Ruthenium-tellurium-selenium ternary composite catalyst as well as preparation method and application thereof

Abstract

The invention discloses a ruthenium-tellurium-selenium ternary composite catalyst and a preparation method and application thereof.The ruthenium-tellurium-selenium ternary composite catalyst comprises a carbon carrier and RuTexSey nanoparticles loaded on the carbon carrier, x represents the molar ratio of tellurium to ruthenium, y represents the molar ratio of selenium to ruthenium, and the sum of x and y is 1; the nanoparticles comprise a composite crystal phase of an orthorhombic phase RuTe2 and a cubic phase RuSe2. The catalyst RuTexSey / C is subjected to heat treatment at the temperature of 300-500 DEG C to form a RuTe2-RuSe2 composite crystal phase, the atomic ratio is accurately regulated and controlled through a Te-Se double chalcogen synergistic strategy, the adsorption capacity of an oxygen-containing intermediate in the OER / ORR process is optimized, due to introduction of Se, particle growth is effectively inhibited, the active specific surface area is increased, meanwhile, the problems of active site coverage and agglomeration caused by excessive Se are solved, and the service life of the catalyst RuTexSey / C is prolonged. Compared with the prior art, the method has the advantages that the ORR half-wave potential is increased to 0.71 V, the performance reaches 57.5% of that of a commercial Pt / C catalyst, the cost is reduced by 60-70%, and the method has the application advantages of high efficiency and low cost in electrolyzed water, metal-air batteries and fuel cells.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical catalysis, and more specifically to a ruthenium, tellurium, and selenium ternary composite catalyst, a preparation method thereof, and applications thereof. Background Art

[0002] With the global energy transition and the growing need for environmental protection, the development of efficient and stable electrochemical energy conversion technologies has become a research priority. The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), core electrochemical processes in clean energy technologies such as fuel cells and water electrolysis for hydrogen production, suffer from slow reaction kinetics and high overpotentials, severely hindering the performance of these devices. However, existing noble metal catalyst systems face numerous challenges, necessitating the development of new, efficient catalysts to overcome these technical bottlenecks.

[0003] In the field of OER catalysis, oxides of the precious metals iridium (Ir) and ruthenium (Ru) (IrO2 and RuO2) are currently commonly used and highly effective catalysts. Although IrO2 exhibits excellent catalytic activity, its scarcity and extremely high cost make it difficult to meet the requirements of large-scale industrial applications. In contrast, RuO2, while relatively inexpensive, is susceptible to corrosion in strongly alkaline conditions, leading to deactivation of active sites and significantly insufficient stability. These issues limit the practical application of existing Ru-based OER catalysts.

[0004] The field of ORR catalysis currently relies primarily on the precious metal platinum (Pt). However, Pt catalysts face challenges such as high price, limited resources, and insufficient durability, hindering their commercial application in hydrogen fuel cells. As the cheapest element in the Pt group, Ru is only 30%–50% as expensive as metallic Pt. Therefore, ruthenium-based catalysts are considered the most promising alternative. Research has shown that the introduction of sulfur (S) to form ruthenium-based chalcogenides can significantly enhance ORR activity. Prior art, such as the Chinese invention patent (CN111939940B), discloses a ruthenium-based catalyst and its preparation method. This technology, by loading a ruthenium-based dichalcogenide on a carbon support, improves the dispersion of catalyst particles and, through the porous structure of the carbon support, prevents particle agglomeration during high-temperature processing. However, this technology still fails to fundamentally address the catalyst's stability under harsh conditions. Stability in both strongly acidic (such as proton exchange membrane fuel cell environments) and strongly alkaline (such as water electrolysis) conditions needs to be improved.

[0005] Therefore, the development of a new ruthenium-based catalyst with excellent OER and ORR activity and good stability has important application value. Summary of the Invention

[0006] Based on this, it is necessary to address the above technical problems. The present invention provides a ruthenium, tellurium and selenium ternary composite catalyst and its preparation method and application. Compared with traditional platinum / iridium-based catalysts, the ruthenium, tellurium and selenium elements used in the present invention have richer reserves and lower prices, and the preparation process does not require complex equipment or high-energy consumption processes, which meets the requirements of green industrial production.

