W-PtM / C catalyst for ORR and preparation method of W-PtM / C catalyst

Abstract

The invention provides a W-PtM / C catalyst for ORR and a preparation method of the W-PtM / C catalyst. The W-PtM / C catalyst comprises W, Pt, transition metal M and a carbon carrier, the mass fraction of W in the W-PtM / C catalyst is 0.1-5 wt%, the mass fraction of Pt in the W-PtM / C catalyst is 10-40 wt%, the mass fraction of transition metal M in the W-PtM / C catalyst is 3-20 wt%, and the balance is the carbon carrier. According to the W-PtM / C catalyst for ORR, a tungsten element is doped in a platinum-based alloy, the doped tungsten element can randomly replace transition metal M in crystal lattices, and meanwhile, due to the fact that the tungsten element has a special electronic structure, dissolution of Pt and the transition metal M in the oxygen reduction reaction process is effectively inhibited, and therefore on the basis that it is guaranteed that the W-PtM / C catalyst has high ORR activity, the W-PtM / C catalyst has the high ORR activity. And the ORR stability of the W-PtM / C catalyst is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oxygen reduction catalysts and relates to a W-PtM / C catalyst for ORR, and in particular to a W-PtM / C catalyst for ORR and a preparation method thereof. Background Art

[0002] In today's energy field, hydrogen energy has attracted much attention as a clean and efficient secondary energy source. Hydrogen energy has many advantages, such as high energy density and the only combustion product is water. It is widely considered to be an important part of the future energy system. However, the efficient use of hydrogen energy is inseparable from advanced catalysts. Platinum-based alloys occupy an important position in the field of hydrogen energy. Platinum has excellent catalytic performance in oxygen reduction reactions, but its resources are scarce and costly.

[0003] In the existing technology, by forming alloys of platinum with other metals, such as platinum-nickel alloys, the electronic structure and surface properties of oxygen reduction catalysts can be adjusted to a certain extent, thereby improving their catalytic activity and stability while reducing costs. Platinum-based alloy catalysts play a key role in hydrogen energy applications such as hydrogen fuel cells, and are of great significance for promoting the development of the hydrogen energy industry.

[0004] However, during the oxygen reduction reaction, the transition metals in the platinum-based alloy catalysts are easily dissolved, resulting in crystal surface damage. As a result, the performance of the platinum-based alloy catalysts gradually decreases with the increase in usage time, and the mass activity decays rapidly, making it difficult to meet the requirements of long-term stable use.

[0005] In the prior art, CN113629258A discloses a platinum-cobalt alloy catalyst with a platinum-rich surface, which is prepared by impregnation and high-temperature calcination, but only provides data on the particle size and oxygen reduction activity of the catalyst, without mentioning the stability of the catalyst. Similarly, CN111092235A discloses a platinum-cobalt alloy catalyst and a preparation method thereof, but the stability of the platinum-cobalt alloy catalyst is also not mentioned.

[0006] The platinum-based alloy catalysts for ORR disclosed in the prior art have the problem that the transition metal in the platinum-based alloy catalyst is easily dissolved during the oxygen reduction reaction, resulting in the platinum-based alloy catalyst being unable to meet the requirements of long-term stable use. Therefore, it is urgent to develop a platinum-based alloy catalyst with high stability on the basis of high activity. Summary of the invention

[0007] In view of the deficiencies in the prior art, the object of the present invention is to provide a W-PtM / C catalyst for ORR and a preparation method thereof. The W-PtM / C catalyst for ORR provided by the present invention is prepared by doping tungsten element in a platinum-based alloy. The doped tungsten element can randomly replace the transition metal M in the lattice. At the same time, since the tungsten element has a special electronic structure, the dissolution of Pt and the transition metal M during the oxygen reduction reaction is effectively inhibited. Therefore, on the basis of ensuring that the W-PtM / C catalyst has high ORR activity, the ORR stability of the W-PtM / C catalyst is greatly improved.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a W-PtM / C catalyst for ORR, wherein the W-PtM / C catalyst comprises W, Pt, a transition metal M and a carbon support;

[0010] Taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of W in the W-PtM / C catalyst is 0.1-5wt%, the mass fraction of Pt is 10-40wt%, the mass fraction of the transition metal M is 3-20wt%, and the remainder is a carbon carrier.

[0011] In the present invention, taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of W in the W-PtM / C catalyst is 0.1-5wt%, for example, it can be 0.1wt%, 0.3wt%, 0.5wt%, 0.7wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt% or 5wt%, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0012] In the present invention, taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of Pt in the W-PtM / C catalyst is 10 to 40wt%, for example, it can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt% or 40wt%, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] In the present invention, based on the mass of the W-PtM / C catalyst as percent, the mass fraction of the transition metal M in the W-PtM / C catalyst is 3 to 20 wt%, for example, 3 wt%, 5 wt%, 7 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt% or 20 wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0014] The W-PtM / C catalyst for ORR provided by the present invention is a platinum-based alloy doped with tungsten, and the doped tungsten element can randomly replace the transition metal M in the lattice. At the same time, since the tungsten element has a special electronic structure, the dissolution of Pt and the transition metal M during the oxygen reduction reaction is effectively suppressed, thereby greatly improving the ORR stability of the W-PtM / C catalyst while ensuring that the W-PtM / C catalyst has high ORR activity.

[0015] Preferably, based on the total mass of the W-PtM / C catalyst, the mass fraction of W in the W-PtM / C catalyst is 0.5-1wt%, the mass fraction of Pt is 25-35wt%, the mass fraction of the transition metal M is 3-10wt%, and the remainder is a carbon carrier.

