Heterostructure catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of catalysts, and particularly relates to a heterostructure catalyst as well as a preparation method and application thereof. The heterostructure catalyst comprises a carbon carrier and metal particles loaded on the carbon carrier, the metal particles comprise PdZn nano alloy and Co nano particles; and a heterojunction interface structure is arranged between the PdZn nano-alloy and the Co nano-particles. The PdZn alloy particles and the Co particles form a particle-particle heterostructure with a strong interface coupling effect, the EOR catalytic activity of the heterostructure catalyst is improved, the EOR catalytic activity is almost 10.7 times of the mass activity of a traditional Pd / C catalyst, and the catalyst can be applied to an anode catalyst of a direct ethanol fuel cell. Meanwhile, the method also has higher C1 pathway selectivity, effectively improves the utilization rate of the ethanol fuel, has a remarkable cost advantage, and can be used for manufacturing ethanol fuel cells.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, and specifically relates to a heterostructure catalyst, its preparation method, and its application. Background Technology

[0002] Direct ethanol fuel cells (DEFCs) are a type of clean energy device that uses ethanol as fuel to directly convert chemical energy into electrical energy. They have advantages such as high energy density, abundant fuel sources, safe and convenient use, and environmental friendliness, and have broad application prospects in portable electronic devices, transportation vehicles, and distributed power generation.

[0003] In DEFCs, the anodic ethanol oxidation (EOR) is a crucial process, involving two parallel but competing electrochemical pathways: the complete C1 pathway and the incomplete C2 pathway. The C1 pathway involves the complete breaking of the C-C bonds in the ethanol molecule, oxidizing it to CO2 via 12-electron transfer, and boasts the highest energy conversion efficiency. The C2 pathway, however, preserves the C-C bonds during ethanol oxidation, generating intermediates containing two carbon atoms (C2) (such as acetaldehyde or acetic acid). However, in actual reactions, the C-C bonds in the ethanol molecule are stable and difficult to break, resulting in C2 products such as acetic acid or acetaldehyde being the predominant products. This significantly reduces fuel utilization and the actual performance of the battery. This problem is one of the technical bottlenecks limiting the widespread application of DEFCs.

[0004] Traditional Pd-based nanomaterials are considered the most active EOR catalysts in alkaline electrolytes; however, they have limited performance in C-C bond cleavage and deep oxidation of intermediates, and it is particularly difficult to balance selectivity and cost.

[0005] Therefore, it is of great significance to provide a catalyst with good anodic ethanol oxidation activity and C1 pathway selectivity. Summary of the Invention

[0006] The present invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial alternative. Specifically, the present invention provides a heterostructure catalyst with good anodic ethanol oxidation activity, which can be applied to direct ethanol fuel cells, and has good C1 pathway selectivity, which can effectively improve the utilization rate of ethanol fuel and has significant cost advantages.

[0007] The inventive concept of this invention: The heterostructure catalyst of this invention includes a carbon support and metal particles supported on the carbon support; the metal particles include PdZn nanoalloys and Co nanoparticles; the PdZn nanoalloys and Co nanoparticles have a heterojunction interface structure.

[0008] This invention constructs a heterostructure catalyst, particularly a "particle-particle" heterostructure formed by PdZn nanoalloys and Co nanoparticles with strong interfacial coupling effects. This allows for the regulation of the heterostructure's interfacial electronic behavior, optimization of intermediate adsorption and reaction pathways, and efficient synergy between C / C bond cleavage and subsequent oxidation reactions. This significantly improves the EOR catalytic activity of the heterostructure catalyst, reaching nearly 10.7 times the mass activity of commercial Pd / C catalysts, making it suitable for use as an anode catalyst in direct ethanol fuel cells. Furthermore, it exhibits higher C1 pathway selectivity, effectively improving ethanol fuel utilization and offering significant cost advantages, making it suitable for manufacturing ethanol fuel cells.

[0009] Therefore, a first aspect of the present invention provides a heterostructure catalyst.

[0010] Specifically, the heterostructure catalyst includes a carbon support and metal particles supported on the carbon support;

[0011] The metal particles include PdZn nanoalloys and Co nanoparticles;

[0012] The PdZn nanoalloy and Co nanoparticles have a heterojunction interface structure.