[0007] In order to solve the above technical problems, the present invention provides a ternary composite catalyst of ruthenium, tellurium and selenium, which comprises a carbon support and RuTe supported thereon. x Se y Nanoparticles, wherein x represents the molar ratio of tellurium to ruthenium, y represents the molar ratio of selenium to ruthenium, and the sum of x and y is 1; the nanoparticles comprise a composite crystal phase of orthorhombic RuTe2 and cubic RuSe2.

[0008] Furthermore, the average particle size of the nanoparticles is less than 5 nm, the value range of x is 0.2 to 0.8, and the value range of y is 0.2 to 0.8.

[0009] Furthermore, the RuTe x Se y The x value of the nanoparticle is 0.8 and the y value is 0.2.

[0010] A second aspect of the present invention provides a method for preparing the above-mentioned ruthenium tellurium selenide ternary composite catalyst, which comprises the following steps: S1, mixing ruthenium trichloride hydrate RuCl3·xH2O, sodium tellurite Na2TeO3, selenium dioxide SeO2 and a carbon support in ethylene glycol; S2, microwave-assisted synthesis; S3, heat treatment at 300~500℃ under an inert atmosphere to obtain the ruthenium tellurium selenide ternary composite catalyst.

[0011] Furthermore, in step S1, ruthenium trichloride hydrate RuCl3·xH2O, sodium tellurite Na2TeO3, selenium dioxide SeO2 and a carbon support are mixed in ethylene glycol according to a molar ratio of ruthenium, tellurium and selenium of 1:(0.2~0.8):(0.2~0.8), and the mass ratio of the ruthenium trichloride hydrate RuCl3·xH2O to the carbon support is 1:1~1.2.

[0012] Furthermore, the power of the microwave-assisted synthesis in step S2 is 700-900 W, and the synthesis reaction time is 2-4 minutes.

[0013] Furthermore, the heat treatment is performed in an inert atmosphere at a heating rate of 5°C / min to 300-500°C and kept at that temperature for 2 hours.

[0014] Furthermore, before the heat treatment, the product is washed with anhydrous ethanol and deionized water in sequence and then vacuum dried.

[0015] Furthermore, the power of the microwave-assisted synthesis in step S2 is 800 W, and the synthesis reaction time is 3 minutes; the heat treatment is to increase the temperature to 400° C. at a heating rate of 5° C. / min under an inert atmosphere and keep the temperature for 2 hours.

[0016] The third aspect of the present invention proposes the ruthenium tellurium selenide ternary composite catalyst RuTe x Se y Application of / C in water electrolysis, metal-air batteries or fuel cells.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a ternary composite catalyst of ruthenium, tellurium and selenium. x Se y / C and its preparation method and application, ruthenium tellurium selenide ternary composite catalyst RuTe x Se y The RuTe2-RuSe2 dual-active site structure is constructed by microwave-assisted synthesis, and the Ru precursor reduction and Te / Se alloying are completed within 3 to 5 minutes by utilizing the reducing properties of ethylene glycol and the efficient heating characteristics of microwaves to form uniformly dispersed nanoparticles. The preparation process is simple, efficient, low in energy consumption and suitable for large-scale production. x Se y / C forms a RuTe2-RuSe2 composite crystal phase after heat treatment at 300-500℃. The atomic ratio is precisely controlled through the Te-Se dichalcogenide synergistic strategy, which optimizes the adsorption capacity of oxygen-containing intermediates in the OER / ORR process. The introduction of Se effectively inhibits particle growth and increases the active specific surface area, while avoiding the problems of active site coverage and agglomeration caused by excessive Se. The ORR half-wave potential is increased to 0.71V, and the performance reaches 57.5% of that of commercial Pt / C catalysts, while the cost is reduced by 60-70%, showing the application advantages of high efficiency and low cost in water electrolysis, metal-air batteries and fuel cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1A is the RuTe of Example 1 0.8 Se 0.2 TEM morphology of / C catalyst; Figure 1B is the RuTe of Example 1 0.8 Se 0.2 / C catalyst nanoparticle size distribution diagram; Figure 1C is the RuTe of Example 1 0.8 Se 0.2 HRTEM lattice fringe pattern of / C catalyst; Figure 1D is the RuTe of Example 1 0.8 Se 0.2 EDS spectrum of / C catalyst; Figure 1E is the RuTe of Example 2 0.6 Se 0.4 TEM morphology of / C catalyst; Figure 1F is the RuTe of Example 2 0.6 Se 0.4 / C catalyst nanoparticle size distribution diagram; Figure 1G is the RuTe of Example 3 0.4 Se 0.6 TEM morphology of / C catalyst; Figure 1H is the RuTe of Example 3 0.4 Se 0.6 / C catalyst nanoparticle size distribution diagram; Figure 1I is the RuTe of Example 4 0.2 Se 0.8 TEM morphology of / C catalyst; Figure 1J is the RuTe of Example 4 0.2 Se 0.8 Nanoparticle size distribution of / C catalyst; Figure 2A TEM morphology of the RuSe / C catalyst obtained in Comparative Example 1; Figure 2B TEM morphology of the RuTe / C catalyst obtained in Comparative Example 2; Figure 3 To verify the ORR polarization curves of the catalysts of Examples 1 to 4 and Comparative Examples 1 to 2 in Example 1; Figure 4 To verify the XRD patterns of the catalysts of Example 1 and Comparative Examples 1-2 in Example 2; Figure 5 To verify the different heat treatment temperatures of Example 3 RuTe 0.8 Se 0.2 ORR polarization curves of / C catalysts; Figure 6 To verify the example 4 RuTe 0.8 Se0.2 Comparison of OER polarization curves between / C and commercial RuO2 catalysts; Figure 7 To verify the cell polarization curves of different cathode catalysts in Example 5; Figure 8 To verify the example 6RuTe 0.8 Se 0.2 Performance comparison of / C catalyst before and after 1000 cycles; Figure 9 To verify the example 6 RuTe 0.8 Se 0.2 HAADF-STEM image of the / C catalyst after 1000 cycles. DETAILED DESCRIPTION