[0016] In the present invention, taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of W in the W-PtM / C catalyst is 0.5-1wt%, for example, it can be 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt% or 1wt%, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In the present invention, taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of Pt in the W-PtM / C catalyst is 25-35wt%, for example, it can be 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt% or 35wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In the present invention, taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of the transition metal M in the W-PtM / C catalyst is 3 to 10wt%, for example, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt% or 10wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the transition metal M in the W-PtM / C catalyst includes any one of Fe, Co, Ni, Cu or Zn or a combination of at least two thereof. Typical but non-limiting combinations include a combination of Fe and Co, a combination of Ni and Cu, a combination of Cu and Zn, or a combination of Fe, Co and Ni.

[0020] Preferably, Pt and transition metal M in the W-PTM / C catalyst form ordered intermetallic alloy nanoparticles dispersed on the surface of the carbon carrier.

[0021] Preferably, the average particle size of the intermetallic ordered alloy nanoparticles is 2 to 8 nm, for example, it can be 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, 6 nm, 6.5 nm, 7 nm, 7.5 nm or 8 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] The average particle size of the intermetallic ordered alloy nanoparticles in the present invention is 2-8 nm, so they have both a high specific surface area and an electrochemically active area. Too large or too small an average particle size will cause a loss in fuel cell performance.

[0023] Preferably, W in the W-PtM / C catalyst is doped in the intermetallic ordered alloy nanoparticles in the form of single atoms.

[0024] The present invention adds W element into the W-PtM / C catalyst, so that the W element is uniformly doped in the bulk phase of the intermetallic ordered alloy nanoparticles, and randomly replaces the transition metal M element in the lattice.

[0025] In a second aspect, the present invention provides a method for preparing the W-PtM / C catalyst according to the first aspect, the preparation method comprising:

[0026] (1) mixing a Pt precursor, an M precursor, a tungsten precursor and a carbon support to obtain a mixture;

[0027] (2) subjecting the mixture obtained in step (1) to a first sintering in a reducing atmosphere, and then subjecting the mixture to a second sintering in a vacuum environment to obtain an intermediate;

[0028] (3) The intermediate obtained in step (2) is subjected to a third sintering in a reducing atmosphere to obtain a W-PtM / C catalyst.

[0029] In the preparation method provided by the present invention, ball milling and sintering are used to prepare the W-PtM / C catalyst. Compared with the mainstream solvent thermal reduction method, it has the advantages of not needing to use organic solvents, not generating organic waste liquid that pollutes the environment, being simple and safe in process, and being easy to promote and use on a large scale.

[0030] In the preparation method provided by the present invention, the second sintering is carried out in a vacuum environment, which is conducive to the flow of the W element in the crystal lattice, so that the W element has a high degree of dispersion in the catalyst, so that the W-PtM / C catalyst has a uniform structure, thereby further improving the stability of the W-PtM / C catalyst in the oxygen reduction reaction.

[0031] Preferably, the mixing method in step (1) includes ball milling, the rotation speed of the ball mill is 150-600 r / min, the time is 0.5-6 h, and the ball-to-material ratio is (5-20):1.

[0032] The rotation speed of the ball mill in the present invention is 150-600 r / min, for example, it can be 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min, 550 r / min or 600 r / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] The ball milling time in the present invention is 0.5 to 6 hours, for example, it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h or 6h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] The ball-to-material ratio of the ball mill described in the present invention is (5-20):1, for example, it can be 5:1, 7:1, 10:1, 12:1, 15:1, 17:1 or 20:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] Preferably, the Pt precursor in step (1) comprises any one of chloroplatinic acid, potassium chloroplatinate, platinum acetylacetonate or platinum-containing chloride, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of chloroplatinic acid and potassium chloroplatinate, a combination of platinum acetylacetonate and platinum-containing chloride, a combination of chloroplatinic acid, potassium chloroplatinate and platinum acetylacetonate, or a combination of chloroplatinic acid, potassium chloroplatinate, platinum acetylacetonate and platinum-containing chloride.

[0036] Preferably, the M precursor in step (1) comprises any one of ferric nitrate, ferric sulfate, ferric chloride, ferric acetylacetonate, cobalt nitrate, cobalt sulfate, cobalt chloride, cobalt acetylacetonate, nickel nitrate, nickel sulfate, nickel chloride, nickel acetylacetonate, copper nitrate, copper sulfate, copper chloride, copper acetylacetonate, zinc nitrate, zinc sulfate, zinc chloride or zinc acetylacetonate, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of ferric nitrate and ferric sulfate, a combination of ferric chloride and ferric acetylacetonate, a combination of ferric acetylacetonate and cobalt nitrate, a combination of cobalt sulfate and cobalt chloride, a combination of cobalt acetylacetonate and nickel nitrate, a combination of nickel acetylacetonate and copper nitrate, a combination of copper sulfate and copper chloride, a combination of copper acetylacetonate and zinc nitrate, or a combination of zinc sulfate, zinc chloride and zinc acetylacetonate.

[0037] Preferably, the tungsten precursor in step (1) comprises tungsten hexacarbonyl.

[0038] Preferably, the carbon carrier in step (1) comprises carbon black.

[0039] Preferably, the carbon black comprises any one of EC300-JD carbon black, EC600-JD carbon black, XC-72 carbon black or BP2000 carbon black, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of EC300-JD carbon black and EC600-JD carbon black, a combination of EC600-JD carbon black and XC-72 carbon black, a combination of XC-72 carbon black and BP2000 carbon black, or a combination of EC300-JD carbon black, EC600-JD carbon black and XC-72 carbon black.

[0040] Preferably, step (2) further comprises subjecting the mixture obtained in step (1) to a first heating in a reducing atmosphere before the first sintering, and the first heating rate is 1 to 10°C / min, for example, 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable. The end point temperature is the temperature of the first sintering.

[0041] Preferably, the reducing atmosphere in step (2) comprises hydrogen or a mixture of hydrogen and a protective gas.

[0042] Preferably, the protective gas comprises nitrogen and / or an inert gas.

