阅读说明：本技术 一种天然导电纳米碳负载的纳米合金催化剂的可控合成方法 (Controllable synthesis method of natural conductive nano carbon loaded nano alloy catalyst ) 是由 单艾娴 刘焕明 腾雪爱 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种天然导电纳米碳负载的纳米催化剂的可控合成方法，所述方法包括以下步骤：将天然导电纳米碳粉末、二种或以上有机金属化合物加入溶剂中，在惰性气体的保护下初步升温并保持一定时间使其均匀混合；升温到反应温度并保持一定时间以反应制得第一反应液；进行固液分离；将分离出来的固体产物清洗，获得天然导电纳米碳负载的纳米合金催化剂。本发明提供了一条有效制备天然导电纳米碳负载的合金纳米催化剂的途径，操作简单，产物均匀性好，对环境影响小；所得到的导电纳米碳负载的合金纳米结构具有很好的稳定性和电化学性，其优异的甲醇氧化催化性质使其在燃料电池领域具有重要的应用价值。(The invention discloses a controllable synthesis method of a natural conductive nano carbon-loaded nano catalyst, which comprises the following steps: adding natural conductive nano carbon powder and two or more organic metal compounds into a solvent, preliminarily heating under the protection of inert gas, and keeping for a certain time to uniformly mix the natural conductive nano carbon powder and the organic metal compounds; heating to a reaction temperature and keeping for a certain time to react to prepare a first reaction liquid; carrying out solid-liquid separation; and cleaning the separated solid product to obtain the natural conductive nano carbon-loaded nano alloy catalyst. The invention provides a way for effectively preparing the natural conductive nano carbon-loaded alloy nano catalyst, and has the advantages of simple operation, good product uniformity and small influence on the environment; the obtained conductive nanocarbon-loaded alloy nanostructure has good stability and electrochemistry, and the excellent methanol oxidation catalysis property of the conductive nanocarbon-loaded alloy nanostructure has important application value in the field of fuel cells.)

1. A controllable synthesis method of a natural conductive nanocarbon supported nanoalloy catalyst, the method comprising the steps of:

adding natural conductive nano carbon powder and two or more organic metal compounds into a solvent, preliminarily heating under the protection of inert gas, and keeping for a certain time to uniformly mix the natural conductive nano carbon powder and the organic metal compounds;

heating to a reaction temperature and keeping for a certain time to react to prepare a first reaction liquid;

carrying out solid-liquid separation;

cleaning the solid product separated in the step 3) to obtain the natural conductive nano carbon loaded nano alloy catalyst.

2. The method of claim 1, wherein the natural conductive nanocarbon comprises a ground nanopowder or slurry of a coal-based material selected from one or more of conductive coal, conductive carbon and coal gangue containing conductive coal.

3. The method of claim 1 or 2, wherein the nanoalloy is a platinum-nickel nanoalloy;

preferably, the organometallic compound includes an organometallic compound of platinum and an organometallic compound of nickel;

preferably, the platinum organometallic compound includes one or both of platinum acetylacetonate and chloroplatinic acid;

preferably, the organometallic compound of nickel comprises one or more of nickel acetylacetonate, nickel acetate and nickel formate;

preferably, the solvent comprises one or more of oleylamine, oleic acid, diphenyl ether and N, N-dimethylamide;

preferably, the inert gas comprises argon or nitrogen.

4. The method according to claim 1 or 2, wherein the holding temperature of the preliminary temperature rise includes 70 to 160 ℃, and the holding time of the preliminary temperature rise exceeds 10 minutes;

preferably, the holding time of the preliminary temperature rise includes 10 to 100 minutes;

preferably, the preliminary elevated temperature holding temperature includes 130 ℃;

preferably, the holding time of the preliminary temperature rise includes 30 minutes.

5. The method according to claim 1 or 2, wherein the reaction temperature comprises 200 ℃ and 400 ℃, and the holding time of the reaction temperature exceeds 10 minutes;

preferably, the holding time of the reaction temperature comprises 10 to 100 minutes;

preferably, the reaction temperature comprises 250 ℃ and the holding time of the reaction temperature comprises 40 minutes.

