A RuO x / C nanocomposites, their preparation methods and applications

Abstract

This invention discloses a RuO x / C nanocomposites, their preparation methods, and applications. The RuO₂ nanocomposite material... x / C nanocomposite materials were prepared by radiation reduction of carbon support and ruthenium precursor. Oxygen atoms were mainly distributed at the defects in the carbon support generated by radiation, forming Ru-O bonds with ruthenium nanoparticles also supported on the carbon support. This enabled the oxygen atoms to regulate the electronic structure of ruthenium, giving the catalyst good inherent activity and stability, thereby enhancing the RuO2 content. x The catalytic ability of / C nanocomposites. RuO x Pt / C nanocomposites, assembled as cathode hydrogen evolution catalysts in alkaline three-electrode electrolyzers and AEM water electrolyzer devices, exhibited superior performance compared to commercially available 20% Pt / C catalysts. The radiation method for synthesizing RuO2 also showed advantages over conventional solvothermal methods. x / C composite nanocatalysts offer mild and controllable reaction conditions, high conversion rates, low energy consumption, and minimal environmental pollution, making them suitable for industrial scale-up and promising for future industrial applications.

Description

Technical Field

[0001] This invention relates to the field of composite catalyst materials technology, and particularly to a RuO x / C composite catalysts, their preparation methods, and applications. Background Technology

[0002] Anion exchange membrane (AEM) water electrolyzers are a green and clean hydrogen production system with advantages such as compact structure, simple design, fast switching response, and high electrolysis efficiency. Unlike proton exchange membrane (PEM) water electrolyzers, AEM water electrolyzers do not require operation in a highly acidic or highly oxidizing electrochemical environment, but OH... - The ion conduction rate is higher than that of H + Due to the slow reaction speed of protons, AEM water electrolyzers suffer from slow catalytic reaction kinetics and poor electrode structure, and the development of key materials remains a challenge. The cathode hydrogen evolution catalyst is a crucial component of the AEM water electrolyzer, and its structure and performance determine the efficiency and lifespan of the AEM water electrolyzer. An ideal cathode hydrogen evolution catalyst should possess the following characteristics: (1) high inherent catalytic performance to ensure high efficiency in catalytic water electrolysis for hydrogen evolution; (2) high stability to ensure the lifespan of the AEM water electrolyzer; (3) high conductivity to ensure lower power loss; and (4) simple preparation and low cost to be commercially competitive. Currently, commercially available 20% platinum-carbon catalysts have advantages such as excellent inherent catalytic performance and good chemical stability. However, platinum is expensive, and commercially available platinum-carbon catalysts have a high platinum content (greater than 20%), making direct application in AEM water electrolyzers costly. Furthermore, there is significant room for improvement in the catalytic performance of platinum-carbon catalysts in AEM water electrolyzers.

[0003] Therefore, researchers have mainly focused on exploring non-precious metal catalysts or reducing the amount of precious metals used in their research on AEM water electrolysis catalysts. The inventors previously (Que X., et al., Applied Surface Science 2021, 541, 148345) used ruthenium trichloride and graphene oxide as precursors to prepare a reduced graphene oxide-supported ruthenium (Ru / rGO) nanocomposite catalyst in one step via γ-radiation reduction at room temperature and pressure. They then assembled an alkaline water electrolysis hydrogen evolution three-electrode system, achieving a yield of 10 mA / cm². 2 At certain current densities, the overpotential of Ru / rGO can be as low as 59.7 mV. However, the product synthesized using the above method contains residual chlorine, which may poison the catalyst and reduce the cycle stability of the system. The inventors previously obtained Chinese invention patents ZL201610600245.7 and ZL201610600352.X, successfully preparing high-performance MoS₂ for hydrogen evolution in acidic water electrolysis. x / C and MoSx O y / C composite nanocatalysts were developed, but the catalytic performance of these two catalysts for AEM water electrolysis still falls short of ideal performance. Lu et al. (Lu B., et al., Nature Communications 2019, 10, 631) synthesized a nitrogen-doped Ru / carbon nanowire hydrogen evolution catalyst with excellent catalytic hydrogen evolution performance through a multi-step solvothermal combined with high-temperature annealing technique. When assembled into a 1MKOH alkaline three-electrode system for catalytic hydrogen evolution reaction, it achieved excellent performance at 10 mA / cm 2 The overpotential at a current density can be as low as 12 mV. However, the preparation method of this catalyst is cumbersome, energy-intensive, and environmentally unfriendly, making it unsuitable for sustainable large-scale industrial production. Yang et al. (Yang Y., et al., Chemical Engineering Journal 2022, 433, 134421) synthesized a Ru-OC structure-supported ruthenium nanocatalyst Ru-rGO on reduced graphene oxide via calcination. This catalyst exhibits an overpotential as low as 12 mV at a current density of 10 mA / cm². 2 The overpotential at the current density can be as low as 23mV, but the preparation method still has the problems of high energy consumption and environmental unfriendliness. Summary of the Invention

