Heteronuclear diatomic catalyst for oxygen reduction electro-catalysis as well as preparation method and application of heteronuclear diatomic catalyst

Abstract

The invention relates to the technical field of fuel cell catalysts, and particularly discloses a heteronuclear diatomic catalyst for oxygen reduction electro-catalysis and a preparation method and application thereof.The heteronuclear diatomic catalyst Ru-Co-NC has the structural characteristic of atom dispersion and has the extremely low metal atom loading capacity, the preparation process is simple, easy to expand and low in price, and the catalyst is suitable for industrial production. And the heteronuclear diatomic catalyst has very excellent oxygen reduction electrocatalytic activity and stability, and the zinc air battery assembled by taking the heteronuclear diatomic catalyst as a cathode active material shows good battery performance. In an oxygen reduction electro-catalysis performance test, the catalyst shows a half-wave potential of 0.858 V vs.RHE, the performance of the catalyst is superior to that of a commercial Pt / C catalyst, and the prepared catalyst has very excellent stability. The zinc air battery assembled by taking the heteronuclear diatomic catalyst Ru-Co-NC as the air cathode catalyst layer realizes high power density, large specific capacity and excellent charge-discharge cycle stability.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell catalysts, and particularly relates to a heteronuclear dual-atom catalyst for oxygen reduction electrocatalysis, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous growth of the demand for clean energy, the development of safe and efficient energy storage systems has become particularly important. Among various energy storage technologies, zinc-air batteries have attracted extensive attention from researchers due to their excellent energy density (1086 Wh / kg), high safety, and cost-effectiveness. Research shows that the energy efficiency of zinc-air batteries is largely limited by the slow kinetics of the oxygen reduction reaction at the cathode. Although catalysts based on noble metal Pt have good catalytic activity, their high cost and unsatisfactory stability have hindered the development of zinc-air batteries. In view of the above problems, many catalyst design strategies have been proposed by researchers, which can be roughly divided into three directions: (1) reducing the amount of noble metal used while improving its utilization rate, such as alloying noble metals with non-noble metals, nanosizing the catalytic material, etc.; (2) replacing noble metals with transition metals to prepare non-noble metal compounds, including metal nitrides (usually metal-nitrogen doped carbon materials); (3) non-metal carbon materials, such as carbon nanotubes, graphene, graphdiyne, heteroatom (B, N, O, P, S) doped carbon materials, etc. Although certain progress has been made in the exploration of these materials, there are still some challenges to be solved. Some reported catalysts have poor stability during long-term operation, resulting in a rapid decline in battery performance, and some catalysts have complex synthesis processes and are not suitable for large-scale production. Summary of the Invention

[0003] To solve the problems existing in the prior art, the present invention provides a heteronuclear dual-atom catalyst for oxygen reduction electrocatalysis, a preparation method thereof, and an application thereof. The catalyst has a structurally characteristic of atomic dispersion, with an extremely low metal atom loading. Its preparation process is simple, easy to scale up, and inexpensive, and it has excellent oxygen reduction electrocatalytic activity and stability. A zinc-air battery assembled with this heteronuclear dual-atom catalyst as the air cathode catalytic layer exhibits good battery performance, solving the problems mentioned in the above background art.

[0004] To achieve the above object, the present invention provides the following technical solution: A heteronuclear dual-atom catalyst for oxygen reduction electrocatalysis, in which Ru and Co metals in the heteronuclear dual-atom catalyst Ru-Co-NC exist in an atomically dispersed form; the heteronuclear dual-atom catalyst Ru-Co-NC presents a dodecahedral morphology with uniform particle size, and the particle size is 200 - 300 nm;

[0005] In the oxygen reduction electrocatalytic performance test, the heteronuclear dual-atom catalyst Ru-Co-NC exhibited a half-wave potential of 0.858 V vs. RHE; in the oxygen reduction electrocatalytic stability test, the current density retention of the heteronuclear dual-atom catalyst Ru-Co-NC reached 95.0%.