[0043] Preferably, the volume concentration of hydrogen in the mixed gas is 2-10%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, in step (2), the first sintering temperature is 600-950° C., preferably 800-900° C., and the sintering time is 100-140 min.

[0045] The temperature of the first sintering in step (2) of the present invention is 600-950°C, for example, it can be 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C or 950°C, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 800-900°C.

[0046] In the step (2) of the present invention, the first sintering time is 100 to 140 min, for example, it can be 100 min, 105 min, 110 min, 115 min, 120 min, 125 min, 130 min, 135 min or 140 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] Preferably, step (2) further includes cooling the material obtained by the first sintering between the first sintering and the second sintering.

[0048] Preferably, between the cooling and the second sintering in step (2), the cooled material is also subjected to a second heating in a vacuum environment, and the rate of the second heating is 1 to 10°C / min, for example, 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable. The end point temperature is the temperature of the second sintering.

[0049] Preferably, the vacuum degree of the vacuum environment in step (2) is not less than 50%, for example, it can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 99%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable, preferably not less than 95%.

[0050] Preferably, in step (2), the second sintering temperature is 350-450° C. and the sintering time is 30-180 min.

[0051] The temperature of the second sintering in step (2) of the present invention is 350-450°C, for example, it can be 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C or 450°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] The second sintering time in step (2) of the present invention is 30 to 180 min, for example, 30 min, 50 min, 70 min, 90 min, 100 min, 120 min, 140 min, 160 min or 180 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] Preferably, before the third sintering in step (3), the intermediate in step (2) is also acid-washed, filtered and dried in sequence.

[0054] Preferably, the pickling temperature is 60-80° C. and the time is 1-2 hours.

[0055] The pickling temperature in the present invention is 60-80°C, for example, it can be 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0056] The pickling time in the present invention is 0.5 to 3 hours, for example, it can be 0.5h, 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, 2h, 2.5h or 3h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0057] Preferably, the acid used for the pickling includes any one of perchloric acid, sulfuric acid or acetic acid or a combination of at least two of them. Typical but non-limiting combinations include a combination of perchloric acid and sulfuric acid, a combination of sulfuric acid and acetic acid, or a combination of perchloric acid, sulfuric acid and acetic acid.

[0058] Preferably, the concentration of the acid used in the pickling is 0.05-0.15 mol / L, for example, it can be 0.05 mol / L, 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, 0.1 mol / L, 0.11 mol / L, 0.12 mol / L, 0.13 mol / L, 0.14 mol / L or 0.15 mol / L, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0059] Preferably, between the drying and the third sintering, the dried solid is also subjected to a third heating in a reducing atmosphere, and the rate of the third heating is 1 to 10°C / min, for example, 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min, and the end point temperature is the temperature of the third sintering.

[0060] Preferably, the reducing atmosphere in step (3) comprises hydrogen or a mixture of hydrogen and a protective gas.

[0061] Preferably, the protective gas comprises nitrogen and / or an inert gas.

[0062] Preferably, the volume concentration of hydrogen in the mixed gas is 2-10%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5% or 10%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0063] Preferably, the temperature of the third sintering in step (3) is 200-500° C., preferably 350-450° C., and the time is 40-80 min.

[0064] The temperature of the third sintering in step (3) of the present invention is 200-500°C, for example, it can be 200°C, 230°C, 300°C, 350°C, 400°C, 450°C or 500°C, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 350-450°C.

[0065] The time for the third sintering in step (3) of the present invention is 40 to 80 min, for example, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min or 80 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0066] As a preferred technical solution of the preparation method of the present invention, the preparation method comprises:

[0067] (1) mixing a Pt precursor, an M precursor, hexacarbonyl tungsten and carbon black by ball milling at a rotation speed of 150 to 600 r / min, a time of 0.5 to 6 h and a ball-to-material ratio of (5 to 20):1 to obtain a mixture;

[0068] (2) heating the mixture obtained in step (1) at a rate of 1 to 10° C. / min in hydrogen or a mixture of hydrogen and protective gas to 600 to 950° C., sintering for 100 to 140 minutes, and then cooling; and then heating the mixture at a rate of 1 to 10° C. / min in a vacuum environment with a vacuum degree of not less than 95% to 350 to 450° C., and then sintering for 30 to 180 minutes to obtain an intermediate;

[0069] (3) The intermediate obtained in step (2) is acid-washed with an acid having a concentration of 0.05 to 0.15 mol / L at 60 to 80° C. for 0.5 to 3 h, filtered and dried in sequence, and the dried solid is heated in hydrogen or a mixture of hydrogen and protective gas at a rate of 1 to 10° C. / min to 200 to 500° C., and then sintered for 40 to 80 min to obtain a W-PtM / C catalyst.

[0070] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] (1) The W-PtM / C catalyst for ORR provided by the present invention is a platinum-based alloy doped with tungsten. The doped tungsten element can randomly replace the transition metal M in the lattice. At the same time, due to the special electronic structure of tungsten, the dissolution of Pt and transition metal M during the oxygen reduction reaction is effectively inhibited, thereby greatly improving the ORR stability of the W-PtM / C catalyst while ensuring that the W-PtM / C catalyst has high ORR activity;

[0073] (2) In the preparation method provided by the present invention, ball milling and sintering are used to prepare the W-PtM / C catalyst. Compared with the mainstream solvent thermal reduction method, it has the advantages of not requiring the use of organic solvents, not generating organic waste liquid that pollutes the environment, being simple and safe in process, and being easy to promote and use on a large scale;

[0074] (3) In the preparation method provided by the present invention, the second sintering is carried out in a vacuum environment, which helps the flow of W element in the crystal lattice and makes the W element highly dispersed in the catalyst, so that the W-PtM / C catalyst has a uniform structure, thereby further improving the stability of the W-PtM / C catalyst in the oxygen reduction reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 is the XRD pattern of the W-PtM / C catalyst for ORR provided in Example 1.