6. The method of claim 1 or 2, wherein the separation process comprises one or both of centrifugation and filtration.

7. The method of claim 1 or 2, wherein the cleaning comprises ultrasonic cleaning;

preferably, the ultrasonic cleaning comprises a first ultrasonic cleaning, a second ultrasonic cleaning and a third ultrasonic cleaning;

preferably, the first ultrasonic cleaning comprises ultrasonic cleaning of the solid product with chloroform;

preferably, the first ultrasonic cleaning comprises ultrasonic cleaning the solid product for 5-10 min by using 1-100mL of chloroform in 50-100 MHz ultrasonic waves to obtain a second product;

preferably, the second ultrasonic cleaning comprises ultrasonic cleaning of the solid product with acetone;

preferably, the second ultrasonic cleaning comprises adding 3-100mL of acetone into the second product, and performing ultrasonic cleaning for 5-10 min under 50-100 MHz ultrasonic waves to obtain a third product;

preferably, the third ultrasonic cleaning comprises ultrasonic cleaning of the solid product with analytically pure alcohol;

preferably, the third ultrasonic cleaning comprises the step of ultrasonically cleaning the third product for 5-10 min in 50-100 MHz ultrasonic wave by using analytically pure alcohol to obtain the natural conductive nano carbon-loaded platinum-nickel nano catalyst.

8. A method according to claim 1 or 2, characterized in that the method comprises the steps of:

the method comprises the following steps: preparing natural conductive nano carbon powder;

preparing the natural conductive nano carbon powder from ground nano dry powder or slurry of a coal-based material selected from conductive coal, conductive carbon, coal gangue containing the conductive coal and a combination of the conductive coal and the coal gangue;

step two: preliminary dissolution;

adding natural conductive nano carbon powder and two or more organic metal compounds into a solvent, introducing inert gas, mixing and stirring; heating the mixed solution to 70-160 ℃ and keeping the temperature for more than 10 minutes to realize preliminary dissolution;

step three: preparing a first reaction solution;

heating to 200 ℃ and 400 ℃, and reacting for more than 10 minutes to obtain a first reaction solution;

step four: centrifugally separating to obtain a first product;

centrifuging the first reaction solution prepared in the third step to obtain a first product;

step five: ultrasonic cleaning to obtain a second product;

ultrasonically cleaning the first product prepared in the fourth step by using trichloromethane to obtain a second product;

step six: ultrasonically cleaning to obtain a third product;

adding acetone into the second product prepared in the fifth step for ultrasonic cleaning to obtain a third product;

step seven: ultrasonic cleaning to obtain a nano alloy catalyst;

and ultrasonically cleaning the third product prepared in the sixth step by using analytically pure alcohol to obtain the natural conductive nano carbon-loaded nano alloy catalyst.

9. A natural conductive nanocarbon-supported nanoalloy catalyst, characterized in that it is prepared by the method of any one of claims 1 to 8.

10. Use of the natural conductive nanocarbon supported nanoalloy catalyst of claim 9 for electrochemical reactions, methanol oxidation reactions of fuel cells or ethanol oxidation reactions of fuel cells.

Technical Field

The invention relates to the technical field of metal catalytic nano materials, in particular to a synthetic method of a natural conductive nano carbon-loaded nano alloy catalyst.

Background

Along with the gradual shortage of traditional fossil energy and the increasing demand of human energy, the fuel cell serving as a novel, green and high-efficiency energy conversion device (hydrogen, methanol, formic acid, ethanol and the like) becomes a research hotspot. Because of the huge reaction energy barrier of the electrocatalytic reaction, a catalyst is generally needed to reduce the energy barrier and thus reduce the energy consumption. Platinum metal has been considered as a pure metal electrocatalytic material with the best catalytic activity for cathode and anode reactions in fuel cells, however, the resource shortage and high price of platinum in the earth crust limit the commercial application of platinum, and in order to solve the problem, catalytic materials are mainly designed from the aspects of improving the performance of platinum-based catalysts and reducing the amount of platinum. Research directions include finding new atomic scale structures of platinum and non-platinum that are more efficient than the traditional metal platinum, and finding more efficient alloy compositions and structures.

The nickel-platinum binary alloy nano material has the excellent catalytic property, so that the nickel-platinum binary alloy nano material has attracted extensive attention in recent years. Compared with a platinum simple substance catalyst, the nickel-platinum bimetallic catalyst has stronger advantages in the aspects of controlling the surface structure and the atomic arrangement, so that the nickel-platinum bimetallic nano material becomes an important fuel cell catalyst.

