Platinum-palladium-based multicomponent alloy sub-nanobelt catalyst as well as preparation method and application thereof

Abstract

The invention provides a platinum-palladium-based multi-component alloy sub-nanobelt catalyst as well as a preparation method and application thereof, and belongs to the technical field of nano material electro-catalysis. The element composition of the platinum-palladium-based multicomponent alloy sub-nanobelt catalyst disclosed by the invention is PtPdM, m is a non-noble metal, and the non-noble metal is one or more of Fe, Co, Ni, Ga and Zn; the preparation method comprises the following steps: ultrasonically mixing a metal precursor solution and a reduction solution to obtain a mixture, heating the mixture to react, centrifugally collecting a product, and calcining to obtain the platinum-palladium-based multicomponent alloy sub-nanobelt catalyst. The synthesis method disclosed by the invention is simple and controllable, and the obtained platinum-palladium-based multicomponent alloy sub-nanobelt catalyst has the characteristics of large specific surface area, rich active sites, low noble metal content and the like, and shows excellent oxygen reduction reaction catalytic performance in an acidic electrolyte.

Description

Technical Field

[0001] The invention belongs to the technical field of nano material electrocatalysis, and in particular relates to a platinum-palladium-based multi-element alloy sub-nanobelt catalyst and a preparation method and application thereof. Background Art

[0002] In today's world, traditional fossil energy is about to be exhausted, and environmental problems such as global warming are becoming increasingly prominent. Therefore, it is urgent to develop clean energy technology to alleviate environmental pollution and energy crisis and promote the transformation of traditional energy structure to clean energy. Hydrogen fuel cell is a typical clean energy technology that can directly convert chemical energy into electrical energy. It has the characteristics of high energy conversion efficiency, good low temperature resistance and fast energy replenishment speed. At the same time, it can truly realize the power supply strategy of zero product pollution. It is considered to be one of the power sources for future transportation and various electronic products. However, the cathode oxygen reduction reaction (ORR) kinetics in hydrogen fuel cells is relatively slow, resulting in high overpotential losses, which greatly limits large-scale application and development. Due to its special d-orbital electronic structure, Pt has good oxygen adsorption and dissociation characteristics and is currently the most widely used cathode catalyst for reducing ORR overpotential. However, Pt resources are low in abundance and expensive, resulting in high catalyst costs, which is difficult to meet the needs of large-scale commercialization of hydrogen fuel cells. At the same time, the non-optimal electronic structure of Pt leads to its strong binding energy with oxygen-containing substances, which increases the overpotential of the catalytic reaction, and the catalytic performance needs to be further improved. Therefore, the current research focus is to rationally design ORR catalyst materials, reduce the amount of Pt and improve the activity and stability of the catalyst.

[0003] At present, people mainly alloy expensive precious metals (Pt, Pd, etc.) with one or more transition metals with abundant reserves and low prices to construct PtPd-based multi-element alloy catalysts with a wide range of adjustable composition and electronic structure. By increasing the types of atoms in the multi-element alloy, the degree of disorder of the alloy configuration can be increased, the diversity of bond lengths and coordination environments can be triggered, the excessive oxygen binding energy of Pt can be improved, and the catalytic performance can be improved.

[0004] Common methods for preparing PtPd-based multi-element alloy catalysts include carbon thermal shock method, pyrolysis method and microwave heating method, but these methods have harsh preparation conditions. The high temperature conditions required make the morphology of the prepared multi-element alloy material uncontrollable, and the surface active sites of the synthesized large-scale zero-dimensional material are limited. Therefore, inventing a simple and controllable universal low-temperature synthesis method to achieve controllable growth of multi-element alloy catalysts at the atomic scale (sub-nanometer scale) is the key to achieving efficient ORR catalysts, which is of great significance in reducing catalyst costs and improving catalyst performance. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a platinum-palladium-based multi-element alloy sub-nanobelt catalyst and its preparation method and application. The method of the present invention has mild preparation conditions and adjustable elemental components. The prepared catalyst has the characteristics of large specific surface area, low precious metal content, high catalytic activity and excellent stability.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention:

[0008] A platinum-palladium-based multi-element alloy sub-nanobelt catalyst (PtPd-based multi-element alloy sub-nanobelt catalyst), the element composition of which is PtPdM; the M is a non-precious metal, and the non-precious metal is one or more of Fe, Co, Ni, Ga and Zn.

