CN104096575A - Method for preparing platinum-nickel nucleocapsid structure fuel cell catalyst through microwave reduction - Google Patents

Abstract

The method for preparing a fuel cell catalyst with a platinum-nickel core-shell structure by microwave reduction comprises the following steps: adding carbon powder and a surfactant to an organic solvent and mixing uniformly to obtain a mixture A; adding a nickel compound to the mixture A and mixing uniformly to obtain a mixture B; Microwave irradiation is carried out on the mixture B, the reaction temperature is 80~800 ℃, the reaction time is 0.01~120min, after standing for cooling, the mixture C is obtained; the platinum compound is added into the mixture C and mixed uniformly, and the mixture D is obtained; The mixture D is irradiated with microwaves, the reaction temperature is 80-800°C, the reaction time is 0.01-120min, and then left to cool to obtain the mixture E, which is obtained after washing and drying. The catalytic performance of the platinum-nickel core-shell catalyst prepared by the invention is comparable to that of commercial platinum carbon, and the performance is excellent, and the electron transfer number can be close to 4.

Description

Preparation method of platinum-nickel core-shell structure fuel cell catalyst by microwave reduction

technical field

The invention belongs to the field of fuel cell catalyst materials with a platinum-nickel core-shell structure, and in particular relates to a method for preparing a fuel cell catalyst with a platinum-nickel core-shell structure through microwave reduction.

Background technique

The existing petrochemical energy is far from meeting people's needs, and the development and application of fuel cells can alleviate the upcoming energy crisis to a certain extent. Fuel cells not only have a high utilization rate, but also can achieve zero pollution. They are a very good source of energy, and the development prospects of fuel cells are very considerable. However, the precious metal platinum catalyst used in fuel cells is not only scarce in resources but also expensive, so researchers have begun to develop research on platinum alloy catalysts. In the preparation of existing platinum alloy catalysts, there are often problems such as uneven alloy distribution, excessive alloy particle size, which is not conducive to the full utilization of platinum, high production costs, and low yields. That is, the preparation method of platinum-nickel alloy catalyst material still has the disadvantages of low utilization rate of platinum, uncontrollable catalyst particle size, uneven dispersion of catalyst particles, high production cost, complex equipment required for reaction, harsh reaction conditions, low yield, and difficulty in industrial production. .

To sum up, solving the above problems has become an urgent technical problem to be solved in the field of fuel cell catalyst materials with platinum-nickel core-shell structure.

Contents of the invention

Technical problem to be solved: the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a platinum-nickel core-shell structure fuel cell catalyst by microwave reduction, and the platinum-nickel core-shell structure fuel cell catalyst material prepared by this method can utilize High efficiency, controllable catalyst particle size, uniform dispersion of catalyst particles, low production cost, simple equipment required, loose experimental conditions, high output and easy industrial production.

Technical scheme of the present invention:

A method for preparing a fuel cell catalyst with a platinum-nickel core-shell structure by microwave reduction, comprising the following steps:

The first step: add carbon powder and surfactant in the organic solvent and mix uniformly to obtain mixture A; wherein, the mass ratio of the organic solvent to carbon powder is 100~2968:1, and the surfactant and carbon The mass ratio of powder is 0.1～50:1, and described organic solvent is at least one in methanol, ethanol, ethylene glycol and glycerol;

The second step: add the nickel compound into the mixture A obtained in step 1 and mix evenly to obtain the mixture B; wherein the mass ratio of the nickel compound to the carbon powder is 0.53~50:1, and the nickel compound is nickel nitrate hexahydrate, At least one of nickel acetate, nickel carbonate, nickel chloride, nickel sulfate, basic nickel carbonate, nickel fluoride, nickel trioxide, nickel oxide and nickelous oxide;

Step 3: Microwave irradiation is carried out on the mixture B obtained in step 2, the reaction temperature is 80-800°C, the reaction time is 0.01-120min, and then left to cool to obtain the mixture C;

Step 4: Add the platinum compound to the mixture C obtained in step 3 and mix evenly to obtain the mixture D; wherein the mass ratio of the platinum compound to the carbon powder is 0.21~50:1, and the platinum compound is platinum fluoride, nitric acid At least one of platinum, platinum phthalocyanine, saturate platinum, platinum oxide, sodium chloroplatinate, platinum subchloride, platinum dichloride, platinum tetrachloride, chloroplatinic acid and potassium chloroplatinate;

Step 5: Microwave irradiation is carried out on the mixture D obtained in step 4, the reaction temperature is 80~800°C, the reaction time is 0.01~120min, and then left to cool to obtain the mixture E, which is washed with distilled water, ethanol or acetone, and dried. The fuel cell catalyst material with a platinum-nickel core-shell structure is obtained.