Catalytic materials in the application process, in order to improve their dispersibility, stability and recyclability, the catalytic materials are usually supported on a specific support. Based on the interaction between the carrier and the catalytic material, a more efficient atomic scale novel structure of the catalyst can be formed through the interface regulation between the carrier and the catalytic material, and the catalytic activity of the catalytic material is improved. As a carrier of the catalytic material, the following conditions are simultaneously satisfied: (1) excellent conductivity to promote electron transfer for catalytic reaction; (2) high specific surface area, no impurities which poison the catalyst, so as to improve the uniform dispersion, the mass activity and the catalytic efficiency of the catalyst on the surface of the carrier; (3) good stability and corrosion resistance; (4) is easy for large-scale preparation; (5) the price is low; but the high catalytic efficiency and the cost performance are obtained at the end.

Currently, catalyst supports for fuel cells are typically carbon materials, including carbon black, carbon nanotubes, carbon fibers, fullerenes, graphene, carbon nanocages, etc., due to the high stability, high conductivity and high active area of carbon materials in acidic and alkaline media. Researches show that carbon nanotubes, graphene and the like used as carriers of catalytic materials have obvious catalytic activity advantage compared with carriers of carbon black and the like and price advantage compared with carriers of carbon nanocages and the like, and become a current research hotspot.

Although carbon nanotubes, graphene and the like are produced on a large scale, the market price is reduced to 3,000 yuan to 60,000 yuan per kilogram, but the price is still far higher than that of engineering materials such as coal, graphite, metal, polymer and the like, so that the large-scale application of the carbon nanotubes, the graphene and the like is limited to a certain extent. The method finds the carbon catalyst carrier which has price competitiveness with carbon black and the like and has performance equivalent to that of carbon nano tubes, graphene and the like, and has important scientific significance and application value.

As an ideal support for catalyst materials, it is required to have a high specific surface area, more defects (active site exposure), and high electrical conductivity. In order to obtain defect structure, researchers usually use strong corrosive and toxic reagents such as concentrated KOH and HF, which limits their widespread use. Therefore, it is very necessary to develop a simple and environmentally friendly method for preparing a carbon-based catalyst having a high specific surface area and high activity.

In recent years, the low-cost production and mass application of nanocarbon crystals to natural mineral resources have been explored. The Tour topic group of the university of Rice in the united states develops a method for extracting nano graphene sheets (called nano graphene or graphene quantum dots for short) from coal, and is popularized to the aspects of electrochemical catalysis, optics and the like, thereby attracting attention of a plurality of topic groups. The method takes coal as a carbon raw material, and prepares a specific nano carbon crystal consisting of nano graphene (graphene quantum dots) by technologies such as oxidative corrosion decomposition, cutting and stripping, wherein the size of the nano graphene is about 2nm generally, and the thickness of the nano graphene is 1-4 atomic layers. The method greatly reduces the cost for producing the graphene on the surface, but in the preparation process, only anthracite and all coals with lower carbonization degree than bituminous coal are adopted, and all the common coals only contain about 10 percent of nano graphene, so the process for preparing the nano graphene by technologies such as oxidative corrosion decomposition, cutting, stripping and the like causes serious environmental pollution and chemical consumption, and the actual total production cost is still high. Many subjects have been dedicated to solving the problem of environmental pollution of this method, and some results have been obtained, but the problem cannot be solved fundamentally.

The method developed by Tour for extracting nano-graphene from coal does not fully consider the diversity and heterogeneity of coal. The formation of coal is subject to tens of millions to hundreds of millions of years of geological deterioration of the earth, a series of chemical reactions occur, and abundant carbon structures are formed. In the reported literature, 134 molecular structures of coal are proposed, and 18 models are experimentally verified to be generally accepted by academia. The nano graphene flakes extracted by Tour et al with the size of 1-2nm mainly come from the high-concentration aromatic carbon atom structure in coal. Other abundant carbon structure materials are converted into waste residues in the extraction process of oxidative corrosion decomposition and the like, so that a great deal of resources are wasted.

On the basis of relevant theories and the exploration of predecessors, a set of simple coal dressing method is provided, and coal containing more than 50% of natural components and conductive nano carbon is screened out; and a low-cost, green and environment-friendly physical wet grinding technology is provided, a conductive nano carbon crystal mixture comprising carbon nano fibers, carbon nano tubes, carbon nano onions, nano graphene and nano graphite sheets is extracted from preferable coal, coal gangue and carbon, and researches show that the nano carbon prepared by the method and the technology has rich defect states on the surface. By popularizing and applying the technology, the cost of using the carbon material as the electrochemical catalyst carrier can be greatly reduced, and the application of using the natural conductive nano carbon as the electrochemical catalytic material carrier is promoted.

