CN114899438A - Preparation method of ternary alloy platinum ruthenium copper catalyst and its application in methanol catalysis - Google Patents

Abstract

The invention belongs to the technical field of fuel cell catalysts, and relates to a preparation method of a ternary alloy platinum-ruthenium-copper catalyst, comprising: dissolving a platinum/ruthenium/copper precursor in a solvent and stirring evenly; dissolving a surfactant and a reducing agent in a solvent to reduce Add the prepared reducing agent solution into the precursor solution under magnetic stirring, seal it at 0-20 °C for 12-16 h, centrifuge, remove impurities, dry and collect; add the prepared platinum-ruthenium-copper alloy into In absolute ethanol, add carbon carrier, continue to ultrasonically mix evenly, keep at room temperature for 4-6 hours, and dry. The synthesis process of the invention is simple, the conditions are mild, and the repeatability is good. The obtained catalyst has better catalytic performance than commercial Pt/C and PtRu/C catalysts, and is used for methanol oxidation test. The results show that the catalyst has the morphology of polymerized nanoflowers, which is derived from high surface area compared with commercial platinum carbon and commercial platinum ruthenium carbon. The abundant active sites and material transport channels brought about have good application prospects and have development value.

Description

Preparation method of ternary alloy platinum ruthenium copper catalyst and its application in methanol catalysis

technical field

The invention belongs to the technical field of fuel cell catalysts, and relates to a methanol fuel cell catalyst, in particular to a preparation method of a ternary alloy platinum ruthenium copper catalyst and its application to methanol catalysis.

Background technique

With the rapid development of industry and the rapid growth of motor vehicles, fossil energy is becoming increasingly depleted, and environmental pollution is becoming more and more serious. How to improve the efficient use of energy and reduce the exhaust emissions of motor vehicles has become the focus of global attention. Energy development and scientific use have become an overall and strategic issue in my country's economic development. Therefore, it is imperative to speed up the transformation and diversification of my country's energy structure, improve energy utilization, and develop green energy technologies. In this context, fuel cell technology and fuel cell vehicles have become research hotspots. The development and promotion of technological equipment powered by direct methanol fuel cells is an effective way to practice the concept of green development, and it is also a sustainable development way to realize the diversification, cleanliness and comprehensive utilization of resources in my country.

Direct methanol fuel cells use liquid methanol as fuel, which is easy to transport and far less dangerous than gasoline, diesel, natural gas and other fuels, and is a relatively safe fuel. In addition, methanol also has the advantages of wide sources and high energy density, and is a clean energy power source with great development and application prospects. At present, the catalysts of direct methanol fuel cells are mainly made of Pt-based nanomaterials. However, during the preparation process of traditional catalysts, side effects such as poisoning and deactivation will occur, which gradually reduces the effective specific activity and mass activity of Pt-based nanocatalysts. Affect the service life of methanol fuel cells. In addition, the high cost of developing pure platinum metal is also an important factor restricting the development of direct methanol fuel cells.

In response to the above problems, the majority of scientific researchers have made various efforts, hoping to increase the corrosion resistance and durability of the catalyst during battery operation while improving the catalytic activity as much as possible. In order to deal with catalyst poisoning, reduce catalyst cost, and improve catalytic performance, Pt is modified by introducing other elements, using second or more transition metal components to bring electron (coordination) effect and synergistic effect to the catalyst. The binding energy of Pt metal was optimized and the adsorption strength of the toxic intermediate carbon monoxide was adjusted, resulting in a more efficient methanol catalytic effect. Numerous studies have shown that Pt-based catalysts with binary, ternary, or even multicomponents have better methanol oxidation activity and stability than monometallic Pt catalysts.

Chinese patent 201911176906.8 discloses a method for preparing a nano-copper oxide-coated palladium nanowire heterogeneous catalyst applied in the field of methanol electrocatalytic oxidation. A simple hydrothermal reaction is used to successively obtain a palladium nanowire catalyst and a crystalline nano-copper oxide. Coated palladium nanowire catalyst. In the specific electrochemical test, the heterogeneous nano-catalytic material of the invention shows high anti-carbon monoxide poisoning ability and methanol oxidation catalytic activity, and has a good application prospect.