[0009] The element components of the platinum-palladium-based multi-element alloy sub-nanobelt catalyst of the present invention can be adjusted from ternary to septenary, for example, it can be composed of elements such as PtPdFe, PtPdFeCo, PtPdFeCoNi, PtPdFeCoNiGa, PtPdFeCoNiGaZn, etc.

[0010] The platinum-palladium-based multi-element alloy sub-nanobelt catalyst of the present invention has a micron-level length and a sub-nano-level thickness.

[0011] The second technical solution of the present invention:

[0012] A method for preparing the platinum-palladium-based multi-element alloy sub-nanobelt catalyst comprises the following steps:

[0013] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and a non-noble metal salt in deionized water, and dissolving by ultrasonication to obtain a metal precursor solution;

[0014] (2) dissolving a reducing agent and a morphology control agent in an organic solvent and performing ultrasonic treatment to obtain a reducing solution;

[0015] (3) Ultrasonic mixing the metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) to obtain a mixture, then heating the mixture for reaction, then collecting the product by centrifugation and calcining it to obtain the platinum-palladium-based multi-element alloy sub-nanobelt catalyst.

[0016] The present invention mainly dissolves a plurality of metal salts in deionized water to obtain a metal precursor solution, dissolves a reducing agent and a morphology control agent in an organic solvent to obtain a reducing solution, fully mixes the two solutions, and under heating conditions, realizes a two-dimensional controllable growth of a multi-component alloy at the atomic scale; and then, through a low-temperature calcination treatment in a reducing atmosphere, the multi-component alloy is highly crystallized to obtain a PtPd-based multi-component alloy sub-nanobelt catalyst. The catalyst has the characteristics of large specific surface area, rich active sites and low precious metal content, and exhibits excellent catalytic activity and stability for oxygen reduction reaction in an acidic electrolyte.

[0017] Furthermore, in the metal precursor solution, the concentration of sodium tetrachloropalladate is 8-25 mM, the concentration of chloroplatinic acid hexahydrate is 0.5-5.0 mM, and the concentration of non-precious metal salt is 3-15 mM. When there are multiple non-precious metal salts, the concentration is the concentration of each non-precious metal salt alone.

[0018] Furthermore, the non-precious metal salt is one or more of ferric chloride hexahydrate, nickel chloride hexahydrate, cobalt chloride hexahydrate, hydrated gallium nitrate and zinc chloride.

[0019] Furthermore, the reducing agent is at least two of glucose, citric acid, ascorbic acid, sodium borohydride, molybdenum hexacarbonyl, cobalt carbonyl and tungsten hexacarbonyl, and the morphology control agent is one of polyvinyl pyrrolidone, tetrabutylammonium bromide, hexadecyltrimethylammonium bromide and sodium dodecylbenzene sulfonate.

[0020] Furthermore, the organic solvent is one of ethylenediamine, diethylenetriamine and oleylamine.

[0021] Furthermore, the concentration of the reducing agent in the reducing solution is 15-75 mM, and the concentration of the morphology control agent is 0.5-2.0 M. When there are multiple reducing agents or morphology control agents, the above concentrations represent the concentration of each reducing agent or morphology control agent alone.

[0022] Furthermore, the volume ratio of the metal precursor solution to the reducing solution is 1:(0.2-5).

[0023] Furthermore, the heating reaction is carried out at a temperature of 90 to 125° C. and for a time of 4 to 16 hours.

[0024] Furthermore, the calcination treatment is carried out in H 2 / Ar atmosphere, heat to 150-300°C at a rate of 5°C / min and keep warm for 0.5-4.0h.

[0025] Furthermore, the H 2 H / Ar atmosphere 2 The volume fraction is 5%.

[0026] Furthermore, the solution used for the centrifugation is water and / or ethanol, the number of centrifugation is 2 to 5 times, the centrifugal speed is 7500 to 10000 r / min, and the time is 3 to 8 min.

[0027] The third technical solution of the present invention:

[0028] The application of the platinum-palladium based multi-element alloy sub-nanobelt catalyst in electrocatalytic oxygen reduction reaction.