[0006] On the other hand, to achieve the above object, the present invention also provides the following technical solution: A preparation method of a heteronuclear dual-atom catalyst for oxygen reduction electrocatalysis, comprising the following steps:

[0007] Step (1): Dissolve a Zn source and a Co source in a methanol solvent as solution A; dissolve 2-methylimidazole in a methanol solvent as solution B; then quickly pour solution B into solution A and mix well, and let it stand at room temperature to obtain Co-ZIF-8;

[0008] Step (2): Disperse the Co-ZIF-8 obtained in step (1) in an ethanol solvent, introduce a Ru source, and then heat and stir to obtain a heteronuclear dual-atom catalyst precursor Ru-Co-ZIF-8;

[0009] Step (3): Place the heteronuclear dual-atom catalyst precursor Ru-Co-ZIF-8 obtained in step (2) in a quartz boat, place it in the center of a tube furnace, and perform high-temperature pyrolysis treatment in an inert gas atmosphere to obtain a heteronuclear dual-atom catalyst Ru-Co-NC.

[0010] Preferably, in step (1), the Zn source is one or a combination of zinc nitrate, zinc acetate, zinc sulfate, zinc chloride; the Co source is one or a combination of cobalt nitrate, cobalt acetate, cobalt chloride, cobalt acetylacetonate.

[0011] Preferably, in step (1), the molar ratio of the Zn source, the Co source and 2-methylimidazole is 40:0.1-1:160; the time for standing at room temperature is 12 hours.

[0012] Preferably, in step (2), the Ru source is one or a combination of ruthenium chloride, ruthenium acetylacetonate.

[0013] Preferably, in step (2), the mass ratio of Co-ZIF-8 and the Ru source is 1:0.01-0.05.

[0014] Preferably, in step (2), the temperature for heating and stirring is 45 °C and the time is 12 hours.

[0015] Preferably, in step (3), the inert gas atmosphere is at least one of high-purity argon and high-purity nitrogen.

[0016] Preferably, in step (3), the temperature of the pyrolysis treatment is 900 - 1000 °C, the heating rate is 10 °C / min, and the temperature holding time is 3 hours.

[0017] On the other hand, to achieve the above object, the present invention also provides the following technical solution: An application of a heteronuclear dual-atom catalyst for oxygen reduction electrocatalysis in the field of catalyzing oxygen reduction at the cathode of a zinc-air battery. The specific capacity of the zinc-air battery assembled with the heteronuclear dual-atom catalyst Ru-Co-NC as the air cathode catalytic layer is 781.1 mAh / g Zn and the power density is 262.0 mW / cm 2 and the charge-discharge cycle time is up to 300 h, and the maximum efficiency of the battery reaches 58.16%.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1) In the heteronuclear dual-atom catalyst Ru-Co-NC prepared by the present invention, Ru and Co metals exist in the form of atomic dispersion, characterized by the absence of metal nanoparticles or alloy nanoparticle structures, with an extremely low metal loading and low cost;

[0020] 2) The preparation process of the heteronuclear dual-atom catalyst Ru-Co-NC prepared by the present invention is simple, easy to expand, has a wide application range, and can be used for large-scale preparation;

[0021] 3) In the oxygen reduction electrocatalytic performance test of the heteronuclear dual-atom catalyst Ru-Co-NC prepared by the present invention, it shows a half-wave potential of 0.858 V vs. RHE, and its performance is superior to that of commercial Pt / C catalysts, and the prepared catalyst has very excellent stability;

[0022] 4) The zinc-air battery assembled with the heteronuclear dual-atom catalyst Ru-Co-NC prepared by the present invention as the air cathode catalytic layer realizes high power density, large specific capacity, and excellent charge-discharge cycle stability performance. Description of the Drawings

[0023] Figure 1 is the basic flow chart for preparing the oxygen reduction electrocatalyst Ru-Co-NC in Example 1;

[0024] Figure 2 is the scanning electron microscope (SEM) image of the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1;

[0025] Figure 3 is the X-ray diffraction (XRD) pattern of the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1;