Disclosure of Invention

The invention aims to provide a controllable synthesis method of a natural conductive nanocarbon-supported alloy nanocatalyst. The method overcomes the defects of complex process and system and high cost in the prior art, the used ingredients are simple, and the obtained natural conductive nanocarbon-loaded alloy nanocatalyst has good uniformity and dispersibility, high purity, controllable components, excellent methanol and ethanol oxidation catalytic performance and better stability.

The invention provides a controllable synthesis method of a natural conductive nano carbon-loaded nano alloy catalyst, which comprises the following steps:

1) adding natural conductive nano carbon powder and two or more organic metal compounds into a solvent, preliminarily heating under the protection of inert gas, and keeping for a certain time to uniformly mix the natural conductive nano carbon powder and the organic metal compounds;

2) heating to a reaction temperature and keeping for a certain time to react to prepare a first reaction liquid;

3) carrying out solid-liquid separation;

4) cleaning the solid product separated in the step 3) to obtain the natural conductive nano carbon loaded nano alloy catalyst.

Preferably, the natural conductive nanocarbon comprises a ground nanopowder or slurry of a coal-based material selected from one or more of conductive coal, conductive carbon and coal gangue containing conductive coal.

Preferably, the nano-alloy is a platinum-nickel nano-alloy;

preferably, the organometallic compound includes an organometallic compound of platinum and an organometallic compound of nickel;

preferably, the platinum organometallic compound includes one or both of platinum acetylacetonate and chloroplatinic acid;

preferably, the organometallic compound of nickel comprises one or more of nickel acetylacetonate, nickel acetate and nickel formate;

preferably, the solvent comprises one or more of oleylamine, oleic acid, diphenyl ether and N, N-dimethylamide;

preferably, the inert gas comprises argon or nitrogen.

Preferably, the holding temperature of the preliminary temperature rise is 70-160 ℃, and the holding time of the preliminary temperature rise exceeds 10 minutes;

preferably, the holding time of the preliminary temperature rise includes 10 to 100 minutes;

preferably, the preliminary elevated temperature holding temperature includes 130 ℃;

preferably, the holding time of the preliminary temperature rise includes 30 minutes.

Preferably, the reaction temperature comprises 200-;

preferably, the holding time of the reaction temperature comprises 10 to 100 minutes;

preferably, the reaction temperature comprises 250 ℃ and the holding time of the reaction temperature comprises 40 minutes.

Preferably, the separation process comprises one or both of centrifugation and filtration.

Preferably, the cleaning comprises ultrasonic cleaning;

preferably, the ultrasonic cleaning comprises a first ultrasonic cleaning, a second ultrasonic cleaning and a third ultrasonic cleaning;

preferably, the first ultrasonic cleaning comprises ultrasonic cleaning of the solid product with chloroform;

preferably, the first ultrasonic cleaning comprises ultrasonic cleaning the solid product for 5-10 min by using 1-100mL of chloroform in 50-100 MHz ultrasonic waves to obtain a second product;

preferably, the second ultrasonic cleaning comprises ultrasonic cleaning of the solid product with acetone;

preferably, the second ultrasonic cleaning comprises adding 3-100mL of acetone into the second product, and performing ultrasonic cleaning for 5-10 min under 50-100 MHz ultrasonic waves to obtain a third product;

preferably, the third ultrasonic cleaning comprises ultrasonic cleaning of the solid product with analytically pure alcohol;

preferably, the third ultrasonic cleaning comprises the step of ultrasonically cleaning the third product for 5-10 min in 50-100 MHz ultrasonic wave by using analytically pure alcohol to obtain the natural conductive nano carbon-loaded platinum-nickel nano catalyst.

