Transition metal doped Pt nanocluster / monatomic catalyst with high CO tolerance as well as preparation method and application of transition metal doped Pt nanocluster / monatomic catalyst

Abstract

The invention provides a transition metal doped Pt nanocluster / monatomic catalyst with high CO tolerance as well as a preparation method and application thereof, and belongs to the technical field of fuel cell catalysts. The preparation method comprises the following steps: preparing a mixed solution from a platinum precursor, a transition metal precursor, a carbon carrier and a polyol mixed solvent, carrying out a reaction on the mixed solution in an inert gas atmosphere, and after the reaction is finished, washing and drying to obtain the transition metal doped Pt nanocluster / monatomic catalyst. According to the invention, oxyphilic metals (such as Fe, Co, Ni, Zn and the like) are introduced into a Pt structure, so that the electronic structure of the catalyst can be adjusted, and the HOR activity and CO poisoning resistance of the catalyst can be effectively enhanced. The preparation method is simple and easy to implement, facilitates large-scale production, and has huge market requirements and application in the fields of fuel cells, petrochemical engineering, electrochemical catalysis, environmental protection and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell catalysts, and particularly relates to a Pt-based catalyst. Background Art

[0002] A fuel cell is a device that directly and efficiently converts the chemical energy of a fuel into electrical energy, also known as an electrochemical generator. It is the fourth generation of power generation technology after hydroelectric power generation, thermal power generation, and nuclear power generation. Among them, proton exchange membrane fuel cells have attracted extensive attention due to their low operating temperature, fast startup, high specific power, simple structure, convenient operation, and environmental friendliness. Currently, the hydrogen source mainly comes from the crude hydrogen in methanol reforming for hydrogen production, with a CO content of about 3%-8%. However, due to the extreme sensitivity of commercial platinum-carbon catalysts for fuel cell anodes to CO and their much stronger adsorption ability for CO than H, a large amount of CO occupies the active sites of the catalyst. Therefore, high-purity H2 (greater than 99.999%) is required to ensure the stable operation of the fuel cell, which greatly increases the hydrogen usage cost. Therefore, in order to reduce the hydrogen production cost and improve the working efficiency of the fuel cell anode, it is urgent to develop a high-performance and high-CO tolerance fuel cell anode catalyst.

[0003] To improve the HOR activity and CO anti-poisoning performance of Pt-based catalysts, researchers have adopted various strategies. One strategy is to combine Pt with other metals through alloying methods to change the position of the d-band center on the catalyst surface, thereby weakening the adsorption energy of the catalyst with H and CO, and synergistically enhancing the activity and CO anti-poisoning ability. For example, Patent Publication No. CN101436669A discloses an anode anti-CO catalyst for proton exchange membrane fuel cells and its preparation method. This method uses supercritical CO2 fluid to deposit metal organic compounds onto a conductive carrier and then obtains the catalyst of the present invention through reduction. Patent Publication No. CN116505007A discloses the preparation and application of a single-atom / nanocluster composite anode catalyst for hydrogen fuel cells, including: a carbon-based carrier; metal Ru nanoclusters are loaded on the carbon-based carrier; single atoms are loaded on the metal Ru nanoclusters; the single atoms are Pt, Pd, Ir or Rh; wherein, the mass percentage of Ru is 1wt%-60wt%; the mass percentage of single-atom metal is 0.1wt%-5wt%. By constructing uniformly dispersed single atoms on the surface of the cluster, not only can the atomic utilization of the single atoms reach 100% but also a large number of atomic-level interface sites can be formed, thereby effectively regulating the electronic structure of the nanoclusters and their catalytic microenvironment. Patent Publication No. CN118553938A discloses an anti-poisoning fuel cell anode catalyst, its preparation method, and a fuel cell. The catalyst includes a carrier and alloy nanoparticle clusters loaded on the carrier; the alloy nanoparticle clusters include ruthenium, platinum, and an optional third metal; the third metal is one or more selected from palladium, molybdenum, cobalt, tin, tungsten; the particle size of the alloy nanoparticle clusters is 1-2.5 nm.

[0004] However, these existing technologies still have certain deficiencies. From the perspective of preparation cost, the preparation process using supercritical CO2 fluid has high requirements for equipment and operation, resulting in a significant increase in production cost; the introduction of precious metals such as Ru and Pd further increases the material cost. During the preparation process, the preparation of the single-atom / nanocluster composite catalyst requires precise control of the loading ratio of each component, and the process is complex and difficult to achieve large-scale production. Summary of the Invention

[0005] In view of the above technical problems, the present invention proposes a high-CO-tolerant transition metal-doped Pt nanocluster / single-atom catalyst, its preparation method, and application. The platinum precursor, transition metal precursor, carbon carrier, etc. used are widely sourced, and the preparation process is simple and easy to control, which is conducive to large-scale production.

