Efficient integrated assembly for PEM exchange membrane water electrolysis hydrogen production system and application of efficient integrated assembly

Abstract

The invention relates to the field of efficient integrated assemblies of PEM water electrolysis hydrogen production systems, and discloses an efficient integrated assembly for a PEM exchange membrane water electrolysis hydrogen production system, an anode electrode unit in the integrated assembly comprises a ruthenium-based high-entropy metal oxide electrocatalyst, and the ruthenium-based high-entropy metal oxide electrocatalyst comprises ruthenium, tin, manganese, chromium and tantalum elements; the preparation method of the ruthenium-based high-entropy metal oxide electrocatalyst comprises the following steps: grinding solid inorganic ruthenium salt, tin salt, manganese salt, chromium salt, tantalum salt and sodium chloride to obtain a metal salt mixture; carrying out ball milling to obtain a high-entropy metal oxide precursor; and carrying out heat treatment and water washing treatment on the precursor to obtain the ruthenium-based high-entropy metal oxide electrocatalyst. The invention also discloses application of the electrocatalyst in water electrolysis oxygen evolution reaction in an acid solution and water electrolysis hydrogen production reaction of a PEM proton exchange membrane, and the electrocatalyst shows excellent electrocatalytic activity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-efficiency integrated components for PEM water electrolysis hydrogen production systems, and in particular to a high-efficiency integrated component for a PEM exchange membrane water electrolysis hydrogen production system and its application. BACKGROUND

[0002] Proton exchange membrane (PEM) water electrolysis hydrogen production technology has gained widespread attention in the hydrogen energy field due to its high energy efficiency, low gas crossover, and compact electrolyzer structure. In the working environment of a PEM water electrolysis hydrogen production cell, the oxygen evolution reaction (OER) occurring at the anode requires a catalyst that can withstand severe acidic conditions, which imposes more stringent requirements on the performance of OER catalysts. Noble metals such as iridium (Ir) and ruthenium (Ru) and their derivatives are the best candidate materials for acid water OER catalysts due to their suitable electronic structure and excellent corrosion and oxidation resistance. From a cost perspective, research on noble metal ruthenium has increased in recent years.

[0003] In related technical research, a Chinese patent document with publication number CN119465237A proposes a preparation method for a chromium-ruthenium binary metal oxide used as an anode catalyst in a PEM hydrogen production water electrolysis cell. This method involves a solvothermal reaction of a raw material solution containing a Ru source, a Cr source, a structure adjusting agent, and an inorganic base, followed by calcination of the solvothermal product at 300-500 o C to construct a catalyst structure that is suitable for high current density and acid corrosion resistance. This technology, despite reducing the Ru content and using a double-metal precursor, still enables the catalyst material to maintain excellent OER activity in high-current, acidic environments. Another Chinese patent document with publication number CN118127561A discloses a rare earth element-doped RuO2 material, its preparation method, and its application. This material has a rutile-type crystal structure, with rare earth elements occupying Ru atomic sites in the rutile-type RuO2 and uniformly distributed in the material's crystal structure, significantly improving the acid OER performance. Although some Ru-based OER catalyst materials have been developed in existing technologies, and these materials can exhibit good OER performance in acidic conditions, there are still significant deficiencies. On the one hand, the content of noble metal Ru in the catalyst material is still relatively high, resulting in high material costs and limiting the large-scale industrial application of PEM water electrolysis; on the other hand, the OER performance of existing Ru-based materials under high current and acidic conditions still has room for improvement to meet the actual needs of high-efficiency PEM water electrolysis hydrogen production.

[0004] In recent years, the high-entropy characteristics of high-entropy metal oxides can provide multiple electronic transmission paths and structural stability, thereby improving the OER performance and stability of ruthenium-based catalysts. SUMMARY

[0005] The application aims to provide an anode efficient integrated assembly of a PEM exchange membrane water electrolysis hydrogen production system and application thereof, wherein the anode electrode unit of the integrated assembly comprises a ruthenium-based high-entropy metal oxide catalyst; and the application also provides application of the above-mentioned catalyst to an acidic water electrolysis oxygen evolution system, which has excellent electrochemical activity in the acidic water electrolysis OER.