The surfactant described in step 1 is one of cationic surfactant, anionic surfactant, nonionic surfactant or amphoteric surfactant.

The cationic surfactant is cetyl trimethyl ammonium bromide, cetyl dimethyl benzyl ammonium bromide, cetyl alcohol polyoxyethylene ether dimethyl octyl ammonium chloride, cetyl Diol polyoxyethylene ether based dimethyl methyl ammonium chloride, octylphenol polyoxyethylene ether based dimethyldecyl ammonium bromide, octylphenol polyoxyethylene ether based dimethyldecyl ammonium chloride One of ammonium or cetyl dimethyloctyl ammonium chloride.

The anionic surfactant is sodium lauryl sulfate, sodium dodecylsulfonate, sodium cetylbenzenesulfonate, sodium octadecylsulfate, sodium N-oleoyl polypeptide, fatty alcohol Sodium polyoxyethylene ether sulfate or disodium polyoxyethylene ether sulfosuccinate monoester.

The nonionic surfactant is polyvinylpyrrolidone, propylene glycol polyoxypropylene polyoxyethylene ether, isomerized alcohol polyoxyethylene polyoxypropylene ether, polyurethane polyoxypropylene polyoxypropylene ether, polyethylene glycol monooleic acid One of esters or stearyl ethylene urea.

The amphoteric surfactant is EO ₂₀ PO ₇₀ EO ₂₀ (P123), EO ₁₀₆ PO ₇₀ EO ₁₀₆ (F127), lauryl dimethyl ammonium oxide, coconut oil alkyl dimethyl ammonium oxide, dodecyl di Methyl ammonium oxide, lauryl dihydroxyethyl ammonium oxide, tetradecyl dihydroxyethyl ammonium oxide, cetyl dihydroxyethyl ammonium oxide, octadecyl dimethyl ammonium oxide or cetyl ammonium oxide One of the alkyl dihydroxyethyl ammonium oxides.

The mixture A described in step 1, the mixture B described in step 2, and the mixture D described in step 4 are uniformly obtained by ultrasonic method or heating and stirring; wherein, the ultrasonic method is obtained when the ultrasonic frequency is 20~40KHz and the ultrasonic power is 200~700W Ultrasound for 30min~1h; heating and stirring at a temperature of 35~70°C and a stirring speed of 150~350r/min, stirring for 25min~3h. .

Beneficial effect

First, the microwave reduction method of the present invention prepares platinum-nickel core-shell structure fuel cell catalysts. Platinum-nickel alloy catalyst particles can be uniformly loaded on carbon nanotubes and have a diameter range of 3 to 10nm, which can be achieved by changing the added platinum compound and The amount of the compound of nickel is used to control the metal ratio and size of the prepared catalyst material platinum-nickel alloy;

Second, the catalytic performance of the platinum-nickel core-shell structure catalyst prepared by the present invention can be compared with that of commercial platinum carbon, and the performance is excellent, and the electron transfer number can be close to 4;

Second, the platinum-nickel core-shell structure fuel cell catalyst material prepared by the present invention has high platinum utilization rate, controllable catalyst particle size, uniform dispersion of catalyst particles, low production cost, simple equipment required, loose experimental conditions, high output and It is easy to realize industrialized production.

Description of drawings

Fig. 1 is the transmission electron micrograph of the fuel cell catalyst prepared in embodiment 1;

Fig. 2 is the cyclic voltammogram of the fuel cell catalyst prepared in Examples 1 to 3;

Fig. 3 is the number of electron transfers during the catalytic process of the fuel cell catalyst prepared in Example 1.