[0026] Figure 4Comparison diagram of linear sweep voltammetry (LSV) curves of the oxygen reduction electrocatalyst Ru-Co-NC prepared in Examples 1-9 and Comparative Example 1 in an alkaline medium;

[0027] Figure 5 Comparison diagram of linear sweep voltammetry (LSV) curves of the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1 and Comparative Example 1 and the oxygen reduction electrocatalysts prepared in Comparative Examples 2-10 in an alkaline medium;

[0028] Figure 6 Comparison diagram of stability test curves of the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1 and Comparative Example 1 in an alkaline medium;

[0029] Figure 7 Comparison diagram of specific capacity curves of zinc-air batteries assembled with the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1 and Comparative Example 1;

[0030] Figure 8 Comparison diagram of discharge polarization curves and power curves of zinc-air batteries assembled with the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1 and Comparative Example 1;

[0031] Figure 9 Comparison diagram of constant current charge-discharge cycle curves of zinc-air batteries assembled with the oxygen reduction electrocatalyst Ru-Co-NC prepared in Example 1 and Comparative Example 1. Detailed implementation mode

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0033] Example 1

[0034] The steps for preparing the heteronuclear diatomic catalyst Ru-Co-NC in this example are as Figure 1 shown, and specifically include the following steps:

[0035] Step (1): Weigh 40 mmol of Zn(NO3)2·6H2O and 0.5 mmol of Co(NO3)2·6H2O into a 1000 mL beaker. Subsequently, add 300 mL of methanol solvent and ultrasonically disperse for 30 min to form a uniform purple transparent solution, denoted as solution A. Weigh 160 mmol of 2-methylimidazole into another 1000 mL beaker, add 300 mL of methanol solvent, and ultrasonically disperse for 30 min to form a uniform colorless transparent solution, denoted as solution B. Then quickly pour solution A into solution B and mix. Magnetically stir for 1 h at room temperature to form a homogeneous solution, and then let it stand at room temperature for 12 h to promote the formation of the product. After the reaction, transfer the suspension containing the product to a centrifuge tube and centrifuge at 8000 rpm for 10 min. After centrifugation, pour out the supernatant in the centrifuge tube, and dry the precipitate at the bottom of the centrifuge tube at 60 °C for 24 h to obtain a purple powder product Co-ZIF-8.

[0036] Step (2): Weigh 2.0 g of Co-ZIF-8 and add it to a beaker containing 0.026 g of RuCl3·3H2O. Then add 200 mL of ethanol solvent, and subsequently perform ultrasonic dispersion treatment on the above system for 1 h to form a homogeneous suspension. After dispersion, add a magnetic stir bar to the beaker and place it in a magnetic heating stirrer. Heat and stir for 24 h, with the heating temperature being 45 °C and the heating rate being 1 °C / min, and adjust the stirring speed to 600 rpm. After the reaction, transfer the suspension to a centrifuge tube and centrifuge at 8000 rpm for 10 min. Then pour out the supernatant in the centrifuge tube, and dry the precipitate at the bottom of the centrifuge tube at 60 °C for 24 h to obtain a light purple powder heteronuclear diatomic catalyst precursor Ru-Co-ZIF-8.

[0037] Step (3): Place the heteronuclear diatomic catalyst precursor Ru-Co-ZIF-8 prepared in step (2) in a quartz boat and put it in the center of a tube furnace. Heat it to 950 °C at a heating rate of 10 °C / min in an atmosphere of high-purity argon with a flow rate of 60 mL / min, and perform high-temperature pyrolysis treatment for 3 h. Then naturally cool to room temperature to obtain the heteronuclear diatomic catalyst Ru-Co-NC.

[0038] Morphology Characterization of Heteronuclear Diatomic Catalyst Ru-Co-NC

[0039] Perform scanning electron microscopy (SEM) characterization on the heteronuclear diatomic catalyst Ru-Co-NC obtained in Example 1 to observe the morphological characteristics of the catalyst. As Figure 2 shown, it can be seen that the bimetallic catalyst presents a dodecahedral morphology with uniform particle size (200 ～ 300 nm).