Chinese patent 202010517924.4 discloses a candied fruit-shaped rhodium-tellurium nanochain catalyst for catalyzing methanol oxidation reaction and a preparation method. Using the high temperature and high pressure environment provided by the autoclave, under the influence of the surfactant polyvinylpyrrolidone and the appropriate weak reducing agent formic acid, and setting the appropriate reaction temperature and time, a candied-curd-shaped rhodium-tellurium nanochain methanol oxidation catalyst with clear and regular appearance was obtained. The material prepared under high temperature and high pressure of the invention has excellent electrochemical methanol oxidation performance and exhibits ideal short-term stability in chronoamperometry.

In summary, on the basis of other metal alloying, further research on the durability and stability of alloy catalysts can be considered from the design and preparation of special structures. For example, alloy catalysts such as cubes, nanowires, and nanodendrites can provide more catalytically active sites due to their increased specific surface area, and special edge atoms and action mechanisms can effectively reduce metal corrosion loss. Such synthetic strategies have incomparable advantages in enhancing the competitiveness of direct methanol fuel cells.

SUMMARY OF THE INVENTION

In view of the deficiencies in the above-mentioned prior art, the purpose of the present invention is to disclose a preparation method of a ternary alloy platinum ruthenium copper catalyst and its application in methanol catalytic oxidation.

The invention adopts a simple and mild method to synthesize a polymer nanoflower ternary alloy catalyst with abundant material transport channels, and by doping ruthenium and copper metal elements, the electronic structure of platinum is regulated, the platinum loading is reduced, and the catalyst activity is improved And reduce the preparation cost and use it in direct methanol fuel cells.

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) Dissolve the platinum precursor, the ruthenium precursor and the copper precursor in the solvent, and stir evenly; in addition, dissolve the surfactant and the reducing agent with an appropriate amount of solvent, and ultrasonically mix them uniformly to obtain a reducing agent solution; mix the prepared reducing agent solution. Slowly add it to the precursor solution under magnetic stirring, seal, react at 0-20 °C for 12-16 h, preferably at 20 °C for 12 h; centrifuge, wash several times with deionized water and absolute ethanol until there are no impurities, dry and collect A platinum-ruthenium-copper alloy; wherein, the molar ratio of the platinum precursor, the ruthenium precursor and the copper precursor is 1-4 mmol: 1-4 mmol: 1-4 mmol, preferably 1 mmol: 1 mmol: 1 mmol; The molar volume ratio is 1mmol:20～30ml, preferably 1mmol:30ml; the molar ratio of metal precursor to surfactant is 1mmol:1～4mmol, preferably 1mmol:3mmol; the molar ratio of pure metal to reducing agent is 1mmol:1～ 14mmol, preferably 1mmol: 2.5mmol;

(2) Add the prepared platinum-ruthenium-copper alloy into absolute ethanol and stir evenly, then add a carbon carrier, continue to ultrasonically mix evenly, keep at room temperature for 4-6 hours, preferably 6 hours, and dry to obtain a ternary alloy platinum-ruthenium-copper catalyst , wherein the solid-liquid ratio of the carbon carrier to absolute ethanol is 1-2 mg: 1-3 ml, preferably 1 mg: 2 ml; the mass ratio of pure metal to carbon carrier is 1 mg: 2-9 mg, preferably 1 mg: 4 mg.

In a preferred disclosure example of the present invention, the platinum precursor in step (1) is any one of chloroplatinic acid hexahydrate, ammonium chloroplatinate, sodium chloroplatinate, platinum bis(acetylacetonate) or potassium chloroplatinate , preferably potassium chloroplatinate; the ruthenium precursor is any of potassium chlororuthenate, ruthenium iodide, ruthenium trichloride, ruthenium oxide, ruthenium acetate or ammonium chlororuthenate, preferably potassium chlororuthenate; The copper precursor is any one of copper bis(acetylacetonate), copper nitrate, copper carbonate, copper chloride, copper hydroxide, and cobalt sulfate, preferably copper chloride.