Detailed ways

In the present invention, the mixture A described in step 1, the mixture B described in step 2, and the mixture D described in step 4 are uniformly obtained by ultrasonic method or heating and stirring. Ultrasonic power is 200~700W, ultrasonic 30min~1h; heating and stirring conditions: at a temperature of 35~70℃, stirring speed of 150~350r/min, stirring for 25min~3h.

The nickel compound of the present invention is at least one of nickel nitrate hexahydrate, nickel acetate, nickel carbonate, nickel chloride, nickel sulfate, basic nickel carbonate, nickel fluoride, nickel trioxide, nickel oxide and nickelous oxide The compound of platinum is platinum fluoride, platinum nitrate, platinum phthalocyanine, saturate platinum, platinum oxide, sodium chloroplatinate, subplatinous chloride, platinum dichloride, platinum tetrachloride, chloroplatinic acid and At least one of potassium chloroplatinate;

The surfactant described in the present invention is: the cationic surfactant is cetyl trimethyl ammonium bromide, cetyl dimethyl benzyl ammonium bromide, cetyl polyoxyethylene ether dimethyl Octyl ammonium chloride, lauryl polyoxyethylene ether group dimethyl methyl ammonium chloride, octylphenol polyoxyethylene ether group dimethyldecyl ammonium bromide, octylphenol polyoxyethylene ether One of dimethyl decyl ammonium chloride or cetyl dimethyl octyl ammonium chloride; anionic surfactants are sodium lauryl sulfate, lauryl Sodium sulfonate, sodium cetylbenzenesulfonate, sodium octadecyl sulfate, sodium N-oleoyl polypeptide, sodium fatty alcohol polyoxyethylene ether sulfate or fatty alcohol polyoxyethylene ether sulfosuccinic acid monoester Disodium; Non-ionic surfactants are polyvinylpyrrolidone, propylene glycol polyoxypropylene polyoxyethylene ether, isomerized alcohol polyoxyethylene polyoxypropylene ether, polyurethane polyoxypropylene polyoxypropylene ether, polyethylene glycol mono oil One of ester or stearyl ethylene urea; the amphoteric surfactant is EO ₂₀ PO ₇₀ EO ₂₀ (P123), EO ₁₀₆ PO ₇₀ EO ₁₀₆ (F127), lauryl dimethyl ammonium oxide, coco alkane Dimethyl ammonium oxide, dodecyl dimethyl ammonium oxide, dodecyl dihydroxyethyl ammonium oxide, tetradecyl dihydroxyethyl ammonium oxide, hexadecyl dihydroxyethyl ammonium oxide, One of octadecyl dimethyl ammonium oxide or cetyl dihydroxyethyl ammonium oxide.

The microwave device used in the present invention is a vacuum microwave reactor or a household microwave oven with a power of 200-2000W; the EO ₂₀ PO ₇₀ EO ₂₀ is P123, and the EO ₁₀₆ PO ₇₀ EO ₁₀₆ is F127. The present invention will be described in further detail below in conjunction with specific embodiments and accompanying drawings. The following embodiments are only used to further illustrate the present invention, and should not be regarded as limiting the scope of the present invention. The reagents or instruments used in the examples, whose manufacturers are not indicated, are all commercially available conventional products.

Example 1

A method for preparing a fuel cell catalyst with a platinum-nickel core-shell structure by microwave reduction, comprising the following steps:

Step 1: Add 18.8mg of carbon powder into 50ml of ethylene glycol solvent, then add 1.88mg of polyvinylpyrrolidone, under the condition of ultrasonic frequency of 20KHz, ultrasonic power of 200W, ultrasonic time of 30min, mix well to obtain mixture A ;

Step 2: Add 10 mg of nickel acetate (nickel element is 2.3 mg) to mixture A, and stir for 30 minutes at a temperature of 35 °C and a stirring speed of 150 r/min to obtain a mixture B;

The third step: Microwave irradiation is carried out on the mixture B, the reaction temperature is 200°C, the reaction time is 2min, and then left to cool to obtain the mixture C;

Step 4: Add 3.9 mg of chloroplatinic acid (the platinum element is 2.3 mg) into mixture C, and stir for 30 minutes at a temperature of 35° C. and a stirring speed of 150 r/min to obtain a mixture D;

Step 5: Microwave irradiation is carried out on the mixture D, the reaction temperature is 200°C, the reaction time is 2min, after standing and cooling, the mixture E is obtained; after that, it is washed with distilled water, and then dried at 60~100°C Alternatively, vacuum-dry at 60° C. for 8 hours to obtain a fuel cell catalyst material with a platinum-nickel core-shell structure.

