阅读说明：本技术 掺氮石墨烯负载二元铂铜核壳结构纳米催化剂、其制备方法和应用 (Nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst, and preparation method and application thereof ) 是由 周尉 徐斌 于 2021-06-11 设计创作，主要内容包括：本发明公开了一种掺氮石墨烯负载二元铂铜核壳结构纳米催化剂、其制备方法和应用,通过置换法获得二元金属核壳结构纳米粒子,再将其负载在掺氮还原氧化石墨烯上,得到掺氮石墨烯负载二元Pt-Cu核壳结构纳米粒子催化剂材料。该发明方法制备的催化剂在离子液体中表现出比铂碳更加优异的氧还原电催化活性。在电催化氧还原反应领域有着很好的应用前景。同时,该发明方法操作简单,易于控制,能够大规模的应用。(The invention discloses a nitrogen-doped graphene-loaded binary platinum copper core-shell structure nano catalyst, and a preparation method and application thereof. The catalyst prepared by the method shows more excellent oxygen reduction electrocatalytic activity in ionic liquid than platinum carbon. Has good application prospect in the field of electrocatalytic oxygen reduction reaction. Meanwhile, the method is simple to operate, easy to control and capable of being applied in a large scale.)

1. A preparation method of a nitrogen-doped graphene-loaded binary platinum copper core-shell structure nano catalyst is characterized by comprising the following steps:

(1) mixing 0.0282g of C₆H₅Na₃O₇And 0.0240g of CuSO₄·5H₂O into a 50mL three-necked flask, at least 20mL of H was added₂O, in N₂Stirring for at least 0.5h under the atmosphere to obtain a mixed solution;

weighing 70.6mg of graphene oxide, putting the graphene oxide into a 100mL clean beaker, covering the mouth of the beaker with a preservative film, putting the mixed solution on a heater with magnetic stirring, heating and reacting, and then setting the volume of the mixed solution within 30 mL;

transferring the remaining mixed solution after the treatment to a stainless steel reaction kettle with the volume of 50mL, measuring 4.4mL of concentrated ammonia water, and adding the concentrated ammonia water into the reaction kettle; then placing the reaction kettle in an oven for heating reaction to obtain nitrogen-doped reduced graphene oxide;

(2) reacting NaBH₄Dissolved in at least 10mL of ultrapure water and then added dropwise to the flask, N₂Stirring for at least 2h under the atmosphere to obtain NaBH₄A solution;

(3) adding 0.0303g of the nitrogen-doped reduced graphene oxide prepared in the step (1) to the NaBH prepared in the step (2)₄Sonicate in solution for at least 45 minutes in N₂Stirring for at least 3h under the atmosphere to obtain Cu/N-rGO;

(4) 0.1693g of Ascorbic Acid (AA) were added to the Cu/N-rGO prepared in said step (3), followed by addition of at least 0.1mLH₂PtCl₆·6H₂Adding O dropwise, heating the reaction mixture to 85 deg.C or higher, and adding N₂Keeping the atmosphere for at least 2 h; and centrifuging the reactant for at least 12 minutes, discarding the supernatant, collecting the precipitate, repeatedly washing the precipitate with ultrapure water and ethanol, and drying the precipitate overnight in a vacuum drying oven at the temperature of not lower than 60 ℃ to obtain the Pt @ Cu/N-rGO.

2. The preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst according to claim 1, which is characterized by comprising the following steps: in the step (1), the reaction temperature is not lower than 80 ℃, and the reaction time is 5-8 hours.

3. The preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst according to claim 1, which is characterized by comprising the following steps: in the step (1), the temperature heated in the oven is not lower than 150 ℃, and the reaction time is kept for at least 4 hours.

4. The preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst according to claim 1, which is characterized by comprising the following steps: in said step (2), sodium borohydride is used in an amount of at least 100 mg.

5. The preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst according to claim 1, which is characterized by comprising the following steps: in the step (3), the mass ratio of the copper to the nitrogen-doped graphene is 1: 5.

6. The preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst according to claim 1, which is characterized by comprising the following steps: in the step (4), the dosage of the chloroplatinic acid is 0.1-1.0 mL.

7. A nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst is characterized in that: the preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst is adopted to prepare the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst.