Preferably, the method comprises the steps of:

the method comprises the following steps: preparing natural conductive nano carbon powder;

preparing the natural conductive nano carbon powder from ground nano dry powder or slurry of a coal-based material selected from conductive coal, conductive carbon, coal gangue containing the conductive coal and a combination of the conductive coal and the coal gangue;

step two: preliminary dissolution;

adding natural conductive nano carbon powder and two or more organic metal compounds into a solvent, introducing inert gas, mixing and stirring; heating the mixed solution to 70-160 ℃ and keeping the temperature for more than 10 minutes to realize preliminary dissolution;

step three: preparing a first reaction solution;

heating to 200 ℃ and 400 ℃, and reacting for more than 10 minutes to obtain a first reaction solution;

step four: centrifugally separating to obtain a first product;

centrifuging the first reaction solution prepared in the third step to obtain a first product;

step five: ultrasonic cleaning to obtain a second product;

ultrasonically cleaning the first product prepared in the fourth step by using trichloromethane to obtain a second product;

step six: ultrasonically cleaning to obtain a third product;

adding acetone into the second product prepared in the fifth step for ultrasonic cleaning to obtain a third product;

step seven: ultrasonic cleaning to obtain a nano alloy catalyst;

and ultrasonically cleaning the third product prepared in the sixth step by using analytically pure alcohol to obtain the natural conductive nano carbon-loaded nano alloy catalyst.

The invention also provides a natural conductive nano carbon-loaded nano alloy catalyst, which is prepared by any one of the methods.

The invention also provides application of the natural conductive nano carbon-supported nano alloy catalyst in electrochemical reaction, methanol oxidation reaction of a fuel cell or ethanol oxidation reaction of the fuel cell.

The invention adopts a solvothermal method of one-step synthesis to prepare the natural conductive nanocarbon-supported alloy nano catalyst, and has the characteristics of simple and easy operation, low cost, good product uniformity and small influence on the environment. By controlling the amount of the natural conductive nano carbon and the reaction precursor, the alloy nano catalyst with controllable components and monodisperse and supported by the natural conductive nano carbon can be obtained. The natural conductive nanocarbon-loaded alloy nano-catalyst obtained by the invention has good stability and physicochemical properties, and particularly has important application value in the field of fuel cells due to the excellent methanol oxidation catalytic property.

The invention utilizes the transition metal nickel and noble metal such as platinum to form alloy nano particles which are loaded on the natural conductive nano carbon carrier, utilizes the synergistic effect, interface coupling effect and the like between the transition metal and the noble metal to improve the comprehensive performance of the alloy catalyst, and has important scientific significance and application value.

Drawings

Fig. 1 shows a flow chart of a controllable synthesis method of the platinum nickel nano catalyst loaded by natural conductive nano carbon.

Fig. 2 shows an XRD pattern of the natural conductive nanocarbon supported platinum nickel nanocatalyst prepared in the present invention.

Fig. 3(a) shows a transmission electron microscope of a natural conductive nanocarbon supported platinum nickel nanocatalyst prepared according to the present invention.

Fig. 3(b) shows a high-resolution electron microscope image of a natural conductive nanocarbon-supported platinum nickel nanocatalyst prepared according to the present invention.

Fig. 3(c) shows the particle size distribution of the natural conductive nanocarbon supported platinum nickel nanocatalyst prepared according to the present invention.

Fig. 3(d) shows STEM images and corresponding component distributions of the natural conductive nanocarbon supported platinum nickel nanocatalyst prepared according to the present invention.

Fig. 3(e) shows an electron diffraction pattern of a platinum nickel nanocatalyst supported on natural conductive nanocarbon prepared according to the present invention.

Fig. 4 shows cyclic voltammograms of working electrodes prepared from natural conductive nanocarbon-supported platinum nickel nano-catalyst (Pt-Ni/NC), platinum nickel nano-particles of the same composition ratio (Pt-Ni), carbon black-supported platinum nickel nano-particles (Pt-Ni/C), and commercial platinum carbon catalyst (Pt/C), respectively, according to the present invention.

Fig. 5 shows transient current densities of working electrodes fabricated with natural conductive nanocarbon-supported platinum nickel nano-catalyst (Pt-Ni/NC), platinum nickel nano-particles of the same composition ratio (Pt-Ni), carbon black-supported platinum nickel nano-particles (Pt-Ni/C), and commercial platinum carbon catalyst (Pt/C) according to the present invention, respectively.

Detailed Description

The invention will now be described in further detail by way of examples with reference to the accompanying drawings, without in any way limiting the scope of the invention.

Fig. 1 shows a flow chart of a controllable synthesis method of the platinum nickel nano catalyst loaded by natural conductive nano carbon. As shown in fig. 1, the controllable synthesis method of the platinum nickel nano catalyst loaded by natural conductive nano carbon of the invention comprises the following steps:

the method comprises the following steps: and (3) preparing natural conductive nano carbon powder.