[0013] Preferably, the mass ratio of Pd, Zn and Co elements in the metal particles is (1.6-2.5):1:(4-6).

[0014] More preferably, the mass ratio of Pd, Zn and Co elements in the metal particles is (1.8-2.2):1:(4.5-5.5).

[0015] More preferably, the mass ratio of Pd, Zn, and Co in the metal particles is 2:1:5.

[0016] Preferably, the particle size of the PdZn nanoalloy is 4.5-33 nm; more preferably, the particle size of the PdZn nanoalloy is 5-30 nm.

[0017] Preferably, the Co nanoparticles have a particle size of 4.5-33 nm; more preferably, the Co nanoparticles have a particle size of 5-30 nm.

[0018] Specifically, the two types of size-matched metal nanoparticles are beneficial for enhancing the tight and uniform contact of the coupled heterogeneous interface, thereby enhancing the charge coupling and strain coordination effect, and thus forming an interfacial active center with synergistic effect.

[0019] A second aspect of the present invention provides a method for preparing the heterostructure catalyst described in the first aspect of the present invention.

[0020] Specifically, the method for preparing the heterostructure catalyst includes the following steps:

[0021] (1) Mix cobalt precursor, zinc precursor, organic ligand and solvent, react to obtain intermediate product;

[0022] (2) The palladium precursor, the intermediate product obtained in step (1) and the solvent are mixed, dried and calcined to obtain the heterostructure catalyst.

[0023] Preferably, in step (1), the cobalt precursor includes at least one of cobalt nitrate hexahydrate, cobalt acetate, and cobalt chloride.

[0024] Specifically, the cobalt precursors of this invention are all non-precious metal elements, which are inexpensive and readily available, resulting in low preparation costs.

[0025] Preferably, in step (1), the zinc precursor includes at least one of zinc nitrate hexahydrate, zinc acetate, and zinc chloride.

[0026] Preferably, in step (1), the organic ligand includes at least one of 2-methylimidazole and 2-ethylimidazole.

[0027] Specifically, the organic ligands of this invention are commercially available raw materials that are inexpensive and readily available.

[0028] Preferably, in step (1), the solvent includes methanol.

[0029] Preferably, in step (1), the mass fractions of each raw material are as follows: 45-110 parts of cobalt precursor, 180-450 parts of zinc precursor, and 550-1600 parts of organic ligand.

[0030] More preferably, in step (1), the mass fractions of each raw material are as follows: 50-100 parts of cobalt precursor, 200-400 parts of zinc precursor, and 600-1500 parts of organic ligand.

[0031] Specifically, under this optimized composition ratio, the present invention can prepare a zeolite imidazole ester framework (ZIF) precursor with a regular topological structure, which is beneficial for the subsequent preparation of carbon-supported particle-particle heterostructure catalysts.

[0032] Preferably, in step (1), the reaction temperature is 75-130°C and the reaction time is 9-18h.

[0033] More preferably, in step (1), the reaction temperature is 80-120℃ and the reaction time is 10-16h.

[0034] Specifically, the reaction is carried out in a polytetrafluoroethylene-lined reactor.

[0035] Specifically, under these optimized reaction conditions, metal ions and organic ligands interact through coordination bonds to construct polyhedral crystals with a topological framework, thus achieving rapid nucleation and uniform growth of ZIF.

[0036] Preferably, in step (1), the reaction is followed by a process of centrifugation and drying.

[0037] Preferably, in step (2), the palladium precursor includes at least one of tetrachlorodiamine palladium, palladium acetylacetonate, and palladium chloride.

[0038] Specifically, the tetrachlorodiamine palladium, palladium acetylacetonate, and palladium chloride of the present invention are all common palladium precursors that are easy to obtain and can provide the noble metal palladium, so that palladium can be loaded onto the ZIF precursor.

[0039] Preferably, in step (2), the solvent includes methanol.

[0040] Preferably, in step (2), the mixture is stirred for 9-18 hours.

[0041] More preferably, in step (2), the mixture is stirred for 10-16 hours.

[0042] Preferably, in step (2), the calcination temperature is 750-1000℃ and the calcination time is 1.8-4.5h.

[0043] More preferably, in step (2), the calcination temperature is 800-950℃ and the calcination time is 2-4h.