[0004] The purpose of this invention is to develop a cathode hydrogen evolution catalyst with good catalytic performance, low cost, and suitable for large-scale industrial production, so as to solve the problems of unsatisfactory catalytic performance, high cost, high energy consumption and environmental unfriendliness of existing cathode hydrogen evolution catalysts.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect of the invention, a RuO is provided. x / C nanocomposite material, wherein 0.05≤x≤0.95, and based on the total mass of the nanocomposite material, the RuO x The mass fraction is 1%–50%.

[0007] Preferably, in the above RuO x In / C nanocomposite materials, the RuO x It has a nanoparticle structure.

[0008] Furthermore, the aforementioned RuO x In / C nanocomposites, the preferred values ​​are 0.1 ≤ x ≤ 0.9.

[0009] Furthermore, the aforementioned RuO x / C nanocomposite material is prepared by radiation reduction of carbon support and ruthenium precursor. Oxygen atoms are mainly distributed in the defects of carbon support generated by radiation, and form Ru-O bonds with ruthenium nanoparticles also loaded on carbon support, thus realizing the control of the electronic structure of ruthenium by oxygen atoms.

[0010] In a second aspect of the invention, the aforementioned RuO is provided. x The preparation method of / C nanocomposite materials includes the following steps:

[0011] 1) The carbon support and ruthenium precursor are mixed evenly in a solvent, sealed, and then subjected to a radiation reduction reaction using γ-rays or electron beams in an inert atmosphere;

[0012] 2) After filtering the reaction mixture, the filter residue was washed several times with water and ethanol, and then vacuum dried to constant weight or spray dried to obtain RuO. x / C nanocomposite materials.

[0013] In step 1) above, the carbon support may be selected from at least one of carbon black, carbon nanotubes, graphite, graphene, graphite oxide, and carbon nanotubes; the ruthenium precursor may be selected from one or more of ruthenium acetate, ruthenium propionate, dodecyltriruthenium, and tetraruthenium perruthenium; and the solvent is preferably an alcohol solvent, which may be selected from one or more of methanol, ethanol, n-propanol, isobutanol, tert-butanol, ethylene glycol, propylene glycol, and glycerol.

[0014] In step 1) above, to ensure thorough mixing of the carbon support and ruthenium precursor in the solvent, vortexing for 30–180 minutes followed by sonication for 1–2 hours is recommended. The inert atmosphere can be nitrogen, argon, or a mixture thereof.

[0015] Step 1) If gamma-ray irradiation is chosen, the sample can be placed in the irradiation tube, mixed thoroughly, and then sealed with inert gas. 60 The gamma rays generated by Co undergo a radiation reduction reaction. Preferably, gamma ray irradiation is performed at room temperature, with a dose rate of 1–500 Gy / min and an absorbed dose of 1–500 kGy.

[0016] Step 1) If electron beam irradiation is chosen, the sample can be mixed, poured into an aluminum foil bag, sealed with inert gas, and subjected to a radiation reduction reaction using an electron accelerator irradiation device. Electron beam irradiation is preferably performed at room temperature, with an electron beam energy of 0.1–100 MeV and a total absorbed dose preferably of 1–500 kGy.

[0017] In some preferred embodiments of the present invention, the concentration of the ruthenium precursor in the mixed solution is 0.1 to 100 mmol / L, preferably 1 to 50 mmol / L, and more preferably 5 to 40 mmol / L.

[0018] In some preferred embodiments of the present invention, the dispersion concentration of the carbon support is 1 to 100 mg / mL, preferably 3 to 50 mg / mL, and more preferably 5 to 30 mg / mL.

[0019] In a third aspect of the invention, the aforementioned RuO is provided. x Application of / C nanocomposites as cathode hydrogen evolution catalysts in electrochemical hydrogen evolution reactions.