In this step, natural conductive nanocarbon powder is prepared from a nano dry powder or slurry ground from a coal-based material selected from conductive coal, conductive carbon, coal gangue containing conductive coal, and combinations thereof.

Step two: and (4) performing primary dissolution.

In the step, adding natural conductive nano carbon powder and two or more organic metal compounds into a solvent, introducing inert gas, mixing and stirring; and heating the mixed solution to 70-160 ℃ and keeping the temperature for more than 10 minutes to realize primary dissolution. In a particular embodiment, the two or more organometallic compounds include an organometallic compound of platinum and an organometallic compound of nickel; preferably, the organometallic compound of platinum includes one or both of platinum acetylacetonate and chloroplatinic acid; the organometallic compound of nickel includes one or more of nickel acetylacetonate, nickel acetate and nickel formate, the solvent includes one or more of oleylamine, oleic acid, diphenyl ether, and N, N-dimethylamide, and the inert gas includes argon or nitrogen. The holding time is preferably 10 to 100 minutes. The flow rate of the inert gas comprises 10-100 mL/min.

In a specific embodiment, 15mg of natural conductive nano carbon powder, 12mg of nickel acetylacetonate and 18mg of platinum acetylacetonate are added into the oleylamine solution, and argon gas (flow rate is 60mL/min) is introduced for mixing and stirring; the mixed solution was heated to 130 ℃ for 30 minutes to effect preliminary dissolution.

Step three: to prepare a first reaction solution.

In the step, the temperature is raised to 200-400 ℃, and the first reaction solution is prepared after the reaction is carried out for more than 10 minutes. Preferably, the reaction time comprises 10 to 100 minutes.

In a specific embodiment, the temperature is raised to 250 ℃, and the first reaction liquid is prepared after 40 minutes of reaction.

Step four: centrifuging to obtain the first product.

In the step, the first reaction solution obtained in the step three is centrifuged to obtain a first product. The centrifugation may be performed by filtration.

In a specific embodiment, the first reaction solution obtained in the third step is centrifuged at 10000-16000 rpm for 3-10 min to obtain a first product.

Step five: and carrying out ultrasonic cleaning to obtain a second product.

In the step, the first product prepared in the step four is subjected to ultrasonic cleaning by using trichloromethane to obtain a second product.

In a specific embodiment, the first product obtained in the fourth step is subjected to ultrasonic cleaning for 5-10 min by using 1-100mL of chloroform in 50-100 MHz ultrasonic waves, so as to obtain a second product.

Step six: ultrasonic cleaning to obtain a third product.

In the step, acetone is added into the second product prepared in the step five for ultrasonic cleaning, and a third product is obtained.

In a specific embodiment, 3-100mL of acetone is added into the second product prepared in the fifth step, and ultrasonic cleaning is performed for 5-10 min under 50-100 MHz ultrasonic waves, so as to obtain a third product.

Step seven: and carrying out ultrasonic cleaning to obtain the nano alloy catalyst.

In the step, the third product prepared in the step six is subjected to ultrasonic cleaning by using analytically pure alcohol to obtain the natural conductive nano carbon-supported nano alloy catalyst.

In a specific embodiment, the third product obtained in the sixth step is subjected to ultrasonic cleaning for 5-10 min in ultrasonic waves of 50-100 MHz by using analytically pure alcohol, so that the natural conductive nano carbon-loaded platinum-nickel nano catalyst is obtained.

Fig. 2 is an X-ray diffraction (XRD) pattern of the platinum nickel nano catalyst supported on natural conductive nanocarbon, in which a curve represented by Pt-Ni/NC is an X-ray diffraction (XRD) pattern of the platinum nickel nano catalyst supported on natural conductive nanocarbon according to the present invention, and Pt #04-0802 is an XRD pattern of pure platinum. As can be seen from fig. 2, the peak position of XRD of the platinum-nickel nano catalyst prepared in the present invention corresponds to that of pure platinum, but since the sample is a platinum-nickel alloy, the diffraction peak of the platinum is shifted to the right with respect to that of pure platinum. Wherein 2 theta represents a Bragg diffraction angle, and the diffraction peak positions of the corresponding crystal planes are respectively marked on (111) (200) (220).