[0044] Specifically, under these optimized reaction conditions, the decomposition and carbonization of the ZIF precursor are favorable, thereby increasing graphitization and improving electrical conductivity. Furthermore, during this optimized high-temperature pyrolysis process, the interaction and structural reorganization of the various metal components effectively regulate the distribution and arrangement of the multimetallic species, resulting in a particle-particle heterostructure with strong interfacial coupling effects.

[0045] Preferably, in step (2), the calcination is carried out in a protective atmosphere.

[0046] Preferably, the protective atmosphere includes hydrogen and argon.

[0047] A third aspect of the present invention provides an ethanol fuel cell.

[0048] Specifically, the ethanol fuel cell includes the heterostructure catalyst described in the first aspect of the present invention.

[0049] Preferably, the ethanol fuel cell is a direct ethanol fuel cell.

[0050] Specifically, this invention applies a carbon-supported particle-particle heterostructure catalyst to the anodic ethanol oxidation reaction of a direct ethanol fuel cell, which can significantly improve the utilization rate of ethanol fuel and the catalytic activity of the reaction, greatly reduce the cost of the direct ethanol fuel cell, and facilitate large-scale promotion and application.

[0051] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows:

[0052] (1) This invention utilizes the coordination self-assembly reaction of cobalt precursor, zinc precursor and organic ligand in solvent to form ZIF precursor with regular topological structure. Under high temperature reaction conditions, metal ions and organic ligands orderly construct polyhedral crystals with topological framework through coordination bond interaction, realizing rapid nucleation and uniform growth of ZIF.

[0053] (2) In this invention, through rapid heating and pyrolysis during the calcination process, some Zn atoms react with adsorbed Pd atoms. 2+ The ions undergo synergistic reduction to form stable PdZn intermetallic nanoparticles. Simultaneously, another portion of Zn volatilizes and escapes at high temperature, reducing the spatial confinement between Co species and thus promoting the migration and aggregation of Co nanoparticles, ultimately achieving their spontaneous formation. The metal interactions and structural reorganization formed in this process effectively regulate the distribution and arrangement of multimetal species, thereby forming a "particle-particle" heterostructure with strong interfacial coupling effects.

[0054] (3) The present invention adopts a pre-loading strategy, that is, the loading of Pd is completed before calcination, which ensures the simultaneous generation of PdZn alloy and Co nanoparticles, so that the "particle-particle" heterostructure interface is formed, thereby improving the EOR catalytic activity of carbon-loaded "particle-particle" heterostructure catalyst.

[0055] (4) The carbon-supported "particle-particle" heterostructure catalyst prepared by the present invention has higher ethanol oxidation catalytic activity than commercial Pd / C catalysts, which is almost 10.7 times that of traditional commercial Pd / C catalysts. It can be used as an anode catalyst for direct ethanol fuel cells.

[0056] (5) The carbon-supported "particle-particle" heterostructure catalyst prepared by the present invention has higher C1 pathway selectivity, effectively improves the utilization rate of ethanol fuel, and has significant cost advantages. Therefore, it can be used to manufacture ethanol fuel cells and is conducive to its application in electric vehicles, spacecraft, and portable electronic devices such as cameras, laptops, and electric toys. Attached Figure Description

[0057] Figure 1This is a transmission electron microscope (TEM) image of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of this invention.

[0058] Figure 2 This is a high-angle annular dark-field scanning transmission electron microscope image of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of this invention.

[0059] Figure 3 This is a statistical diagram of the particle size distribution of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of the present invention;

[0060] Figure 4 The X-ray diffraction pattern of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of this invention;

[0061] Figure 5 This is a high-magnification transmission electron microscope image of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of the present invention and an elemental energy spectrum at this location.

[0062] Figure 6 The graphs show the ethanol oxidation reaction curves of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of this invention, the commercial Pd / C catalyst, the PdZn / C catalyst prepared in Comparative Example 1, and the Co / C catalyst prepared in Comparative Example 2.