[0029] Compared with the prior art, the present invention has the following advantages and technical effects:

[0030] (1) The synthesis method of the present invention is simple and controllable, does not require complicated and expensive equipment, can realize multi-element alloying of Pt with a variety of non-precious metals, and the product composition is controllable, which has strong universality.

[0031] (2) The catalyst prepared by the present invention has an ultra-thin two-dimensional structure with a thickness of up to sub-nanometer scale, a high surface atomic exposure rate, and abundant active sites, thus realizing the controllable construction of atomic-scale two-dimensional multi-element alloy catalytic materials.

[0032] (3) The Pt atomic content in the platinum-palladium-based multi-element alloy sub-nanobelt catalyst obtained by the present invention only accounts for 5% to 10% of the total atomic content, which significantly reduces the preparation cost of the catalyst. The constructed multi-element alloy sub-nanomaterial with a wide range of adjustable components and electronic structures stimulates the diversity of active sites and achieves a significant improvement in electrocatalytic activity; at the same time, due to the formation of more bonding states between different metals, the structure of the multi-element alloy is more compact and has excellent stability. The rich regulation of the atomic / electronic structure of the catalytic material is achieved through multi-element alloying, and the high exposure of the active sites of the catalytic material is achieved through atomic-scale two-dimensional structuring, which provides important technical support for the design and preparation of new alloy materials (high entropy / medium entropy) catalysts.

[0033] (4) The platinum-palladium-based multi-element alloy sub-nanobelt catalyst obtained in the present invention exhibits excellent ORR catalytic performance in acidic electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] Figure 1 1 is a transmission electron microscope (TEM) image of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 1 of the present invention, wherein a is a low-magnification TEM image of the PtPd-based five-element alloy sub-nanobelt catalyst, and b is a high-magnification TEM image of the PtPd-based five-element alloy sub-nanobelt catalyst;

[0036] Figure 2 The X-ray diffraction (XRD) patterns of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 2 of the present invention before and after calcination;

[0037] Figure 3 The ORR performance comparison diagram of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 3 of the present invention and the commercial Pt / C catalyst (Comparative Example 1) in an acidic electrolyte, wherein a is the ORR performance comparison diagram of the PtPd-based five-element alloy sub-nanobelt catalyst and the commercial Pt / C catalyst in 0.1M HClO 4 A comparison of ORR performance curves in acidic electrolytes, b is a comparison of mass activity (MA) of PtPd-based five-element alloy sub-nanobelt catalysts and commercial Pt / C catalysts;

[0038] Figure 4 This is a comparison chart of the ORR performance curves of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 3 of the present invention and the commercial Pt / C catalyst (Comparative Example 1) before and after 30,000 cycles in an acidic electrolyte, wherein a is a comparison chart of the ORR performance curves of the PtPd-based five-element alloy sub-nanobelt catalyst before and after 30,000 cycles, and b is a comparison chart of the ORR performance curves of the commercial Pt / C catalyst before and after 30,000 cycles. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0041] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0042] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0043] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0044] The embodiment of the present invention proposes a platinum-palladium-based multi-element alloy sub-nanobelt catalyst (PtPd-based multi-element alloy sub-nanobelt catalyst), the element composition of which is PtPdM; the M is a non-precious metal, and the non-precious metal is one or more of Fe, Co, Ni, Ga and Zn.

[0045] In the embodiment of the present invention, the elemental composition of the platinum-palladium-based multi-element alloy sub-nanobelt catalyst can be adjusted from ternary to septenary, for example, it can be composed of elements such as PtPdFe, PtPdFeCo, PtPdFeCoNi, PtPdFeCoNiGa, PtPdFeCoNiGaZn, etc.; the embodiment of the present invention takes a quinary alloy sub-nanobelt catalyst as an example for preparation, but it is not intended to limit the technical solution of the present invention.

[0046] The embodiment of the present invention also provides a method for preparing the platinum-palladium-based multi-element alloy sub-nanobelt catalyst, comprising the following steps:

[0047] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and a non-noble metal salt in deionized water, and dissolving by ultrasonication to obtain a metal precursor solution;

[0048] (2) dissolving a reducing agent and a morphology control agent in an organic solvent and performing ultrasonic treatment to obtain a reducing solution;

[0049] (3) Ultrasonic mixing the metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) to obtain a mixture, then heating the mixture for reaction, then collecting the product by centrifugation and calcining it to obtain the platinum-palladium-based multi-element alloy sub-nanobelt catalyst.