[0020] In order to help those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0021] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below.

[0022] Description of instruments and chemical reagents used in the embodiments of the present invention Table 1 List of instruments and equipment used in the embodiments of the present invention Table 2 List of chemical reagents used in the embodiments of the present invention The ruthenium loading in the ruthenium-tellurium-selenium ternary composite catalyst described in the embodiments of the present invention is based on the total catalyst mass (including ruthenium, tellurium, selenium, and the carbon support), with a designed theoretical ruthenium loading of 20.0 wt%. The loading is controlled by adjusting the mass ratio of RuCl₃•xH₂O (x = 1-3) to the carbon support. The amounts of Te and Se introduced in each example were adjusted based on their molar ratio to Ru, while maintaining a constant theoretical Ru loading.

[0023] Example 1 This embodiment provides a ternary composite catalyst of ruthenium, tellurium and selenium. x Se y / C preparation method, which comprises the following steps: S1. Raw material preparation and mixing: Place 50 mL of ethylene glycol in a 100 mL beaker, add 57.3 mg of carbon black as a carrier material, and stir on a magnetic stirrer at 800 rpm for 30 minutes until completely dispersed. Then, add 54.6 mg of ruthenium trichloride (RuCl3•xH2O), 35.5 mg of sodium tellurite (Na2TeO3), and 4.5 mg of selenium dioxide (SeO2) in a molar ratio of ruthenium (Ru), tellurium (Te), and selenium (Se) of 1:0.8:0.2.

[0024] S2. Precursor Treatment: The mixed solution was placed in an ultrasonic cleaner and treated in a water bath at 40 kHz for 30 minutes to ensure thorough mixing of the components. The beaker was then placed in a microwave oven, set to 800 W, and subjected to a 3-minute reaction time for microwave-assisted synthesis. This step utilizes the reducing properties of ethylene glycol and the rapid and uniform heating properties of microwaves to complete precursor reduction and alloying in a very short time, avoiding the long reaction times required by traditional hydrothermal methods and improving preparation efficiency.

[0025] S3. Post-treatment: After the reaction is complete, cool the product to room temperature (25 ± 2°C) and filter it using a Buchner funnel. Wash it three times with 50 mL of anhydrous ethanol and then with deionized water. Transfer the resulting solid product to a vacuum drying oven and dry it at 65°C for 12 hours.

[0026] S4. Heat treatment: The dried sample was placed in a quartz boat in a tubular furnace and introduced with inert gas. In this embodiment, high-purity nitrogen (99.999%) was used as the protective gas. The temperature was raised to 400°C at a rate of 5°C / min, kept at this temperature for 2 hours, and then cooled to room temperature in the furnace. Finally, the target product, ruthenium tellurium selenide composite catalyst, was obtained, which was recorded as RuTe 0.8 Se 0.2 / C, where x = 0.8 and y = 0.2 represent the molar ratios of Te, Se, and Ru, respectively. This heat treatment not only removes residual organic matter on the surface but also induces the formation of RuTe2 and RuSe2 crystalline phases, while also strengthening the binding force between the nanoparticles and the carbon support and improving stability.