[0063] Figure 7 The images show the Faraday efficiency of the PdZn-Co / C heterostructure catalyst prepared in Example 1 of this invention, the commercial Pd / C catalyst, and the PdZn / C catalyst prepared in Comparative Example 1. Detailed Implementation

[0064] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0065] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0066] Example 1

[0067] A method for preparing a carbon-supported "particle-particle" heterostructure catalyst includes the following steps:

[0068] (1) By weight, take 50 parts of cobalt precursor cobalt nitrate hexahydrate, 200 parts of zinc precursor zinc nitrate hexahydrate and 750 parts of organic ligand 2-methylimidazole, dissolve them in methanol solution, stir for 30 min to obtain a purple mixed solution. The concentration of cobalt precursor in the mixed solution is 1 mg / mL, the concentration of zinc precursor is 4 mg / mL and the concentration of organic ligand is 15 mg / mL.

[0069] (2) The mixed solution obtained in step (1) was transferred to a polytetrafluoroethylene-lined reactor and reacted at 120°C for 12 hours. Then it was centrifuged and finally dried at 60°C for 8 hours to obtain the intermediate product.

[0070] (3) Dissolve 26 mg of palladium precursor palladium acetylacetonate in 10 mL of methanol solution to prepare palladium precursor solution. Disperse 2 mL of palladium precursor solution and 1 g of intermediate product obtained in step (2) evenly in methanol solution, stir for 10 h, and dry by vacuum rotary evaporation to obtain purple solid.

[0071] (4) The purple solid obtained in step (3) was calcined in a hydrogen / argon atmosphere at a temperature of 900°C for 2 hours and then naturally cooled to room temperature to obtain a carbon-supported particle-particle heterostructure catalyst, denoted as PdZn-Co / C heterostructure catalyst, wherein the content of Pd was 4wt%.

[0072] Example 2

[0073] The only difference between Example 2 and Example 1 is that the amount of palladium precursor solution used in step (3) is 1 mL, and the content of Pd in ​​the prepared PdZn-Co / C heterostructure catalyst is 2 wt%, while the rest is the same as in Example 1.

[0074] Example 3

[0075] The only difference between Example 3 and Example 1 is that the amount of palladium precursor solution used in step (3) is 3 mL, and the content of Pd in ​​the prepared PdZn-Co / C heterostructure catalyst is 6 wt%, and the rest is the same as in Example 1.

[0076] Example 4

[0077] The only difference between Example 4 and Example 1 is that the amount of palladium precursor solution used in step (3) is 4 mL, and the content of Pd in ​​the prepared PdZn-Co / C heterostructure catalyst is 8 wt%, while the rest is the same as in Example 1.

[0078] Example 5

[0079] The only difference between Example 5 and Example 1 is that the amount of palladium precursor solution used in step (3) is 5 mL, and the content of Pd in ​​the prepared PdZn-Co / C heterostructure catalyst is 10 wt%, while the rest is the same as in Example 1.

[0080] Comparative Example 1

[0081] Comparative Example 1 is a PdZn / C catalyst, which differs from Example 1 only in that no Co precursor was added during the preparation process; otherwise, it is the same as Example 1.

[0082] Comparative Example 2

[0083] Comparative Example 2 is a Co / C catalyst. The only difference between it and Example 1 is that no Pd precursor was added during the preparation process. Otherwise, it is the same as Example 1.

[0084] During calcination, Zn will completely volatilize at high temperature. If a Pd precursor is added, Pd will act as an anchor, causing some Zn to combine with Pd to form a PdZn alloy. In Comparative Example 2, Zn was added, but since no Pd was added, Zn will completely volatilize during calcination, resulting in a Co / C catalyst.

[0085] Performance testing

[0086] 1. Transmission electron microscopy test

[0087] The PdZn-Co / C heterostructure catalysts prepared in Examples 1-5 were examined using transmission electron microscopy (TEM). Taking Example 1 as an example, the PdZn-Co / C heterostructure catalyst prepared in Example 1 was observed using TEM, and the TEM image is shown below. Figure 1 As shown, the high-angle annular dark-field scanning transmission electron microscope image is as follows. Figure 2 As shown.

[0088] Depend on Figure 1 and 2 It can be observed that most nanoparticles have obvious particle-particle interfaces. Similarly, the PdZn-Co / C heterostructure catalysts prepared in Examples 2-5 of this invention also have obvious particle-particle interfaces.

[0089] In addition, the particle size distribution of the PdZn-Co / C heterostructure catalyst prepared in Example 1 was statistically analyzed. 200 particles were randomly selected, and the particle size distribution chart was obtained, as shown below. Figure 3 As shown, the PdZn-Co / C heterostructure catalysts prepared in Examples 2-5 of this invention have similar particle size distributions.