[0006] To achieve the above object, the technical solution of the present invention is realized as follows:

[0007] A preparation method of a high-CO-tolerant transition metal-doped Pt nanocluster / single-atom catalyst, the preparation method includes:

[0008] (1) Pre-mix a platinum precursor, a transition metal precursor, a carbon support, and a polyol through a certain mixing method.

[0009] (2) React the mixed solution described in step (1) in an environment of inert gas protection and high temperature. After the reaction is completed, cool it to room temperature, wash the surface organic solvent clean, and dry it to obtain a transition metal-doped Pt nanocluster / single-atom catalyst.

[0010] Preferably, the molar ratio of the platinum precursor to the transition metal precursor is 1:0.1 to 10, and preferably the molar ratio is 1:0.1 to 3.

[0011] Preferably, the mass ratio of the platinum precursor to the carbon support is 1:0.5 to 4, and preferably the mass ratio is 1:1 to 2.

[0012] Preferably, the molar ratio of the platinum precursor to ethylene glycol is 1:1000 to 4000.

[0013] Preferably, the mixing method used includes one or more of ultrasonic, stirring, or oscillation.

[0014] Preferably, the reaction temperature is 150 to 190 °C, and the time is 0.5 to 3 h.

[0015] Preferably, the drying temperature is 50 to 80 °C, and the time is 12 to 24 h.

[0016] Preferably, the polyol is ethylene glycol, propylene glycol, glycerol, or triethylene glycol.

[0017] Preferably, the platinum precursor is chloroplatinic acid, platinum chloride, or sodium chloroplatinate, and the transition metal in the transition metal precursor is any one of cobalt, nickel, iron, zinc, manganese, cadmium, chromium, silver, and molybdenum; the transition metal precursor is cobalt acetate tetrahydrate, nickel acetate tetrahydrate, iron acetate, zinc acetate dihydrate, silver acetate tetrahydrate, manganese acetate tetrahydrate, copper acetate monohydrate, cadmium acetate dihydrate, cobalt nitrate hexahydrate, copper nitrate trihydrate, manganese nitrate tetrahydrate, nickel nitrate hexahydrate, chromium nitrate nonahydrate, molybdenum nitrate pentahydrate, iron nitrate nonahydrate, zinc nitrate hexahydrate, iron sulfate hydrate, cobalt sulfate heptahydrate, nickel sulfate heptahydrate, zinc sulfate heptahydrate, or copper sulfate hexahydrate.

[0018] Preferably, the carbon support is Vulcan XC-72, EC-300J, EC-600J, ECP-600JD, Blackpearls2000, PRINTEX XE2-B, PRINTEX L6, or HIBLAXK40B2.

[0019] Preferably, the inert gas is one of argon, helium, and nitrogen.

[0020] In a second aspect, the present invention provides a transition metal-doped Pt nanocluster / single-atom catalyst, which is prepared by the preparation method described in the first aspect.

[0021] The catalyst prepared by the present invention is a transition metal-doped Pt nanocluster / single-atom, and the size of a single particle is only about 2 nm, and it has good catalytic performance and anti-CO poisoning performance.

[0022] Advantages of the present invention:

[0023] (1) In the present invention, a platinum precursor, a transition metal precursor, and a carbon support are mixed in ethylene glycol and reduced at high temperature to obtain a transition metal platinum nanocluster catalyst. The preparation method is simple and easy to implement. By controlling the ratio of Pt to the transition metal, the position of the d-band center on the catalyst surface can be changed, thereby weakening the adsorption energy of the catalyst with H and CO, and the activity and anti-CO poisoning ability can be synergistically improved.

[0024] (2) Due to its small size, the catalyst prepared by the present invention is easy to expose more active sites and defects, thereby improving the HOR and CO oxidation activities of the catalyst. Introducing an oxygenophilic metal (such as Fe, Co, Ni, Zn, etc.) into the Pt structure can adjust the electronic structure of the catalyst and effectively enhance its HOR activity and anti-CO poisoning performance.

[0025] (3) The platinum precursor, transition metal precursor, and carbon support used in the present invention are widely sourced, and the preparation process is simple and easy to control, which is conducive to large-scale production. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 It is the atomic-level HAADF-STEM image of the transition metal-doped Pt nanocluster / single-atom catalyst in Embodiments 1-3 of the present invention.

[0028] Figure 2 It is the XRD pattern of the transition metal-doped Pt nanocluster / single-atom catalyst in Embodiments 1-3 of the present invention.

[0029] Figure 3It is the XPS diagram of the transition metal-doped Pt nanocluster / single-atom catalyst in Examples 1-3 of the present invention and Pt / C in Comparative Example 1.