In the preferred disclosure example of the present invention, the solvent in step (1) is ultrapure water, absolute ethanol, isopropanol, acetone, tetrahydrofuran, n-butanol, oleylamine, dimethyl sulfoxide, toluene or N,N - One or more of dimethylformamide, preferably ultrapure water.

In the preferred disclosure example of the present invention, the surfactant in step (1) is cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, polyvinylpyrrolidone, dodecylbenzenesulfonic acid One or more of sodium, polyoxypropylene polyoxyethylene copolymer P123 or tetradecyl trimethyl ammonium bromide, preferably cetyl trimethyl ammonium chloride.

In a preferred disclosure example of the present invention, the reducing agent in step (1) is oxalic acid, sodium citrate, glucose, ascorbic acid, L-ascorbic acid, ethylene glycol, N,N-dimethylformamide, formic acid or sodium borohydride One or more of them, preferably oxalic acid.

In the preferred disclosure example of the present invention, the carbon carrier in step (2) is Vulcan XC-72R carbon powder, short multi-wall carbon nanotube, oxygen-reduced graphene, carbon aerogel, carbon nanofiber, hollow carbon, mesoporous Any of carbon and carbon nano-molecular sieves, preferably Vulcan XC-72R carbon powder.

The ternary alloy platinum-ruthenium-copper polymerized nanoflower catalyst prepared according to the method of the present invention is formed by alloying two metals platinum and ruthenium supported on a carbon carrier and doped with transition metal copper. The obtained polymerized nanoflower ternary The size of the alloy catalyst is about 30-50 nm, and the morphology is nano-flower particles formed by the polymerization of nanoparticles with a size of 2-3 nm.

Another object of the present invention is to apply the prepared ternary alloy platinum ruthenium copper polymer nanoflower catalyst to methanol catalytic oxidation.

The term "pure metal" as used in the present invention refers to platinum, ruthenium and copper obtained after the reduction reaction.

beneficial effect

The synthesis process of the invention is simple, the conditions are mild, and the repeatability is good. For methanol oxidation test, the results show that the synthesized platinum-ruthenium-copper direct methanol fuel cell alloy catalyst has the morphology of aggregated nanoflowers. Compared with commercial platinum-carbon and commercial platinum-ruthenium carbon, the higher activity and durability are derived from high surface area bands abundant active sites and material transport channels. Its facile synthesis steps can be mass-produced, and its high catalytic performance is beneficial to commercialization. It has better catalytic performance than commercial Pt/C and PtRu/C catalysts, and has good application prospects and development value.

Description of drawings

Fig. 1. TEM image of the ternary metal platinum ruthenium copper cobalt direct methanol fuel cell catalyst prepared in Example 1;

Figure 2. Analysis and characterization of methanol oxidation in Example 1, Comparative Example 1 and Comparative Example 2 (CV characterization, tested in 0.1M HClO ₄ +0.5 MCH ₃ OH mixed solution);

Figure 3. Characterization of electrochemical stability of Example 1, Comparative Example 1, and Comparative Example 2 (chronoamperometry curve, tested in a mixed solution of 0.1M HClO ₄ +0.5M CH ₃ OH).

Detailed ways

The present invention will be described in detail below in conjunction with the examples, so that those skilled in the art can better understand the present invention, but the present invention is not limited to the following examples.

Example 1

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) Take potassium chloroplatinate, potassium chlororuthenate and copper chloride (the molar ratio of platinum-ruthenium-copper precursor is 1:1:1, and the total amount added is 0.15mmol) are dissolved in 15ml ultrapure as metal precursors respectively In water, stir at room temperature for 10-20 minutes until the mixture is uniform. Dissolve 640 mg of CTAC and 15 ml of oxalic acid solution in 15 ml of ultrapure water in another beaker, and mix them uniformly by ultrasonication for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) adding platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stirring evenly, then adding Vulcan XC-72R (the mass ratio of pure metal and Vulcan XC-72R is w/w=1/4, so that the total pure metal load is 20%), continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst. The catalyst is a Pt-based alloy polymerized nanoflower, and the size of the nanoflower is 30-50 nm.