[0040] Structural Characterization of Heteronuclear Diatomic Catalyst Ru-Co-NC

[0041] The heteronuclear diatomic catalyst Ru-Co-NC obtained in Example 1 was characterized by X-ray diffraction (XRD). As Figure 3 shown, there are two broad peaks in the XRD pattern of Ru-Co-NC at around 23° and 44°, corresponding to the (002) and (100) crystal planes of graphite carbon respectively, and there are no peaks in the standard cards of Co metal particles (PDF#96-901-2930) and Ru metal particles (PDF#96-210-0455). Thus, it can be seen that the Ru and Co metal elements exist in the form of primary dispersion in the catalyst.

[0042] Detection of Metal Element Content in Heteronuclear Diatomic Catalyst Ru-Co-NC

[0043] The Ru-Co-NC catalyst prepared in Example 1 was tested by inductively coupled plasma mass spectrometry (ICP-MS), and the measured Ru and Co metal content data are shown in Table 1:

[0044] Table 1 Ru and Co Metal Content

[0045] Sample Ru (wt%) Co (wt%) Example 1 0.11 1.32

[0046] As can be seen from Table 1, the mass contents of Ru and Co metals in the heteronuclear diatomic catalyst Ru-Co-NC prepared in Example 1 are 0.11 wt% and 1.32 wt% respectively. Compared with commercial 20 wt% Pt / C, Ru-Co-NC has an extremely low metal loading.

[0047] Example 2

[0048] Same as Example 1, except that the addition amount of Co(NO3)2·6H2O in step (1) is 0.1 mmol.

[0049] Example 3

[0050] Same as Example 1, except that the addition amount of Co(NO3)2·6H2O in step (1) is 0.7 mmol.

[0051] Example 4

[0052] Same as Example 1, except that the addition amount of Co(NO3)2·6H2O in step (1) is 1 mmol.

[0053] Example 5

[0054] Same as Example 1, except that the addition amount of RuCl3·3H2O in step (2) is 0.01 g.

[0055] Example 6

[0056] Same as Example 1, except that in step (2), the addition amount of RuCl3·3H2O is 0.05 g.

[0057] Example 7

[0058] Same as Example 1, except that in step (3), it is heated to 900 °C at a heating rate of 10 °C / min in an atmosphere of high-purity argon with a flow rate of 60 mL / min.

[0059] Example 8

[0060] Same as Example 1, except that in step (3), it is heated to 1000 °C at a heating rate of 10 °C / min in an atmosphere of high-purity argon with a flow rate of 60 mL / min.

[0061] Example 9

[0062] Same as Example 1, except that in step (1), the addition amount of Co(NO3)2·6H2O is 0.7 mmol, in step (2), the addition amount of RuCl3·3H2O is 0.05 g, and in step (3), it is heated to 1000 °C.

[0063] Comparative Example 1

[0064] In this comparative example, 20 wt% commercial Pt / C is used as a control.

[0065] Comparative Example 2

[0066] Same as Example 1, except that step (2) is not carried out, and Co(NO3)2·6H2O is not added in step (1). The obtained product is labeled as ZIF-8. At the same time, the precursor in step (3) is replaced by ZIF-8, and the finally obtained Comparative Example 2 is labeled as NC.

[0067] Comparative Example 3

[0068] Same as Example 1, except that step (2) is not carried out, and the precursor in step (3) is replaced by Co-ZIF-8. The finally obtained Comparative Example 3 is labeled as Co-NC.

[0069] Comparative Example 4

[0070] Same as Example 1, except that in step (1), Co(NO3)2·6H2O is not added, and the obtained product is labeled as ZIF-8. In step (2), Co-ZIF-8 is replaced by ZIF-8, and the precursor obtained according to step (2) is labeled as Ru-ZIF-8. In step (3), the precursor for pyrolysis treatment is replaced by Ru-ZIF-8, and the finally obtained Comparative Example 4 is labeled as Ru-NC.

[0071] Comparative Example 5

[0072] Same as Example 1, except that in step (1), the addition amount of Co(NO3)2·6H2O is 0.05 mmol.