[0020] Furthermore, the present invention provides a cathode electrode, the cathode electrode comprising a substrate electrode and RuO coated on the surface of the substrate electrode. x / C nanocomposite material. The substrate electrode is an inert electrode, preferably selected from gold electrodes, platinum electrodes, titanium electrodes, stainless steel electrodes, ITO electrodes, FTO electrodes, and graphite electrodes.

[0021] This invention provides a membrane electrode comprising an ion exchange membrane and the aforementioned RuO₂. x / C nanocomposite material, wherein the ion exchange membrane of the membrane electrode is preferably a perfluorosulfonic acid membrane or a polyvinylidene fluoride radiation-grafted membrane; RuO x / C nanocomposite material is attached or adhered to one side of the ion exchange membrane as the cathode side and the other side as the anode side of the membrane electrode by means of spraying, dripping, or other methods. It should be noted that, for the membrane electrode provided by the present invention, the anode side can be implemented using relevant technical solutions in the prior art, and the present invention does not limit it.

[0022] This invention provides a water electrolysis hydrogen production device, which includes a membrane electrode as described above. It should be noted that, for the water electrolysis hydrogen production device provided by this invention, apart from the membrane electrode being the one provided by this invention, other components required for the water electrolysis hydrogen production device, such as the peristaltic pump, temperature controller, bipolar plate, current collector, and electrolyte, can all be implemented using relevant existing technical solutions, and this invention does not limit these solutions.

[0023] This invention provides a fuel cell device comprising a membrane electrode assembly (MEA) as described above. The fuel cell device can be a hydrogen fuel cell device, a methanol fuel cell device, or the like. It should be noted that, for the fuel cell device provided by this invention, apart from the MEA being provided by this invention, other components required to form the fuel cell device, such as bipolar plates, current collectors, and electrolytes, can all be implemented using existing technologies, and this invention does not limit their application.

[0024] This invention provides an electric equipment product comprising a water electrolysis hydrogen production device or a fuel cell device as described above. It should be noted that other parts of this equipment product besides the aforementioned device can be implemented using relevant existing technical solutions, and this invention does not limit them. The electric equipment product is preferably a hydrogen generator, an oxygen generator, or a fuel cell vehicle.

[0025] Compared with the prior art, the present invention has the following technical advantages:

[0026] (1) In this invention, highly conductive carbon material is selected as the catalyst support, and RuO is synthesized by radiation method. x / C nanocomposites. In this study, the radiation-synthesized product does not produce catalyst poisoning. Introducing defects into the carbon substrate via radiation alters the electronic environment of the supported Ru nanoparticles through strong metal-support interactions. Furthermore, it can generate more oxygen doping. As reported (Yang Y., et al., Chemical Engineering Journal 2022, 433, 134421), the strong Ru-O bond-induced interactions can endow the catalyst with good intrinsic activity and stability, thereby further enhancing the RuO₂ content. x Catalytic ability of / C nanocomposites.

[0027] (2) RuO synthesized in this invention x The / C nanocomposite material, when assembled in an alkaline three-electrode electrolyzer and an AEM water electrolyzer device, outperformed commercial 20% Pt / C catalysts.

[0028] (3) Compared with the traditional solvothermal method, the radiation method is used to synthesize RuO x / C composite nanocatalysts offer mild and controllable reaction conditions, high conversion rates, low energy consumption, and minimal environmental pollution, making them suitable for industrial scale-up and promising for future industrial applications. Attached Figure Description

[0029] Figure 1 RuO prepared in Example 1 x Transmission electron microscopy (TEM) image of / C nanocomposite material.

[0030] Figure 2A RuO prepared in Example 1 x X-ray photoelectron spectroscopy (XPS) of / C nanocomposites.

[0031] Figure 2B RuO prepared in Example 1 x XPS high-resolution image of Ru in / C nanocomposites.

[0032] Figure 2C RuO prepared in Example 1 x XPS high-resolution image of O in / C nanocomposites.

[0033] Figure 3A .RuO x LSV curves of hydrogen evolution catalysis using / C composite nanocatalyst and 20% Pt / C in an alkaline three-electrode system.

[0034] Figure 3B .RuO x The η values ​​of / C composite nanocatalysts and 20% Pt / C under different catalytic hydrogen evolution current densities in an alkaline three-electrode system.