The obtained ternary alloy platinum ruthenium copper direct methanol fuel cell catalyst material was first characterized by low magnification transmission electron microscope and high magnification transmission electron microscope. As shown in Figure 1, the ternary alloy platinum-ruthenium-copper direct methanol fuel cell catalyst was uniformly dispersed, and the morphology showed a clear nano-flower shape. The nano-flowers were aggregated from small particles with a size of only 2-3 nm. The average size of the nanoflowers is 30-50 nm. The small particles have narrow gaps between 1-2 nm. A typical TEM image of a ternary alloy platinum-ruthenium-copper direct methanol fuel cell catalyst shows an interplanar spacing of 0.229 nm, which is significantly smaller than that of pure Pt (111) planes (0.24 nm), a result that clearly indicates ternary alloy polymerization Formation of nanoflowers.

The prepared ternary alloy platinum ruthenium copper direct methanol fuel cell catalyst was tested in the traditional three-electrode system for the electrochemical performance of methanol oxidation.

Figure 2 represents the cyclic voltammetry plots of the ternary alloy platinum ruthenium copper direct methanol fuel cell catalyst and platinum carbon and platinum ruthenium carbon in 0.1M HClO ₄ +0.5M CH ₃ OH. In Figure 2, the black dashed line represents platinum carbon (Pt/C), the black dotted line represents platinum ruthenium carbon (PtRu/C), and the black solid line represents the ternary alloy platinum ruthenium copper direct methanol fuel cell catalyst (PtRuCu/ C). It can be clearly seen in the figure that PtRuCu/C (2.05A·mg ^-1 _Pt ) exhibited significantly improved mass activity, respectively, commercial Pt/C (0.48A·mg ^-1 _Pt ) and commercial PtRu/C ( 0.53A·mg ^-1 _Pt ) 3.9, 4.04 times. On the one hand, the better catalytic activity comes from the proper electronic regulation brought about by alloying, and on the other hand, the abundant active sites and efficient material transport also play a positive role. It is worth noting that the oxide reduction peak on PtRuCu/C obviously shifted to the high potential region during the reverse scan, reflecting the weaker bonding strength between the oxidized intermediate and the catalyst interface, which is considered to be the MOR dynamic. key factor in learning. The higher ECSA and weaker binding strength of oxidative intermediates together indicate that the ternary alloyed platinum-ruthenium-copper catalyst has a significant electrochemical performance improvement for MOR.

Figure 3 represents the stability test graph of the ternary alloy platinum-ruthenium-copper direct methanol fuel cell catalyst and platinum-carbon and platinum-ruthenium carbon in 0.1M HClO ₄ +0.5M CH ₃ OH. The black dashed dashed line represents platinum carbon (Pt/C, prepared in Comparative Example 1), the black dotted dashed line represents platinum ruthenium carbon (PtRu/C, prepared in Comparative Example 2), and the black solid line represents the ternary alloy platinum ruthenium Copper direct methanol fuel cell catalyst (PtRuCuCo/C). Figure 3 shows the chronoampere curves of the three catalysts, from which their short-term stability can be compared. In the chronoamperometry test at 3600 s, PtRuCu/C exhibited significant stability differences relative to the commercial samples. At 2000s, the current densities of PtRuCu/C, Pt/C, and PtRu/C remained at 0.074A·mg ^-1 _Pt , 0.014A·mg ^-1 _Pt , 0.056A·mg ^-1 _Pt , respectively. The decay performance of medium and commercial Pt/C is particularly obvious, verifying that the special structure and alloy effect can significantly improve the MOR activity and stability, further confirming the advantages of this alloy catalyst system with special morphology.

