阅读说明：本技术 一种碳载铂锌纳米合金催化剂及其制备方法和应用 (Carbon-supported platinum-zinc nano alloy catalyst and preparation method and application thereof ) 是由 胡超权 蒋志成 许雪冰 邵明远 于 2021-11-03 设计创作，主要内容包括：本发明提供了一种碳载铂锌纳米合金催化剂及其制备方法和应用,所述制备方法包括：(1)将碳载体、铂化合物和锌化合物在分散液中混合和干燥,然后在还原性气氛中300～500℃还原,得到催化剂前驱体；(2)将步骤(1)所述催化剂前驱体进行电化学去合金化,得到所述碳载铂锌纳米合金催化剂。本发明将碳载体、铂化合物和锌化合物混合,在特定的温度下还原后进行去合金化,制备表面富铂的碳载铂锌纳米合金催化剂,制备方法简单,减少了铂的用量,制备得到的碳载铂锌纳米合金催化剂粒径小、分散性好、氧还原性能强、催化活性优异、稳定性良好,使用所述碳载铂锌纳米合金催化剂制备的铝空气电池具有较高的功率密度和良好的稳定性。(The invention provides a carbon-supported platinum-zinc nano alloy catalyst and a preparation method and application thereof, wherein the preparation method comprises the following steps: (1) mixing and drying a carbon carrier, a platinum compound and a zinc compound in a dispersion liquid, and then reducing at 300-500 ℃ in a reducing atmosphere to obtain a catalyst precursor; (2) and (2) carrying out electrochemical dealloying on the catalyst precursor in the step (1) to obtain the carbon-supported platinum-zinc nano alloy catalyst. According to the invention, the carbon carrier, the platinum compound and the zinc compound are mixed, and the carbon-supported platinum-zinc nano alloy catalyst with rich platinum on the surface is prepared by dealloying after reduction at a specific temperature, the preparation method is simple, the platinum dosage is reduced, the prepared carbon-supported platinum-zinc nano alloy catalyst has small particle size, good dispersibility, strong oxygen reduction performance, excellent catalytic activity and good stability, and the aluminum air battery prepared by using the carbon-supported platinum-zinc nano alloy catalyst has higher power density and good stability.)

1. A preparation method of a carbon-supported platinum-zinc nano alloy catalyst is characterized by comprising the following steps:

(1) mixing a carbon carrier, a platinum compound and a zinc compound in a dispersion liquid, drying, and then reducing at 300-500 ℃ in a reducing atmosphere to obtain a catalyst precursor;

(2) and (2) carrying out electrochemical dealloying on the catalyst precursor in the step (1) to obtain the carbon-supported platinum-zinc nano alloy catalyst.

2. The preparation method according to claim 1, wherein the molar ratio of the platinum compound to the zinc compound in the step (1) is 1 (0.1-2);

the mass ratio of platinum to the carbon carrier in the platinum compound is 1 (2.5-100);

the mass-volume ratio of the carbon carrier to the dispersion liquid is 1 (0.1-2) mg/mL.

3. The method according to claim 1, wherein the carbon support of step (1) comprises any one or a combination of at least two of VXC-72 type carbon black, graphene, carbon nanotubes, or ketjen black.

4. The method according to claim 1, wherein the mixing in step (1) is carried out in the following manner:

adding the carbon carrier into the dispersion liquid, adding the platinum compound and the zinc compound after uniform ultrasonic dispersion, and performing ultrasonic dispersion again.

5. The preparation method according to claim 1, wherein the temperature of the reduction in the step (1) is 350 to 450 ℃;

the reduction time in the step (1) is 1-6 h;

the gas in the reducing atmosphere in the step (1) is hydrogen and argon, and the volume ratio of the hydrogen to the argon is 1 (1-20).

6. The method of claim 1, wherein the electrochemical dealloying of step (2) is performed in the following manner:

mixing the catalyst precursor in the step (1) with a solvent to obtain slurry, dripping the slurry on a working electrode, and scanning the potential;

the potential range of the potential scanning is-0.214-0.936V;

the scanning speed of the potential scanning is 50-500 mV/s;

the scanning number of the potential scanning is 10-500 circles.

7. The carbon-supported platinum-zinc nano alloy catalyst is characterized by being prepared by the preparation method of any one of claims 1 to 6, and comprising a carbon carrier and platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles.

8. The carbon-supported platinum-zinc nano alloy catalyst according to claim 7, wherein the content of platinum element in the carbon-supported platinum-zinc nano alloy catalyst is 1-40 wt% based on 100% by mass of the carbon-supported platinum-zinc nano alloy catalyst;

the content of zinc element in the carbon-supported platinum-zinc nano alloy catalyst is 0.3-40 wt% based on 100% of the mass of the carbon-supported platinum-zinc nano alloy catalyst;

the shape of the platinum-zinc nano alloy particles is spherical;

the average particle size of the platinum-zinc nano alloy particles is 1.5-5 nm.

9. An aluminum air cell comprising an anode, a cathode and an electrolyte, wherein the cathode comprises the carbon-supported platinum zinc nanoalloy catalyst of claim 7 or 8.