[0030] Figure 4 It is the HOR polarization curve diagram of the transition metal-doped Pt nanocluster / single-atom catalyst in Examples 1-3 of the present invention and Pt / C in Comparative Example 1 under acidic conditions.

[0031] Figure 5 It is the stability test curve of the transition metal-doped Pt nanocluster / single-atom catalyst in Examples 1-3 of the present invention and Pt / C in Comparative Example 1 by chronoamperometry (CA) in a 0.1 M HClO4 solution saturated with H2.

[0032] Figure 6 It is the polarization curve of the transition metal-doped Pt nanocluster / single-atom catalyst in Examples 1-3 of the present invention and Pt / C in a 0.1 M HClO4 saturated with H2 / 50 ppm CO.

[0033] Figure 7 It is the stability test curve of the transition metal-doped Pt nanocluster / single-atom catalyst in Examples 1-3 of the present invention and Pt / C by chronoamperometry (CA) in a 0.1 M HClO4 solution saturated with H2 / 50 ppm CO. Detailed implementation manners

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Example 1

[0036] A highly CO-tolerant transition metal-doped Pt nanocluster / single-atom catalyst, and the preparation method includes the following steps:

[0037] (1) Put 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of iron acetate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol into a three-necked flask, and mix them under ultrasonic for 1 h to obtain a mixed solution A.

[0038] (2) Heat the mixed solution A obtained in step (1) to 160 °C under argon, keep it for 1 h, immediately transfer it to an ice bath after the reaction ends, and cool it to room temperature to obtain a mixed solution B.

[0039] (3) The mixture B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Fe-doped Pt nanoclusters / single atoms.

[0040] Example 2

[0041] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, and the preparation method comprises the following steps:

[0042] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of cobalt acetate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixture A.

[0043] (2) The mixture A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixture B.

[0044] (3) The mixture B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Co-doped Pt nanoclusters / single atoms.

[0045] Example 3

[0046] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, and the preparation method comprises the following steps:

[0047] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of nickel acetate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixture A.

[0048] (2) The mixture A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixture B.

[0049] (3) The mixture B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Ni-doped Pt nanoclusters / single atoms.

[0050] Example 4

[0051] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, and the preparation method comprises the following steps:

[0052] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of zinc acetate dihydrate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixed solution A.

[0053] (2) The mixed solution A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. Immediately after the reaction, it was transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0054] (3) The precipitate was collected by centrifuging the mixed solution B obtained in step (2) at 10000 rpm, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Zn-doped Pt nanoclusters / single atoms.

[0055] Example 5

[0056] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method includes the following steps:

[0057] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of manganese acetate tetrahydrate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixed solution A.

[0058] (2) The mixed solution A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. Immediately after the reaction, it was transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0059] (3) The precipitate was collected by centrifuging the mixed solution B obtained in step (2) at 10000 rpm, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Mn-doped Pt nanoclusters / single atoms.

[0060] Example 6

[0061] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method includes the following steps:

[0062] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of copper nitrate trihydrate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixed solution A.

[0063] (2) The mixed solution A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. Immediately after the reaction, it was transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0064] (3) The mixture B obtained in step (2) was centrifuged at 10,000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Cu-doped Pt nanoclusters / single atoms.

[0065] Example 7

[0066] A highly CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method comprising the following steps:

[0067] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of chromium nitrate nonahydrate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixture A.

[0068] (2) The mixture A obtained in step (1) was heated to 160 °C under argon and held for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixture B.

[0069] (3) The mixture B obtained in step (2) was centrifuged at 10,000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Cr-doped Pt nanoclusters / single atoms.

[0070] Example 8

[0071] A highly CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method comprising the following steps:

[0072] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of molybdenum nitrate tetrahydrate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasonic for 1 h to obtain a mixture A.

[0073] (2) The mixture A obtained in step (1) was heated to 160 °C under argon and held for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixture B.

[0074] (3) The mixture B obtained in step (2) was centrifuged at 10,000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Mo-doped Pt nanoclusters / single atoms.

[0075] Example 9

[0076] A highly CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method comprising the following steps:

[0077] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of silver acetate tetrahydrate, 60 mg of Vulcan XC-72, and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixed solution A.

[0078] (2) The mixed solution A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0079] (3) The mixed solution B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Ag-doped Pt nanoclusters / single atoms.

[0080] Example 10

[0081] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, and the preparation method comprises the following steps:

[0082] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of cadmium acetate dihydrate, 60 mg of Vulcan XC-72, and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixed solution A.

[0083] (2) The mixed solution A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0084] (3) The mixed solution B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Cd-doped Pt nanoclusters / single atoms.

[0085] Example 11

[0086] A high CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, and the preparation method comprises the following steps:

[0087] (1) 0.09 mmol of sodium chloroplatinate, 0.009 mmol of iron acetate dihydrate, 20 mg of PRINTEX XE2-B, and 6 ml of propylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixed solution A.