8. The application of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst is characterized in that: the nitrogen-doped graphene-supported binary platinum copper core-shell structure nano catalyst prepared by the preparation method of the nitrogen-doped graphene-supported binary platinum copper core-shell structure nano catalyst according to claim 1 is used for carrying out electrocatalytic oxygen reduction reaction in ionic liquid.

Technical Field

The invention relates to a preparation method of a nitrogen-doped graphene composite platinum-copper core-shell structure nano catalyst, which is applied to the field of electrocatalytic oxygen reduction reaction in ionic liquid.

Background

Fuel cells are a very promising green new energy device. The function of a polymer electrolyte membrane fuel cell involves the cathodic reduction of oxygen to water and fuel for anodic oxidation. The slow electron transfer kinetics of the cathodic Oxygen Reduction Reaction (ORR) requires a highly efficient electrocatalyst. The Pt-based catalyst shows excellent electrocatalytic activity in ORR, but its high cost hinders the development of the Pt-based catalyst. Therefore, it is most important to increase the catalytic activity of the platinum-based catalyst and to reduce the amount of platinum supported. Another important factor to be considered in developing a core-shell structured Pt-M nanoparticle synthesis method is to optimize the type of M atom. The type of core metal M has a significant influence on the catalytic action of the platinum shell. Different elemental compositions and atomic arrangements can alter the electronic structure of platinum, thereby affecting the catalytic activity of platinum.

Of the transition metals, copper has attracted attention due to its abundant reserves and platinum near the top of the "volcano". When copper is used as the core metal, the electronic properties of the metal shell may be changed due to the ligand effect of copper, and the electrocatalytic activity of the metal shell may be improved. The graphene-based material has excellent conductivity and a large specific surface area, and is widely applied to the field of electrocatalysis. Furthermore, nitrogen doping of the carbon material can change its own electronic structure and improve electrocatalytic activity, since the charge distribution caused by doping changes O₂The chemisorption mode of (a), weakens the O-O bonds and promotes the oxygen reduction process. Moreover, among the various types of low-cost alternative catalysts, the nitrogen-doped carbon material-supported transition metal is the most promising material in terms of catalytic activity and durability.

On the other hand, the use of an alkaline aqueous solution as the electrolyte easily causes evaporation of water in the electrolyte, and in an open cell system, the electrolyte absorbs CO in the air₂And gradually carbonating the electrolyte, thereby greatly reducing the conductivity of the electrolyte and increasing the internal resistance of the battery. Ionic liquids are salts (IL) consisting of anions and cations. Due to their high thermal and chemical stability, the problems of electrolyte volatilization and carbonation can be effectively solved.

Disclosure of Invention

In order to solve the problems in the prior art, the invention aims to overcome the defects in the prior art and provide the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst, and the preparation method and the application thereof.

In order to achieve the purpose, the invention adopts the following inventive concept:

the binary metal core-shell structure nano-particles are prepared by a simple chemical replacement method. By taking copper as a core and platinum as a shell, the catalytic performance of the catalyst can be effectively improved by the synergistic effect of the binary metals. After the nano particles are loaded on the nitrogen-doped reduced graphene oxide, the electrocatalytic oxygen reduction reaction performance of the material can be optimized

According to the inventive concept, the invention adopts the following technical scheme:

a preparation method of a nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst comprises the following steps:

(1) mixing 0.0282g of C₆H₅Na₃O₇And 0.0240g of CuSO₄·5H₂O into a 50mL three-necked flask, at least 20mL of H was added₂O, in N₂Stirring for at least 0.5h under the atmosphere to obtain a mixed solution;

weighing 70.6mg of graphene oxide, putting the graphene oxide into a 100mL clean beaker, covering the mouth of the beaker with a preservative film, putting the mixed solution on a heater with magnetic stirring, heating and reacting, and then setting the volume of the mixed solution within 30 mL;

transferring the remaining mixed solution after the treatment to a stainless steel reaction kettle with the volume of 50mL, measuring 4.4mL of concentrated ammonia water, and adding the concentrated ammonia water into the reaction kettle; then placing the reaction kettle in an oven for heating reaction to obtain nitrogen-doped reduced graphene oxide;

(2) reacting NaBH₄Dissolved in at least 10mL of ultrapure water and then added dropwise to the flask, N₂Stirring for at least 2h under the atmosphere to obtain NaBH₄A solution;