Example 2

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get hexahydrate chloroplatinic acid, ruthenium acetate and copper hydroxide (the molar ratio of platinum-ruthenium-copper precursor is 1:1:3, and the specific total amount of addition is 0.25mmol) are respectively dissolved in 15ml ultra-thin as metal precursor. In pure water, stir at room temperature for 10-20 minutes until the mixture is uniform. Dissolve 540 mg of CTAC and 15 ml of oxalic acid solution in 15 ml of ultrapure water in another beaker, and mix uniformly by ultrasonication for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) Add platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stir evenly, then add multi-walled carbon nanotubes (the mass ratio of pure metal and multi-walled carbon nanotubes is w/w=1/4, so that the total pure The metal loading amount is 20%), continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a three-metal platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.93A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 3

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get platinum acetylacetonate, ruthenium acetate and copper hydroxide (the mol ratio of platinum-ruthenium-copper precursor is 2:1:1, and the specific total amount added is 0.2mmol) and dissolve in 15ml IPA as metal precursor respectively, Stir at room temperature for 10-20 minutes until the mixture is uniform. In another beaker, 15 ml of ultrapure water was used to dissolve 640 mg of PVP and 70 mg of NaBH ₄ , and ultrasonically mixed for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) Add platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stir evenly, then add rGO (the mass ratio of pure metal and rGO is w/w=1/4, so that the total pure metal loading is 20%), Continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.880A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 4

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) Get platinum acetylacetonate, ruthenium trichloride and copper carbonate (the molar ratio of platinum ruthenium copper precursor is 2:2:1, and the specific total amount added is 0.15mmol) and dissolve in 15ml IPA as metal precursors respectively , stir at room temperature for 10-20min until the mixture is uniform. In another beaker, 640 mg of CTAB and 70 mg of NaBH ₄ were dissolved in 15 ml of EtOH, and the mixture was sonicated for 10 min and mixed uniformly. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) adding platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stirring evenly, then adding Vulcan XC-72R (the mass ratio of pure metal and Vulcan XC-72R is w/w=1/4, so that the total pure metal load is 20%), continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.360A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 5

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get chloroplatinic acid hexahydrate, ruthenium trichloride and copper sulfate (the molar ratio of platinum-ruthenium-copper precursor is 3:3:1, and the specific total amount added is 0.35mmol) and dissolve in 15ml as metal precursors respectively of DMF, stir at room temperature for 10-20min until the mixture is uniform. In another beaker, 400 mg of PVP and 100 mg of glucose were dissolved with 15 ml of DMF, and the mixture was sonicated for 10 min and mixed uniformly. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) adding platinum-ruthenium-copper alloy into 30ml of absolute ethanol and stirring evenly, then adding Vulcan XC-72R (the mass ratio of pure metal and Vulcan XC-72R is w/w=1/3, so that the total pure metal load is 25%), continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.960A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 6

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get hexahydrate chloroplatinic acid, ruthenium iodide and copper acetylacetonate (the molar ratio of platinum-ruthenium-copper precursor is 1:2:2, and the specific total amount added is 0.25mmol) are respectively dissolved in 15ml as metal precursors In the OAM, stir at room temperature for 10-20min until the mixture is uniform. In another beaker, 600 mg of PVP and 100 mg of sodium citrate were dissolved with 15 ml of OAM, and mixed uniformly by ultrasonication for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) Add platinum-ruthenium-copper alloy into 30ml of absolute ethanol and stir evenly, then add porous carbon (the mass ratio of pure metal and porous carbon is w/w=1/3, so that the total pure metal loading is 25% ), continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.710A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 7

A preparation method of a ternary alloy platinum-ruthenium-copper polymerized nano-flower catalyst, comprising the following steps:

(1) get hexahydrate chloroplatinic acid, ammonium chlororuthenate and copper nitrate (the molar ratio of platinum-ruthenium-copper precursor is 1:3:3, and the specific total amount of addition is 0.35mmol) are respectively dissolved in 15ml as metal precursors In ultrapure water, stir at room temperature for 10-20min until the mixture is uniform. In another beaker, 700 mg of TTAC and 70 mg of L-AA were dissolved in 15 ml of ultrapure water, and mixed uniformly by ultrasonication for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0～20°C for 12～16h, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, and then dry and collect to obtain platinum ruthenium copper alloy.