[0006] In order to achieve the above-mentioned application purposes, the application provides the following technical solutions. An efficient integrated assembly for a PEM exchange membrane water electrolysis hydrogen production system, wherein the anode electrode unit of the integrated assembly comprises a ruthenium-based high-entropy metal oxide electrocatalyst, and the ruthenium-based high-entropy metal oxide electrocatalyst comprises ruthenium, tin, manganese, chromium and tantalum. The ruthenium-based high-entropy metal oxide provided by the application has excellent oxygen evolution performance in an acidic environment and acid corrosion resistance; the core advantage lies in that the high-entropy oxide structure is constructed, the oxygen evolution activity and corrosion resistance of the material in an acidic system are significantly improved, key material support is provided for structural optimization and performance upgrading of green energy conversion devices, and the application has important value for promoting the technical development and industrial application in the field of green energy conversion.

[0007] The ruthenium-based high-entropy metal oxide electrocatalyst has a rutile structure, and the ruthenium, tin, manganese, chromium and tantalum elements in the ruthenium-based high-entropy metal oxide electrocatalyst are arranged in disorder.

[0008] The preparation method of the ruthenium-based high-entropy metal oxide catalyst comprises the following steps: (1) grinding solid inorganic ruthenium salt, tin salt, manganese salt, chromium salt and tantalum salt and sodium chloride to obtain a metal salt mixture; (2) ball-milling the metal salt mixture to obtain a precursor; (3) heat-treating the precursor to obtain a ruthenium-based high-entropy metal oxide catalyst containing sodium chloride; (4) washing the ruthenium-based high-entropy metal oxide catalyst containing sodium chloride to obtain a ruthenium-based high-entropy metal oxide electrocatalyst.

[0009] The preparation principle of the ruthenium-based high-entropy metal oxide electrocatalyst provided by the application is as follows: sodium chloride and a metal precursor solid solution are formed through ball-milling treatment, and then a metal oxide solid solution is formed through calcination treatment. All reaction steps are completed in the same system, the reactants are uniformly dispersed, the ruthenium and tin, manganese, chromium and tantalum metal elements are fully mixed and interacted at the atomic level, the obtained high-entropy metal oxide catalyst has a highly uniform microstructure and element composition distribution, and the consistency and stability of the catalyst performance are ensured, The solid ruthenium salt, tin salt, manganese salt, chromium salt and tantalum salt in step (1) are all soluble salts: the ruthenium salt is ruthenium chloride, the tin salt is tin dichloride dihydrate, the manganese salt is manganese chloride, the chromium salt is chromium chloride hexahydrate, and the tantalum salt is tantalum pentachloride.

[0010] The ruthenium salt in step (1) is a main metal salt, and the molar amount of the main metal salt is greater than the total molar amount of the tin salt, manganese salt, chromium salt and tantalum salt.

[0011] Preferably, the molar ratio of the total molar amount of the tin salt, manganese salt, chromium salt and tantalum salt to the main metal salt is 1:3-4.

[0012] The ruthenium salt is a main metal salt, and the molar ratio of the tin salt, manganese salt, chromium salt and tantalum salt to the main metal salt is 1:3-4. When the content of the tin salt, manganese salt, chromium salt and tantalum salt is low, it is difficult to form a high-entropy metal oxide. Because at this time, the internal synergy of metal elements cannot be used to break the immiscibility gap between metal elements, and thus the influence on the electronic structure of the ruthenium site in the catalyst is minimal, resulting in insignificant improvement in OER activity and stability. On the contrary, when the content of the tin salt, manganese salt, chromium salt and tantalum salt is high, it is easy to generate metal oxide compounds such as tin dioxide, manganese dioxide, chromium dioxide, tantalum dioxide and ruthenium dioxide, which causes a decrease in OER activity.

[0013] Preferably, the molar ratio of the ruthenium salt, tin salt, manganese salt, chromium salt and tantalum salt in step (1) is 75:6:6:6:6-80:5:5:5:5.

[0014] In step (1), the molar ratio of sodium chloride to the precursor is 8.5:1. When the content of sodium chloride is too low, the precursor appears uneven dispersion, resulting in low catalyst yield, so the amount of sodium chloride needs to be controlled to be sufficient. In step (1), the grinding time is 10 min.