10. The aluminum-air battery according to claim 9, wherein the electrolyte comprises any one of a sodium chloride solution, a potassium chloride solution, or a calcium chloride solution, or a mixed solution of at least two of them;

the concentration of the electrolyte is greater than or equal to 3 mol/L.

Technical Field

The invention belongs to the technical field of new energy, relates to a cathode oxygen reduction catalyst for a metal-air battery, and particularly relates to a carbon-supported platinum-zinc nano alloy catalyst and a preparation method and application thereof.

Background

The aluminum-air battery as an energy storage device has the advantages of high energy density, low manufacturing cost, large capacity, stable discharge voltage and the like, and has great development potential in the fields of new energy automobiles, emergency power supplies and the like. One focus of aluminum air cells is to obtain efficient and inexpensive oxygen reduction catalysts. The platinum group catalysts most commonly used at present have high activity and stability in the electrochemical reaction process, but due to the limited resources and high cost of platinum, it is necessary to reduce the platinum loading of the platinum-based catalysts.

At present, the method for reducing the platinum load in the platinum-based catalyst at home and abroad mainly comprises alloying, namely alloying platinum and transition metal, optimizing the catalytic performance of the catalyst and reducing the cost to obtain the catalyst with catalytic activity much higher than that of pure platinum nanoparticles.

CN103035930A discloses a bifunctional catalyst for a lithium-air battery, which takes a metal oxide with a catalytic oxygen precipitation function as a carrier and then loads a noble metal with a catalytic oxygen reduction function as an active component, thereby solving the problem of single function of the existing catalyst and improving the performance of the battery. CN102593472B discloses an active particle-containing catalyst comprising a core having a first metal tungsten oxide and a shell comprising an alloy of a second metal and the reduction product of the first metal oxide, which combines a plurality of alloys, improving the electrochemical performance of the cell. CN110265679A discloses a substituted platinum-phosphorus alloy catalyst, which uses phosphorus atoms to replace the lattice positions of platinum atoms, and improves the activity and stability of the catalyst.

The technical scheme adopts a transition metal alloying mode to reduce the content of noble metal and improve the performance of the catalyst; however, the preparation method of the catalyst not only enables the platinum content in the catalyst to be low, most of the platinum to be located in the catalyst, but also enables the morphology of the catalyst to be poor, and reduces the catalytic activity of the catalyst, so that the development of the platinum-based alloy catalyst for the metal-air battery, which has the advantages of simple process, low cost and high catalytic activity and can be produced in a large scale, is urgently needed.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a carbon-supported platinum-zinc nano alloy catalyst and a preparation method and application thereof. According to the invention, the carbon-supported platinum-zinc nano alloy catalyst with rich platinum on the surface is prepared by mixing the carbon carrier, the platinum compound and the zinc compound, reducing the mixture at a specific temperature and then dealloying the mixture, the preparation method is simple, the platinum dosage is reduced, large-scale production is facilitated, the prepared carbon-supported platinum-zinc nano alloy catalyst has the advantages of small particle size, good dispersibility, strong oxygen reduction performance, excellent catalytic activity and good stability, and an aluminum air battery prepared by using the carbon-supported platinum-zinc nano alloy catalyst has higher power density and good stability.

The "platinum-rich" in the present invention means that the content of platinum element outside the platinum-zinc nano alloy particles in the carbon-supported platinum-zinc nano alloy catalyst is higher than the content of platinum element inside the platinum-zinc nano alloy particles.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) mixing a carbon carrier, a platinum compound and a zinc compound in a dispersion liquid, drying, and then reducing at 300-500 ℃ in a reducing atmosphere to obtain a catalyst precursor;

(2) and (2) carrying out electrochemical dealloying on the catalyst precursor in the step (1) to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The temperature of the reduction in the step (1) of the present invention is 300 to 500 ℃, and may be, for example, 300 ℃, 320 ℃, 350 ℃, 380 ℃, 400 ℃, 450 ℃, or 500 ℃.

According to the invention, a carbon carrier, a platinum compound and a zinc compound are mixed and reduced at low temperature in a reducing atmosphere, wherein after noble metal platinum and transition metal zinc are alloyed, the oxygen reduction activity can be obviously improved due to compressive strain and an electronic ligand effect, the consumption of platinum is greatly reduced, the carbon carrier can improve the dispersibility of platinum and zinc, and a three-dimensional structure is constructed; meanwhile, the reduction is carried out at a specific temperature, so that the obtained catalyst precursor has smaller particle size and better size uniformity, is uniformly dispersed, and is beneficial to subsequent treatment. After the catalyst precursor with good size is subjected to electrochemical dealloying, platinum is concentrated on the surface of the catalyst, a catalytic activity center can be exposed to the maximum extent, and the prepared carbon-supported platinum-zinc nano alloy catalyst is small in particle size, multiple in active site, good in dispersity, high in oxygen reduction performance and remarkably superior to the catalytic activity and stability of the traditional platinum-based catalyst.

In a preferred embodiment of the present invention, the molar ratio of the platinum compound and the zinc compound in step (1) is 1 (0.1 to 2), and may be, for example, 1:0.1, 1:0.2, 1:0.3, 1:0.5, 1:0.8, 1:1, 1:1.1, 1:1.2, 1:1.5, 1:1.8, or 1:2.