[0076] Figure 2 is a TEM image of the W-PtM / C catalyst for ORR provided in Example 1.

[0077] Figure 3 It is a comparison chart of the initial ORR polarization curves of the commercial Pt / C catalyst, the commercial binary alloy PtCo / C catalyst and the W-PtM / C catalyst for ORR provided in Example 1.

[0078] Figure 4 It is a comparison chart of the initial ORR polarization curve of the W-PtM / C catalyst for ORR provided in Example 1 and the ORR polarization curve after 30,000 cycles.

[0079] Figure 5These are the initial CV curve and the CV curve after 30,000 cycles of the W-PtM / C catalyst for ORR provided in Example 1. DETAILED DESCRIPTION

[0080] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0081] Example 1

[0082] This embodiment provides a W-PtM / C catalyst for ORR, where the mass fraction of W in the W-PtM / C catalyst is 1.1wt%, the mass fraction of Pt is 30.2wt%, the mass fraction of transition metal Co is 4.2wt%, and the balance is EC300-JD carbon black;

[0083] Pt and transition metal Co in the W-PTM / C catalyst form intermetallic ordered alloy nanoparticles with an average particle size of 3.7 nm dispersed on the surface of EC300-JD carbon black, and W in the W-PtM / C catalyst is doped in the intermetallic ordered alloy nanoparticles in the form of single atoms.

[0084] The preparation method of the W-PtM / C catalyst comprises:

[0085] (1) mixing platinum acetylacetonate, cobalt acetylacetonate, hexacarbonyl tungsten and EC300-JD carbon black by ball milling at a speed of 300 r / min for 3 h and a ball-to-material ratio of 10:1 to obtain a mixture;

[0086] (2) heating the mixture obtained in step (1) in a mixture of hydrogen and argon (the volume concentration of hydrogen is 5%) at a rate of 5° C. / min to 850° C., sintering for 120 min, and then cooling; and then heating the mixture in a vacuum environment with a vacuum degree of 96% at a rate of 5° C. / min to 400° C., and then performing a second sintering for 120 min to obtain an intermediate;

[0087] (3) The intermediate obtained in step (2) was acid-washed with 0.1 mol / L perchloric acid at 60°C for 1 h to remove part of the cobalt on the surface of the nanoparticles, and then filtered, washed and dried in sequence. The dried solid was heated in a mixture of hydrogen and argon (the volume concentration of hydrogen was 5%) at a rate of 5°C / min to 350°C and then sintered for 40 min to obtain a W-PtM / C catalyst.

[0088] Example 2

[0089] This embodiment provides a W-PtM / C catalyst for ORR, where the mass fraction of W in the W-PtM / C catalyst is 0.5wt%, the mass fraction of Pt is 35.3wt%, the mass fraction of transition metal Co is 6.1wt%, and the remainder is EC600-JD carbon black;

[0090] Pt and transition metal Co in the W-PtM / C catalyst form metallic ordered alloy nanoparticles with an average particle size of 4.2 nm dispersed on the surface of EC600-JD carbon black, and W in the W-PtM / C catalyst is doped in the metallic ordered alloy nanoparticles in the form of single atoms.

[0091] The preparation method of the W-PtM / C catalyst comprises:

[0092] (1) mixing potassium chloroplatinate, cobalt chloride, hexacarbonyl tungsten and EC600-JD carbon black by ball milling at a speed of 300 r / min for 4 h and a ball-to-material ratio of 15:1 to obtain a mixture;

[0093] (2) heating the mixture obtained in step (1) in a mixed gas of hydrogen and nitrogen (the volume concentration of hydrogen is 3%) at a rate of 3° C. / min to 800° C., sintering for 130 min, and then cooling; and then heating the mixture in a vacuum environment with a vacuum degree of 95.5% at a rate of 3° C. / min to 420° C., and then performing a second sintering for 120 min to obtain an intermediate;

[0094] (3) The intermediate obtained in step (2) was acid-washed with 0.08 mol / L acetic acid at 75°C for 1.8 h, filtered, washed and dried in sequence, and the dried solid was heated at a rate of 3°C / min to 400°C in a mixed gas of hydrogen and nitrogen (the volume concentration of hydrogen was 3%), and then sintered for 70 min to obtain a W-PtM / C catalyst.

[0095] Example 3

[0096] This embodiment provides a W-PtM / C catalyst for ORR, wherein the mass fraction of W in the W-PtM / C catalyst is 1.4wt%, the mass fraction of Pt is 25.7wt%, the mass fraction of transition metal Co is 10.5wt%, and the remainder is XC-72 carbon black;

[0097] Pt and transition metal Co in the W-PtM / C catalyst form intermetallic ordered alloy nanoparticles with an average particle size of 4.6 nm dispersed on the surface of XC-72 carbon black, and W in the W-PtM / C catalyst is doped in the intermetallic ordered alloy nanoparticles in the form of single atoms.

[0098] The preparation method of the W-PtM / C catalyst comprises:

[0099] (1) mixing chloroplatinic acid, cobalt nitrate, hexacarbonyl tungsten and XC-72 carbon black by ball milling at a speed of 500 r / min, a time of 1.5 h and a ball-to-material ratio of 8:1 to obtain a mixture;

[0100] (2) heating the mixture obtained in step (1) in a mixture of hydrogen and argon (the volume concentration of hydrogen is 8%) at a rate of 8° C. / min to 900° C., sintering for 110 min, and then cooling, and then heating to 380° C. at a rate of 8° C. / min in a vacuum environment with a vacuum degree of 98%, and then performing a second sintering for 30 min to obtain an intermediate;

[0101] (3) The intermediate obtained in step (2) was acid-washed with 0.12 mol / L perchloric acid at 65°C for 1.2 h, filtered and dried in sequence, and the dried solid was heated at a rate of 8°C / min to 450°C in a mixture of hydrogen and argon (the volume concentration of hydrogen was 8%), and then sintered for 50 min to obtain a W-PtM / C catalyst.