(3) adding 0.0303g of the nitrogen-doped reduced graphene oxide prepared in the step (1) to the NaBH prepared in the step (2)₄Sonicate in solution for at least 45 minutes in N₂Stirring for at least 3h under the atmosphere to obtain Cu/N-rGO;

(4) 0.1693g of Ascorbic Acid (AA) were added to the Cu/N-rGO prepared in said step (3), followed by addition of at least 0.1mLH₂PtCl₆·6H₂Adding O dropwise, heating the reaction mixture to 85 deg.C or higher, and adding N₂Keeping the atmosphere for at least 2 h; and centrifuging the reactant for at least 12 minutes, discarding the supernatant, collecting the precipitate, repeatedly washing the precipitate with ultrapure water and ethanol, and drying the precipitate overnight in a vacuum drying oven at the temperature of not lower than 60 ℃ to obtain the Pt @ Cu/N-rGO.

Preferably, in the step (1), the reaction temperature is not lower than 80 ℃ and the reaction time is 5 to 8 hours.

Preferably, in the step (1), the temperature heated in the oven is not lower than 150 ℃, and the reaction time is kept for at least 4 hours.

Preferably, in said step (2), sodium borohydride is used in an amount of at least 100 mg.

Preferably, in the step (3), the mass ratio of the copper to the nitrogen-doped graphene is 1: 5.

Preferably, in the step (4), the chloroplatinic acid is used in an amount of 0.1 to 1.0 mL.

The invention discloses a nitrogen-doped graphene-loaded binary platinum copper core-shell structure nano catalyst, which is prepared by adopting the preparation method of the nitrogen-doped graphene-loaded binary platinum copper core-shell structure nano catalyst.

The invention discloses an application of a nitrogen-doped graphene loaded binary platinum copper core-shell structure nano catalyst, which is prepared by adopting the preparation method of the nitrogen-doped graphene loaded binary platinum copper core-shell structure nano catalyst and is used for carrying out electrocatalytic oxygen reduction reaction in ionic liquid.

Compared with the prior art, the invention has the following obvious and prominent substantive characteristics and remarkable advantages:

1. the catalyst prepared by the method has smaller particle size, and has larger surface area; the catalyst prepared by the method is loaded on the nitrogen-doped reduced graphene oxide, and has better conductivity;

2. the catalyst prepared by the method has more excellent oxygen reduction catalytic performance than platinum and carbon in the ionic liquid; the catalyst prepared by the method effectively reduces the use amount of noble metal and improves the utilization rate of the noble metal;

3. the method is simple and easy to implement, low in cost and suitable for popularization and application.

Drawings

FIG. 1 is a scanning electron microscope image and a transmission electron microscope image according to an embodiment of the present invention.

Fig. 2 is an X-ray diffraction pattern of the first embodiment of the present invention.

FIG. 3 is an X-ray photoelectron spectrum according to a first embodiment of the present invention.

FIG. 4 shows a diagram of a first embodiment of the present invention₂And O₂Cyclic voltammetry test curves in saturated ionic liquids.

FIG. 5 is a plot of cyclic voltammetry measurements for example one, example two, example three, example four, and Pt/C (20 wt%).

FIG. 6 shows the results of example one, example two, example three, and example four with Pt/C (20 wt%) in O₂Saturated [ Bmim]BF₄Linear scan curve in solution.

FIG. 7 is the Tafel slope for example one, example two, example three, example four and Pt/C (20 wt%).

Detailed Description

The above-described scheme is further illustrated below with reference to specific embodiments, which are detailed below:

the first embodiment is as follows:

in this embodiment, a preparation method of a nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst includes the following steps:

(1) mixing 0.0282g of C₆H₅Na₃O₇And 0.0240g of CuSO₄·5H₂O into a 50mL three-necked flask, at least 20mL of H was added₂O, in N₂Stirring for 0.5h under the atmosphere to obtain a mixed solution;

weighing 70.6mg of graphene oxide, putting the graphene oxide into a 100mL clean beaker, covering the mouth of the beaker with a preservative film, putting the mixed solution on a heater with magnetic stirring, heating, reacting, heating to 80 ℃, keeping for 5-8 hours, and then setting the volume of the mixed solution within 30 mL;

transferring the remaining mixed solution after the treatment to a stainless steel reaction kettle with the volume of 50mL, measuring 4.4mL of concentrated ammonia water, and adding the concentrated ammonia water into the reaction kettle; then placing the reaction kettle in an oven, heating to 150 ℃ and reacting for 4 hours to obtain nitrogen-doped reduced graphene oxide;

