阅读说明：本技术 一种燃料电池用抗反极催化剂及其制备方法 (Anti-reversal catalyst for fuel cell and preparation method thereof ) 是由 熊鑫 余金礼 丁俊杰 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种燃料电池用抗反极催化剂及其制备方法。该催化剂是以贵金属铂为主要活性元素,以其他金属铁、钴、镍、铜、锡、铋、锰、钨、钇、钯、铑、钌(或)和铱为调控组分,以耐腐蚀的多孔纳米导电材料为载体的担载型铂基催化剂。该催化剂具有非常优异的催化活性、稳定性、抗毒性和抗反极能力,并且具有铂含量低、利用率高的优点,总体成本低等优点。该催化剂是通过多步骤还原和化学置换所得,先通过合成普通金属的纳米粒子核心,此后通过化学置换和进一步还原得到目标催化剂。该制备方法稳定可靠,扩展方便,成本低廉。(The invention discloses an anti-reversal catalyst for a fuel cell and a preparation method thereof. The catalyst is a supported platinum-based catalyst which takes noble metal platinum as a main active element, takes other metals such as iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, yttrium, palladium, rhodium, ruthenium (or) and iridium as regulation and control components, and takes a corrosion-resistant porous nano conductive material as a carrier. The catalyst has the advantages of excellent catalytic activity, stability, antitoxicity and antipole resistance, low platinum content, high utilization rate, low overall cost and the like. The catalyst is obtained through multi-step reduction and chemical replacement, and the target catalyst is obtained through synthesizing the nanoparticle core of common metal and then through chemical replacement and further reduction. The preparation method is stable and reliable, convenient to expand and low in cost.)

1. A antipole catalyst for fuel cell contains at least three components, which is a supported platinum-based catalyst using noble metal platinum as main active element, iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, molybdenum, yttrium, gold, palladium, rhodium, ruthenium (or) and iridium as regulation and control components, and porous nano conductive material as carrier.

2. The catalyst structure of claim 1 has a core-shell structure with platinum or a platinum alloy as a shell and an alloy of a control component metal and platinum or (and) a control component metal as a core; the obtained catalyst is in one of a nanosphere, a nanowire or a nano cage-shaped framework structure. Preferably, the catalyst is a platinum-based multi-element catalyst with a core-shell structure nanosphere or nano cage-shaped framework structure. As a further preferable example, the catalyst is a platinum-based multi-component catalyst which necessarily includes a core-shell structure nanosphere or nanocage skeleton structure containing one or more elements of gold, palladium, ruthenium, rhodium, iridium, and the like.

3. The porous nano-conductor material of claim 1 is one or more of porous titanium nitride, carbon black, carbon nano-tube, graphene, etc. with conductive ability. The material has the size of 20-200 nm, the porosity of 30-50% and the pore diameter of 2-50 nm, and is preferably conductive porous titanium nitride or carbon black.

4. A fuel cell catalyst preparation method employs a multi-step reduction and chemical displacement process. The specific method comprises the following steps:

s1, one or more of porous titanium nitride, carbon black, carbon nano-tube, graphene and the like are subjected to heat treatment in inert or reducing atmosphere. The heating rate is 0.5-20 DEG/min; the treatment temperature is 100-2000 ℃, and the treatment time is 0.1-10 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. Preferably, the inert gas is one or a mixture of nitrogen, ammonia, methane, hydrogen, argon and the like.

S2, dispersing the carrier material of the step S1 in a solution with weak reducibility. The dispersion can be ultrasonic, ball milling, stirring or cutting.

S3, adding one or more metal salt precursors containing iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, molybdenum, yttrium, gold, palladium, rhodium, platinum, ruthenium or (and) iridium into the solution in the step S2, and adding a certain amount of surfactant, structure directing agent and/or reducing agent. Then, the pH value of the solution is adjusted to 9-13 by using an alkaline solution.

S4, placing the step S3 into a reaction kettle or a tubular reactor for heating reduction. The metal salt precursor added is completely reduced. The reaction temperature is 40-400 ℃, and the reaction time is 1-24 hours. After that, the temperature is kept constant until stirring is kept for standby.