(2) adding platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stirring evenly, then adding Vulcan XC-72R (the mass ratio of pure metal and Vulcan XC-72R is w/w=1/2, so that the total pure metal load is 33%), continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 2.01A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 8

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get potassium chloroplatinate, potassium chlororuthenate and copper acetylacetonate (the molar ratio of platinum-ruthenium-copper precursor is 1:3:1, and the specific total amount added is 0.25mmol) are respectively dissolved in 15ml as metal precursors In ultrapure water, stir at room temperature for 10-20min until the mixture is uniform. Dissolve 550 mg of CTAB and 30 ml of formic acid solution in 15 ml of ultrapure water in another beaker, and mix them uniformly by ultrasonication for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) Add platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stir evenly, then add mesoporous carbon (the mass ratio of pure metal and mesoporous carbon is w/w=1/2, so that the total pure metal loading is 33%), continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.580A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 9

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get sodium chloroplatinate, potassium chlororuthenate and copper acetylacetonate (the mol ratio of platinum ruthenium copper precursor is 1:3:1, and the specific total amount added is 0.25mmol) are dissolved in 15ml as metal precursors respectively In the acetone, stir at room temperature for 10-20min until the mixture is uniform. In another beaker, 550 mg of CTAB and 30 ml of formic acid solution were dissolved in 15 ml of acetone, and mixed uniformly by ultrasonication for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) adding platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stirring evenly, then adding hollow carbon (the mass ratio of pure metal and hollow carbon is w/w=1/2, so that the total pure metal loading is 33% ), continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.770A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 10

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get ammonium chloroplatinate, potassium chlororuthenate and copper chloride (the mol ratio of platinum ruthenium copper precursor is 1:1:1, and the specific total amount added is 0.25mmol) are dissolved in 15ml as metal precursors respectively In the IPA, stir at room temperature for 10-20min until the mixture is uniform. In another beaker, 15 ml of IPA was used to dissolve 550 mg of P123 and 30 ml of formic acid solution, and sonicated for 10 min to mix uniformly. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0～20°C for 12～16h, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, and then dry and collect to obtain platinum ruthenium copper alloy.

(2) Add platinum-ruthenium-copper alloy into 30ml of absolute ethanol and stir evenly, then add rGO (the mass ratio of pure metal and rGO is w/w=1/2, so that the total pure metal loading is 33%), Continue to ultrasonically mix uniformly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.690A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 11

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get sodium chloroplatinate, potassium chlororuthenate and cupric chloride (the mol ratio of platinum ruthenium copper precursor is 3:3:1, and the specific total amount added is 0.25mmol) are dissolved in 15ml as metal precursors respectively In ultrapure water, stir at room temperature for 10-20min until the mixture is uniform. Dissolve 550 mg of SDBS and 30 ml of oxalic acid solution in 15 ml of ultrapure water in another beaker, and mix uniformly by ultrasonicating for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0～20°C for 12～16h, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, and then dry and collect to obtain platinum ruthenium copper alloy.

(2) adding platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stirring evenly, then adding Vulcan XC-72R (the mass ratio of pure metal and Vulcan XC-72R is w/w=1/2, so that the total pure metal load is 33%), continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a trimetallic platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.830A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Example 12

A preparation method of a ternary alloy platinum ruthenium copper catalyst, comprising the following steps:

(1) get ammonium chloroplatinate, ruthenium chloride and cupric chloride (the mol ratio of platinum ruthenium copper precursor is 3:3:1, and the specific total amount added is 0.25mmol) are dissolved in 15ml as metal precursor respectively In EtOH, stir at room temperature for 10-20 min until the mixture is uniform. In another beaker, 15 ml of EtOH was used to dissolve 550 mg of P123 and 30 ml of ascorbic acid solution, and ultrasonically mixed for 10 min. The prepared reducing agent solution was slowly added to the precursor solution under magnetic stirring, and the plastic wrap was sealed. React at 0-20°C for 12-16 hours, centrifuge, wash with deionized water and absolute ethanol for several times until no impurities exist, dry and collect to obtain platinum-ruthenium-copper alloy.