(2) 100mg of NaBH₄Dissolved in 10mL of ultrapure water and added dropwise to the flask, N₂Stirring for 2h under the atmosphere to obtain NaBH₄A solution;

(3) adding 0.0303g of the nitrogen-doped reduced graphene oxide prepared in the step (1) to the NaBH prepared in the step (2)₄Sonication in solution for 45 minutes in N₂Stirring for 3 hours under the atmosphere to obtain Cu/N-rGO; wherein mCu: mN-rGO ═ 1: 5;

(4) 0.1693g Ascorbic Acid (AA) was added to the Cu/N-rGO prepared in step (3) and then 0.1mL H₂PtCl₆·6H₂O is added dropwise, the reaction is heated to 85 ℃ under N₂Keeping the atmosphere for 2 h; the reaction was then centrifuged for 12 minutes, the supernatant discarded, the precipitate collected, washed repeatedly with ultrapure water and ethanol, and dried in a vacuum oven at 60 ℃ overnight to give Pt @ Cu/N-rGO.

Example two

This embodiment is substantially the same as the first embodiment, and is characterized in that:

in this embodiment, a method for preparing Cu/N-rGO includes the following steps:

(1) mixing 0.0282g of C₆H₅Na₃O₇And 0.0240g of CuSO₄·5H₂O into a 50mL three-necked flask, at least 20mL of H was added₂O, in N₂Stirring for 0.5h under the atmosphere to obtain a mixed solution;

weighing 70.6mg of graphene oxide, putting the graphene oxide into a 100mL clean beaker, covering the mouth of the beaker with a preservative film, putting the mixed solution on a heater with magnetic stirring, heating, reacting, heating to 80 ℃, keeping for 5-8 hours, and then setting the volume of the mixed solution within 30 mL;

transferring the remaining mixed solution after the treatment to a stainless steel reaction kettle with the volume of 50mL, measuring 4.4mL of concentrated ammonia water, and adding the concentrated ammonia water into the reaction kettle; then placing the reaction kettle in an oven, heating to 150 ℃ and reacting for 4 hours to obtain nitrogen-doped reduced graphene oxide;

(2) 100mg of NaBH₄Dissolved in 10mL of ultrapure water and added dropwise to the flask, N₂Stirring for 2h under the atmosphere to obtain NaBH₄A solution;

(3) adding 0.0303g of the nitrogen-doped reduced graphene oxide prepared in the step (1) to the NaBH prepared in the step (2)₄Sonication in solution for 45 minutes in N₂Stirring for 3 hours under the atmosphere to obtain Cu/N-rGO; wherein mCu: mN-rGO ═ 1: 5.

EXAMPLE III

This embodiment is substantially the same as the above embodiment, and is characterized in that:

in this embodiment, a method for preparing CuNPs includes the following steps:

(1) mixing 0.0282g of C₆H₅Na₃O₇And 0.0240g of CuSO₄·5H₂O into a 50mL three-necked flask, at least 20mL of H was added₂O, in N₂Stirring for 0.5h under the atmosphere to obtain a mixed solution;

(2) 100mg of NaBH₄Dissolved in 10mL of ultrapure water and then added dropwise to the flask of step (1), N₂Stirring for 2h under the atmosphere to obtain NaBH₄A solution;

(3) adding 0.0303g of the nitrogen-doped reduced graphene oxide prepared in the step (1) to the NaBH prepared in the step (2)₄Sonication in solution for 45 minutes in N₂Stirring for 3h under the atmosphere to obtain CuNPs.

Example four

This embodiment is substantially the same as the above embodiment, and is characterized in that:

in this embodiment, a method for preparing nitrogen-doped reduced graphene oxide includes the following steps:

mixing 0.0282g of C₆H₅Na₃O₇And 0.0240g of CuSO₄·5H₂O into a 50mL three-necked flask, at least 20mL of H was added₂O, in N₂Stirring for 0.5h under the atmosphere to obtain a mixed solution;

weighing 70.6mg of graphene oxide, putting the graphene oxide into a 100mL clean beaker, covering the mouth of the beaker with a preservative film, putting the mixed solution on a heater with magnetic stirring, heating, reacting, heating to 80 ℃, keeping for 5-8 hours, and then setting the volume of the mixed solution within 30 mL;

transferring the remaining mixed solution after the treatment to a stainless steel reaction kettle with the volume of 50mL, measuring 4.4mL of concentrated ammonia water, and adding the concentrated ammonia water into the reaction kettle; and then placing the reaction kettle in an oven, heating to 150 ℃ and reacting for 4 hours to obtain the nitrogen-doped reduced graphene oxide.