Fig. 3(a) shows a transmission electron microscope of a natural conductive nanocarbon-supported platinum nickel nanocatalyst prepared according to the present invention, fig. 3(b) shows a high-resolution electron microscope image of a natural conductive nanocarbon-supported platinum nickel nanocatalyst prepared according to the present invention, fig. 3(c) shows a particle size distribution of a natural conductive nanocarbon-supported platinum nickel nanocatalyst prepared according to the present invention, fig. 3(d) shows a STEM image of a natural conductive nanocarbon-supported platinum nickel nanocatalyst prepared according to the present invention and a corresponding component distribution, and fig. 3(e) shows an electron diffraction pattern of a natural conductive nanocarbon-supported platinum nickel nanocatalyst prepared according to the present invention. As shown in fig. 3(a) and 3(b), the platinum nickel particles of the natural conductive nanocarbon supported platinum nickel nanocatalyst prepared by the invention are uniformly distributed on the natural conductive nanocarbon carrier, and the platinum nickel particles are in a single crystal structure. As shown in fig. 3(c), the platinum-nickel catalyst particles have a particle size distribution diameter of 5nm to 12 nm; the spectrometer showed a Ni to Pt composition ratio of about 1: 1. As shown in fig. 3(d), the platinum-nickel catalyst particles have an alloy structure, and the platinum and nickel elements are uniformly distributed. As shown in fig. 3(e), the electron diffraction pattern shows the lattice structure and interplanar spacing of the sample.

The invention adopts a solvothermal method of one-step synthesis to prepare the natural conductive nanocarbon-supported alloy nano catalyst, and has the characteristics of simple and easy operation, low cost, good product uniformity and small influence on the environment. By controlling the amount of the natural conductive nano carbon and the reaction precursor, the alloy nano catalyst with controllable components and monodisperse and supported by the natural conductive nano carbon can be obtained. The natural conductive nanocarbon-loaded alloy nano-catalyst obtained by the invention has good stability and physicochemical properties, and particularly has important application value in the field of fuel cells due to the excellent methanol oxidation catalytic property.

The invention utilizes the transition metal nickel and noble metal such as platinum to form alloy nano particles which are loaded on the natural conductive nano carbon carrier, utilizes the synergistic effect, interface coupling effect and the like between the transition metal and the noble metal to improve the comprehensive performance of the alloy catalyst, and has important scientific significance and application value.

In order to test that the natural conductive nano carbon-loaded platinum nickel nano catalyst prepared by the invention has excellent methanol oxidation catalysis characteristics, the glassy carbon electrode loaded with the catalyst to be tested is used as a working electrode, and the Pt content in the loaded catalyst is ensured to be consistent and is 20.4 mu g/cm²A mixed solution of 0.5M sulfuric acid and 1M methanol was used as a test solution; the sample No. 1 is a platinum-nickel nano catalyst (Pt-Ni/NC) loaded by natural conductive nano carbon, the sample No. 2 is a platinum-nickel nano catalyst (Pt-Ni/C) loaded by carbon black, the sample No. 3 is a platinum-nickel nano catalyst (Pt-Ni), and the sample No. 4 is a commercial platinum-carbon catalyst (Pt/C).

FIG. 4 is a measured cyclic voltammogram, wherein the scan voltage was 0 to 1V and the scan rate was 50 mV/s. As can be seen from FIG. 4, the peak current of the commercial Pt/C catalyst was 404.4mA/cm²mg_Pt ^-1(ii) a The peak current of Pt-Ni nanoparticles carried without a carbon material is770.7mA/cm²mg_Pt ^-1The catalytic property of the catalyst is obviously improved compared with that of a commercial Pt/C catalyst; the peak current of the carbon black loaded Pt-Ni nano catalyst Pt-Ni/C is 994.4mA/cm²mg_Pt ^-1And the peak current of the platinum-nickel nano catalyst Pt-Ni/NC loaded by natural conductive nano carbon reaches 1500.3mA/cm²mg_Pt ^-1Much higher than the other three samples.

Fig. 5 is a transient current density graph of methanol oxidation measured by a chronoamperometry, showing that the platinum nickel nano-catalyst supported by natural conductive nanocarbon always maintains the best catalytic activity and has good catalytic stability compared with the other three catalysts within the 6000s test range.

The natural conductive nanocarbon is an excellent catalyst carrier material, the platinum nickel nano catalyst loaded by the natural conductive nanocarbon prepared by the method has more excellent properties in performance, and the preparation method is simple, low in cost and very wide in application prospect.