[0102] Example 4

[0103] This embodiment provides a W-PtM / C catalyst for ORR, where the mass fraction of W in the W-PtM / C catalyst is 0.1wt%, the mass fraction of Pt is 40wt%, the mass fraction of transition metal Co is 3.3wt%, and the remainder is BP2000 carbon black;

[0104] Pt and transition metal Co in the W-PtM / C catalyst form intermetallic ordered alloy nanoparticles with an average particle size of 2.3 nm dispersed on the surface of BP2000 carbon black, and W in the W-PtM / C catalyst is doped in the intermetallic ordered alloy nanoparticles in the form of single atoms.

[0105] The preparation method of the W-PtM / C catalyst comprises:

[0106] (1) mixing platinum acetylacetonate, cobalt acetylacetonate, hexacarbonyl tungsten and BP2000 carbon black by ball milling at a speed of 600 r / min, a time of 0.5 h and a ball-to-material ratio of 20:1 to obtain a mixture;

[0107] (2) heating the mixture obtained in step (1) in hydrogen at a rate of 1°C / min to 650°C, sintering for 140 minutes, and then cooling; and then heating the mixture in a vacuum environment with a vacuum degree of 95% at a rate of 10°C / min to 450°C, and then performing a second sintering for 180 minutes to obtain an intermediate;

[0108] (3) The intermediate obtained in step (2) is acid-washed with 0.05 mol / L perchloric acid at 80°C for 3 h, filtered, washed and dried in sequence, and the dried solid is heated in hydrogen at a rate of 1°C / min to 200°C and then sintered for 80 min to obtain a W-PtM / C catalyst.

[0109] Example 5

[0110] This embodiment provides a W-PtM / C catalyst for ORR, where the mass fraction of W in the W-PtM / C catalyst is 5wt%, the mass fraction of Pt is 10.3wt%, the mass fraction of transition metal Co is 20wt%, and the balance is EC300-JD carbon black;

[0111] Pt and transition metal Co in the W-PtM / C catalyst form intermetallic ordered alloy nanoparticles with an average particle size of 8 nm dispersed on the surface of EC300-JD carbon black, and W in the W-PtM / C catalyst is doped in the intermetallic ordered alloy nanoparticles in the form of single atoms.

[0112] The preparation method of the W-PtM / C catalyst comprises:

[0113] (1) mixing platinum acetylacetonate, cobalt sulfate, hexacarbonyl tungsten and EC300-JD carbon black by ball milling at a speed of 150 r / min for 6 h and a ball-to-material ratio of 5:1 to obtain a mixture;

[0114] (2) heating the mixture obtained in step (1) in a mixture of hydrogen and argon (the volume concentration of hydrogen is 10%) at a rate of 10° C. / min to 950° C., sintering for 100 min, and then cooling; and then heating the mixture in a vacuum environment with a vacuum degree of 99% at a rate of 1° C. / min to 350° C., and then performing a second sintering for 120 min to obtain an intermediate;

[0115] (3) The intermediate obtained in step (2) was acid-washed with 0.15 mol / L perchloric acid at 60°C for 0.5 h, filtered, washed and dried in sequence, and the dried solid was heated in a mixture of hydrogen and argon (the volume concentration of hydrogen was 10%) at a rate of 10°C / min to 500°C, and then sintered for 40 min to obtain a W-PtM / C catalyst.

[0116] Example 6

[0117] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.0wt%, the mass fraction of Pt is 29.6wt%, the transition metal is Ni and the mass fraction of the transition metal Ni is 3.9wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.3nm. In addition, the cobalt acetylacetonate in the preparation method of the W-PtM / C catalyst is replaced with nickel acetylacetonate.

[0118] Example 7

[0119] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 0.9wt%, the mass fraction of Pt is 29.7wt%, the mass fraction of transition metal Co is 4.0wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 3.6nm, that is, the EC300-JD carbon black in the W-PtM / C catalyst is replaced with XC-72 carbon black.

[0120] Example 8

[0121] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.3wt%, the mass fraction of Pt is 30.3wt%, the mass fraction of transition metal Co is 4.1wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.0nm. In the preparation method of the W-PtM / C catalyst, platinum acetylacetonate is replaced by potassium chloroplatinate, and cobalt acetylacetonate is replaced by cobalt chloride.

[0122] Example 9

[0123] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.1wt%, the mass fraction of Pt is 29.3wt%, the transition metal is Zn and the mass fraction of the transition metal Zn is 3.7wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.7nm. In the preparation method of the W-PtM / C catalyst, platinum acetylacetonate is replaced by potassium chloroplatinate, and cobalt acetylacetonate is replaced by zinc acetylacetonate.

[0124] Example 10

[0125] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 0.7wt%, the mass fraction of Pt is 30.1wt%, the mass fraction of transition metal Co is 3.8wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 3.2nm, that is, the sintering temperature in the mixed gas in step (2) of the preparation method of the W-PtM / C catalyst is 600°C.

[0126] Embodiment 11

[0127] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as that in Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.0wt%, the mass fraction of Pt is 30.7wt%, the mass fraction of transition metal Co is 4.2wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.5nm, that is, the sintering temperature in the mixed gas in step (2) of the preparation method of the W-PtM / C catalyst is 950°C.

[0128] Example 12

[0129] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.2wt%, the mass fraction of Pt is 29.3wt%, the mass fraction of transition metal Co is 4.0wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 3.8nm, that is, the vacuum degree of the vacuum environment in step (2) of the preparation method of the W-PtM / C catalyst is 50%.