The mass ratio of platinum to the carbon carrier in the platinum compound is 1 (2.5-100), and may be, for example, 1:2.5, 1:2.6, 1:3, 1:4, 1:6, 1:8, 1:10, 1:20, 1:30, 1:50, 1:80, or 1:100, and when the platinum content in the platinum compound is relatively high, the particle size and dispersibility of the carbon-supported platinum-zinc nano alloy catalyst are affected.

The mass-to-volume ratio of the carbon carrier to the dispersion is 1 (0.1 to 2) mg/mL, and may be, for example, 1:0.1mg/mL, 1:0.2mg/mL, 1:0.3mg/mL, 1:0.5mg/mL, 1:0.8mg/mL, 1:1mg/mL, 1:1.1mg/mL, 1:1.2mg/mL, 1:1.3mg/mL, 1:1.5mg/mL, 1:1.8mg/mL, 1:2mg/mL or the like; the mass-to-volume ratio in the present invention means a ratio of the mass of the carbon support to the volume of the dispersion, and for example, 1:0.1mg/mL means that the volume of the dispersion is 0.1mL when the mass of the carbon support is 1 mg.

As a preferred embodiment of the present invention, the carbon carrier in step (1) comprises any one or a combination of at least two of VXC-72 type carbon black, graphene, carbon nanotubes, and ketjen black, and may be, for example, a combination of VXC-72 type carbon black and graphene, a combination of graphene and carbon nanotubes, a combination of carbon nanotubes and ketjen black, or a combination of VXC-72 type carbon black, graphene, carbon nanotubes, and ketjen black.

The present invention is not limited to the kinds of the platinum compound and the zinc compound, and in one embodiment, the platinum compound in the step (1) may include any one or a combination of at least two of chloroplatinic acid, platinum nitrate, platinum acetylacetonate, and potassium chloroplatinate, and for example, the platinum compound may be a combination of chloroplatinic acid and platinum nitrate, a combination of platinum nitrate and platinum acetylacetonate, a combination of platinum acetylacetonate and potassium chloroplatinate, a combination of chloroplatinic acid, platinum nitrate, platinum acetylacetonate, and potassium chloroplatinate, or the like.

In one embodiment, the zinc compound in step (1) comprises any one or a combination of at least two of zinc nitrate, zinc chloride or zinc hydroxide, and may be, for example, a combination of zinc nitrate and zinc chloride, a combination of zinc chloride and zinc hydroxide, a combination of zinc nitrate and zinc hydroxide, or a combination of zinc nitrate, zinc chloride and zinc hydroxide.

As a preferred embodiment of the present invention, the mixing in step (1) is carried out in the following manner:

adding the carbon carrier into the dispersion liquid, adding the platinum compound and the zinc compound after uniform ultrasonic dispersion, and performing ultrasonic dispersion again.

In the invention, the carbon carrier is added into the dispersion liquid and then mixed with the platinum compound and the zinc compound, so that the agglomeration can be reduced, and the dispersibility of the mixture can be improved.

As a preferable technical scheme of the invention, the reduction temperature in the step (1) is 350-450 ℃.

The reduction time in the step (1) is 1-6 h, for example, 1h, 1.5h, 2h, 2.5h, 3h, 4h, 5h or 6 h; in order to better achieve the reduction effect and improve the appearance of the catalyst, the reduction time is preferably 3-4 h.

The gas in the reducing atmosphere in the step (1) is hydrogen and argon, the volume ratio of the hydrogen to the argon is 1 (1-20), and the volume ratio can be 1:1, 1:2, 1:3, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18 or 1:20, and the like; in order to better adjust the reduction rate and adjust the morphology of the catalyst, the volume ratio of the hydrogen to the argon is further preferably 1 (1-3).

The reduction temperature and atmosphere in the invention can influence the size and the dispersity of the prepared carbon-supported platinum-zinc nano alloy catalyst. When the reduction temperature is higher, the platinum-zinc nano alloy particles in the carbon-supported platinum-zinc nano alloy catalyst are agglomerated, the size of the catalyst particles is increased, the comprehensive performance of the catalyst is reduced, and when the reduction temperature is lower, the reduction effect is deviated. When the reducing atmosphere is a combined gas of hydrogen and argon, a better reducing effect can be achieved.

As a preferred technical scheme of the invention, the electrochemical dealloying in the step (2) is carried out according to the following modes:

and (2) mixing the catalyst precursor in the step (1) with a solvent to obtain slurry, dripping the slurry on a working electrode, and carrying out potential scanning.

The potential range of the potential scanning is-0.214-0.936V, for example, -0.214-0.5V, -0.214-0.6V, -0.214-0.7V, -0.214-0.8V, -0.214-0.936V, -0.2-0.5V, -0.15-0.6V, -0.15-0.8V, -0.2-0.936V, -0.15-0.936V, -0.1-0.936V or-0.214-0.936V, and the like.