[0090] 2. X-ray diffraction analysis

[0091] The PdZn-Co / C heterostructure catalysts prepared in Examples 1-5 were analyzed using X-ray diffraction. Taking Example 1 as an example, the X-ray diffraction (XRD) pattern of the PdZn-Co / C heterostructure catalyst prepared in Example 1 is shown below. Figure 4 As shown.

[0092] Depend on Figure 4 It can be observed that the PdZn-Co / C heterostructure catalyst synthesized in Example 1 exhibits obvious characteristic peaks of the (111), (200), (002), (112), (310), and (311) PdZn alloy crystal planes, which are consistent with those of the standard PdZn alloy (JCPDS No. 06-0620), and the peak positions show no significant shift. Furthermore, characteristic diffraction peaks of the (111), (200), and (220) crystal planes, which can be attributed to Co nanoparticles (JCPDS No. 50-1443), were also detected in the sample, indicating the coexistence of Co particles and the PdZn alloy.

[0093] 3. Elemental energy dispersive spectroscopy analysis

[0094] The PdZn-Co / C heterostructure catalysts prepared in Examples 1-5 were analyzed using energy dispersive spectroscopy (EDS). Taking Example 1 as an example, the high-magnification transmission electron microscope (TEM) image and elemental energy dispersive spectroscopy (EDS) spectrum of the PdZn-Co / C heterostructure catalyst prepared in Example 1 are shown below. Figure 5 As shown. Among them, Figure 5 Figure (a) shows a high-angle annular dark-field scanning transmission electron microscope (HAADF-TEM) image of PdZn-Co / C. Figure 5 Figure (b) in the figure is the overall distribution of all elements corresponding to the HAADF-TEM image, and the red circles in Figures (a) and (b) represent PdZn alloy particles, and the blue circles represent Co particles; Figure 5 Figures (c), (d), (e), and (f) show the distribution of Pd, Zn, Co, and C elements, respectively.

[0095] Depend on Figure 5 It can be observed that the PdZn alloy particles and Co particles are tightly bonded together, confirming the existence of a Co-PdZn particle-particle heterostructure. The Pd / Zn signal intensity gradually decreases from the nanoparticles to the interface region, while the Co signal appears and is correspondingly enhanced, indicating the formation of strong particle-particle interactions at the interface.

[0096] 4. Ethanol oxidation reactivity test

[0097] Electrochemical comparative experiments were conducted using a commercial Pd / C catalyst (10% palladium by mass) produced by Sigma, the PdZn / C catalysts prepared in Comparative Examples 1 and 2, and the Co / C catalyst, compared with the PdZn-Co / C heterostructure catalysts prepared in Examples 1-5 of this invention. The specific test procedures are as follows:

[0098] The PdZn-Co / C heterostructure catalysts prepared in Examples 1-5 and the comparative catalysts (Pd / C catalyst, PdZn / C catalyst, Co / C catalyst) were used as working electrodes, respectively. A graphite electrode and a mercury / mercury oxide (Hg / HgO) electrode were used as auxiliary and reference electrodes, respectively. Nitrogen gas was bubbled through a 1 mol / L potassium argonium hydroxide solution until saturated. Then, the working electrodes were bubbled in N2 at 50 mV·s. -1 The sweep speed is between 0V and 1.2V. RHE The potential range was cyclically scanned 60 times. After electrode activation, the electrode was immersed in a nitrogen-saturated mixed solution of 1 mol / L potassium argon hydroxide and 1 mol / L ethanol at a rate of 50 mV·s. -1 The sweep speed is between 0V and 1.2V. RHE Cyclic scanning test of the potential range.

[0099] Taking the test results of Example 1 as an example, the ethanol oxidation reaction curves of the PdZn-Co / C heterostructure catalyst prepared in Example 1, the commercial Pd / C catalyst, the PdZn / C catalyst prepared in Comparative Example 1, and the Co / C catalyst prepared in Comparative Example 2 are as follows: Figure 6 As shown.