And S5, adding a proper amount of platinum salt precursor solution into the solution obtained in the step S4, and continuing to react for 1-24 hours after the platinum salt is added. And then adding a small amount of one or more of precursors of metal salts of gold, ruthenium or (and) iridium, reacting for 1-3 hours, and further placing the obtained solution into a reaction kettle or a tubular reactor for full reaction. And then filtering, washing and drying for later use.

S6, carrying out high-temperature treatment on the catalyst obtained in the step S5, wherein the treatment temperature is 100-1200 ℃.

5. The reducing solvent in the step S2 is preferably one or a mixture of liquid small molecular alcohol organic matters with weak reducibility and/or oleylamine, oleic acid, nitrogen and nitrogen dimethylformamide. Further preferably, the solvent is one of ethanol, glycol, glycerol, acetone, oleylamine, oleic acid, nitrogen dimethylformamide or a mixture thereof.

6. The surfactant according to claim 4, step S3, preferably being one or a combination of polyvinyl ethyl pyrrolidone, nitrogen ethyl pyrrolidone, cetyl trimethyl ammonium bromide, citric acid, sodium citrate, potassium citrate, ammonium citrate; the structure directing agent is one or more of potassium iodide, potassium bromide, potassium chloride and the like; the reducing agent is one or more of formaldehyde, formic acid and formate, sodium borohydride and the like.

7. The reactor according to step S4 of claim 4, wherein the reactor is an intermittent reactor or a continuous tubular reactor. The heating mode is indirect heating jacket or medium heating, and can also be microwave heating. Preferably, the reactor is a continuous tubular reactor, and the heating mode is microwave heating.

8. According to step S5 of claim 4, the platinum salt precursor is one or a combination of chloroplatinic acid, potassium chloroplatinate, ammonium chloroplatinate, platinum acetylacetonate, etc. The concentration of the precursor solution is 1 millimole value-100 millimole, and the adding amount is 0.01 time to 5 times of the mass of the carrier. The dropping time is from 0.1 to 5 hours. The precursor solution of ruthenium salt and iridium salt is one or the combination of nitrate, halogen salt, acetyl propyl salt and acetate. The addition amount is 0.01-40% of the platinum dosage. The platinum content in the finally obtained catalyst is 10-80%.

9. The technique can also be used with other such metal nanoparticles, metal oxide nanoparticles, or alloys thereof, without the addition of platinum. Including, but not limited to, metal nanoparticles, metal oxide nanoparticles, and/or alloys thereof of iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, molybdenum, yttrium, gold, palladium, rhodium, ruthenium, or (and) iridium.

Technical Field

The invention relates to the field of fuel cells, in particular to an anti-reversal catalyst for a fuel cell and a preparation method thereof. The invention is also suitable for nano materials and preparation thereof, metal-air batteries or various membrane electrolytic cells.