[0015] In step (2), the ball milling time is 1 h, and the rotation speed is 500 rpm, so as to promote the uniform dispersion of the ruthenium salt, tin salt, manganese salt, chromium salt and tantalum salt in sodium chloride. In step (2), after the metal salt mixture is ball milled, a sodium hydroxide solution is added dropwise, and then ball milling treatment is performed: the concentration of the sodium hydroxide solution is 0-100 mmol / L, and the ratio of the amount of sodium hydroxide solution added to the metal salt is 0.5 mL of sodium hydroxide solution per mole of metal salt. Preferably, the concentration of the sodium hydroxide solution is 5 mmol / L, and the molar ratio of sodium chloride to the precursor is 8.5:1.

[0016] In step (3), the temperature of the heat treatment is 300-500 oThe heat treatment time is 4-6 h. Too high calcination temperature will result in too high crystallinity of the generated metal oxide, reducing the electrocatalytic performance; and when the calcination temperature is too low, amorphous and microcrystalline mixed structures will be formed, reducing the conductivity of the catalyst.

[0017] Preferably, the heat treatment atmosphere condition is air. The temperature and time are controlled to better balance the crystallinity and conductivity of the catalyst. Further preferably, the calcination temperature is 350 o C, and the calcination time is 6 h.

[0018] As preferred, the molar ratio of the total moles of the ruthenium-based high-entropy metal oxide electrocatalyst to the moles of the ruthenium-based high-entropy metal oxide electrocatalyst is 4:1, and the molar ratio of the tin salt, the manganese salt, the chromium salt and the tantalum salt is 1:1:1:1, and the catalyst is SnMnCrTaRu 0.8 O2. The above high-entropy metal oxide with a rutile phase enables synergistic effects between various metal atoms; at the same time, this structure significantly improves the stability of the catalyst.

[0019] The ruthenium-based high-entropy metal oxide electrocatalyst provided by the application uses a high-entropy metal oxide composed of ruthenium, tin, manganese, chromium, tantalum and other metal elements as the main component of the catalyst, avoiding the high cost problem of traditional noble metal ruthenium catalysts.

[0020] The ball milling process adopted by the application is simple and low in cost. Compared with the traditional multi-stage synthesis process, the ball milling synthesis enables various reactants to fully contact, mix and uniformly disperse under the mediation of the agate grinding medium balls in one reaction system, ensuring that the ruthenium and the tin, manganese, chromium and tantalum and other metal elements are fully mixed and interact at the atomic level, the obtained high-entropy metal oxide catalyst has a highly uniform microstructure and element composition distribution, and more importantly, the whole catalyst manufacturing process is simplified, the production process is easier to control and manage, and it is conducive to realizing stable and uniform catalyst product output in large-scale industrial production.

[0021] The application also provides an application of the integrated assembly in a water electrolysis hydrogen production system. The ruthenium-based high-entropy metal oxide electrocatalyst is used as an anode electrode unit in an acid solution PEM water electrolysis oxygen evolution reaction (water electrolysis OER reaction).

[0022] In the water electrolysis OER reaction, a three-electrode system is adopted, an Hg / Hg2SO4 electrode is used as a reference electrode, a carbon rod is used as a counter electrode, a glassy carbon electrode loaded with the ruthenium-based high-entropy metal oxide provided by the application is used as a working electrode, and a 0.5 M sulfuric acid solution is used as an electrolyte.

[0023] The application also provides application of the ruthenium-based high-entropy metal oxide catalyst in a hydrogen production membrane electrode of a proton exchange membrane water electrolysis system, uses a Pt / C catalyst as a cathode, uses the ruthenium-based high-entropy metal oxide provided by the application as an anode, uses a 0.5 M sulfuric acid solution as an electrolyte, and uses a proton exchange membrane N212 as a proton conduction membrane.

[0024] In addition, by constructing the rutile structure ruthenium-based high-entropy metal oxide, the electronic structure of the catalyst is optimized, the OER activity and stability of the catalyst are improved, and the water electrolysis efficiency is significantly improved. Compared with the traditional Ru and Ir noble metal-based anode catalyst, by the synergistic effect of the multi-metal high-entropy structure, the overpotential of the anode water electrolysis oxygen evolution reaction is reduced. The preparation process has the advantages of material cost and adaptability to large-scale production, and provides a solution for the efficient development of the acid water electrolysis OER equipment.

