continuous operation. This is beneficial for maintaining the stability of the electrode interface and catalyst layer structure, thus supporting its long-term stable operation.

[0076] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although detailed descriptions have been made with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An IrO2@NiRuO3 formulation for PEM water electrolysis x A method for preparing an anode catalyst, characterized in that, The method includes the following steps: (1) The ruthenium salt, nickel salt and carbon material are mixed evenly in an acid solution, and then rotary evaporated and dried to obtain a precursor mixture; (2) The precursor mixture was successively calcined in a reducing atmosphere and in an air atmosphere, then soaked in an acid solution, and finally washed and dried to obtain the Ni-doped Ru oxide core NiRuO. x ; (3) Add iridium precursor and Ni-doped Ru oxide core NiRuO to the alcohol solvent system x After stirring and impregnation for 1-4 hours, nitrate is added and stirring and impregnation continues for 0.25-1 hour. Then, the solvent is removed to obtain NiRuO supported on the iridium precursor. x ; (4) NiRuO loaded with iridium precursor x IrO2@NiRuO2 for PEM water electrolysis was prepared by calcining at 480-520℃ for 10-60 min in air atmosphere, followed by washing and drying. x Anode catalyst.

2. The preparation method according to claim 1, characterized in that, In step (1): The ruthenium salt is a water-soluble ruthenium salt, which is one or more of ruthenium chloride hydrate and ruthenium nitrate. The nickel salt is a water-soluble nickel salt, which is one or more of nickel chloride hydrate, nickel nitrate, and nickel acetate. The carbon material is a low-dimensional carbon nanomaterial, which is one or more of carbon black, graphene, and carbon nanotubes. The concentration of the acid solution is 0.2~2 mol / L; The acid solution is one or more of hydrochloric acid solution, nitric acid solution, and acetic acid solution; The molar ratio of nickel in the nickel salt to ruthenium in the ruthenium salt is 1:(2~4); and / or The ratio of the sum of the mass of the ruthenium salt and the nickel salt to the mass of the carbon material is 1:(0.1~3).

3. The preparation method according to claim 1, characterized in that, In step (2): The reducing atmosphere is a mixture of hydrogen and an inert gas, wherein the volume fraction of hydrogen in the mixture is 1-10 vol%; and / or Calcination at 800-950℃ for 0.5-4 hours under a reducing atmosphere.

4. The preparation method according to claim 1, characterized in that, In step (2): Calcination at 400-500℃ for 1-4 hours in air atmosphere.

5. The preparation method according to claim 1, characterized in that, In step (2): The concentration of the acid solution used in the acid immersion treatment is 0.2~2 mol / L; The acid solution used in the acid immersion treatment is one or more of hydrochloric acid solution, nitric acid solution, sulfuric acid solution, and acetic acid solution; and / or The acid solution immersion treatment is performed by immersing at 15~80℃ for 4~24 hours.

6. The preparation method according to claim 1, characterized in that, In step (3): The alcohol solvent system comprises 0.5-30% water and 70-99.5% alcohol solvent by volume, wherein the alcohol solvent is one or more of isopropanol, ethanol, and methanol; The iridium precursor is one or more of chloroiridium acid, iridium nitrate, and iridium acetylacetonate; and / or The nitrate is one or more of sodium nitrate, potassium nitrate, and ammonium nitrate.

7. The preparation method according to claim 1, characterized in that, In step (3): The molar ratio of the nitrate to the iridium contained in the iridium precursor is (20~300):1; and / or Adding Ni-doped Ru oxide core NiRuO x Subsequently, the Ni-doped Ru oxide core NiRuO x The concentration in alcohol solvent systems is 2~50 mg / mL.

8. The preparation method according to claim 1, characterized in that, In step (4): Heating to 480-520℃ at a heating rate of 3-10℃ / min; and / or The IrO2@NiRuO x The iridium content in the anode catalyst is 20-70% by mass.

9. An IrO2@NiRuO3 formulation for PEM water electrolysis x Anode catalyst, characterized in that: The IrO2@NiRuO x The anode catalyst is prepared by the method described in any one of claims 1 to 8; The IrO2@NiRuO x The anode catalyst contains a Ni-doped Ru oxide core, NiRuO. x And an IrO2 shell layer covering the surface of the Ni-doped Ru oxide core NiRuOx, wherein the thickness of the IrO2 shell layer is 0.5~10nm.

10. An IrO2@NiRuO3 formulation for PEM water electrolysis x The application of anode catalysts in high-pressure PEM water electrolysis for hydrogen production is characterized by: The IrO2@NiRuO x The anode catalyst is prepared by the method described in any one of claims 1 to 8; The high-pressure PEM electrolysis for hydrogen production has a pressure ≥30 bar and a current density ≥1 A / cm². 2 .

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