[0035] Figure 4 .RuO x Current-voltage performance curves of / C composite nanocatalyst and 20% Pt / C assembled in an AEM water electrolyzer device. Detailed Implementation

[0036] The present invention will be further illustrated in detail below through embodiments, but the scope of the invention is not limited in any way.

[0037] Example 1

[0038] 100 mg of ruthenium acetate was added to 20 mL of ethylene glycol and stirred to form a homogeneous solution. Then, 200 mg of carbon black powder was added, and the mixture was vortexed at 3000 rpm for 30 min. After ultrasonic treatment for 1 h to form a homogeneous dispersion, oxygen was removed by purging with N2. The mixture was then sealed and irradiated with a cobalt source using gamma rays at a dose rate of 50 Gy / min, with a total absorbed dose of 50 kGy. After irradiation, the mixture was filtered, and the filter residue was washed 3–5 times with deionized water and ethanol, respectively. Finally, it was dried in a vacuum oven at 80 °C for 48 h to obtain RuO. x / C catalyst.

[0039] The RuO x The TEM and XPS images of the / C catalyst are shown below. Figure 1 and Figures 2A-2C As shown, from Figure 1 It can be seen that RuO x Uniformly distributed on a carbon substrate in the form of nanoparticles Figures 2A-2C This indicates that RuO2 was successfully synthesized via radiosynthesis. x A carbon substrate was introduced, and the oxygen content of the product increased significantly.

[0040] A mixed solvent was prepared by mixing isopropanol and ethanol in a 2:1 volume ratio. Then, 1 / 25 volume of a 5% Nafion solution and 1 / 50 volume of a PVDF (polyvinylidene fluoride) DMF (N,N-dimethylformamide) solution were added to this mixture to prepare a dispersion solvent. A certain amount of RuO was weighed...x / C catalyst, mixed with a dispersing solvent, to prepare RuO x Catalyst ink with a concentration of 4 mg / mL was used for testing the hydrogen evolution catalytic performance of an alkaline three-electrode system and for testing an AEM water electrolyzer device.

[0041] 1) In an alkaline three-electrode system, catalyst ink was drop-coated onto the surface of a 3mm rotating glassy carbon electrode and allowed to dry, resulting in a catalyst loading of 0.275 mg / cm³. 2 The catalyst working electrode was used. A three-electrode system was formed by the catalyst working electrode, the counter electrode (graphite), and the reference electrode (mercuric oxide electrode, with a salt bridge solution of 1M KOH) in 1M KOH solution. The system was subjected to a 25°C isothermal alkaline HER catalytic hydrogen evolution test under continuous nitrogen purging.

[0042] 2) During the testing of the AEM water electrolyzer device, catalyst ink was ultrasonically sprayed onto one side of the AEM and dried to allow RuO2 to form. x The loading capacity of / C is 3 mg / cm³. 2 Then, using the same method, the anode catalyst was sprayed onto the other side of the AEM, and hot-pressed with the diffusion layer to form a 4cm² area. 2 The CCM membrane electrode (full name: Catalyst coating membrane electrode) was assembled in an AEM water electrolyzer, and the alkaline water electrolysis device was tested using 1M KOH solution at 80°C.

[0043] RuO tested using the above method x / C catalyst, its catalytic performance in an alkaline three-electrode system is as follows Figure 3A , Figure 3B As shown, its η 10 (i.e., current density of 10 mA / cm²) 2 The overpotential (hereinafter the same) is as low as 37mV, η 100 As low as 161mV, η 200 The voltage is as low as 216 mV, which is superior to commercial 20% Pt / C catalysts. Furthermore, the cathode is coated with RuO. x The performance of the membrane electrode assembly of the / C catalyst in the AEM water electrolyzer unit is as follows: Figure 4 As shown, the AEM water electrolyzer can achieve a current intensity of 2.01A under an applied DC voltage of 1.7V and a current intensity of 6.01A under an applied DC voltage of 1.9V, which is superior to the AEM water electrolyzer assembled under the same conditions using a commercial 20% Pt / C catalyst.