The scanning rate of the potential scanning is 50-500 mV/s, for example, 50mV/s, 80mV/s, 100mV/s, 150mV/s, 200mV/s, 300mV/s, 400mV/s or 500mV/s, etc., when the scanning rate is lower, the dealloying degree is poor, and when the scanning rate is higher, the morphology of the catalyst is damaged, and the performance of the catalyst is influenced.

The scanning number of the potential scanning is 10-500 circles, for example, 10 circles, 15 circles, 20 circles, 30 circles, 50 circles, 100 circles, 200 circles, 300 circles, 400 circles or 500 circles, and the like, if the scanning number is too many, a platinum-rich shell layer is thicker, so that platinum is gathered, lattice compression is relieved, and the electro-catalytic performance of the catalyst is affected.

In a second aspect, the invention provides a carbon-supported platinum-zinc nano alloy catalyst, which is prepared by the preparation method of the first aspect, and the carbon-supported platinum-zinc nano alloy catalyst comprises a carbon carrier and platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the content of platinum elements outside the platinum-zinc nano alloy particles is higher than the content of platinum elements inside the platinum-zinc nano alloy particles.

The carbon-supported platinum-zinc nano alloy catalyst provided by the invention has the advantages that noble metal platinum and transition metal zinc are alloyed, so that the oxygen reduction activity can be improved, and the consumption of platinum can be reduced; meanwhile, the surface of the platinum-zinc nano alloy particle is an atomic layer rich in platinum, so that the oxygen reduction performance is further improved, and the prepared catalyst has the advantages of small particle size, high size uniformity, high dispersibility, high oxygen reduction performance, excellent catalytic activity and high stability.

In a preferred embodiment of the present invention, the content of platinum element in the carbon-supported platinum-zinc nano alloy catalyst is 1 to 40wt%, for example, 1wt%, 2wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, or 40wt%, based on 100% by mass of the carbon-supported platinum-zinc nano alloy catalyst.

The content of zinc element in the carbon-supported platinum-zinc nano alloy catalyst is 0.3 to 40wt%, for example, 0.3wt%, 0.5wt%, 1wt%, 2wt%, 5wt%, 10wt%, 15wt%, 20wt%, 30wt%, or 40wt%, based on 100% by mass of the carbon-supported platinum-zinc nano alloy catalyst.

The shape of the platinum-zinc nano alloy particles is spherical.

The average particle size of the platinum-zinc nano alloy particles is 1.5-5 nm, for example, the average particle size can be 1.5nm, 2nm, 2.5nm, 3nm, 3.5nm, 4nm, 4.5nm or 5nm, and the like, and the small particle size can provide more active sites for catalysis.

In a third aspect, the invention provides an aluminium-air battery comprising an anode, a cathode and an electrolyte, the cathode comprising the carbon-supported platinum-zinc nanoalloy catalyst of the second aspect.

The carbon-supported platinum-zinc nano alloy catalyst is applied to the preparation of the cathode material of the aluminum-air battery, and the prepared aluminum-air battery has higher power density and good cycle stability.

As a preferred embodiment of the present invention, the electrolyte includes any one of a sodium chloride solution, a potassium chloride solution, and a calcium chloride solution, or a mixed solution of at least two of them.

The concentration of the electrolyte is not less than 3mol/L, and may be, for example, 3mol/L, 3.5mol/L, 4mol/L, 5mol/L, 10mol/L, 20mol/L, or 30 mol/L.

When the catalyst is applied to the aluminum-air battery, the electrolyte is generally acidic electrolyte and alkaline electrolyte, which can bring about serious hydrogen evolution self-corrosion problem, lead to corrosion and passivation of the aluminum surface, reduce the capacity and discharge efficiency of the battery, and restrict the development of the aluminum-air battery. The electrolyte in the invention is preferably neutral high-concentration salt solution, the concentration of the electrolyte is more than 3mol/L, the problem of reaction of zinc atoms in acidic and alkaline electrolytes can be effectively solved, the problem of hydrogen evolution self-corrosion of electrodes can be obviously inhibited, the electrolyte can be normally used at low temperature, and the electrolyte has potential application prospect in aluminum-air batteries.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, the carbon carrier, the platinum compound and the zinc compound are mixed and reduced, wherein after noble metal platinum and transition metal zinc are alloyed, the oxygen reduction activity can be obviously improved due to compressive strain and electronic ligand effect, the consumption of platinum is greatly reduced, the carbon carrier can improve the dispersibility of platinum and zinc, and a three-dimensional structure is constructed; meanwhile, the reduction is carried out at a specific temperature, so that the obtained catalyst precursor has smaller particle size and better size uniformity, is uniformly dispersed, and is beneficial to subsequent treatment. After the catalyst precursor with good size is subjected to electrochemical dealloying, platinum is concentrated on the surface of the catalyst, a catalytic activity center can be exposed to the maximum extent, and the prepared carbon-supported platinum-zinc nano alloy catalyst is small in particle size, multiple in active site, good in dispersity, high in oxygen reduction performance and remarkably superior to the catalytic activity and stability of the traditional platinum-based catalyst.

Drawings

Fig. 1 is a TEM image of a carbon-supported platinum-zinc nano-alloy catalyst provided in example 1 of the present invention.

Fig. 2 is a particle size distribution diagram of the carbon supported platinum-zinc nano-alloy catalyst provided in example 1 of the present invention.