Background

The revolution of energy power makes the fuel cell technology develop rapidly, and as a clean energy conversion technology, the fuel cell has the advantages of high efficiency, high specific power, cleanness, environmental protection and the like, so the fuel cell is considered as a fourth power generation mode. The problem of platinum-based catalysts, which are the core material of fuel cells, has long restricted fuel cell development. Specifically, due to the scarcity of platinum, the cost of platinum-based catalysts is high, and it is a necessary path in the field of fuel cells to reduce the content of platinum and improve the utilization rate of platinum. CN200610019303 discloses a method for preparing a core-shell catalyst by a chemical replacement method, which firstly synthesizes non-noble metal nano particles, then adds noble metal salt solution to carry out chemical replacement to obtain a core-shell structure catalyst solution which takes noble metal as a shell and non-noble metal nano particles as a core, and finally adds a carbon carrier to the non-supported core-shell catalyst solution to carry out adsorption to obtain the supported core-shell catalyst. Chinese patent CN 109830702a discloses a method for preparing a platinum-nickel catalyst, which adopts high-temperature high-pressure reaction to prepare a PtNi catalyst with a nano-alloy structure. CN 111082074 a reports a dealloying method to synthesize a porous platinum-based catalyst, in which a platinum salt and a non-platinum metal salt are co-reduced, and then added into a carrier, and then acid-washed. At present, most of the production processes of the catalysts adopt intermittent production processes, the proportion of non-noble metals and noble metals cannot be controlled, the metal yield is low, the noble metal conversion rate is low, the product performance is general, the stability is poor, the consistency is poor, and the antipole function of the catalysts is rarely concerned. The improvement of catalyst structure and components, and the preparation method are effective methods for improving the conversion rate of platinum and the product performance. Furthermore, the composition of the catalyst has a crucial influence on the antipole resistance of the membrane electrode. Particularly, in actual conditions, the membrane electrode is fatally damaged due to the reverse pole phenomenon caused by frequent load change of the fuel cell. The stability and the anti-reversal capability of the catalyst can be simultaneously improved by adding anti-reversal components, such as cerium, iridium, ruthenium and the like. In summary, the development of a novel catalyst preparation technology and the improvement of the structure and components of the catalyst are important ways for developing a new generation of catalyst and promoting the development of the fuel cell industry.

Disclosure of Invention

The invention provides a counter-electrode resistant catalyst for a fuel cell and a preparation method thereof. The preparation method adopts a multi-step reduction method, and the technical scheme adopted by the invention is as follows:

a catalyst for fuel cell contains at least three components, which is a supported platinum-based catalyst using noble metal platinum as main active element, one or more of iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, molybdenum, yttrium, gold, palladium, rhodium, ruthenium (or) and iridium as regulation component, and porous nano conductive material as carrier.

Preferably, the catalyst structure takes platinum or platinum alloy as a shell, and takes alloy formed by regulating and controlling component metal and platinum or (and) regulating and controlling component metal as a core-shell structure of a core; the obtained catalyst is in one of a nanosphere, a nanowire or a nano cage-shaped framework structure. Preferably, the catalyst is a platinum-based multi-element catalyst with a nanosphere or nanocage framework structure with a core-shell structure. As a further preferable example, the catalyst is a platinum-based multi-component catalyst which necessarily includes a core-shell structure nanosphere or nanocage skeleton structure containing one or more elements of gold, palladium, ruthenium, rhodium, iridium, and the like.

Preferably, the porous nano conductor material is one or more of porous titanium nitride, carbon black, carbon nano tube, graphene and the like with electric conductivity. The material has the size of 20-200 nm, the porosity of 30-50% and the pore diameter of 2-50 nm, and is further preferably conductive porous titanium nitride or carbon black.

A fuel cell catalyst preparation method employs a multi-step reduction and chemical displacement process. The specific method comprises the following steps:

s1, one or more of porous titanium nitride, carbon black, carbon nano-tube, graphene and the like are subjected to heat treatment in inert or weak reducing atmosphere. The heating rate is 0.5-20 DEG/min; the treatment temperature is 100-2000 ℃, and the treatment time is 0.1-10 hours. Preferably, the inert gas is one or a mixture of nitrogen, ammonia, methane, hydrogen, argon and the like. Naturally cooling, replacing with nitrogen, and sealing for later use.

S2, dispersing the carrier material of the step S1 in a solution with weak reducibility. The dispersion mode is one or more of ultrasonic, ball milling, stirring or cutting and the like.

S3, adding one or more metal salt precursors containing iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, molybdenum, yttrium, gold, palladium, rhodium, platinum, ruthenium or (and) iridium into the solution in the step S2, and adding a certain amount of surfactant, structure directing agent and/or reducing agent. Then, the pH value of the solution is adjusted to 9-13 by using an alkaline solution.

S4, placing the step S3 into a reaction kettle or a tubular reactor for heating reduction. The metal salt precursor added is completely reduced. The reaction temperature is 40-400 ℃, and the reaction time is 1-24 hours. After that, the temperature is kept constant until stirring is kept for standby.