EXAMPLE five

This embodiment is substantially the same as the above embodiment, and is characterized in that:

in this embodiment, an application of the nitrogen-doped graphene-supported binary platinum copper core-shell structure nano catalyst is that the nitrogen-doped graphene-supported binary platinum copper core-shell structure nano catalyst prepared by the preparation method of the nitrogen-doped graphene-supported binary platinum copper core-shell structure nano catalyst is subjected to an electrocatalytic oxygen reduction reaction in an ionic liquid.

TABLE 1 in [ Bmim ]]BF₄Comparison of electrochemical parameters of example one, example two, example three, and example four with Pt/C (20 wt%) in solution

TABLE 1 is [ Bmim ]]BF₄Comparison of electrochemical parameters of example one, example two, example three, and example four with Pt/C (20 wt%) in solution, as can be seen from the table, in the ionic liquid [ Bmim [ ]]BF₄In the middle, the oxygen reduction onset potential of Pt @ Cu/N-rGO is more positive, peak-to-peak, than the onset potentials of CuNPs, N-rGO, Cu/N-rGO and Pt/C (20 wt%)The current density was also greater than the other four catalysts.

Fig. 1 is an SEM image and a TEM image of example one. Fig. 1 shows that Pt @ Cu nanoparticles are uniformly supported on N-doped reduced graphene oxide. As can be seen from fig. 1(B), the Pt @ Cu nanoparticles are spherical or ellipsoidal, having a particle size of about 5 nm. As can be seen from FIGS. 1(C) and (D), lattice fringes with lattice spacings of 0.226nm and 0.138nm were observed at the edge regions of the Pt @ Cu nanoparticles, corresponding to the Pt (111) plane and the (220) plane (PDF #04-0802), respectively. Furthermore, as shown in fig. 1(D), the lattice spacing observed at the center of the nanoparticles was 0.153 nm, between 0.138nm and 0.158nm, indicating a small portion of alloying at the Pt shell-Cu core interface. The result shows that the surface of the Pt @ Cu nano particle is mainly a Pt (111) crystal face.

Fig. 2 is an XRD image of example one. As can be seen from fig. 2, there are three peaks at 2 θ ═ 43.2 °, 50.4 ° and 74.1 °, corresponding to the (111), (200) and (220) planes of Cu (PDF #04-0836), respectively, and the peak at 43.2 ° is stronger, indicating that the synthesized CuNPs are mainly the (111) plane. A distinct peak at 43.2 ° 2 θ can be clearly observed in Cu/N-rGO, which is attributed to the Cu (111) crystal plane. The peak at 26.3 ° 2 θ is attributed to the (002) crystal plane of carbon. In the Pt @ Cu/N-rGO composite, the metal Pt has a strong peak of 39.7 degrees and two weak peaks of 46.2 degrees, 67.8 degrees, which correspond to the (111) (200) and (220) crystal planes of Pt. Among them, the (220) crystal plane was shifted forward by about 0.4 °, indicating that the catalyst contained a small amount of metallic Cu, which had an effect on the (220) crystal plane of Pt, and peaks at 36.4 ° and 61.5 ° 2 θ were attributed to CuO or Cu₂And O. All results indicate that Pt @ Cu nanoparticles were successfully prepared and uniformly supported on N-rGO.