[0073] Comparative Example 6

[0074] Same as Example 1, except that in step (1), the addition amount of Co(NO3)2·6H2O is 2 mmol.

[0075] Comparative Example 7

[0076] Same as Example 1, except that in step (2), the addition amount of RuCl3·3H2O is 0.001 g.

[0077] Comparative Example 8

[0078] Same as Example 1, except that in step (2), the addition amount of RuCl3·3H2O is 0.1 g.

[0079] Comparative Example 9

[0080] Same as Example 1, except that in step (3), it is heated to 800 °C at a heating rate of 10 °C / min in a high-purity argon atmosphere with a flow rate of 60 mL / min.

[0081] Comparative Example 10

[0082] Same as Example 1, except that in step (3), it is heated to 1100 °C at a heating rate of 10 °C / min in a high-purity argon atmosphere with a flow rate of 60 mL / min.

[0083] Characterization of the oxygen reduction electrocatalytic performance of the heteronuclear dual-atom catalyst Ru-Co-NC

[0084] The heteronuclear dual-atom catalyst Ru-Co-NC, ethanol, water, and nafion solution obtained in Examples 1-9 were formulated into a mixed slurry in a certain proportion (the content of the catalyst is 5 mg / mL). Then the mixed slurry was coated on a rotating ring-disk electrode, and linear sweep voltammetry was tested in a three-electrode system to obtain the LSV curve of the catalyst, as Figure 4As shown. Among them, the tested electrolyte is 0.1 M KOH aqueous solution saturated with O2, the working electrode is a rotating ring-disk electrode, the reference electrode is an Ag / AgCl electrode, and the counter electrode is a Pt wire electrode. Then, the catalysts obtained in Comparative Examples 1-10 are respectively prepared into mixed slurries according to the above method, and linear sweep voltammetry tests are carried out in a three-electrode system to obtain the corresponding LSV curves. The results are as Figure 5 shown.

[0085] From Figure 4 and Figure 5 in the LSV curves, it can be seen that the heteronuclear dual-atom catalysts Ru-Co-NC prepared in Examples 1-9 all have very excellent oxygen reduction electrocatalytic activity. Their half-wave potential is higher than that of 20 wt% commercial Pt / C in Comparative Example 1, and is significantly higher than the half-wave potentials of the catalysts obtained in Comparative Examples 2-10.

[0086] Oxygen reduction electrocatalytic stability test of heteronuclear dual-atom catalyst Ru-Co-NC

[0087] The oxygen reduction electrocatalytic stability test was carried out on the heteronuclear dual-atom catalyst Ru-Co-NC obtained in Example 1 and 20 wt% commercial Pt / C obtained in Comparative Example 1. The tested curves were normalized. The results are as Figure 6 shown. It can be seen from the normalized test curves that the current density retention of the heteronuclear dual-atom catalyst Ru-Co-NC after the stability test reached 95.0%, which is much higher than 63.2% of 20 wt% commercial Pt / C, showing excellent stability.

[0088] Application: Performance characterization of a zinc-air battery assembled with a heteronuclear dual-atom catalyst Ru-Co-NC as an air cathode catalytic layer

[0089] The heteronuclear dual-atom catalyst Ru-Co-NC obtained in Example 1, ethanol, water, and nafion solution were formulated into a slurry in a certain proportion. The slurry was coated on a composite electrode substrate (the loading amount of the heteronuclear dual-atom catalyst Ru-Co-NC is 1 mg / cm 2 ) and assembled into a zinc-air battery module as an air cathode catalytic layer. Similarly, 20 wt% commercial Pt / C was assembled into a corresponding zinc-air battery according to the above method. Subsequently, the specific capacity ( Figure 7 ), power density ( Figure 8 ), and charge-discharge cycle curve ( Figure 9 ) of the zinc-air battery were tested. The results show that the specific capacity of the zinc-air battery assembled with the heteronuclear dual-atom catalyst Ru-Co-NC as the air cathode catalytic layer is 781.1 mAh / g Zn , and the power density is 262.0 mW / cm 2, the charge-discharge cycle time is up to 300 h, the maximum efficiency of the battery reaches 58.16%, and under the same test conditions, the specific capacity of the zinc-air battery assembled with 20 wt% commercial Pt / C as the air cathode catalyst layer is 718.9 mAh / g Zn , the power density is 218.2 mW / cm 2 , the charge-discharge cycle time is less than 80 h, and the maximum efficiency of the battery is only 53.69%. It can be seen that the zinc-air battery assembled with the heteronuclear dual-atom catalyst Ru-Co-NC of the present invention as the air cathode catalyst layer exhibits very excellent battery performance.