The transmission electron microscope photograph of the platinum-nickel core-shell structure fuel cell catalyst material that the present embodiment makes is as shown in Figure 1, as can be seen from the figure, the product is evenly dispersed on the carbon powder, and the particle size is about 5nm; The cyclic voltammogram of the platinum-nickel core-shell structure fuel cell catalyst material is shown in Figure 2, the open circuit potential is 0.72V, and the oxygen reduction peak is about 0.5V. The electron transfer number of the platinum-nickel core-shell structure fuel cell catalyst material prepared in this example in the oxidation-reduction process is shown in Figure 3, and the electron transfer number of the catalyst material when the platinum-nickel mass ratio is 1:1 is higher than the same loading The electron transfer number of metal commercial platinum carbon is closer to 4, indicating that the mass ratio of platinum to nickel is 1:1, which is more conducive to the reaction.

Example 2

The steps of this embodiment are the same as those of Example 1, except that the nickel acetate added in step 2 is 30 mg.

The cyclic voltammogram of the fuel cell catalyst material with a platinum-nickel core-shell structure prepared in this example is shown in Figure 2. The open circuit potential is corrected at 0.68V, and the oxygen reduction peak is about 0.53V.

Example 3

The steps of this embodiment are the same as those of Example 1, except that the nickel acetate added in step 2 is 50 mg.

The cyclic voltammogram of the fuel cell catalyst material with a platinum-nickel core-shell structure prepared in this example is shown in Figure 2, the open circuit potential is 0.69V, and the oxygen reduction peak is about 0.54V.

Example 4

A method for preparing a fuel cell catalyst with a platinum-nickel core-shell structure by microwave reduction, comprising the following steps:

Step 1: Add 18.8mg of carbon powder into 50ml of ethanol solvent, then add 940mg of polyvinylpyrrolidone, under the condition of ultrasonic frequency of 40KHz, ultrasonic power of 700W, ultrasonic time of 1h, mix well to obtain mixture A;

Step 2: Add 940mg of nickel acetate to mixture A, and stir for 3 hours at a temperature of 70°C and a stirring speed of 350r/min to obtain mixture B;

The third step: Microwave irradiation is carried out on the mixture B, the reaction temperature is 800°C, the reaction time is 1min, and then left to cool to obtain the mixture C;

Step 4: Add 940mg of chloroplatinic acid into mixture C, and stir for 3 hours at a temperature of 70°C and a stirring speed of 350r/min to obtain mixture D;

Step 5: Microwave irradiation is carried out on the mixture D, the reaction temperature is 800°C, the reaction time is 120min, and the mixture E is obtained after standing and cooling; then, it is washed with ethanol, and vacuum-dried at 80°C for 6 hours to obtain the platinum-nickel nucleus Shell structure fuel cell catalyst materials.

Example 5

A method for preparing a fuel cell catalyst with a platinum-nickel core-shell structure by microwave reduction, comprising the following steps:

The first step: add 18.8mg of carbon powder to 1.88g of glycerol solvent, then add 564mg of polyvinylpyrrolidone, under the condition of ultrasonic frequency of 30KHz, ultrasonic power of 400W, ultrasonic time of 30min, mix well to obtain mixture A ;

Step 2: Add 10 mg of nickel acetate to mixture A, and stir for 25 minutes at a temperature of 35°C and a stirring speed of 300 r/min to obtain mixture B;

Step 3: Microwave irradiation is carried out on the mixture B, the reaction temperature is 300°C, the reaction time is 1min, and then left to cool to obtain the mixture C;

Step 4: Add 607.8 mg of chloroplatinic acid to mixture C, and stir for 25 minutes at a temperature of 35°C and a stirring speed of 300 r/min to obtain mixture D;

Step 5: Microwave irradiation is carried out on the mixture D, the reaction temperature is 300°C, and the reaction time is 1min. After standing and cooling, the mixture E is obtained; then washed with acetone, and vacuum-dried at 60°C for 8 hours to obtain the platinum-nickel nucleus Shell structure fuel cell catalyst materials.