[0025] Compared with the prior art, the application has the following beneficial effects: 1. The ruthenium-based high-entropy metal oxide catalyst of the anode electrode unit of the PEM exchange membrane water electrolysis hydrogen production system provided by the application has a high-entropy effect, and the stability of the solid solution is significantly improved by using configuration entropy; and the multi-component synergistic effect between the metals effectively inhibits the migration and loss of the rutile phase under high potential or in an acid environment, and the interaction between the metals inhibits the excessive growth of the crystal grains, and the strong bonding between the different metal ions and oxygen can resist acid corrosion and redox impact, so that the structure of the anode catalyst can be maintained in a long-period operation.

[0026] 2. In the ruthenium-based high-entropy metal oxide catalyst of the anode electrode unit of the PEM exchange membrane water electrolysis hydrogen production system provided by the application, the high-activity Ru monatomic atom is used as a main active center, and the incorporation of tin, manganese, chromium and tantalum metals not only forms a unique structure of the high-entropy oxide to inhibit the Ru peroxidation dissolution, but also optimizes the adsorption energy of the reaction intermediates through the interaction between the metals, effectively improves the intrinsic catalytic activity of the anode catalyst in the acid OER, and further leads to the high activity of the anode catalyst in the PEM exchange membrane water electrolysis system. At the same time, the incorporation of tin, manganese, chromium and tantalum optimizes the active sites, reduces the reaction energy barrier and stabilizes the structure; the tin and tantalum can improve the stability, the chromium and manganese can optimize the activity, and the problem that the activity and stability are difficult to be considered together is solved.

[0027] 3. The method for preparing the ruthenium-based high-entropy metal oxide catalyst is simple and feasible, the cost is greatly reduced compared with the commercial RuO2 anode catalyst, is suitable for mass production of the catalyst, and has an industrial application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The catalyst SnMnCrTaRu prepared in Example 10.8 Scanning electron microscope image of O2; Figure 2 Catalyst SnMnCrTaRu prepared for Example 1 0.8 Energy dispersive X-ray spectroscopy image of O2; Figure 3 Catalyst SnMnCrTaRu prepared for Example 1 0.8 X-ray diffraction XRD image of O2; Figure 4 Catalyst SnMnCrTaRu prepared for Example 1 0.8 O2 and SnMnCoNiRu 0.8 O2, SnMnFeWRu 0.8 Polarization curve of O2 and commercial RuO2 as anode for electrolysis of water in application example; Figure 5 Catalyst SnMnCrTaRu prepared for Example 1 0.8 O2 and SnMnCrTaRu 0.85 O2, SnMnCrTaRu 0.75 Polarization curve of O2 and commercial RuO2 as anode for electrolysis of water in application example; Figure 6 Catalyst SnMnCrTaRu prepared for Example 1 0.8 CV test of O2 as anode for electrolysis of water in application example; Figure 7 Catalyst SnMnCrTaRu prepared for Example 1 0.8 Electrochemical active area comparison of O2, commercial ruthenium oxide as anode for electrolysis of water in application example; Figure 8 Catalyst SnMnCrTaRu prepared for Example 1 0.8 O2, commercial ruthenium oxide as anode, 20% Pt / C catalyst as cathode, polarization curve of proton exchange membrane electrolysis of water to produce hydrogen under 80 o C conditions. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. Those skilled in the art can modify or replace equivalently without departing from the spirit and scope of the present application, which should be covered within the protection scope of the present application.

[0030] The raw materials used in the following specific embodiments are all purchased from the market.