[0050] In a preferred embodiment of the present invention, in the metal precursor solution, the concentration of sodium tetrachloropalladate is 8-25 mM, the concentration of chloroplatinic acid hexahydrate is 0.5-5.0 mM, and the concentration of the non-precious metal salt is 3-15 mM. When there are multiple non-precious metal salts, the concentration is the concentration of each non-precious metal salt alone.

[0051] In a preferred embodiment of the present invention, the non-precious metal salt is one or more of ferric chloride hexahydrate, nickel chloride hexahydrate, cobalt chloride hexahydrate, hydrated gallium nitrate and zinc chloride.

[0052] In a preferred embodiment of the present invention, the reducing agent is at least two of glucose, citric acid, ascorbic acid, sodium borohydride, molybdenum hexacarbonyl, cobalt carbonyl and tungsten hexacarbonyl, and the morphology control agent is one of polyvinyl pyrrolidone, tetrabutylammonium bromide, hexadecyltrimethylammonium bromide and sodium dodecylbenzene sulfonate.

[0053] In a preferred embodiment of the present invention, the organic solvent is one of ethylenediamine, diethylenetriamine and oleylamine.

[0054] In a preferred embodiment of the present invention, the concentration of the reducing agent in the reducing solution is 15-75 mM, and the concentration of the morphology control agent is 0.5-2.0 M. When there are multiple reducing agents or morphology control agents, the above concentrations represent the concentration of each reducing agent or morphology control agent alone.

[0055] In a preferred embodiment of the present invention, the volume ratio of the metal precursor solution to the reducing solution is 1:(0.2-5).

[0056] In a preferred embodiment of the present invention, the temperature of the heating reaction is 90-125° C. and the time is 4-16 hours.

[0057] In a preferred embodiment of the present invention, the calcination treatment is carried out in H 2 / Ar atmosphere, heat to 150-300°C at a rate of 5°C / min and keep warm for 0.5-4.0h.

[0058] In a preferred embodiment of the present invention, the H 2 H / Ar atmosphere 2 The volume fraction is 5%.

[0059] In a preferred embodiment of the present invention, the centrifugal solution is water and / or ethanol, the number of centrifugation is 2 to 5 times, the centrifugal speed is 7500 to 10000 r / min, and the time is 3 to 8 min.

[0060] All raw materials used in the examples of the present invention are commercially available.

[0061] The technical solution of the present invention is further illustrated by the following embodiments.

[0062] Example 1

[0063] A method for preparing a PtPdFeCoNi five-element alloy sub-nanobelt catalyst comprises the following steps:

[0064] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and non-precious metal salts (ferric chloride hexahydrate, cobalt chloride hexahydrate and nickel chloride hexahydrate) in a centrifuge tube filled with deionized water, and ultrasonicating for 60 minutes to obtain a metal precursor solution, wherein the concentration of sodium tetrachloropalladate in the metal precursor solution is 25 mM, the concentration of chloroplatinic acid hexahydrate is 5 mM, the concentration of ferric chloride hexahydrate is 10 mM, the concentration of cobalt chloride hexahydrate is 12 mM, and the concentration of nickel chloride hexahydrate is 15 mM;

[0065] (2) dissolving glucose, cobalt carbonyl and tetrabutylammonium bromide in a diethylenetriamine solvent, and subjecting the mixture to ultrasonic treatment for 90 min to obtain a reduction solution, wherein the concentration of glucose in the reduction solution is 70 mM, the concentration of cobalt carbonyl is 40 mM, and the concentration of tetrabutylammonium bromide is 2.0 M;

[0066] (3) The metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) were mixed in a volume ratio of 1:5, and the mixture was obtained after being fully mixed by ultrasonic treatment for 60 minutes. The mixture was then heated at 90° C. for 16 hours. The solution after the reaction was washed with water and ethanol respectively and centrifuged twice at a centrifugal speed of 7500 r / min for 8 minutes. The centrifugal product was collected after drying and then centrifuged in 5% H 2 / Ar atmosphere, and heated to 150°C at a rate of 5°C / min and kept warm for 4.0 h to obtain a PtPdFeCoNi quinary alloy sub-nanobelt catalyst.