Fig. 3 is an XRD spectrum of the carbon supported platinum-zinc nano-alloy catalyst provided in example 1 of the present invention.

Fig. 4 is a TEM image of the carbon supported platinum-zinc nano alloy catalyst provided in example 3 of the present invention.

Fig. 5 is a TEM image of the carbon supported platinum-zinc nano-alloy catalyst provided in example 7 of the present invention.

FIG. 6 is a comparison graph of cyclic voltammetry curves of carbon-supported platinum-zinc nano-alloy catalysts provided in examples 1-2, comparative example 1 and comparative example 5 of the present invention.

Fig. 7 is a cyclic voltammogram of a durability test of the carbon-supported platinum-zinc nano-alloy catalyst provided in example 1 of the present invention.

FIG. 8 is a comparison graph of oxygen reduction polarization curves of the carbon-supported platinum-zinc nano-alloy catalysts provided in examples 1-2 and comparative example 5 of the present invention.

FIG. 9 is a comparison graph of current density-voltage and current density-power density curves of the carbon-supported platinum-zinc nano alloy catalysts provided in examples 1-2, comparative example 1 and comparative example 5 of the present invention.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 400 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano-alloy catalyst Pt prepared in the embodiment₃Zn/C comprises a carbon carrier and spherical platinum-zinc nano alloy particles Pt loaded on the carbon carrier₃Zn, the spherical Pt-Zn nano alloy particles₃The average grain diameter of Zn is 1.88nm, and the platinum-zinc nano alloy particles Pt₃The content of the platinum element outside Zn is higher than that of the platinum-zinc nano alloy particles Pt₃The content of platinum element in Zn, and the carbon-supported platinum-zinc nano alloy catalyst Pt₃The mass of Zn/C is 100 percent, and the carbon-supported platinum-zinc nano alloy catalyst Pt₃The content of platinum element in Zn/C is 10wt%, and the content of zinc element is 1.11 wt%.

FIG. 1 shows the carbon-supported Pt-Zn nano-alloy catalyst Pt prepared in this example₃TEM image of Zn/C, from which spherical Pt/Zn nano-alloy particles Pt can be seen₃Zn is uniformly loaded on carbon, figure 2 is a size distribution diagram of carbon-loaded platinum-zinc nano alloy catalyst particles provided by the embodiment 1 of the invention, and spherical platinum-zinc nano alloy particles Pt can be seen from the figure₃The Zn size is smaller, and more electrochemical active area can be provided.

FIG. 3 shows the carbon-supported Pt-Zn nano-alloy catalyst Pt prepared in this example₃XRD (X-ray diffraction) spectrum of Zn/C, and XRD characterization results show the peak type, peak position and Pt of metal₃The peak position of the Zn standard card is well corresponded, and no independent Pt peak and Zn peak appear, which indicates that the product component is Pt₃Zn alloy, the prepared product has high alloy degree and no impurity peak; the peak around 25 degrees is the position of the peak corresponding to carbon, and the product is shown asPt₃Zn/C。

Example 2

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.41mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 400 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst PtZn/C prepared in this embodiment includes a carbon carrier and spherical platinum-zinc nano alloy particles PtZn supported on the carbon carrier, the particle size of the spherical platinum-zinc nano alloy particles PtZn is 2.27nm, the content of platinum element outside the platinum-zinc nano alloy particles PtZn is higher than the content of platinum element inside the platinum-zinc nano alloy particles PtZn, and the content of platinum element in the carbon-supported platinum-zinc nano alloy catalyst PtZn/C is 10wt% and the content of zinc element is 3.33wt% based on 100% of the mass of the carbon-supported platinum-zinc nano alloy catalyst PtZn/C.

Example 3

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 110mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 400 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 4.32nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 40wt%, and the content of zinc elements is 4.48 wt%.

Fig. 4 is a TEM image of the carbon-supported platinum-zinc nano alloy catalyst prepared in this example, and it can be seen from the figure that decreasing the content of the carbon support and increasing the mass ratio of platinum to the carbon support in the platinum compound increases the agglomeration of the catalyst, resulting in an increase in the particle size.

Example 4

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 1600mg of VXC-72 carbon black into 10mL of a mixed solvent of absolute ethyl alcohol and isopropanol with the volume ratio of 1:1, performing ultrasonic dispersion for 30min, adding 0.41mmol of platinum nitrate solution and 0.61mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 1:3 at 350 ℃ for 6h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 2.05nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that inside the platinum-zinc nano alloy particles, and based on 100% of the mass of the carbon-supported platinum-zinc nano alloy catalyst, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 4.8wt%, and the content of zinc elements is 2.4 wt%.

Example 5

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 300mg of graphene into 10mL of absolute ethyl alcohol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of chloroplatinic acid solution and 0.137mmol of zinc hydroxide solution, and performing ultrasonic dispersion for 30min again to obtain dispersion liquid slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 80 ℃ for 6h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 1:2 at 450 ℃ for 1h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, and dripping the slurry on a glassy carbon electrode to obtain the catalyst precursorOn the working electrode, silver/silver chloride electrode as reference electrode, platinum sheet as counter electrode, 0.1M HClO saturated in nitrogen₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 3.37nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than the content of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 20wt%, and the content of zinc elements is 2.22 wt%.