Example 6

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step 1 is sodium dodecylsulfonate, the compound of nickel added in step 2 is nickel nitrate hexahydrate, and the platinum added in step 4 The compound is platinum fluoride.

Example 7

Present embodiment is identical with embodiment 1 step, and difference is that the tensio-active agent that adds in the step 1 is cetyltrimethylammonium bromide, and used solvent is methyl alcohol, and the compound of the nickel that adds in the step 2 is nickel carbonate, The platinum compound added in step 4 is platinum nitrate.

Example 8

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step 1 is lauryl dimethyl ammonium oxide, the compound of nickel added in step 2 is nickel chloride, and the compound of platinum added in step 4 is The compound is platinum phthalocyanine.

Example 9

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step 1 is cetyl dimethyl benzyl ammonium bromide, and the compound of nickel added in step 2 is nickel sulfate. The added platinum compound is Saite Platinum.

Example 10

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step 1 is cetyl dimethyl benzyl ammonium bromide, and the compound of nickel added in step 2 is nickel sulfate. The added platinum compound is Saite Platinum.

Example 11

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step 1 is propylene glycol polyoxypropylene polyoxyethylene ether, the compound of nickel added in step 2 is basic nickel carbonate, and the surfactant added in step 4 The compound of platinum is platinum oxide.

Example 12

This example is the same as Example 1, except that the surfactant added in step 1 is EO ₂₀ PO ₇₀ EO ₂₀ , the nickel compound added in step 2 is nickel fluoride, and the platinum compound added in step 4 to platinum oxide.

Example 13

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step 1 is isomerized alcohol polyoxyethylene polyoxypropylene ether, the compound of nickel added in step 2 is nickel oxide, and the surfactant added in step 4 is nickel oxide. The compound of platinum is sodium chloroplatinate.

Example 14

The steps of this embodiment are the same as those of Example 1, except that the surfactant added in step 1 is sodium lauryl sulfate, the compound of nickel added in step 2 is nickel trioxide, and the compound of platinum added in step 4 The compound is platinum chloride.

Example 15

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step one is polyurethane polyoxypropylene polyoxypropylene ether, the compound of nickel added in step two is nickelous oxide, and the platinum added in step four The compound is platinum dichloride.

Example 16

The steps of this embodiment are the same as those of Example 1, except that the surfactant added in step 1 is EO ₁₀₆ PO ₇₀ EO ₁₀₆ , the compound of nickel added in step 2 is nickel acetate, and the compound of platinum added in step 4 is Platinum tetrachloride.

Example 17

The steps of this embodiment are the same as in Example 1, except that the surfactant added in step one is polyurethane polyoxypropylene polyoxypropylene ether, the compound of nickel added in step two is nickel acetate, and the compound of platinum added in step four is The compound is potassium chloroplatinate.

Claims (7)