[0067] Example 2

[0068] A method for preparing a PtPdCoNiZn five-element alloy sub-nanobelt catalyst comprises the following steps:

[0069] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and non-precious metal salts (cobalt chloride hexahydrate, nickel chloride hexahydrate and zinc chloride) in a centrifuge tube filled with deionized water, and ultrasonicating for 10 minutes to obtain a metal precursor solution, wherein the concentration of sodium tetrachloropalladate in the metal precursor solution is 8 mM, the concentration of chloroplatinic acid hexahydrate is 0.5 mM, the concentration of cobalt chloride hexahydrate is 3 mM, the concentration of nickel chloride hexahydrate is 5 mM, and the concentration of zinc chloride is 4 mM;

[0070] (2) dissolving sodium borohydride, molybdenum hexacarbonyl and hexadecyltrimethylammonium bromide in an ethylenediamine solvent, and subjecting the solution to ultrasonic treatment for 10 minutes to obtain a reduction solution, wherein the concentration of sodium borohydride in the reduction solution is 15 mM, the concentration of molybdenum hexacarbonyl is 75 mM, and the concentration of hexadecyltrimethylammonium bromide is 0.5 M;

[0071] (3) The metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) were mixed in a volume ratio of 1:0.2, and the mixture was obtained after being fully mixed by ultrasonic treatment for 20 minutes. The mixture was then heated at 125° C. for 4 hours. The solution after the reaction was washed with water and ethanol respectively and centrifuged 5 times at a centrifugal speed of 10000 r / min for 3 minutes. The product was collected after drying and centrifuged at 5% H 2 / Ar atmosphere, and heated to 300°C at a rate of 5°C / min and kept warm for 0.5h to obtain a PtPdCoNiZn quinary alloy sub-nanobelt catalyst.

[0072] Example 3

[0073] A method for preparing a PtPdCoGaZn five-element alloy sub-nanobelt catalyst comprises the following steps:

[0074] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and non-precious metal salts (cobalt chloride hexahydrate, gallium nitrate hydrate and zinc chloride) in a centrifuge tube filled with deionized water, and ultrasonicating for 30 minutes to obtain a metal precursor solution, wherein the concentration of sodium tetrachloropalladate in the metal precursor solution is 15 mM, the concentration of chloroplatinic acid hexahydrate is 3 mM, the concentration of cobalt chloride hexahydrate is 10 mM, the concentration of gallium nitrate hydrate is 10 mM, and the concentration of zinc chloride is 10 mM;

[0075] (2) dissolving citric acid, cobalt carbonyl and sodium dodecylbenzene sulfonate in ethylenediamine solvent, and subjecting to ultrasonic treatment for 60 min to obtain a reduction solution, wherein the concentration of citric acid in the reduction solution is 40 mM, the concentration of cobalt carbonyl is 60 mM, and the concentration of sodium dodecylbenzene sulfonate is 1.2 M;

[0076] (3) The metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) were mixed in a volume ratio of 1:3, and the mixture was obtained after being fully mixed by ultrasonic treatment for 50 minutes. The mixture was then heated at 110° C. for 10 hours. The solution after the reaction was washed with water and ethanol respectively and centrifuged 4 times at a centrifugal speed of 9000 r / min for 5 minutes. The product was collected after drying and centrifuged at 5% H 2 / Ar atmosphere, and heated to 200°C at a rate of 5°C / min and kept warm for 2h to obtain a PtPdCoGaZn quinary alloy sub-nanobelt catalyst.

[0077] Example 4

[0078] A method for preparing a PtPdFeNiGa five-element alloy sub-nanobelt catalyst comprises the following steps:

[0079] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and non-precious metal salts (ferric chloride hexahydrate, gallium nitrate hydrate and nickel chloride hexahydrate) in a centrifuge tube filled with deionized water, and ultrasonicating for 20 minutes to obtain a metal precursor solution, wherein the concentration of sodium tetrachloropalladate in the metal precursor solution is 12 mM, the concentration of chloroplatinic acid hexahydrate is 4 mM, the concentration of ferric chloride hexahydrate is 6 mM, the concentration of gallium nitrate hydrate is 10 mM, and the concentration of nickel chloride hexahydrate is 6 mM;