Example 6

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a 50 ℃ vacuum drying oven for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 450 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 2.47nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 10wt%, and the content of zinc elements is 1.11 wt%.

Example 7

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a 50 ℃ vacuum drying oven for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 500 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 3.15nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 10wt%, and the content of zinc elements is 1.11 wt%.

Fig. 5 is a TEM image of the carbon-supported platinum-zinc nano-alloy catalyst prepared in this example, and it can be seen from the TEM image that the platinum-zinc nano-alloy particle agglomeration phenomenon is increased and the catalyst particle size is increased, so that the performance is reduced.

Example 8

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 400 ℃ for 2h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 1.96nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than the content of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 10wt%, and the content of zinc elements is 1.11 wt%.

Example 9

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 2:3 at 400 ℃ for 5h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 4.32nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 10wt%, and the content of zinc elements is 1.11 wt%.

Example 10

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in a mixed atmosphere of hydrogen and argon at a volume ratio of 1:9 at 400 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄And (3) carrying out potential scanning in the solution, wherein the scanning range of the potential scanning is-0.214-0.936V, the scanning speed is 500mV/s, and the number of scanning circles is 200 circles, so as to obtain the carbon-supported platinum-zinc nano alloy catalyst.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 2.01nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 10wt%, and the content of zinc elements is 1.11 wt%.

Example 11

The embodiment provides a preparation method of a carbon-supported platinum-zinc nano alloy catalyst, which comprises the following steps:

(1) adding 710mg of VXC-72 carbon black into 10mL of absolute ethanol, performing ultrasonic dispersion for 30min, then adding 0.41mmol of platinum nitrate solution and 0.137mmol of zinc nitrate solution, and performing ultrasonic dispersion for 30min again to obtain dispersion slurry;

(2) drying the dispersion slurry obtained in the step (1) in a vacuum drying oven at 50 ℃ for 12h, reducing in hydrogen at 400 ℃ for 3h, and cooling to 25 ℃ to obtain a catalyst precursor;

(3) preparing the catalyst precursor obtained in the step (1) into slurry, dripping the slurry on a glassy carbon electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, and performing nitrogen saturation on 0.1M HClO₄The potential scan is carried out in the solution,and the scanning range of potential scanning is-0.214-0.936V, the scanning rate is 500mV/s, and the number of scanning turns is 200 circles, so that the carbon-supported platinum-zinc nano alloy catalyst is obtained.

The carbon-supported platinum-zinc nano alloy catalyst prepared by the embodiment comprises a carbon carrier and spherical platinum-zinc nano alloy particles loaded on the carbon carrier, wherein the average particle size of the spherical platinum-zinc nano alloy particles is 2.36nm, the content of platinum elements outside the platinum-zinc nano alloy particles is higher than that of platinum elements inside the platinum-zinc nano alloy particles, and by taking the mass of the carbon-supported platinum-zinc nano alloy catalyst as 100%, the content of platinum elements in the carbon-supported platinum-zinc nano alloy catalyst is 10wt%, and the content of zinc elements is 1.11 wt%.

Comparative example 1

The catalyst prepared was the same as in example 1 except that no zinc nitrate solution was added in step (1), and was designated as Pt/C-400 ℃.

Comparative example 2

The procedure of example 1 was repeated except that the operation of step (3) was not conducted.

Comparative example 3

The same procedure as in example 1 was repeated except that the temperature for the reduction in step (2) was 200 ℃.

Comparative example 4

The same procedure as in example 1 was repeated except that the temperature for the reduction in step (2) was 600 ℃.

Comparative example 5

This comparative example provides a commercial Pt/C catalyst (JM Hispec 4000) having a Pt content of 40 wt%.

The catalysts of examples 1 to 11 and comparative examples 1 to 5 were subjected to cyclic voltammetry and oxygen reduction activity tests. Then, the catalysts of examples 1 to 11 and comparative examples 1 to 5 were used as a cathode catalyst, an aluminum sheet was used as an anode, and a sodium chloride solution having a concentration of 23.1wt% was used as an electrolyte to prepare an aluminum-air battery, and the power of the prepared aluminum-air battery was tested.

Firstly, cyclic voltammetry testing: adding 600 μ L deionized water, 400 μ L ethanol and 20 μ L Nafion into 10mg catalyst to obtain catalyst ink, and dripping the inkUsing glassy carbon electrode as working electrode, silver/silver chloride electrode as reference electrode, platinum sheet as counter electrode, and 0.1M HClO saturated in nitrogen₄Potential sweeps were run at 50mV/s in the solution and current-voltage data were recorded for each catalyst. The catalyst stability test is also a cyclic voltammetry test method, and is characterized in that the sweep rate is increased to a rate of 500mV/s to carry out cyclic voltammetry scanning, and the current-voltage data of the first circle, 1000 circles, 3000 circles and 5000 circles of different catalysts are respectively recorded.