[0090] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A heteronuclear diatomic catalyst for oxygen reduction electrocatalysis, characterized in that, In the heteronuclear diatomic catalyst Ru-Co-NC for oxygen reduction electrocatalysis, Ru and Co metals exist in an atomically dispersed form; the heteronuclear diatomic catalyst Ru-Co-NC exhibits a dodecahedral morphology with uniform particle size, and the particle size is 200 - 300 nm; In the oxygen reduction electrocatalytic performance test, the heteronuclear diatomic catalyst Ru-Co-NC shows a half-wave potential of 0.858 V vs. RHE; in the oxygen reduction electrocatalytic stability test, the current density retention of the heteronuclear diatomic catalyst Ru-Co-NC reaches 95.0%.

2. A preparation method of a heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 1, characterized in that: It includes the following steps: Step (1): Dissolve a Zn source and a Co source in a methanol solvent to obtain solution A; dissolve 2-methylimidazole in a methanol solvent to obtain solution B; then quickly pour solution B into solution A and mix well, and let it stand at room temperature to obtain Co-ZIF-8; Step (2): Disperse the Co-ZIF-8 obtained in step (1) in an ethanol solvent, introduce a Ru source, and then heat and stir to obtain a heteronuclear diatomic catalyst precursor Ru-Co-ZIF-8; Step (3): Place the heteronuclear diatomic catalyst precursor Ru-Co-ZIF-8 obtained in step (2) in a quartz boat, place it in the center of a tubular furnace, and perform high-temperature pyrolysis treatment in an inert gas atmosphere to obtain the heteronuclear diatomic catalyst Ru-Co-NC.

3. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, wherein: In step (1), the Zn source is one or a combination of zinc nitrate, zinc acetate, zinc sulfate, zinc chloride; the Co source is one or a combination of cobalt nitrate, cobalt acetate, cobalt chloride, cobalt acetylacetonate.

4. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, characterized in that: In step (1), the molar ratio between the Zn source, Co source and 2-methylimidazole is 40:0.1 - 1:160; the time for standing at room temperature is 12 hours.

5. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, characterized in that: In step (2), the Ru source is one or a combination of ruthenium chloride, ruthenium acetylacetonate.

6. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, characterized in that: In step (2), the mass ratio between Co-ZIF-8 and the Ru source is 1:0.01 - 0.

05.

7. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, characterized in that: In step (2), the temperature for heating and stirring is 45 °C, and the time is 12 hours.

8. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, wherein: In step (3), the inert gas atmosphere is at least one of high-purity argon and high-purity nitrogen.

9. The preparation method of the heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 2, wherein: In step (3), the temperature for pyrolysis treatment is 900 - 1000 °C, the heating rate is 10 °C / min, and the temperature holding time is 3 hours.

10. Use of a heteronuclear diatomic catalyst for oxygen reduction electrocatalysis according to claim 1 or a heteronuclear diatomic catalyst for oxygen reduction electrocatalysis prepared by the preparation method according to any one of claims 2 to 9 in the field of catalyzing oxygen reduction at the cathode of a zinc-air battery, characterized in that: The specific capacity of the zinc-air battery assembled with the heteronuclear diatomic catalyst Ru-Co-NC as the air cathode catalytic layer is 781.1 mAh / g Zn , the power density is 262.0 mW / cm 2 , the charge-discharge cycle time is as high as 300 h, and the maximum efficiency of the battery reaches 58.16%.

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