1. microwave reduction prepares the method for platinum-nickel core-shell structure fuel cell catalyst, is characterized in that, comprises the following steps: The first step: add carbon powder and surfactant in the organic solvent and mix uniformly to obtain mixture A; wherein, the mass ratio of the organic solvent to carbon powder is 100~2968:1, and the surfactant and carbon The mass ratio of powder is 0.1～50:1, and described organic solvent is at least one in methanol, ethanol, ethylene glycol and glycerol; The second step: add the nickel compound into the mixture A obtained in step 1 and mix evenly to obtain the mixture B; wherein the mass ratio of the nickel compound to the carbon powder is 0.53~50:1, and the nickel compound is nickel nitrate hexahydrate, At least one of nickel acetate, nickel carbonate, nickel chloride, nickel sulfate, basic nickel carbonate, nickel fluoride, nickel trioxide, nickel oxide and nickelous oxide; Step 3: Microwave irradiation is carried out on the mixture B obtained in step 2, the reaction temperature is 80-800°C, the reaction time is 0.01-120min, and then left to cool to obtain the mixture C; Step 4: Add the platinum compound to the mixture C obtained in step 3 and mix evenly to obtain the mixture D; wherein the mass ratio of the platinum compound to the carbon powder is 0.21~50:1, and the platinum compound is platinum fluoride, nitric acid At least one of platinum, platinum phthalocyanine, saturate platinum, platinum oxide, sodium chloroplatinate, platinum subchloride, platinum dichloride, platinum tetrachloride, chloroplatinic acid and potassium chloroplatinate; Step 5: Microwave irradiation is carried out on the mixture D obtained in step 4, the reaction temperature is 80~800°C, the reaction time is 0.01~120min, and then left to cool to obtain the mixture E, which is washed with distilled water, ethanol or acetone, and dried. The fuel cell catalyst material with a platinum-nickel core-shell structure is obtained. 2. microwave reduction according to claim 1 prepares the method for platinum-nickel core-shell structure fuel cell catalyst, it is characterized in that, the surfactant described in step one is cationic surfactant, anionic surfactant, nonionic surfactant One of active agent or amphoteric surfactant. 3. microwave reduction according to claim 2 prepares the method for platinum-nickel core-shell structure fuel cell catalyst, is characterized in that, described cationic surfactant is cetyl trimethyl ammonium bromide, cetyl di Methyl benzyl ammonium bromide, cetyl polyoxyethylene ether dimethyl octyl ammonium chloride, lauryl polyoxyethylene ether dimethyl methyl ammonium chloride, octylphenol polyoxyethylene ether One of dimethyl decyl ammonium bromide, octylphenol polyoxyethylene ether dimethyl decyl ammonium chloride or cetyl alcohol polyoxyethylene ether dimethyl octyl ammonium chloride . 4. microwave reduction according to claim 3 prepares the method for platinum-nickel core-shell structure fuel cell catalyst, is characterized in that, described anionic surfactant is sodium lauryl sulfate, sodium lauryl sulfonate, Sodium cetylbenzene sulfonate, sodium stearyl sulfate, sodium N-oleoyl polypeptide, sodium fatty alcohol polyoxyethylene ether sulfate or disodium fatty alcohol polyoxyethylene ether sulfosuccinate monoester. 5. microwave reduction according to claim 4 prepares the method for platinum-nickel core-shell structure fuel cell catalyst, is characterized in that, described nonionic surfactant is polyvinylpyrrolidone, propylene glycol polyoxypropylene polyoxyethylene ether, One of isomeric alcohol polyoxyethylene polyoxypropylene ether, polyurethane polyoxypropylene polyoxypropylene ether, polyethylene glycol monooleate or stearyl ethylene urea. 6. The method for preparing a platinum-nickel core-shell structure fuel cell catalyst by microwave reduction according to claim 5, wherein the amphoteric surfactant is EO ₂₀ PO ₇₀ EO ₂₀ , EO ₁₀₆ PO ₇₀ EO ₁₀₆ , lauryl Dimethyl Ammonium Oxide, Cocoalkyl Dimethyl Ammonium Oxide, Lauryl Dimethyl Ammonium Oxide, Lauryl Dihydroxyethyl Ammonium Oxide, Tetradecyl Dihydroxyethyl Ammonium Oxide, Cetyl Dihydroxyethyl Ammonium Oxide One of alkyl dihydroxyethyl ammonium oxide, octadecyl dimethyl ammonium oxide or cetyl dihydroxyethyl ammonium oxide. 7. microwave reduction according to claim 6 prepares the method for platinum-nickel core-shell structure fuel cell catalyst, is characterized in that, the mixture A described in step 1, the mixture B described in step 2, the mixture D described in step 4 are by ultrasonic method Or heating and stirring to mix evenly; Among them, the ultrasonic method is at an ultrasonic frequency of 20~40KHz, ultrasonic power is 200~700W, ultrasonic 30min~1h; heating and stirring is at a temperature of 35~70°C, and a stirring speed of 150~ Stir for 25min~3h at 350r/min.