[0044] Example 2

[0045] The γ-ray irradiation in Example 1 was replaced with radiation reaction using an electron accelerator irradiation device to prepare RuO. x / C catalyst, with a total absorbed dose of 100 kGy, and the feedstock input was 100 times that of Example 1. RuO tested using the above method. x The Pt / C catalyst, when assembled in an alkaline three-electrode system, exhibits slightly lower basic hydrogen evolution catalytic performance and device performance in an AEM water electrolyzer compared to the product of Example 1, but is still superior to the commercial 20% Pt / C catalyst, and its single-batch production can reach 100 times that of Example 1. Its η in the three-electrode system... 10 41mV, η 100 170mV, η 200 The current is 239mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 1.89A under a DC voltage of 1.7V and 5.86A under a DC voltage of 1.9V.

[0046] Example 3

[0047] The ruthenium precursor in Example 1 was changed from ruthenium acetate to tetraruthenium perruthenate, while other preparation conditions remained the same as in Example 1. The RuO2 synthesized using the above method under irradiation... x Introducing a small amount of amino groups into the Pt / C catalyst resulted in a slight decrease in its basic catalytic performance in a three-electrode system compared to Example 1, but it was still superior to the commercial 20% Pt / C catalyst. 10 45mV, η 100 176mV, η 200 The voltage is 256 mV; however, the amino groups in the catalyst enhance the ionic bonding ability between the catalyst and the ion exchange membrane, reducing the overall resistance of the membrane electrode, making the device assembled in the AEM water electrolyzer perform better than that in Example 1. The AEM water electrolyzer can achieve a current intensity of 2.12 A under a DC voltage of 1.7 V and a current intensity of 6.25 A under a DC voltage of 1.9 V.

[0048] Example 4

[0049] The amount of ruthenium acetate used in Example 1 was changed to 200 mg, while other preparation conditions remained the same as in Example 1. RuO2 was tested using the above method. x / C catalyst, RuO x The loading rate was 1.5 times that of Example 1. Its basic catalytic performance in the three-electrode system and the device performance in the AEM water electrolyzer were both slightly improved compared to Example 1, but the improvement was not significant. In the three-electrode system, η... 10 35mV, η 100 155mV, η 200The current is 206 mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 2.5 A at a DC voltage of 1.7 V and 7 A at a DC voltage of 1.9 V. This is superior to commercial 20% Pt / C catalysts.

[0050] Example 5

[0051] The carbon support in Example 1 was replaced with graphite, and other preparation conditions were the same as in Example 1. RuO was tested using the above method. x The Pt / C catalyst, when assembled in a three-electrode system, exhibits slightly lower basic catalytic performance and device performance in an AEM water electrolyzer compared to Example 1, but still outperforms the commercial 20% Pt / C catalyst. The catalyst is assembled in a three-electrode system with η 10 39mV, η 100 169mV, η 200 The current is 222mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 1.92A under a DC voltage of 1.7V and 5.90A under a DC voltage of 1.9V.

[0052] Example 6

[0053] The amount of carbon black powder used in Example 1 was changed to 500 mg, while other preparation conditions remained the same as in Example 1. RuO was tested using the above method. x / C catalyst, RuO x The loading rate was 40% of that in Example 1. Its basic catalytic performance in the three-electrode system and its device performance in the AEM water electrolyzer both decreased to some extent compared to Example 1, but remained comparable to a commercially available 20% Pt / C catalyst. The catalyst assembled in the three-electrode system η 10 80mV, η 100 185mV, η 200 The current is 257mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 1.64A under a DC voltage of 1.7V and 5.19A under a DC voltage of 1.9V.

[0054] Example 7

[0055] The reaction solvent in Example 1 was changed to ethanol, while other preparation conditions remained the same as in Example 1. RuO was tested using the above method. x The Pt / C catalyst, assembled in a three-electrode system, exhibits a slight decrease in basic catalytic performance and device performance in the AEM water electrolyzer compared to Example 1, but still outperforms the commercial 20% Pt / C catalyst. The catalyst is assembled in a three-electrode system with η 10 46mV, η 100 174mV, η200 The current is 233mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 1.95A under a DC voltage of 1.7V and 5.96A under a DC voltage of 1.9V.

[0056] Example 8

[0057] The reaction solvent in Example 1 was changed to isobutanol, while other preparation conditions remained the same as in Example 1. RuO was tested using the above method. x The / C catalyst, assembled in a three-electrode system, showed no significant decrease in basic catalytic performance or device performance in the AEM water electrolyzer compared to Example 1, indicating that isobutanol is a viable alternative solvent. The catalyst assembled in the three-electrode system η 10 39mV, η 100 160mV, η 200 The current is 219mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 2.03A under a DC voltage of 1.7V and 5.92A under a DC voltage of 1.9V.