FIG. 6 is a comparison graph of cyclic voltammetry curves of carbon-supported platinum-zinc nano alloy catalysts provided in examples 1-2, comparative example 1 and comparative example 5 of the present invention, and it can be seen from the graph that the catalyst Pt in example 1₃The electrochemical active areas of Zn/C and the catalyst PtZn/C in the embodiment 2 are obviously higher than that of Pt/C-400 ℃ in the comparative example 1 and commercial Pt/C in the comparative example 5, which shows that the carbon-supported platinum-zinc nano alloy catalyst prepared by the preparation method has more active sites, can improve the catalytic activity of the catalyst, and cannot achieve the technical effect of the invention without adding zinc compounds or carrying out electrochemical dealloying treatment.

FIG. 7 is a cyclic voltammogram of a durability test of the carbon-supported platinum-zinc nano-alloy catalyst prepared in example 1 of the present invention, catalyst Pt in example 1₃The differences of the cyclic voltammetry curves of Zn/C after 1000, 3000 and 5000 cycles of circulation are not large, which shows that the carbon-supported platinum-zinc nano alloy catalyst prepared by the invention has better cyclic stability.

In comparative examples 1-2, zinc nitrate solution is not added and electrochemical dealloying treatment is not performed, so that the prepared carbon-supported platinum-zinc nano alloy catalyst is poor in catalytic effect and stability after multiple cycles; in the comparative example 3, the reduction temperature is too low, so that the platinum compound and the zinc compound cannot be sufficiently reduced, impurities are contained in the catalyst, and the circulation stability of the catalyst is influenced, while in the comparative example 4, the platinum-zinc alloy particles are agglomerated together due to too high reduction temperature, the morphology is poor, and the circulation stability of the catalyst is influenced; the commercial Pt/C catalyst of comparative example 5 also had poor cycle stability.

Two, oxygen reductionAnd (3) activity test: coating catalyst ink on a disk electrode as a working electrode, a silver/silver chloride electrode as a reference electrode, a platinum sheet counter electrode, wherein the rotation speed of the disk electrode is 1600rpm, and the disk electrode is saturated with oxygen and is 0.1M HClO₄The potential was swept in the solution at 10mV/s and the current-voltage data for the different catalysts were recorded using linear sweep voltammetry. The corresponding potential is a half-wave potential when the current density is 1/2 of the limiting current density, the half-wave potential represents the oxygen reduction activity of the catalyst, and the test result is shown in table 1.

TABLE 1

	Half-wave potential (V)
		Example 1	0.92
Example 2	0.88
		Example 3	0.85
Example 4	0.82
		Example 5	0.83
Example 6	0.84
		Example 7	0.82
Example 8	0.84
		Example 9	0.83
Example 10	0.84
		Example 11	0.85
Comparative example 1	0.81
		Comparative example 2	0.80
Comparative example 3	0.77
		Comparative example 4	0.78
Comparative example 5	0.84

As can be seen from table 1, the carbon-supported platinum-zinc nano alloy catalyst with a platinum-rich surface prepared by mixing a carbon support, a platinum compound and a zinc compound, reducing the mixture at a specific temperature and then dealloying the mixture can improve the oxygen reduction activity of the catalyst.

FIG. 8 is a graph comparing oxygen reduction polarization curves of carbon-supported platinum-zinc nano-alloy catalysts provided in examples 1-2 and comparative example 5 of the present invention, and it can be seen from FIG. 8 that in comparative example 5, commercial platinum-zinc nano-alloy catalystThe half-wave potential of the Pt/C catalyst was lower than that of Pt in example 1₃Zn/C and PtZn/C in example 2 show that the carbon-supported platinum-zinc nano alloy catalysts prepared in the invention in the examples 1 and 2 have high oxygen reduction activity.

As can be seen from the comparison between example 3 and example 1, when the mass ratio of platinum to carbon carrier in the platinum compound is higher, part of the platinum-zinc nano-alloy particles agglomerate and affect the catalytic activity of the carbon-supported platinum-zinc nano-alloy catalyst, so the half-wave potential of example 3 is lower than that of example 1.

It can be known from comparison between examples 6 to 9 and example 1 that the reduction temperature and time can affect the catalytic activity of the carbon-supported platinum-zinc nano alloy catalyst, and when the reduction temperature is higher or the reduction time is longer, zinc in the carbon-supported platinum-zinc nano alloy catalyst is easy to dissolve and agglomerate, so that the morphology of the catalyst can be affected, and the catalytic activity of the catalyst can be reduced; when the reduction temperature is low or the reduction time is short, the zinc compound and the platinum compound cannot be completely reduced, and the catalytic effect of the catalyst is reduced, so that the half-wave potential of the embodiment 1 is higher than that of the embodiments 6 to 9.

It can be known from comparison between examples 10 to 11 and example 1 that the reducing atmosphere affects the catalytic activity of the carbon-supported platinum-zinc nano alloy catalyst, when the volume ratio of hydrogen to argon in the atmosphere is relatively low, the content of argon in the atmosphere is relatively high, the zinc compound and the platinum compound cannot be completely reduced, the morphology of the catalyst can be better regulated and controlled by mixing the two gases in a relatively proper proportion in example 1, the synthesized catalyst has a more proper particle size, and better catalytic activity is obtained.