[0031] Example 1 The present embodiment provides a preparation method of a ruthenium-based high-entropy oxide catalyst anode electrode unit, which comprises the following steps: (1) 0.166 g of ruthenium chloride, 0.023 g of tin dichloride dihydrate, 0.006 g of manganese chloride, 0.013 g of chromium chloride hexahydrate, 0.018 g of tantalum chloride, and 0.5 g of sodium chloride are weighed and placed in a mortar, and ground for 5 min to mix them thoroughly; (2) The ground mixed solid is poured into a ball mill tank, and an appropriate amount of agate grinding medium balls of different sizes are added, and ball milling is carried out at 500 rpm for 1 h; (3) Then 0.5 mL of 5 mmol / L sodium hydroxide solution is added to the ball mill tank, and ball milling is continued at 500 rpm for 1 h; (4) The precursor after ball milling is dried, and the dried precursor is calcined at 350 o under a C air atmosphere for 6 h; (5) The ruthenium-based high-entropy metal oxide containing sodium chloride obtained in step (4) is subjected to water washing treatment to obtain a ruthenium-based high-entropy metal oxide catalyst (SnMnCrTaRu 0.8 O2).

[0032] The macroscopic morphology and element distribution of the prepared SnMnCrTaRu 0.8 O2 catalyst are observed by scanning electron microscopy and scanning transmission electron microscopy. The scanning electron microscopy results are shown in Figure 1 , and the catalyst presents a fine particle morphology in a stacked state, and the particle size distribution is uniform; the scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy diagram is shown in Figure 2 , and it can be clearly seen that each metal is uniformly dispersed in SnMnCrTaRu 0.8 O2. The X-ray diffraction XRD pattern of the SnMnCrTaRu 0.8 O2 catalyst prepared in the present embodiment is shown in Figure 3 , and it can be seen that SnMnCrTaRu 0.8 O2 still retains the characteristic peaks of rutile phase metal oxide, proving the successful synthesis of SnMnCrTaRu 0.8 O2.

[0033] Example 2 The procedure of Example 1 was followed with the amounts in step (1) changed to 0.156 g of ruthenium chloride, 0.014 g of tin dichloride dihydrate, 0.008 g of manganese chloride, 0.016 g of chromium chloride hexahydrate, and 0.022 g of tantalum chloride to give the catalyst SnMnCrTaRu 0.75 O2.

[0034] Comparative Example 1 The procedure of Example 1 was followed with the 0.013 g of chromium chloride hexahydrate and 0.018 g of tantalum chloride in step (1) changed to 0.007 g of cobalt chloride anhydrous and 0.006 g of nickel chloride anhydrous to give the catalyst SnMnCoNiRu 0.8 O2.

[0035] Comparative Example 2 The procedure of Example 1 was followed with the 0.013 g of chromium chloride hexahydrate and 0.018 g of tantalum chloride in step (1) changed to 0.008 g of iron chloride anhydrous and 0.020 g of tungsten chloride to give the catalyst SnMnFeWRu 0.8 O2.

[0036] Comparative Example 3 The procedure of Example 1 was followed with the amounts in step (1) changed to 0.176 g of ruthenium chloride, 0.008 g of tin dichloride dihydrate, 0.004 g of manganese chloride, 0.010 g of chromium chloride hexahydrate, and 0.012 g of tantalum chloride to give the catalyst SnMnCrTaRu 0.85 O2.

[0037] Test Example 1 (1) A three-electrode system was used, with the catalyst-loaded glassy carbon electrode prepared in Example 1 as the working electrode, a carbon rod as the counter electrode, a Hg / Hg2SO4 reference electrode, and a 0.5 M sulfuric acid solution as the electrolyte; (2) Cyclic voltammetry (CV) activation: A Shanghai Chenhua CHI 760E electrochemical workstation was used. The CV program was used, with a test interval of 0.4-1.1 V vs. RHE, a scan rate of 50 mV / s, and 40 cycles of CV cyclic scanning, until the electrode reached a stable state.

[0038] After the electrocatalysts prepared in Example 1, a commercial ruthenium oxide catalyst, and the electrocatalyst prepared in Comparative Example 1 were activated by CV, the program was switched to a linear sweep voltammetry (LSV) program, with a test interval of 1.25-1.70 V vs. RHE, a scan rate of 5 mV / s, and an overpotential of 0 V vs. the reversible hydrogen electrode and 10 mA / cm 2 The potential difference was measured.