[0058] Example 9

[0059] In Example 1, the nitrogen atmosphere in the radiation synthesis system was replaced with argon gas for deoxygenation, while other preparation conditions remained the same as in Example 1. RuO₂ was tested using the above method. x The / C catalyst, assembled in a three-electrode system, showed no significant decrease in basic catalytic performance or device performance in the AEM water electrolyzer compared to Example 1, indicating that argon is a viable alternative protective gas. The catalyst assembled in the three-electrode system η 10 37mV, η 100 166mV, η 200 The current is 217mV; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 2.00A under a DC voltage of 1.7V and 5.99A under a DC voltage of 1.9V.

[0060] Example 10

[0061] The product drying method in Example 1 was changed to spray drying, while other preparation conditions remained the same as in Example 1. RuO2 was tested using the above method. x The / C catalyst, assembled in a three-electrode system, exhibits slightly improved basic catalytic performance and device performance in the AEM water electrolyzer compared to Example 1, indicating that spray drying is more suitable for product drying than vacuum drying. The catalyst is assembled in a three-electrode system. 10 35mV, η 100 159mV, η 200The current is 209 mV; when assembled in an AEM water electrolyzer, it achieves a current intensity of 2.16 A at a DC voltage of 1.7 V and 6.23 A at a DC voltage of 1.9 V. This performance is superior to commercial 20% Pt / C catalysts.

[0062] Example 11

[0063] In the three-electrode system of Example 1, the catalyst loading in the working electrode was changed to 0.1 mg / cm³. 2 Other preparation conditions were the same as in Example 1. Because the catalyst loading was reduced to 35% of that in Example 1, RuO... x The catalytic performance of both RuO and commercial 20% Pt / C catalysts assembled in a three-electrode system decreased significantly. x / C of η 10 89mV, η 100 182mV, η 200 At 278mV, it is still superior to commercial 20% Pt / C catalysts.

[0064] Example 12

[0065] The method is the same as in Example 1, except that the catalyst loading in the membrane electrode is 5 mg / cm³. 2 RuO tested using the above method x The performance of the AEM water electrolyzer assembled with the 20% Pt / C catalyst is improved compared to that of the device in Example 1, but the improvement is not proportional to the increase in catalyst loading. The assembled AEM water electrolyzer can achieve a current intensity of 2.7A under a DC voltage of 1.7V and 7.4A under a DC voltage of 1.9V, which is superior to the AEM water electrolyzer assembled under the same conditions using a commercially available 20% Pt / C catalyst.

[0066] Example 13

[0067] The catalyst was assembled into a three-electrode system or a CCM membrane electrode was prepared and assembled into an AEM water electrolyzer using the same method as in Example 1, except that the electrolyte was pure water. RuO2 was tested using the above method. x The basic catalytic performance of the / C catalyst and the commercial 20% Pt / C catalyst assembled in the three-electrode system, as well as the device performance in the AEM water electrolyzer, were significantly lower than those in Example 1. This was because the ionic conductivity of the device decreased after the electrolyte was changed to pure water. The RuO x / C catalyst assembled in a three-electrode system η 10The current intensity is 264 mV, which is superior to commercial 20% Pt / C catalysts. When assembled in an AEM water electrolyzer, it can achieve a current intensity of 0.6 A at a DC voltage of 1.7 V and 1.5 A at a DC voltage of 1.9 V, which is also superior to commercial 20% Pt / C catalysts.

[0068] Example 14

[0069] The catalyst was assembled in a three-electrode system or a CCM membrane electrode was prepared and assembled in an AEM water electrolyzer using the same method as in Example 1, except that the electrolyte was changed to 3.5M KOH. RuO2 was tested using the above method. x The basic catalytic performance of the 20% Pt / C catalyst assembled in the three-electrode system and the device performance in the AEM water electrolyzer showed a significant decrease compared to Example 1. This is because the ionic conductivity of the device increases with the increase of the electrolyte concentration. The catalyst assembled in the three-electrode system... 10 32mV, η 100 149mV, η 200 The current intensity is 202mV, which is superior to commercial 20% Pt / C catalysts; when assembled in an AEM water electrolyzer, it can achieve a current intensity of 2.3A under a DC voltage of 1.7V and 7.2A under a DC voltage of 1.9V.