[0027] The obtained RuTe 0.8 Se 0.2 The / C composite catalyst was characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Figure 1A to Figure 1D As shown. Figure 1A The transmission electron microscope image shows RuTe 0.8 Se 0.2 The nanoparticles were evenly distributed on the surface of the carbon support, and no obvious agglomeration was observed; Figure 1B100 nanoparticles were randomly selected for statistics, and the average particle size was found to be 4.1 nm. Figure 1C The high-resolution TEM image shows that the interplanar spacing of 0.286nm and 0.265nm corresponds to the (111) crystal plane of the orthorhombic phase RuTe2 and the (210) crystal plane of the cubic phase RuSe2, respectively, confirming the formation of a dual active site structure in the material. Figure 1D The EDS analysis results confirmed that the catalyst mainly contained C, O, Se, Ru and Te elements, among which the molar ratio of Ru, Te and Se was 2.6:2.5:1.1.

[0028] Example 2 This embodiment provides a ternary composite catalyst of ruthenium, tellurium and selenium. x Se y / C preparation method, which differs from Example 1 in that: the molar ratio of each raw material is adjusted to Ru:Te:Se=1:0.6:0.4, and the specific steps include: S1, taking 50 mL of ethylene glycol in a beaker, adding 59.2 mg of carbon black, and adding 54.6 mg of RuCl3•xH2O, 26.6 mg of Na2TeO3 and 9.0 mg of SeO2 in sequence after magnetic stirring and dispersion; S2, after water bath ultrasonication for 30 minutes, 700 W microwave reaction for 4 minutes, the product is washed with ethanol / deionized water and then vacuum dried at 60°C for 14 hours; S3, heat treatment at 400°C under nitrogen atmosphere for 2 hours, and finally obtaining the target product ruthenium tellurium selenide composite catalyst, recorded as RuTe 0.6 Se 0.4 / C.

[0029] Example 3 This embodiment provides a ternary composite catalyst of ruthenium, tellurium and selenium. x Se y / C preparation method, which differs from Example 1 in that: the molar ratio of each raw material is Ru:Te:Se=1:0.4:0.6, and the specific steps are: S1, adding 61.2mg carbon black, 54.6mg RuCl3•xH2O, 17.7mg Na2TeO3 and 13.5mg SeO2; S2, after water bath ultrasonication for 30 minutes, 900W microwave reaction for 2 minutes, the product is washed with ethanol / deionized water and vacuum dried at 70°C for 10 hours; subsequent treatment is the same as in Example 1, and finally the target product ruthenium tellurium selenide composite catalyst is obtained, which is recorded as RuTe 0.4 Se 0.6 / C.

[0030] Example 4 This embodiment provides a ternary composite catalyst of ruthenium, tellurium and selenium. x Se y / C preparation method, which differs from Example 1 in that the molar ratio of the raw materials is Ru:Te:Se=1:0.2:0.8, and the specific steps are: S1, adding 63.1mg carbon black, 54.6mgRuCl3•xH2O, 8.9mgNa2TeO3 and 17.9mgSeO2; the subsequent treatment is the same as Example 1, and finally the target product ruthenium tellurium selenide composite catalyst is obtained, which is recorded as RuTe 0.2 Se 0.8 / C.

[0031] The catalyst nanoparticles obtained in Examples 2 to 4 were subjected to transmission electron microscopy (TEM) and the particle size of the nanoparticles was statistically analyzed. The results are as follows: Figure 1E to Figure 1J As shown; all three-way catalysts (RuTe x Se y / C) are all in a uniformly dispersed state with no obvious agglomeration, and the particle size is distributed in the range of 3-5 nm, which is similar to that of Example 1 (RuTe 0.8 Se 0.2 / C), which proves that Te / Se co-doping has universal applicability in size regulation of Ru nanoparticles.

[0032] Comparative Example 1 This comparative example provides a preparation method of a ruthenium-selenium binary catalyst RuSe / C, which differs from Example 1 in that only Ru and Se precursors are used, and the molar ratio of Ru to Se is 1:1. The specific steps are as follows: S1, take 50 mL of ethylene glycol in a beaker, add 65.1 mg of carbon black, and after magnetic stirring and dispersion, add 54.6 mg of RuCl3•xH2O and 22.4 mg of SeO2 (without adding Na2TeO3) in sequence; steps S2 to S4 are the same as in Example 1, and finally a RuSe / C catalyst is obtained.