(2) Add platinum-ruthenium-copper alloy to 30ml of absolute ethanol and stir evenly, then add multi-wall carbon nanotubes (the mass ratio of pure metal and multi-wall carbon nanotubes is w/w=1/2, so that the total pure The metal loading amount is 33%), continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain a three-metal platinum ruthenium copper direct methanol fuel cell catalyst.

After electrochemical tests, the methanol oxidation activity of the obtained ternary metal platinum-ruthenium-copper catalyst was 1.810A·mg ^-1 , which was better than that of PtRu/C (0.53A·mg ^-1 ) and standard Pt/C (0.48A·mg ^{-1 )} ).

Comparative Example 1

A preparation method of a direct methanol fuel cell catalyst, which can be used for the preparation of a platinum carbon catalyst, comprises the following steps:

(1). Add chloroplatinic acid hexahydrate to 20ml of ultrapure water and stir at room temperature for 5min. In another beaker, 15ml of oxalic acid was dissolved and added, and the oxalic acid was used as a reducing agent. After the two solutions are evenly mixed, react at 0 to 20°C for 12 to 16 hours, centrifuge, wash, and dry for collection.

(2). Add the above metal catalyst into absolute ethanol and stir evenly, then add Vulcan XC-72R, continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain the platinum Carbon methanol fuel cell catalyst. Finally, nanoparticles with a platinum loading of 20% are obtained, and the size of the metal particles is 3-5 nm.

Comparative Example 2

A preparation method of a direct methanol fuel cell catalyst, which can be used for the preparation of a platinum ruthenium carbon catalyst, comprises the following steps:

(1). Add chloroplatinic acid hexahydrate and ruthenium trichloride to 20ml of ultrapure water, and stir at room temperature for 5min. In another beaker, 15ml of oxalic acid was dissolved and added, and the oxalic acid was used as a reducing agent. After the two solutions are evenly mixed, react at 0 to 20°C for 12 to 16 hours, centrifuge, wash, and dry for collection.

(2). Add the above metal catalyst into absolute ethanol and stir evenly, then add Vulcan XC-72R, continue to ultrasonically mix evenly, stir at room temperature for 4-6 hours, and directly dry in a blast dryer to obtain the platinum Ruthenium carbon methanol fuel cell catalyst. Finally, nanoparticles with platinum and ruthenium loading of 20% are obtained, and the size of the alloy particles is 3-5 nm.

The above descriptions are only the embodiments of the present invention, and are not intended to limit the scope of the patent of the present invention. Any equivalent structure or equivalent process transformation made by the description of the present invention, or directly or indirectly applied in other related technical fields, are the same as The principles are included in the scope of patent protection of the present invention.

Claims (10)