[0070] Example 15

[0071] The CCM membrane electrode was prepared and assembled in the AEM water electrolyzer using the same method as in Example 1, except that the membrane electrode area was changed to 50 cm². 2 Other conditions were the same as in Example 1. The AEM water electrolyzer assembled using the above method had a conductive area 12.5 times that of Example 1, and its current intensity increased proportionally with the membrane electrode area at the same voltage. This AEM water electrolyzer achieved a current intensity of 25A at a DC voltage of 1.7V and 75A at a DC voltage of 1.9V, which is still superior to the AEM water electrolyzer assembled under the same conditions using a commercially available 20% Pt / C catalyst.

Claims

1. A RuO x nanocomposite, wherein 0.05 ≤ x ≤ 0.95, and the mass fraction of RuO x is 1-50% based on the total mass of the nanocomposite; the RuO x nanocomposite is prepared by radiation reduction from a carbon carrier and a ruthenium precursor, and oxygen atoms are mainly distributed at defects of the carbon carrier generated by radiation to form Ru-O bonds with ruthenium nanoparticles also loaded on the carbon carrier, wherein, The ruthenium precursor is selected from one or more of ruthenium acetate, ruthenium propionate, triruthenium dodecacarbonyl, and tetraaminoperuthenate.

2. The RuO x / C nanocomposite according to claim 1, characterized in that, The RuO x is a nanoparticle structure.

3. The RuO x A method for preparing a RuO nanocomposite, comprising the steps of: 1) mixing the carbon carrier and the ruthenium precursor in a solvent, and performing a radiation reduction reaction in an inert atmosphere after sealing, wherein the ruthenium precursor is selected from one or more of ruthenium acetate, ruthenium propionate, triruthenium dodecacarbonyl, and tetraaminoperuthenate; 2) After the reaction, the system is filtered, the residue is washed with water and ethanol several times, and then vacuum dried to constant weight or spray dried to obtain RuO x / C nanocomposite.

4. The production method according to claim 3, wherein The carbon carrier in step 1) is selected from at least one of carbon black, carbon nanotubes, graphite, graphene, graphite oxide, and carbon nanohorns; and the solvent is an alcohol solvent.

5. The production method according to claim 3, wherein Step 1) irradiation by γ-rays, the sample is put into an irradiation tube, mixed and sealed by inert gas, and then subjected to radiation reduction reaction at room temperature by γ-rays generated by Co with a radiation dose rate of 1 ~ 500 Gy / min and an absorbed dose of 1 ~ 500 kGy. 60 Step 1) irradiation by γ-rays, the sample is put into an irradiation tube, mixed and sealed by inert gas, and then subjected to radiation reduction reaction at room temperature by γ-rays generated by Co with a radiation dose rate of 1 ~ 500 Gy / min and an absorbed dose of 1 ~ 500 kGy.

6. The production method according to claim 3, wherein In step 1), electron beam irradiation is used, the sample is mixed uniformly, then poured into an aluminum foil bag and sealed with inert gas, and a radiation reduction reaction is performed at room temperature using an electron accelerator irradiation device, the energy of the electron beam is 0.1-100 MeV, and the total absorbed dose is 1-500 kGy.

7. The production method according to claim 3, wherein In step 1), the concentration of the ruthenium precursor in the mixed solution is 0.1-100 mmol / L, and the dispersion concentration of the carbon carrier is 1-100 mg / mL.

8. The RuO x Application of RuO / C nanocomposites as cathodic hydrogen evolution catalysts in electrochemical hydrogen evolution reaction.

9. A cathode electrode comprising a base electrode and a RuO2 nanocomposite as claimed in claim 1 or 2 coated on the surface of the base electrode, the base electrode being an inert electrode. x / C nanocomposite.

10. A membrane electrode comprising an ion exchange membrane and the RuO2 / C nanocomposite of claim 1 or 2. x The RuO x The RuO / C nanocomposite is attached to one side surface of an ion exchange membrane as a cathode side, and the other side as an anode side of a membrane electrode. ​ 11. A water electrolysis hydrogen production device comprising the membrane electrode of claim 10.

12. A fuel cell device comprising the membrane electrode of claim 10.

13. An electric device comprising the water electrolysis hydrogen production device of claim 11 or the fuel cell device of claim 12.

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