And S5, adding a proper amount of platinum salt precursor solution into the solution obtained in the step S4, and continuing to react for 1-24 hours after the platinum salt is added. And then adding a small amount of one or more of precursors of metal salts of gold, ruthenium or (and) iridium, reacting for 1-3 hours, and further placing the obtained solution into a reaction kettle or a tubular reactor for full reaction. And then filtering, washing and drying for later use.

S6, carrying out high-temperature treatment on the catalyst obtained in the step S5, wherein the treatment temperature is 100-1200 ℃.

Preferably, the reducing solvent in step S2 is preferably one or a mixture of a liquid small-molecular alcohol organic substance with weak reducibility and (or) oleylamine, oleic acid, nitrogen dimethylformamide. Further preferably, the solvent is one of ethanol, glycol, glycerol, acetone, oleylamine, oleic acid, nitrogen dimethylformamide or a mixture thereof.

Preferably, the surfactant in step S3 is one or a combination of polyvinylpyrrolidone, nitrogen ethyl pyrrolidone, cetyl trimethyl ammonium bromide, citric acid, sodium citrate, potassium citrate and ammonium citrate; the structure directing agent is one or more of potassium iodide, potassium bromide, potassium chloride and the like; the reducing agent is one or more of formaldehyde, formic acid and formate, sodium borohydride and the like.

Preferably, the reactor of step S3 may be an intermittent reactor or a continuous tubular reactor. The heating mode is indirect heating or medium heating, and can also be microwave heating. More preferably, the reactor is a continuous tubular reactor, and the heating method is microwave heating.

Preferably, the platinum salt precursor in step S5 is one or a combination of chloroplatinic acid, potassium chloroplatinate, ammonium chloroplatinate, platinum acetylacetonate, and the like. The concentration of the precursor solution is 1 millimole-100 millimole, and the adding amount is 0.01 time to 5 times of the carrier mass. The dropping time is from 0.1 to 5 hours.

Preferably, the precursor solution of ruthenium salt and iridium salt in step S5 is one or a combination of nitrate, halide, acetylacetonate and acetate. The addition amount is 0.01-40% of the platinum dosage.

When no platinum is added, the technique can also be used for other metal nanoparticles and their alloys and/or oxide nanoparticles. And can be obtained as nanoparticles, and/or materials having a core-shell structure and/or a nanocage-like framework structure, including, but not limited to, metal nanoparticles, metal oxide nanoparticles, or alloys thereof of iron, cobalt, nickel, copper, tin, bismuth, manganese, tungsten, molybdenum, yttrium, gold, palladium, rhodium, ruthenium, or (and) iridium.

Compared with the prior art, the catalyst for the fuel cell and the preparation method thereof provided by the invention have the beneficial effects that:

the preparation method emphasizes and optimizes the anti-reversal capacity of the catalyst. Compared with the traditional platinum-carbon catalyst and platinum-two-gold catalyst alloy, the technology improves the catalytic activity, stability and anti-reversal capability of the catalyst by adding anti-reversal components such as gold, palladium, ruthenium, iridium, cerium and the like. The synthesis method has the advantages of high utilization rate of raw materials, reliable preparation process, consistent product batch, energy conservation and high efficiency. The obtained product has the advantages of excellent antipole resistance, high activity, high stability and low platinum content. Solves the problems of low utilization rate of raw materials, poor product consistency and low yield in the traditional preparation process.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, it should be obvious that the embodiments are described for facilitating the understanding of the present invention by the relevant persons, and do not constitute a limitation to the content of the present invention, and based on any modification of the embodiments or the patent content, the hacking or the use should fall within the protection scope of the present patent.

The specific embodiment is as follows:

example 1

1g of porous carbon black is weighed and placed in a tube furnace, the temperature is 950 ℃ from the normal temperature treatment temperature at the heating rate of 2 ℃/min, and the temperature is kept for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 800 ml of ethylene glycol solution and then fully dispersed by means of a high speed cutter, ultrasonic charging, and the like. Thereafter 2.5 g nickel acetate, 10g polyvinylpyrrolidone and 10g ammonium citrate are added, after which the pH is adjusted to 12 with sodium hydroxide, after thorough cutting and sonication, heating is carried out by microwaves at 180 ℃ for 10 minutes. The reaction was followed by lowering the temperature to 80 ℃ until use. The results of the product-related tests are shown in fig. 1, fig. 2 and fig. 3.