1. a preparation method of a ternary alloy platinum ruthenium copper catalyst, is characterized in that, comprises the following steps: (1) Dissolve the platinum precursor, the ruthenium precursor and the copper precursor in the solvent, and stir evenly; in addition, dissolve the surfactant and the reducing agent with an appropriate amount of solvent, and ultrasonically mix them uniformly to obtain a reducing agent solution; mix the prepared reducing agent solution. Slowly added to the precursor solution under magnetic stirring, sealed, reacted at 0-20 °C for 12-16 h; centrifuged, washed with deionized water and absolute ethanol for several times until there were no impurities, dried and collected to obtain platinum-ruthenium-copper alloy; wherein , the molar ratio of the platinum precursor, the ruthenium precursor and the copper precursor is 1-4 mmol: 1-4 mmol: 1-4 mmol; the molar volume ratio of the metal precursor and the solvent is 1 mmol: 20-30 ml; the metal precursor and the The molar ratio of surfactant is 1mmol: 1～4mmol; the molar ratio of pure metal and reducing agent is 1mmol:1～14mmol; (2) Add the prepared platinum-ruthenium-copper alloy into absolute ethanol and stir evenly, then add a carbon carrier, continue to ultrasonically mix evenly, keep at room temperature for 4-6 hours, preferably 6 hours, and dry to obtain a ternary alloy platinum-ruthenium-copper catalyst , wherein the solid-to-liquid ratio of the carbon carrier to absolute ethanol is 1-2 mg: 1-3 ml, preferably 1 mg: 2 ml; the mass ratio of pure metal to carbon carrier is 1 mg: 2-9 mg, preferably 1 mg: 4 mg. 2. the preparation method of ternary alloy platinum ruthenium copper catalyst according to claim 1, is characterized in that: the platinum precursor described in step (1) is hexahydrate chloroplatinic acid, ammonium chloroplatinate, sodium chloroplatinate , any one in two (acetylacetonate) platinum or potassium chloroplatinate; Described ruthenium precursor is in potassium chlororuthenate, ruthenium iodide, ruthenium trichloride, ruthenium oxide, ruthenium acetate or ammonium chlororuthenate Any one; the copper precursor is any one of copper bis(acetylacetonate), copper nitrate, copper carbonate, copper chloride, copper hydroxide, and cobalt sulfate. 3. the preparation method of ternary alloy platinum ruthenium copper catalyst according to claim 1, is characterized in that: the platinum precursor described in step (1) is potassium chloroplatinate, and described ruthenium precursor is potassium chlororuthenate , the copper precursor is copper chloride. 4. the preparation method of ternary alloy platinum ruthenium copper catalyst according to claim 1, is characterized in that: solvent described in step (1) is ultrapure water, dehydrated alcohol, isopropanol, acetone, tetrahydrofuran, normal One or more of butanol, oleylamine, dimethyl sulfoxide, toluene or N,N-dimethylformamide, preferably ultrapure water; the surfactant is cetyltrimethyl bromide One of ammonium chloride, cetyltrimethylammonium chloride, polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, polyoxypropylene polyoxyethylene copolymer P123 or tetradecyltrimethylammonium bromide One or more, preferably cetyl trimethyl ammonium chloride; The reducing agent is oxalic acid, sodium citrate, glucose, ascorbic acid, L-ascorbic acid, ethylene glycol, N,N-dimethylformamide, One or more of formic acid or sodium borohydride, preferably oxalic acid. 5. the preparation method of ternary alloy platinum-ruthenium-copper catalyst according to claim 1, is characterized in that: described in step (1), the reducing agent solution prepared is slowly added in the precursor solution under magnetic stirring, Sealed and reacted at 20°C for 12h. 6. the preparation method of ternary alloy platinum ruthenium copper catalyst according to claim 1, is characterized in that: the mol ratio of platinum precursor, ruthenium precursor and copper precursor described in step (1) is 1mmol:1mmol: 1 mmol; the molar volume ratio of metal precursor to solvent is 1 1 mmol: 30 ml; the molar ratio of metal precursor to surfactant is 1 mmol: 3 mmol; the molar ratio of pure metal to reducing agent is 1 mmol: 2.5 mmol. 7. the preparation method of ternary alloy platinum ruthenium copper catalyst according to claim 1, is characterized in that: carbon carrier described in step (2) is Vulcan XC-72R carbon powder, short multi-wall carbon nanotube, oxygen reduction Any of graphene, carbon aerogel, carbon nanofiber, hollow carbon, mesoporous carbon, and carbon nanomolecular sieve, preferably Vulcan XC-72R carbon powder. 8. The ternary alloy platinum ruthenium copper catalyst prepared according to any one of claims 1-7. 9. The ternary alloy platinum-ruthenium-copper catalyst according to claim 8, characterized in that: the carbon carrier supports two metals platinum and ruthenium and is alloyed with transition metal copper, and the prepared polymeric nanoflower three The size of the meta-alloy catalyst is about 30-50 nm, and the morphology is nano-flower particles aggregated by nanoparticles with a size of 2-3 nm. 10. An application of the ternary alloy platinum ruthenium copper catalyst according to claim 8 or 9, characterized in that: it is applied to methanol catalytic oxidation.

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