[0039] Figure 4 The SnMnCrTaRu provided for this example0.8 Polarization curve of O2catalyst and commercial RuO2for water electrolysis OER reaction in 0.5 M H2SO4solution, from Figure 4 It can be seen that in the acidic electrolyte, SnMnCrTaRu 0.8 O2catalyst has a overpotential of 255 mV at 10 mA / cm 2 2, and its performance is better than that of commercial RuO2and SnMnCoNiRu 0.8 O2. Figure 5 The SnMnCrTaRu 0.8 O2catalyst provided in this embodiment 1 has an electrochemical CV test graph for water electrolysis oxygen evolution reaction in 0.5 M H2SO4solution. Figure 6 The electrochemical active area comparison graph of the catalyst prepared in embodiment 1, commercial RuO2as anode for water electrolysis oxygen evolution reaction in application example, it can be seen that in the acidic electrolyte, SnMnCrTaRu 0.8 O 22 2catalyst has a larger electrochemical active area than commercial RuO2.

[0040] Application example 1: The catalyst prepared in embodiment 1 is applied to PEM water electrolysis hydrogen production reaction The catalyst SnMnCrTaRu 0.8 O2prepared in embodiment 1 or commercial RuO2is used as anode, 20% Pt / C catalyst is used as cathode, 0.5 M sulfuric acid solution is used as electrolyte, proton exchange membrane N212 is used as proton conductive membrane, and the LSV program test interval is 1.2~2.1 V at a scan rate of 5 mV / s under the condition of 80 o C. The catalyst SnMnCrTaRu 0.8 O2provided in this embodiment, commercial RuO2as anode for PEM water electrolysis hydrogen production has a polarization curve graph as shown in Figure 7 It can be seen that in the acidic electrolyte, SnMnCrTaRu 0.8 O2only needs a cell voltage of 1.68 V to achieve a current density of 2 A / cm 2 2, and its performance is better than that of commercial RuO2catalyst.

Claims

1. A high efficiency integrated assembly for PEM exchange membrane electrolysis water to hydrogen system, characterized in that, The anode electrode unit in the integrated assembly comprises a ruthenium-based high-entropy metal oxide electrocatalyst, which comprises ruthenium, tin, manganese, chromium and tantalum elements.

2. The high efficiency integrated assembly for PEM exchange membrane electrolysis water to hydrogen system of claim 1, wherein, The ruthenium-based high-entropy metal oxide electrocatalyst has a rutile structure, and the ruthenium, tin, manganese, chromium and tantalum elements in the ruthenium-based high-entropy metal oxide electrocatalyst are arranged in disorder.

3. The high efficiency integrated assembly for PEM exchange membrane electrolysis water to hydrogen system of claim 1, wherein, The preparation method of the ruthenium-based high-entropy metal oxide catalyst comprises: (1) grinding solid inorganic ruthenium salt, tin salt, manganese salt, chromium salt, tantalum salt and sodium chloride to obtain a metal salt mixture; (2) ball milling the metal salt mixture to obtain a precursor; (3) heat treating the precursor to obtain a ruthenium-based high-entropy metal oxide catalyst containing sodium chloride; (4) washing the ruthenium-based high-entropy metal oxide catalyst containing sodium chloride with water to obtain a ruthenium-based high-entropy metal oxide electrocatalyst.

4. The high efficiency integrated assembly for PEM exchange membrane electrolysis water to hydrogen system of claim 3, wherein, In step (1), the ruthenium salt is a main metal salt, and the total molar amount of the tin salt, manganese salt, chromium salt and tantalum salt is 1:3-4 times the molar amount of the main metal salt.

5. The high efficient integrated assembly for PEM exchange membrane electrolysis water to hydrogen system according to claim 3, characterized in that, In step (1), the molar ratio of the ruthenium salt, tin salt, manganese salt, chromium salt and tantalum salt is 75:6:6:6:6-80:5:5:5:

5.

6. The high efficient integrated assembly for PEM exchange membrane electrolysis water to hydrogen system according to claim 3, characterized in that, The temperature of the heat treatment in step (3) is 300-500 o The time of the heat treatment is 4-6 h.

7. The integrated assembly according to any one of claims 1-6 is applied in a water electrolysis hydrogen production system.

8. Use according to claim 7, characterized in that, The ruthenium-based high-entropy metal oxide electrocatalyst is applied as an anode electrode unit in a PEM water electrolysis oxygen evolution reaction in an acidic solution.

Images