[0130] Embodiment 13

[0131] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.1wt%, the mass fraction of Pt is 29.9wt%, the mass fraction of transition metal Co is 4.1wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 3.6nm, that is, the sintering temperature in step (3) of the preparation method of the W-PtM / C catalyst is 200°C.

[0132] Embodiment 14

[0133] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.1wt%, the mass fraction of Pt is 30.3wt%, the mass fraction of transition metal Co is 4.1wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 3.8nm, that is, the sintering temperature in step (3) of the preparation method of the W-PtM / C catalyst is 500°C.

[0134] Embodiment 15

[0135] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.5wt%, the mass fraction of Pt is 30.7wt%, the mass fraction of transition metal Co is 4.3wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 5.2nm, that is, the sintering temperature in the mixed gas in step (2) of the preparation method of the W-PtM / C catalyst is 500°C.

[0136] Example 16

[0137] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as that in Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.4wt%, the mass fraction of Pt is 31.2wt%, the mass fraction of transition metal Co is 4.6wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 7.7nm, that is, the sintering temperature in the mixed gas in step (2) of the preparation method of the W-PtM / C catalyst is 1050°C.

[0138] Embodiment 17

[0139] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.6wt%, the mass fraction of Pt is 29.8wt%, the mass fraction of transition metal Co is 4.4wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.1nm, that is, the sintering temperature in step (3) of the preparation method of the W-PtM / C catalyst is 150°C.

[0140] Embodiment 18

[0141] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.1wt%, the mass fraction of Pt is 30.3wt%, the mass fraction of transition metal Co is 3.8wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.8nm, that is, the sintering temperature in step (3) of the preparation method of the W-PtM / C catalyst is 600°C.

[0142] Embodiment 19

[0143] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 1.1wt%, the mass fraction of Pt is 30.2wt%, the mass fraction of transition metal Co is 3.6wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.1nm, that is, the second sintering in a vacuum environment in step (2) of the preparation method of the W-PtM / C catalyst is omitted.

[0144] Embodiment 20

[0145] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 2.1wt%, the mass fraction of Pt is 32.3wt%, the mass fraction of transition metal Co is 3.7wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 4.9nm, that is, the vacuum degree of the vacuum environment in step (2) of the preparation method of the W-PtM / C catalyst is replaced with 80%.

[0146] Embodiment 21

[0147] The present embodiment provides a W-PtM / C catalyst for ORR, which is the same as Example 20 except that the mass fraction of W in the W-PtM / C catalyst is 1.2wt%, the mass fraction of Pt is 29.5wt%, the mass fraction of transition metal Co is 3.8wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 3.5nm. In step (2) of the preparation method of the W-PtM / C catalyst, the vacuum environment with a vacuum degree of 80% is replaced with a mixed gas of hydrogen and argon (the volume concentration of hydrogen is 5%).

[0148] Comparative Example 1

[0149] This comparative example provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 0wt%, the mass fraction of Pt is 29.1wt%, the mass fraction of transition metal Co is 2.9wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 16.4nm, that is, the mixing of hexacarbonyl tungsten in step (1) of the preparation method of the W-PtM / C catalyst is omitted.

[0150] Comparative Example 2

[0151] This comparative example provides a W-PtM / C catalyst for ORR, which is the same as Example 1 except that the mass fraction of W in the W-PtM / C catalyst is 10wt%, the mass fraction of Pt is 30.8wt%, the mass fraction of transition metal Co is 3.9wt%, and the average particle size of the intermetallic ordered alloy nanoparticles is 5.2nm, that is, the amount of tungsten hexacarbonyl added in step (1) of the preparation method of the W-PtM / C catalyst is increased.

[0152] The W-PtM / C catalyst for ORR provided in Example 1 was subjected to an X-ray diffraction (XRD) test. The test method was as follows: the powder sample was evenly flattened in the groove of the quartz plate and placed in the test instrument, the instrument tube voltage and tube current were adjusted to 40 kV and 15 mA, respectively, the test angle was 10° to 90°, and the scanning speed was 5° / min; the XRD pattern of the W-PtM / C catalyst for ORR provided in Example 1 was obtained by testing. Figure 1 shown.

[0153] The W-PtM / C catalyst for ORR provided in Example 1 was tested by transmission electron microscopy (TEM). The TEM image of the W-PtM / C catalyst for ORR provided in Example 1 was obtained. Figure 2 As shown;

[0154] Depend on Figure 1It can be seen that the W-PtM / C catalyst for ORR provided in Example 1 is a standard ordered intermetallic alloy, which corresponds one to one with the standard comparison card; Figure 2 It can be seen that in the W-PtM / C catalyst for ORR provided in Example 1, the intermetallic ordered alloy nanoparticles are uniformly dispersed on the carbon carrier, with an average particle size of 3.7 nm, and the intermetallic ordered alloy nanoparticles are highly dispersed and uniform.

[0155] The commercial Pt / C catalyst, the commercial binary alloy PtCo / C catalyst and the W-PtM / C catalyst for ORR provided in the above examples and comparative examples were applied to the rotating disk electrode for testing. The testing method was as follows: a certain amount of catalyst was dispersed in a mixture of 980 μL of isopropanol and deionized water, 20 μL of 5% Nafion solution was added, and a dispersion was obtained after ultrasonic dispersion. The dispersion was dropwise applied to the disk electrode (0.2475 cm 2 ) and fully dried under a baking lamp to make 40μg Pt / cm 2 The electrode head loaded with catalyst is used for electrochemical characterization test; the electrochemical characterization test is carried out in a standard three-electrode system, the counter electrode is a carbon rod, the reference electrode is a saturated calomel electrode, the test is carried out at room temperature, the ORR polarization curve is measured in an O2-saturated 0.1M HClO4 electrolyte, and the background CV curve is measured in a N2-saturated 0.1M HClO4 electrolyte; the specific scanning potential is 0.1~1.1V RHE ,The scanning rate is 10mV / s;