1g of chloroplatinic acid (200 mg) of ruthenium chloride was weighed out and dispersed in 500mL of ethylene glycol, 5g of polyvinylpyrrolidone was added thereto and dispersed sufficiently, and then the solution was added dropwise at a rate of 10 mL/min and stirred slowly at 200 rpm for 12 hours. Then heating the mixed solution for 5 minutes at 150 ℃ by microwave, filtering and drying to obtain the finished product catalyst. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.

Example 2

1g of porous carbon black is weighed and placed in a tube furnace, the temperature is 950 ℃ from the normal temperature treatment temperature at the heating rate of 2 ℃/min, and the temperature is kept for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 800 ml of a nitrogen, nitrogen-dimethylformamide solution and then fully dispersed by means of a high-speed cutter, ultrasonic charging, and the like. After this 2.5 g nickel acetate, 15g polyvinylpyrrolidone were added, after which the pH was adjusted to 12 with sodium hydroxide, after thorough cutting and sonication, heating was carried out by microwaves at 180 ℃ for 10 minutes. The reaction was followed by lowering the temperature to 80 ℃ until use.

1g of chloroplatinic acid was further weighed and dispersed in 500mL of ethylene glycol, 5g of ammonium citrate and 5g of potassium iodide were added thereto and dispersed sufficiently, and then the solution was added dropwise at a rate of 10 mL/min, followed by slow stirring at 200 rpm for 6 hours, and thereafter a solution of ethylene glycol containing 200 mg of iridium chloride was added dropwise and the stirring was continued slowly for 6 hours. Then heating the mixed solution for 5 minutes at 150 ℃ by microwave, filtering and drying to obtain the finished product catalyst. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.

Example 3

1g of porous carbon black is weighed and placed in a tube furnace, the temperature is 950 ℃ from the normal temperature treatment temperature at the heating rate of 2 ℃/min, and the temperature is kept for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 400 ml of ethylene glycol solution and then fully dispersed by means of a high speed cutter, ultrasonic charging, and the like. Thereafter, 1.82 g of cobalt nitrate, 10g of ammonium citrate were added, after which the pH was adjusted to 12 with sodium hydroxide, after thereafter sufficiently cutting and sonication, the temperature was maintained by heating the reaction vessel at 180 ℃ and 50mL of a 3% formaldehyde solution was added dropwise at 2 mL/min. After reacting for 3 hours, the temperature is reduced to 80 ℃ for standby.

1g of platinum acetylacetonate and 100 mg of chloroauric acid were separately weighed and dispersed in 100mL of ethylene glycol, 10mL of potassium iodide was added thereto, and after sufficient dispersion, the solution was added dropwise at a rate of 5 mL/min, followed by slow stirring at 200 rpm for 12 hours. Then heating the mixed solution for 5 minutes at 150 ℃ by microwave, filtering and drying to obtain the finished product catalyst. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.

Example 4

1g of porous carbon black is weighed and placed in a tube furnace, the temperature is 950 ℃ from the normal temperature treatment temperature at the heating rate of 2 ℃/min, and the temperature is kept for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 400 ml of ethylene glycol solution and then fully dispersed by means of a high speed cutter, ultrasonic charging, and the like. After this time 0.2 g of ruthenium chloride, 10g of ammonium citrate are added, after which the pH is adjusted to 12 with sodium hydroxide, after intensive cutting and sonication, the temperature is maintained by heating the reaction vessel at 180 ℃ and 50mL of 3% formaldehyde solution are added dropwise at 2 mL/min. After reacting for 3 hours, the temperature is reduced to 80 ℃ for standby.