[0100] Depend on Figure 6 It can be observed that the Co / C catalyst is almost inactive. Compared with the commercial Pd / C catalyst and PdZn / C catalyst, the carbon-supported "particle-particle" heterostructure catalyst obtained in Example 1 has better ethanol oxidation activity, with mass activities that are 10.7 times and 9.1 times that of the commercial Pd / C catalyst and PdZn / C catalyst, respectively.

[0101] 5. Faraday efficiency

[0102] The carbon-supported "particle-to-particle" heterostructure catalysts prepared in Examples 1-5, a commercial Pd / C catalyst (10% palladium by mass), and the PdZn / C catalyst prepared in Comparative Example 1 were subjected to a temperature of 0.7V. REH A long-term reaction was carried out at a potential, and the products were quantitatively analyzed. Taking the test results of Example 1 as an example, the Faradaic efficiencies of the PdZn-Co / C heterostructure catalyst of Example 1, the commercial Pd / C catalyst, and the PdZn / C catalyst of Comparative Example 1 are as follows: Figure 7 As shown.

[0103] Depend on Figure 7It can be observed that, compared with traditional Pd / C catalysts and PdZn / C catalysts, the PdZn-Co / C heterostructure catalyst obtained in Example 1 exhibits higher C1 pathway selectivity at 0.7V. RHE It achieves 100% Faraday efficiency for the C1 path.

[0104] In summary, this invention, by constructing a heterostructure catalyst, particularly a particle-to-particle heterostructure of PdZn alloy particles and Co particles with strong interfacial coupling effects, can regulate interfacial electronic behavior, optimize intermediate adsorption and reaction pathways, and achieve highly efficient synergy between C / C bond cleavage and subsequent oxidation reactions. This improves the EOR catalytic activity of the heterostructure catalyst to almost 10.7 times the mass activity of traditional Pd / C catalysts, making it applicable as an anode catalyst for direct ethanol fuel cells. Furthermore, it exhibits higher C1 pathway selectivity, effectively improving the utilization rate of ethanol fuel, and has significant cost advantages, making it suitable for manufacturing ethanol fuel cells.

[0105] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A heterostructure catalyst, characterized in that, Includes a carbon support and metal particles supported on the carbon support; The metal particles include PdZn nanoalloys and Co nanoparticles; The PdZn nanoalloy and Co nanoparticles have a heterojunction interface structure.

2. The heterostructure catalyst according to claim 1, characterized in that, The mass ratio of Pd, Zn and Co elements in the metal particles is (1.6-2.5):1:(4-6).

3. The heterostructure catalyst according to claim 1, characterized in that, The PdZn nanoalloy has a particle size of 4.5-35 nm; and / or, the Co nanoparticles have a particle size of 4.5-35 nm.

4. The method for preparing the heterostructure catalyst according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Mix cobalt precursor, zinc precursor, organic ligand and solvent, react to obtain intermediate product; (2) The palladium precursor, the intermediate product obtained in step (1) and the solvent are mixed, dried and calcined to obtain the heterostructure catalyst.

5. The preparation method according to claim 4, characterized in that, In step (1), the cobalt precursor includes at least one of cobalt nitrate hexahydrate, cobalt acetate, and cobalt chloride; and / or, the zinc precursor includes at least one of zinc nitrate hexahydrate, zinc acetate, and zinc chloride; and / or, the organic ligand includes at least one of 2-methylimidazole and 2-ethylimidazole; and / or, the solvent includes methanol.

6. The preparation method according to claim 4, characterized in that, In step (1), the mass fractions of each raw material are as follows: 45-110 parts of cobalt precursor, 180-450 parts of zinc precursor, and 550-1600 parts of organic ligand.

7. The preparation method according to claim 4, characterized in that, In step (1), the reaction temperature is 75-130℃, the reaction time is 9-18h; and / or, the reaction is followed by centrifugation and drying.

8. The preparation method according to claim 4, characterized in that, In step (2), the palladium precursor includes at least one of tetrachlorodiamine palladium, palladium acetylacetonate, and palladium chloride; and / or, the solvent includes methanol.

9. The preparation method according to claim 4, characterized in that, In step (2), the mixture is stirred for 9-18 hours; and / or the calcination temperature is 750-1000℃ and the calcination time is 1.8-4.5 hours.

10. An ethanol fuel cell, characterized in that, Including the heterostructure catalyst according to any one of claims 1-3.

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