[0080] (2) dissolving ascorbic acid, molybdenum hexacarbonyl and polyvinyl pyrrolidone in ethylenediamine solvent and subjecting to ultrasonic treatment for 40 min to obtain a reduction solution, wherein the concentration of ascorbic acid in the reduction solution is 30 mM, the concentration of molybdenum hexacarbonyl is 50 mM, and the concentration of polyvinyl pyrrolidone is 1.5 M;

[0081] (3) The metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) were mixed in a volume ratio of 1:2, and the mixture was obtained after being fully mixed by ultrasonication for 30 minutes. The mixture was then heated at 120° C. for 8 hours. The solution after the reaction was washed with water and ethanol respectively and centrifuged 3 times at a centrifugal speed of 8000 r / min for 3 minutes. The product was collected after drying and centrifuged at 5% H 2 / Ar atmosphere, and then the temperature was raised to 250°C at a rate of 5°C / min and kept at this temperature for 1 h to obtain a PtPdFeNiGa quinary alloy sub-nanobelt catalyst.

[0082] Example 5

[0083] A method for preparing a PtPdNiGaZn five-element alloy sub-nanobelt catalyst comprises the following steps:

[0084] (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and non-precious metal salts (hydrated zinc chloride, hydrated gallium nitrate and hexahydrated nickel chloride) in a centrifuge tube filled with deionized water, and ultrasonicating for 40 minutes to obtain a metal precursor solution, wherein the concentration of sodium tetrachloropalladate in the metal precursor solution is 20 mM, the concentration of chloroplatinic acid hexahydrate is 4 mM, the concentration of zinc chloride hydrate is 15 mM, the concentration of gallium nitrate hydrate is 15 mM, and the concentration of nickel chloride hexahydrate is 15 mM;

[0085] (2) dissolving citric acid, molybdenum hexacarbonyl and cetyltrimethylammonium bromide in an oleylamine solvent, and subjecting the solution to ultrasonic treatment for 80 min to obtain a reduction solution, wherein the concentration of citric acid in the reduction solution is 60 mM, the concentration of molybdenum hexacarbonyl is 70 mM, and the concentration of cetyltrimethylammonium bromide is 1.8 M;

[0086] (3) The metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) were mixed in a volume ratio of 1:1, and the mixture was obtained after being fully mixed by ultrasonic treatment for 40 minutes. The mixture was then heated at 100° C. for 12 hours. The solution after the reaction was washed with water and ethanol respectively and centrifuged twice at a centrifugal speed of 8500 r / min for 4 minutes. The product was collected after drying and centrifuged at 5% H 2 / Ar atmosphere, the temperature was raised to 220°C at a rate of 5°C / min and kept warm for 3 h to obtain a PtPdNiGaZn quinary alloy sub-nanobelt catalyst.

[0087] Comparative Example 1

[0088] Commercial Pt / C catalyst (purchased from Suzhou Yilongsheng Energy Technology Co., Ltd.).

[0089] Performance Testing

[0090] Figure 1 The transmission electron microscope (TEM) image of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 1 of the present invention. Among them, a is a low-magnification TEM image of the PtPd-based five-element alloy sub-nanobelt catalyst, and b is a high-magnification TEM image of the PtPd-based five-element alloy sub-nanobelt catalyst. It can be seen that the prepared PtPd-based five-element alloy sub-nanobelt catalyst has a micron-level length and a sub-nanoscale thickness of 0.7 to 1.0 nm.

[0091] Figure 2 The X-ray diffraction (XRD) patterns of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 2 of the present invention before and after calcination show that the PtPd-based five-element alloy sub-nanobelt catalyst has poor crystallinity before calcination, and has a face-centered cubic phase structure with high crystallinity after low-temperature calcination without segregation.

[0092] Figure 3 The ORR performance comparison diagram of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 3 of the present invention and the commercial Pt / C catalyst (Comparative Example 1) in an acidic electrolyte, wherein a is the ORR performance comparison diagram of the PtPd-based five-element alloy sub-nanobelt catalyst and the commercial Pt / C catalyst in 0.1M HClO 4 The ORR performance curve comparison of acidic electrolyte shows that the half-wave potential of the PtPd-based five-element alloy sub-nanobelt catalyst can reach 0.90V (relative to the standard hydrogen potential), which is higher than the half-wave potential of commercial Pt / C of 0.85V; b is a comparison of the mass activity (MA) of the PtPd-based five-element alloy sub-nanobelt catalyst and the commercial Pt / C catalyst. It can be seen that the mass activity of the PtPd-based five-element alloy sub-nanobelt catalyst at 0.9V is 3.02A / mg Pt, which is the same as commercial Pt / C (0.18A / mg Pt ) 16.8 times. This proves that the PtPd-based five-element alloy sub-nanobelt catalyst prepared in the embodiment of the present invention has excellent acidic ORR activity in acidic electrolyte.