1g of platinum acetylacetonate and 100 mg of chloroauric acid were separately weighed and dispersed in 100mL of ethylene glycol, 10mL of potassium iodide was added thereto, and after sufficient dispersion, the solution was added dropwise at a rate of 5 mL/min, followed by slow stirring at 200 rpm for 12 hours. Then heating the mixed solution for 5 minutes at 150 ℃ by microwave, filtering and drying to obtain the finished product catalyst. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.

Example 5

1g of porous carbon black is weighed and placed in a tube furnace, the temperature is 950 ℃ from the normal temperature treatment temperature at the heating rate of 2 ℃/min, and the temperature is kept for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 400 ml of ethylene glycol solution and then fully dispersed by means of a high speed cutter, ultrasonic charging, and the like. Thereafter, 1.82 g of cobalt nitrate, 10g of ammonium citrate were added, after which the pH was adjusted to 12 with sodium hydroxide, after thereafter sufficiently cutting and sonication, the temperature was maintained by heating the reaction vessel at 180 ℃ and 50mL of a 3% formaldehyde solution was added dropwise at 2 mL/min. After reacting for 3 hours, the temperature is reduced to 80 ℃ for standby.

1g of ruthenium acetylacetonate and 100 mg of iridium chloride were separately weighed and dispersed in 100mL of ethylene glycol, 10mL of potassium iodide was added thereto, and after sufficiently dispersing the mixture, the mixture was added dropwise to the above solution at a rate of 5 mL/min, followed by slowly stirring at 200 rpm for 12 hours. Then heating the mixed solution for 5 minutes at 150 ℃ by microwave, filtering and drying to obtain the finished product catalyst. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.

To further clarify the explanation of the embodiments of the present invention or the technical solutions in the prior art, the prior art will be referred to as comparative examples below.

Comparative example: 1

Weighing 1g of porous carbon powder, placing the porous carbon powder in a tube furnace, treating the porous carbon powder at a normal temperature of 650 ℃ at a heating rate of 2 ℃/min, and preserving the heat for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 800 ml of ethylene glycol solution and then fully dispersed by means of a high speed cutter, ultrasonic charging, and the like.

Additionally, 1 gram of chloroplatinic acid was weighed, dispersed in 500mL of ethylene glycol, 5 grams of polyvinylpyrrolidone was added for sufficient dispersion, 10 grams of ammonium citrate was added thereafter, the pH was adjusted to 12 with sodium hydroxide, after sufficient cutting and sonication, heated by microwave at 180 ℃ for 10 minutes. After the reaction, the temperature is reduced to 80 ℃ for standby, and the finished product catalyst can be obtained after filtration and drying. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.

Comparative example: 2

Weighing 1g of porous titanium nitride, placing the porous titanium nitride in a tube furnace, treating the porous titanium nitride at 1050 ℃ from normal temperature at a heating rate of 2 ℃/min, and preserving the heat for 3 hours. Naturally cooling, replacing with nitrogen, and sealing for later use. The ammonia-treated support material was dispersed in 800 ml of ethylene glycol solution and then fully dispersed by means of a high speed cutter, ultrasonic charging, and the like. Thereafter 2.5 g of cobalt acetate, 10g of polyvinylpyrrolidone and 10g of ammonium citrate are added, after which the pH is adjusted to 12 with sodium hydroxide, after thorough cutting and sonication, heating is carried out by microwaves at 180 ℃ for 10 minutes. The reaction was followed by lowering the temperature to 80 ℃ until use.

1g of chloroplatinic acid was weighed out and dispersed in 500mL of ethylene glycol, 5g of polyvinylpyrrolidone was added thereto and dispersed sufficiently, and then the resulting solution was added dropwise at a rate of 10 mL/min and stirred slowly at 200 rpm for 12 hours. Then heating the mixed solution for 5 minutes at 150 ℃ by microwave, filtering and drying to obtain the finished product catalyst. And finally, placing the catalyst in a nitrogen atmosphere, treating at 650 ℃ for 3 hours, and naturally cooling to obtain the finished catalyst.