[0033] Comparative Example 2 This comparative example provides a preparation method of a ruthenium tellurium binary catalyst (RuTe / C), which differs from Example 1 in that only Ru and Te precursors are used, and the molar ratio of Ru to Te is 1:1. The specific preparation steps are as follows: S1, take 50 mL of ethylene glycol in a beaker, add 55.3 mg of carbon black, and after magnetic stirring and dispersion, add 54.6 mg of RuCl3•xH2O and 44.4 mg of Na2TeO3 (without SeO2) in sequence; steps S2 to S4 are the same as in Example 1, and finally a RuTe / C catalyst is obtained.

[0034] Comparative Example 3 This comparative example provides a preparation method of a ruthenium monometallic catalyst (Ru / C), which differs from Example 1 only in that: no Te and Se precursors are added, and only RuCl3•xH2O is used as the metal source. The specific adjustments are as follows: S1, take 50 mL of ethylene glycol in a beaker, add 81.9 mg of carbon black (corresponding to 20 wt% Ru loading), after magnetic stirring and dispersion, only 54.6 mg of RuCl3•xH2O is added (without adding Na2TeO3 and SeO2); steps S2 to S4 are the same as in Example 1, and finally a Ru / C catalyst is obtained.

[0035] The RuTe / C and RuSe / C catalysts obtained in Comparative Examples 1 and 2 were characterized by transmission electron microscopy (TEM). Figure 2A-2B As shown, the RuTe / C and RuSe / C catalysts have poor uniformity in nanoparticle distribution.

[0036] To more intuitively demonstrate the differences in raw material composition between Examples 1 to 4 and Comparative Examples 1 to 3, Table 3 lists the molar ratios of Ru, Te, and Se in different catalysts and the corresponding raw material amounts.

[0037] Table 3: Molar ratio of catalyst and raw material dosage in Examples 1 to 4 and Comparative Examples 1 to 2 Comparative Example 4 This comparative example provides a ruthenium tellurium selenide ternary composite catalyst RuTe x Se y The preparation method of / C is different from that of Example 1 only in that the heat treatment temperature in step S4 is adjusted to 300°C (other conditions are the same), and finally RuTe 0.8 Se 0.2 / C catalyst.

[0038] Comparative Example 5 This comparative example provides a ruthenium tellurium selenide ternary composite catalyst RuTe x Se y The preparation method of / C is different from that of Example 1 only in that the heat treatment temperature in step S4 is adjusted to 500°C (other conditions are the same), and finally RuTe 0.8 Se 0.2 / C catalyst.

[0039] Comparative Example 6 This comparative example provides a ruthenium tellurium selenide ternary composite catalyst RuTe x Se y The preparation method of / C is different from that of Example 1 only in that the heat treatment in step S4 is not performed (only drying treatment is performed), and finally the unheated RuTe0.8 Se 0.2 / C catalyst.

[0040] Verification Example 1 In this verification example, the composite catalysts prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were tested for oxygen reduction reaction (ORR) performance. The test conditions were: 0.1 mol / L HClO4 solution saturated with oxygen, room temperature, and polarization curves were measured using the rotating disk electrode method. The test results are shown in Figure 2. Figure 3 As shown in the figure, the half-wave potential (E 1 / 2 ) are: RuTe 0.8 Se 0.2 / C catalyst 0.71V, RuTe 0.6 Se 0.4 / C catalyst 0.70V, RuTe 0.4 Se 0.6 / C catalyst 0.69V, RuTe 0.2 Se 0.8 / C catalyst 0.66V, RuSe / C catalyst 0.63V, RuTe / C catalyst 0.66V. The results show that the RuTe prepared in Example 1 0.8 Se 0.2 / C catalyst exhibits the best ORR catalytic activity, and its half-wave potential is increased by 80mV and 50mV compared with the single component RuSe / C and RuTe / C in Comparative Examples 1 and 2, respectively, which fully proves that the oxygen reduction performance of the catalyst can be significantly improved by constructing a composite active site of RuTe2 and RuSe2.