As can be seen from the comparison between comparative example 1 and example 1, when no zinc is contained in the carbon-supported platinum-zinc nano-alloy catalyst, only platinum in the catalyst functions, and the catalytic activity of the catalyst is weak.

It can be seen from the comparison between comparative example 2 and example 1 that when the carbon-supported platinum-zinc nano-alloy catalyst is not subjected to alloying treatment, the platinum content on the surface of the catalyst is low, and the catalytic activity of the catalyst is poor.

As can be seen from comparison between comparative examples 3-4 and example 1, the reduction temperature affects the catalytic performance of the carbon-supported platinum-zinc nano alloy catalyst, when the reduction temperature is too high, the catalyst is agglomerated, and when the reduction temperature is too low, the platinum compound and the zinc compound in the catalyst cannot be completely reduced, which affects the catalytic performance, so that the half-wave potential of example 1 is higher and the catalytic activity is better than that of comparative examples 3-4.

Thirdly, power testing: respectively taking 10mg of the catalysts prepared in examples 1-11 and comparative examples 1-5 to prepare a cathode material of an air battery, taking an aluminum sheet as an anode and taking a 23.1wt% sodium chloride solution as an electrolyte, recording a current-voltage curve of the catalyst on an electrochemical workstation by using a linear sweep voltammetry after the battery is assembled, and calculating a corresponding current-power curve. The test results are shown in table 2.

TABLE 2

	Peak power density (mW cm)-2)
		Example 1	140
Example 2	108
		Example 3	105
Example 4	100
		Example 5	103
Example 6	105
		Example 7	106
Example 8	104
		Example 9	103
Example 10	104
		Example 11	105
Comparative example 1	110
		Comparative example 2	99
Comparative example 3	97
		Comparative example 4	99
Comparative example 5	105

As can be seen from table 2, the carbon-supported platinum-zinc nano alloy catalyst with a platinum-rich surface prepared by mixing a carbon carrier, a platinum compound and a zinc compound, reducing the mixture at a specific temperature and then dealloying the mixture can improve the power density of the catalyst.

FIG. 9 is a graph comparing current density-voltage and current density-power density curves of the carbon-supported Pt-Zn nano alloy catalysts prepared in examples 1-2, comparative example 1 and comparative example 5 of the present invention, and it can be seen from the graph that the carbon-supported Pt-Zn nano alloy catalyst prepared in example 1 of the present invention₃Zn/C can provide larger power density, and the peak power density can reach 140mW cm^-2The Pt/C-400℃ higher than comparative example 1 and the commercial Pt/C catalyst of comparative example 5 indicate that the power characteristics of the aluminum-air cell fabricated using the catalyst provided by the present invention are better.

As can be seen from the comparison between example 3 and example 1, when the mass ratio of platinum to carbon carrier in the platinum compound is higher, part of the platinum-zinc nano alloy particles will agglomerate, and the power density of the carbon-supported platinum-zinc nano alloy catalyst will be affected, and the peak power density is only 105 mW cm^-2It is shown that the ratio of platinum to carbon support of example 1 is more suitable.

It can be known from comparison between examples 6 to 9 and example 1 that the reduction temperature and time can affect the power density of the carbon-supported platinum-zinc nano alloy catalyst, and when the reduction temperature is higher or the reduction time is longer, zinc in the carbon-supported platinum-zinc nano alloy catalyst is easy to dissolve and agglomerate, so that the morphology of the catalyst can be affected, and the catalytic activity of the catalyst can be reduced; when the reduction temperature is lower or the reduction time is shorter, the zinc compound and the platinum compound cannot be completely reduced, and the catalytic effect of the catalyst is reduced, so that the maximum power density of the embodiment 1 is higher than that of the embodiments 6 to 9.

It can be known from comparison between example 10 and example 1 that the reducing atmosphere affects the power density of the carbon-supported platinum-zinc nano alloy catalyst, when the volume ratio of hydrogen to argon in the atmosphere is relatively low, the content of argon in the atmosphere is relatively large, the zinc compound and the platinum compound cannot be completely reduced, the morphology of the catalyst can be better regulated and controlled by mixing the two gases in a relatively proper ratio in example 1, the synthesized catalyst has a more proper particle size, and better catalytic activity is obtained. Thereby achieving a higher power density.

As can be seen from the comparison of comparative example 1 and example 1, when no zinc is contained in the carbon-supported platinum-zinc nano-alloy catalyst, only platinum in the catalyst functions, and the power density of the battery is low.

As can be seen from the comparison of comparative example 2 and example 1, when the carbon-supported platinum-zinc nano-alloy catalyst was not subjected to the alloying treatment, the platinum content on the surface of the catalyst was low, and the power density of the battery was low.

As can be seen from comparison between comparative examples 3 to 4 and example 1, the reduction temperature affects the power performance of the carbon-supported platinum-zinc nano alloy catalyst, when the reduction temperature is too high, the catalyst is agglomerated, and when the reduction temperature is too low, the platinum compound and the zinc compound in the catalyst cannot be completely reduced, which affects the power, so that the power density of example 1 is the highest compared with comparative examples 3 to 4.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.