Fig. 3 is an XPS image of the first embodiment. Fig. 3(a) shows a Pt4f spectrum. The peaks at 73.9eV and 70.6eV correspond to Pt4f_5/2And Pt4f_7/2. The weaker peaks at 74.9eV and 71.5eV are the oxidation state peaks for Pt. Metal Pt4f_5/2And Pt4f_7/2The binding energy is remarkably reduced relative to the standard Pt4f (Pt4 f)_5/274.4eV, Pt4f_7/271.0eV) because the d-band center of Pt decreases. The high resolution spectrum of Cu 2p in FIG. 3(B) shows at 931Two peaks at 3eV and 951.2eV correspond to Cu 2p, respectively_3/2And Cu 2p_1/2. The two peaks at 933.9eV and 953.8 correspond to Cu²⁺The peaks at 941.6eV and 962.4eV are satellite peaks. FIG. 3(C) shows XPS spectra for N with pyridine-N (398.6eV), pyrrole-N (399.5eV), graphite-N (400.5eV) and Cu-N (397.6eV), respectively, the Cu-N bond probably due to the combination of uncoated Cu and N-rGO. At the same time, the high content of pyridine-N enhances the electron conductivity. As can be seen from the C1 s spectrum in fig. 3(D), C is mainly C ═ C (283.8eV), C — C (284.4eV), C — O (286.0eV) and O — C ═ C (289.2 eV). The formation of C-C bonds and C ═ C bonds is due to NaBH₄GO is reduced.

FIG. 4 shows a cross-section at N₂And O₂Saturated [ Bmim]BF₄The cyclic voltammetry test curve of example one. And N₂Saturation (black line) ratio at O₂Saturated [ Bmim]BF₄The redox peak is observed at-1.38V on the cyclic voltammogram of medium Pt @ Cu/N-rGO, and the peak current density is 1.38 mA-cm^-2。

FIG. 5 is a plot of cyclic voltammetry measurements for example one, example two, example three, example four, and Pt/C (20 wt%), with Pt @ Cu/N-rGO showing the best ORR catalytic performance. The peak current density of Pt @ Cu/N-rGO is greater than that of Pt/C (20 wt%), being-1.38 mA cm^-2About 2.26 times the Pt/C (20 wt%). Although the peak potential was slightly negative compared to Pt/C (20 wt%), the ORR onset potential was more positive (plus 140 mV). During the forward scan, an oxidation peak appears at a potential of-0.97V, with a peak current density of about 5.8 times that of Pt/C (20 wt%). The results show that Pt @ Cu/N-rGO has more excellent ORR/OER dual functionality than Pt/C (20 wt%) catalysts.

FIG. 6 is a graph at O₂Saturated [ Bmim]BF₄Linear scan curves of example one, example two, example three, example four and Pt/C (20 wt%) in solution. Of all the catalysts, Pt @ Cu/N-rGO has the best electrocatalytic activity and the limiting current density is about 0.202mA cm^-2. And the ORR onset potential of Pt @ Cu/N-rGO is shifted positive by about 95mV compared to Pt/C (20 wt%).

FIG. 7 shows the first embodiment, the second embodiment, the third embodiment,Tafel slopes for example four and Pt/C (20 wt%). The values are 452mV dec, respectively^-1、421mV dec^-1、210mV dec^-1、460mV dec^-1And 304mV dec^-1. Research shows that the oxygen reduction reaction is a reversible process in the ionic liquid, and can generate superoxide anions which can exist stably: o is₂+e-→O₂ ^·-In [ Bmim ]]BF₄When used as an electrolyte, the reversibility of ORR can be improved.

In summary, the embodiment adopts a simple replacement method to prepare the nitrogen-doped graphene-loaded Pt @ Cu shell-core nanoparticle, and shows superior oxygen reduction catalytic activity in ionic liquid compared with platinum and carbon. The material prepared by the method has excellent oxygen reduction catalytic performance and has good application prospect in the field of electrocatalytic oxygen reduction reaction. The preparation method of the nitrogen-doped graphene-loaded binary platinum-copper core-shell structure nano catalyst provided by the embodiment of the invention is applied to the technical field of electrocatalytic oxygen reduction reaction in ionic liquid. Obtaining binary metal core-shell structure nanoparticles by a displacement method, and loading the nanoparticles on nitrogen-doped reduced graphene oxide to obtain the nitrogen-doped graphene loaded binary Pt-Cu core-shell structure nanoparticle catalyst material. The catalyst prepared by the method shows more excellent oxygen reduction electrocatalytic activity in ionic liquid than platinum carbon. Has good application prospect in the field of electrocatalytic oxygen reduction reaction. Meanwhile, the method is simple to operate, easy to control and capable of being applied in a large scale.

The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the embodiments, and various changes and modifications can be made according to the purpose of the invention, and any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention shall be equivalent substitutions, as long as the purpose of the present invention is met, and the present invention shall fall within the protection scope of the present invention without departing from the technical principle and inventive concept of the present invention.