[0156] The initial ORR half-wave potential of the W-PtM / C catalyst for ORR obtained by electrochemical characterization test is shown in Table 1, and the attenuation of the half-wave potential after 30,000 cycles of accelerated decay and the attenuation ratio of the mass specific activity are shown in Table 1; wherein, the attenuation rate of mass specific activity = (initial mass specific activity - mass specific activity after 30,000 cycles of accelerated decay) / initial mass specific activity;

[0157] The initial ORR polarization curve comparison diagram (initial activity comparison diagram) of the commercial Pt / C catalyst, the commercial binary alloy PtCo / C catalyst and the W-PtM / C catalyst for ORR provided in Example 1 was obtained by electrochemical characterization test. Figure 3 As shown;

[0158] The comparison of the initial ORR polarization curve of the W-PtM / C catalyst for ORR provided in Example 1 and the ORR polarization curve after 30,000 cycles is shown in the figure below: Figure 4 As shown;

[0159] The comparison diagram of the initial CV curve of the W-PtM / C catalyst for ORR provided in Example 1 and the CV curve after 30,000 cycles is shown in the figure below: Figure 5 As shown;

[0160] Table 1

[0161]

[0162]

[0163] From Table 1, we can get:

[0164] (1) The initial ORR half-wave potential of the W-PtM / C catalyst for ORR provided in Example 1 was 0.96 V. After 30,000 cycles of accelerated decay, the half-wave potential was basically not decayed, and the area specific activity (SA) increased from 1.904 mA cm -2 Reduced to 1.823 mA cm -2 , decayed by 4.25%, and the mass specific activity (MA) increased from 1.107A·mg Pt -1 Reduced to 1.077A·mg Pt -1 , attenuation 2.7%, the attenuation is low, meeting the requirements of practical application; in addition, the chemically active area (ECSA) of the W-PtM / C catalyst for ORR provided in Example 1 does not change much after 30,000 cycles of accelerated attenuation, and the catalyst exhibits excellent ORR stability, which is due to the doping of tungsten elements and their random distribution in the bulk phase. The doped tungsten elements can randomly replace the transition metal M in the lattice, and at the same time, they have a special electronic structure, which effectively inhibits the dissolution of Pt and Co during the ORR process, thereby greatly improving the ORR stability of the ordered platinum-cobalt metal alloy; in addition, sintering in a vacuum environment in step (2) of the preparation method can help the flow of tungsten elements in the lattice, so that it has a high degree of dispersion in the catalyst, laying a necessary foundation for the high ORR stability of the catalyst;

[0165] (2) The W-PtM / C catalysts for ORR provided in Examples 1 to 14 of the present invention all have a relatively high initial ORR half-wave potential, and the attenuation of the half-wave potential and the attenuation ratio of the mass specific activity after 30,000 cycles of accelerated attenuation are relatively small;

[0166] (3) By comparing Example 1 with Examples 10-11 and 15-16, it can be seen that the temperature of sintering in the mixed gas in step (2) of the preparation method of the W-PtM / C catalyst of the present invention will affect the performance of the W-PtM / C catalyst; when the sintering temperature is 600-950°C, it is conducive to obtaining a W-PtM / C catalyst with better performance. This is because when the sintering temperature is too low, the Pt alloy cannot nucleate, and when the sintering temperature is too high, the catalyst is easy to agglomerate, thereby affecting the ORR performance;

[0167] (4) By comparing Example 1 with Examples 13-14 and 17-18, it can be seen that the sintering temperature in step (3) of the preparation method of the W-PtM / C catalyst of the present invention will affect the performance of the W-PtM / C catalyst; when the sintering temperature is 200-500°C, it is conducive to obtaining a W-PtM / C catalyst with better performance. This is because when the sintering temperature is too low, the oxygen species on the alloy surface cannot be removed, and when the sintering temperature is too high, the catalyst is easy to agglomerate, thereby affecting the ORR performance;

[0168] (5) By comparing Example 1 with Example 19, it can be seen that after omitting the second sintering in a vacuum environment in step (2) of the preparation method of the W-PtM / C catalyst, the particle size is 4.1 nm, the ORR half-wave potential is only 0.92 V, and after 30,000 cycles of stability testing, the half-wave potential decays by 19.7 mV, indicating that the second sintering in a vacuum environment does not substantially affect the particle size of the W-PtM / C catalyst, but after the W-PtM / C catalyst is subjected to the second sintering in a vacuum environment, the oxygen reduction catalytic performance will be greatly improved;

[0169] (6) By comparing Example 1 with Example 20, it can be seen that when the sintering environment vacuum in step (2) of the preparation method of the W-PtM / C catalyst is too low, the performance of the W-PtM / C catalyst will be reduced. This is because the doping element W cannot be well distributed in the lattice, and thus cannot play a role;

[0170] (7) By comparing Example 1 with Example 20 and Example 21, it can be seen that after the vacuum environment with a vacuum degree of 80% in step (2) of the preparation method of the W-PtM / C catalyst is replaced with a mixed gas of hydrogen and argon, the particle size of the synthesized W-PtM / C catalyst is 3.5nm, and the ORR half-wave potential is only 0.92V. After 30,000 cycles of stability testing, the half-wave potential decays by 20.3mV, indicating that when the vacuum degree of the sintering environment in step (2) of the preparation method is too low, the performance of the W-PtM / C catalyst will be reduced. This is because the doping element W cannot be well distributed in the lattice, and thus cannot play a role;