[0041] Verification Example 2 In this verification example, X-ray diffractometer (XRD) was used to characterize the catalysts prepared in Example 1 and Comparative Examples 1-2. The results are as follows: Figure 4 As shown in the graph, the results show that the main phase structure of RuTe / C catalyst is orthorhombic RuTe2, while the main phase structure of RuSe / C catalyst is cubic RuSe2, RuTe 0.8 Se 0.2 The crystallization peaks of orthorhombic RuTe2 and cubic RuSe2 can be observed simultaneously in the / C catalyst, which confirms the formation of a dual-active site structure of RuTe2 and RuSe2. The introduction of Se reduces the crystallinity, resulting in the formation of RuTe2 and RuSe2. 0.8 Se 0.2 The crystallinity of the RuTe / C catalyst is obviously lower than that of the RuTe / C catalyst.

[0042] Verification Example 3 In this verification example, the rotating disk electrode method was used to verify the effect of heat treatment temperature on RuTe 0.8 Se 0.2Effect of the ORR performance of the catalyst of / C was studied. The RuTe was synthesized by different heat treatment temperatures in Example 1 and Comparative Examples 4 to 6. 0.8 Se 0.2 The ORR polarization curve of the / C catalyst was tested under oxygen saturation 0.1 mol / L HClO4 conditions. The results are shown in Figure 5 The test results show that the half-wave potential of the unheated catalyst in Comparative Example 6 (None) was 0.66V; after heat treatment in Comparative Example 4 (300°C), Example 1 (400°C), and Comparative Example 5 (500°C), the half-wave potential increased to 0.68V, 0.71V, and 0.67V, respectively. The sample in Example 1, heat-treated at 400°C, exhibited the best catalytic activity, increasing by 50mV compared to the unheat-treated sample in Comparative Example 5, demonstrating the controllable effect of heat treatment temperature on catalyst performance.

[0043] Verification Example 4 This verification example uses an electrochemical workstation to measure the RuTe prepared in Example 1. 0.8 Se 0.2 The OER polarization curves of the / C catalyst under 1.0 mol / LKOH conditions were compared with those of the common commercial catalyst RuO2. Figure 6 As shown. Figure 6 It can be seen that when the driving current density is 10mA / cm 2 When RuTe 0.8 Se 0.2 The external overpotential required for the RuTe / C catalyst is 273 mV, which is about 27 mV lower than the 300 mV of commercial RuO2. 0.8 Se 0.2 The / C catalyst has excellent catalytic activity for water electrolysis, which further illustrates that the synergistic effect of Te-Se dual elements optimizes the electronic structure of Ru active sites, thereby improving the catalytic efficiency.

[0044] Verification Example 5 This verification example uses a fuel cell test system to test the RuTe 0.8 Se 0.2 / C, RuTe / C prepared in comparative example 2, Ru / C prepared in comparative example 3, and commercial Pt / C were used as cathode catalysts for hydrogen / oxygen proton exchange membrane fuel cell performance tests. The tests were conducted at a constant temperature of 80°C, with mass flow controllers used to precisely control the inlet flow rates of pure hydrogen (200 mL / min) and pure oxygen (400 mL / min). The cathode metal loading was 0.2 mg·cm -2 , the back pressure is controlled at 50kPa, and the single cell is assembled using NF211 proton exchange membrane, Figure 7 The polarization curve and power density curve of the test are shown. The results show that RuTe 0.8 Se0.2 The maximum power density of the C catalyst reached 802 mW / cm 2 , compared with 641mW / cm of RuTe / C 2 , Ru / C 462mW / cm 2 and 672 mW / cm of the best Ru-based catalyst reported in the literature. 2 The performance of commercial Pt / C catalysts has been significantly improved, reaching 1395mW / cm 2 Ru is the cheapest platinum group metal, and the price of Ru metal is only 30%~50% of Pt, which has obvious cost advantages. 0.8 Se 0.2 / C catalyst shows good commercial application prospects.

[0045] Verification Example 6 This verification example verifies RuTe by accelerated aging test 0.8 Se 0.2 The stability of the / C catalyst was investigated by applying a potential cycle of 0.05 to 0.90 V (vs. RHE) (50 mV / s scan rate) to the catalyst in an oxygen-saturated 0.1 M HClO4 solution for 1000 times. Figure 8 As shown, RuTe 0.8 Se 0.2 / C catalyst oxygen reduction half-wave potential (E 1 / 2 ) only decayed by 30 mV, with a decay rate of 4.5%, indicating that the catalyst has excellent stability and can maintain good activity in long-term operation; after 1000 cycles of stability testing, the RuTe 0.8 Se 0.2 The STEM-EDS elemental analysis of the / C catalyst was carried out. Figure 9 As shown, RuTe 0.8 Se 0.2 The metal nanoparticles (bright areas) in the α / C catalyst remain well dispersed, which is consistent with its excellent electrochemical stability.