[0093] Figure 4 The ORR performance curve comparison diagram of the PtPd-based five-element alloy sub-nanobelt catalyst prepared in Example 3 of the present invention and the commercial Pt / C catalyst (Comparative Example 1) before and after 30,000 cycles in an acidic electrolyte. Among them, b is a comparison diagram of the ORR performance curve of the commercial Pt / C catalyst before and after 30,000 cycles. It can be seen that after 30,000 cycles, the half-wave potential of the commercial Pt / C catalyst is 0.80V, which is 0.05V lower than before the cycle test. a is a comparison diagram of the ORR performance curve of the PtPd-based five-element alloy sub-nanobelt catalyst before and after 30,000 cycles. It can be seen that after 30,000 cycles, the half-wave potential of the PtPd-based five-element alloy sub-nanobelt catalyst is still maintained at 0.88V, which is only 0.02V lower than before the cycle test. This proves that the PtPd-based five-element alloy sub-nanobelt catalyst prepared by the present invention has relatively excellent ORR stability.

[0094] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A platinum-palladium-based multi-element alloy sub-nanobelt catalyst, characterized in that: The elemental composition is PtPdM; The M is a non-precious metal, and the non-precious metal is one or more of Fe, Co, Ni, Ga and Zn.

2. A method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 1, characterized in that: The following steps are involved: (1) dissolving sodium tetrachloropalladate, chloroplatinic acid hexahydrate and a non-noble metal salt in deionized water, and dissolving by ultrasonication to obtain a metal precursor solution; (2) dissolving a reducing agent and a morphology control agent in an organic solvent and performing ultrasonic treatment to obtain a reducing solution; (3) Ultrasonic mixing the metal precursor solution obtained in step (1) and the reducing solution obtained in step (2) to obtain a mixture, then heating the mixture for reaction, then collecting the product by centrifugation and calcining it to obtain the platinum-palladium-based multi-element alloy sub-nanobelt catalyst.

3. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: In the metal precursor solution, the concentration of sodium tetrachloropalladate is 8-25 mM, the concentration of chloroplatinic acid hexahydrate is 0.5-5.0 mM, and the concentration of the non-noble metal salt is 3-15 mM.

4. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: The non-noble metal salt is one or more of ferric chloride hexahydrate, nickel chloride hexahydrate, cobalt chloride hexahydrate, hydrated gallium nitrate and zinc chloride.

5. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: The reducing agent is at least two of glucose, citric acid, ascorbic acid, sodium borohydride, molybdenum hexacarbonyl, cobalt carbonyl and tungsten hexacarbonyl; the morphology control agent is one of polyvinyl pyrrolidone, tetrabutylammonium bromide, hexadecyltrimethylammonium bromide and sodium dodecylbenzene sulfonate; and the organic solvent is one of ethylenediamine, diethylenetriamine and oleylamine.

6. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: The concentration of the reducing agent in the reducing solution is 15-75 mM, and the concentration of the morphology controlling agent is 0.5-2.0 M.

7. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: The volume ratio of the metal precursor solution to the reducing solution is 1:(0.2-5).

8. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: The heating reaction temperature is 90-125°C and the time is 4-16 hours; and / or, The centrifugal solution is water and / or ethanol, the number of centrifugation is 2 to 5 times, the centrifugal speed is 7500 to 10000 r / min, and the time is 3 to 8 minutes.

9. The method for preparing the platinum-palladium based multi-element alloy sub-nanobelt catalyst according to claim 2, characterized in that: The calcination treatment is carried out in a H2 / Ar atmosphere, with the temperature being raised to 150-300°C at a rate of 5°C / min and kept at that temperature for 0.5-4.0h.

10. Use of the platinum-palladium-based multi-element alloy sub-nanobelt catalyst as claimed in claim 1 in an electrocatalytic oxygen reduction reaction.

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