[0171] (8) By comparing Example 1 with Comparative Example 1, it can be seen that after omitting the mixing of hexacarbonyl tungsten in step (1) of the preparation method of the W-PtM / C catalyst, the particle size of the obtained catalyst is 16.4 nm, the particles are agglomerated, the ORR half-wave potential is 0.90 V, and after 30,000 cycles of stability testing, the half-wave potential decays by 27.5 mV, which indicates that the addition of tungsten element has a significant enhancement effect on the catalyst particle size, catalytic activity and stability;

[0172] (9) By comparing Example 1 with Comparative Example 2, it can be seen that when the amount of hexacarbonyl tungsten added in step (1) of the preparation method of the W-PtM / C catalyst is too much, the performance of the W-PtM / C catalyst will be reduced. This is because excessive doping of tungsten destroys the ordered metal structure of the platinum-based alloy to a certain extent, thereby affecting its ORR performance;

[0173] In summary, the W-PtM / C catalyst for ORR provided by the present invention is a platinum-based alloy doped with tungsten, and the doped tungsten element can randomly replace the transition metal M in the lattice. At the same time, due to the special electronic structure of tungsten, the dissolution of Pt and transition metal M in the oxygen reduction reaction process is effectively inhibited, thereby ensuring that the W-PtM / C catalyst has high ORR activity. On the basis of greatly improving the ORR stability of the W-PtM / C catalyst; in the preparation method provided by the present invention, ball milling and sintering are used to prepare the W-PTM / C catalyst. Compared with the mainstream solvent thermal reduction method, it has the advantages of not needing to use organic solvents, not generating organic waste liquid that pollutes the environment, and being simple and safe in process and easy to promote and use on a large scale; in the preparation method provided by the present invention, the second sintering is carried out in a vacuum environment, which is conducive to the flow of W elements in the lattice, so that the W element has a high degree of dispersion in the catalyst, so that the W-PTM / C catalyst has a uniform structure, thereby further improving the stability of the W-PTM / C catalyst in the oxygen reduction reaction.

[0174] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A W-PtM / C catalyst for ORR, characterized in that: The W-PtM / C catalyst comprises W, Pt, a transition metal M and a carbon support; Taking the mass of the W-PtM / C catalyst as 100%, the mass fraction of W in the W-PtM / C catalyst is 0.1-5wt%, the mass fraction of Pt is 10-40wt%, the mass fraction of the transition metal M is 3-20wt%, and the remainder is a carbon carrier.

2. The W-PtM / C catalyst according to claim 1, characterized in that Based on the total mass of the W-PtM / C catalyst, the mass fraction of W in the W-PtM / C catalyst is 0.5-1wt%, the mass fraction of Pt is 25-35wt%, the mass fraction of the transition metal M is 3-10wt%, and the remainder is a carbon carrier.

3. The W-PtM / C catalyst according to claim 1 or 2, characterized in that Pt and transition metal M in the W-PTM / C catalyst form ordered intermetallic alloy nanoparticles dispersed on the surface of the carbon carrier.

4. The W-PtM / C catalyst according to claim 3, characterized in that The average particle size of the intermetallic ordered alloy nanoparticles is 2 to 8 nm.

5. The W-PtM / C catalyst according to claim 3 or 4, characterized in that The W in the W-PtM / C catalyst is doped in the intermetallic ordered alloy nanoparticles in the form of single atoms.

6. A method for preparing the W-PtM / C catalyst according to any one of claims 1 to 5, characterized in that: The preparation method comprises: (1) mixing a Pt precursor, an M precursor, a tungsten precursor and a carbon support to obtain a mixture; (2) subjecting the mixture obtained in step (1) to a first sintering in a reducing atmosphere, and then subjecting the mixture to a second sintering in a vacuum environment to obtain an intermediate; (3) The intermediate obtained in step (2) is subjected to a third sintering in a reducing atmosphere to obtain a W-PtM / C catalyst.

7. The preparation method according to claim 6, characterized in that: The mixing method in step (1) includes ball milling, the speed of the ball milling is 150-600 r / min, the time is 0.5-6 h, and the ball-to-material ratio is (5-20):1; Preferably, the tungsten precursor in step (1) comprises tungsten hexacarbonyl.

8. The preparation method according to claim 6 or 7, characterized in that: Step (2) The first sintering temperature is 600-950° C., preferably 800-900° C., and the time is 100-140 min; Preferably, the vacuum degree of the vacuum environment in step (2) is not less than 50%, preferably not less than 95%; Preferably, in step (2), the second sintering temperature is 350-450° C. and the sintering time is 30-180 min.

9. The preparation method according to any one of claims 6 to 8, characterized in that: Before the third sintering in step (3), the intermediate in step (2) is acid-washed, filtered and dried in sequence; Preferably, the temperature of the third sintering in step (3) is 200-500° C., preferably 350-450° C., and the time is 40-80 min.

10. The preparation method according to any one of claims 6 to 9, characterized in that: The preparation method comprises: (1) mixing a Pt precursor, an M precursor, hexacarbonyl tungsten and carbon black by ball milling at a rotation speed of 150 to 600 r / min, a time of 0.5 to 6 h and a ball-to-material ratio of (5 to 20):1 to obtain a mixture; (2) heating the mixture obtained in step (1) at a rate of 1 to 10° C. / min in hydrogen or a mixture of hydrogen and protective gas to 600 to 950° C., sintering for 100 to 140 minutes, and then cooling; and then heating the mixture at a rate of 1 to 10° C. / min in a vacuum environment with a vacuum degree of not less than 95% to 350 to 450° C., and then sintering for 30 to 180 minutes to obtain an intermediate; (3) The intermediate obtained in step (2) is acid-washed with an acid having a concentration of 0.05 to 0.15 mol / L at 60 to 80° C. for 0.5 to 3 h, filtered and dried in sequence, and the dried solid is heated in hydrogen or a mixture of hydrogen and protective gas at a rate of 1 to 10° C. / min to 200 to 500° C., and then sintered for 40 to 80 min to obtain a W-PtM / C catalyst.

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