[0046] The above-mentioned system verification shows that the ruthenium, tellurium, and selenium ternary composite catalyst of the present invention exhibits good catalytic activity and stability in oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and fuel cell applications through the synergistic effect of the dual active site structure of RuTe2 and RuSe2 and the optimized nanoparticle dispersion. As a highly efficient bifunctional electrocatalyst, the ruthenium, tellurium, and selenium ternary composite catalyst of the present invention is particularly suitable for use as an oxygen evolution anode and / or hydrogen evolution cathode in water electrolysis devices, as an air electrode in metal-air batteries, and as a cathode catalyst in fuel cells. It can significantly improve the overall efficiency of energy conversion equipment and has significant advantages in practical applications.

[0047] Obviously, the embodiments described above are only some of the embodiments of the present application, rather than all of the embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present application specification and the accompanying drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present application.

Claims

1. A ruthenium, tellurium, and selenium ternary composite catalyst, characterized in that: Including carbon support and RuTe supported on the carbon support x Se y Nanoparticles, wherein x represents the molar ratio of tellurium to ruthenium, y represents the molar ratio of selenium to ruthenium, and the sum of x and y is 1; the nanoparticles comprise a composite crystal phase of orthorhombic RuTe2 and cubic RuSe2.

2. The ruthenium, tellurium, and selenium ternary composite catalyst according to claim 1, characterized in that: The average particle size of the nanoparticles is less than 5 nm, the value range of x is 0.2 to 0.8, and the value range of y is 0.2 to 0.

8.

3. The ruthenium, tellurium, and selenium ternary composite catalyst according to claim 2, characterized in that: The RuTe x Se y The x value of the nanoparticle is 0.8 and the y value is 0.

2.

4. A method for preparing the ruthenium, tellurium and selenium ternary composite catalyst according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Mixing ruthenium trichloride hydrate RuCl3·xH2O, sodium tellurite Na2TeO3, selenium dioxide SeO2 and a carbon support in ethylene glycol; S2. Microwave-assisted synthesis; S3. Heat treatment at 300-500°C under an inert atmosphere to obtain a ruthenium-tellurium-selenium ternary composite catalyst.

5. The method for preparing the ruthenium, tellurium and selenium ternary composite catalyst according to claim 4, characterized in that: In step S1, ruthenium trichloride hydrate RuCl3·xH2O, sodium tellurite Na2TeO3, selenium dioxide SeO2 and a carbon support are mixed in ethylene glycol according to a molar ratio of ruthenium, tellurium and selenium of 1:(0.2~0.8):(0.2~0.8), and the mass ratio of the ruthenium trichloride hydrate RuCl3·xH2O to the carbon support is 1:1~1.

2.

6. The method for preparing the ruthenium, tellurium and selenium ternary composite catalyst according to claim 5, characterized in that: The power of the microwave-assisted synthesis in step S2 is 700-900 W, and the synthesis reaction time is 2-4 minutes.

7. The method for preparing the ruthenium, tellurium and selenium ternary composite catalyst according to claim 5, characterized in that: The heat treatment is carried out in an inert atmosphere at a heating rate of 5°C / min to 300-500°C and keeping the temperature for 2 hours.

8. The method for preparing the ruthenium, tellurium and selenium ternary composite catalyst according to claim 5, characterized in that: Before the heat treatment, the product is washed with anhydrous ethanol and deionized water in sequence and then vacuum dried.

9. The method for preparing the ruthenium, tellurium and selenium ternary composite catalyst according to claim 7, characterized in that: The power of the microwave-assisted synthesis in step S2 is 800 W, and the synthesis reaction time is 3 minutes; the heat treatment is to increase the temperature to 400° C. at a heating rate of 5° C. / min under an inert atmosphere and keep the temperature for 2 hours.

10. Use of the ruthenium, tellurium and selenium ternary composite catalyst according to any one of claims 1 to 3 in water electrolysis, metal-air batteries or fuel cells.

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