[0088] (2) The mixed solution A obtained in step (1) was heated to 120 °C under argon and maintained for 5 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0089] (3) The mixture B obtained in step (2) was centrifuged at 10,000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Fe-doped Pt nanoclusters / single atoms.

[0090] Example 12

[0091] A highly CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method comprising the following steps:

[0092] (1) 0.01 mmol of chloroplatinic acid hexahydrate, 0.1 mmol of iron(II) acetate dihydrate, 21 mg of EC-300J and 4.2 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixture A.

[0093] (2) The mixture A obtained in step (1) was heated to 190 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixture B.

[0094] (3) The mixture B obtained in step (2) was centrifuged at 10,000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Fe-doped Pt nanoclusters / single atoms.

[0095] Example 13

[0096] A highly CO-tolerant transition metal-doped Pt nanoclusters / single atom catalyst, the preparation method comprising the following steps:

[0097] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of iron(II) acetate dihydrate, 60 mg of Vulcan XC-72 and 5 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixture A.

[0098] (2) The mixture A obtained in step (1) was heated to 160 °C under argon and maintained for 0.5 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixture B.

[0099] (3) The mixture B obtained in step (2) was centrifuged at 10,000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Fe-doped Pt nanoclusters / single atoms.

[0100] The transition metal-doped Pt nanoclusters / single atom catalysts prepared in Examples 1-3 were analyzed for the microscopic morphology and particle size distribution of the catalysts by atomic-level HAADF-STEM, and the corresponding images are as Figure 1As shown, the nanoparticles in Fe-doped Pt nanoclusters / single atoms, Co-doped Pt nanoclusters / single atoms, and Ni-doped Pt nanoclusters / single atoms are uniformly distributed on the carbon substrate, with average particle sizes of 2.39 nm, 2.02 nm, and 2.12 nm, respectively. Pt is distributed on the surface of the carbon support in the form of nanoclusters and atoms, while Co, Ni, and Fe are distributed on the Pt nanoclusters and the carbon support in the atomic form, regulating the electronic structure of Pt at the atomic scale, shifting the d-band center negatively, changing the binding energy with H and CO, and effectively enhancing the HOR activity and CO anti-poisoning performance of the catalyst.

[0101] The catalysts of Examples 1-3 were subjected to XRD and XPS analyses. As Figure 2 and Figure 3 shown, it can be seen from the figure that compared with the standard card of Pt (PDF#04-0802), the transition metal-doped Pt nanocluster / single atom catalysts all exhibit a face-centered cubic structure (fcc). However, due to the small particle size, the crystallinity of the catalyst is poor, so the intensity of the diffraction peaks is low.

[0102] Comparative Example 1

[0103] This comparative example provides a commercial platinum-carbon catalyst Pt / C (Shenger Nuo 60 wt%).

[0104] Comparative Example 2

[0105] A catalyst, the preparation method includes the following steps:

[0106] (1) Put 0.09 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of iron acetate, 60 mg of Vulcan XC-72, and 20 ml of ethylene glycol into a three-necked flask, adjust the pH to 8 with sodium hydroxide solution, and mix for 1 h under ultrasonic to obtain a mixed solution A.

[0107] (2) Heat the mixed solution A obtained in step (1) to 160 °C under argon, keep it for 1 h, immediately transfer it to an ice bath after the reaction ends, and cool it to room temperature to obtain a mixed solution B.

[0108] (3) Centrifuge the mixed solution B obtained in step (2) at 10000 rpm to collect the precipitate, wash it with ethanol more than 5 times, and dry the washed product in a vacuum oven at 60 °C for 18 h to obtain a catalyst named Fe-doped Pt nanoclusters.

[0109] Comparative Example 3

[0110] A catalyst, the preparation method includes the following steps:

[0111] (1) 0.09 mmol of chloroplatinic acid hexahydrate, 60 mg of Vulcan XC-72 and 20 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixed solution A.

[0112] (2) The mixed solution A obtained in step (1) was heated to 160 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0113] (3) The mixed solution B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain the catalyst Pt nanoclusters / single atoms.

[0114] Comparative Example 4

[0115] (1) 0.27 mmol of chloroplatinic acid hexahydrate, 0.27 mmol of iron acetate, 60 mg of porous carbon and 10 ml of ethylene glycol were placed in a three-necked flask and mixed under ultrasound for 1 h to obtain a mixed solution A.

[0116] (2) The mixed solution A obtained in step (1) was heated to 200 °C under argon and maintained for 1 h. After the reaction was completed, it was immediately transferred to an ice bath and cooled to room temperature to obtain a mixed solution B.

[0117] (3) The mixed solution B obtained in step (2) was centrifuged at 10000 rpm to collect the precipitate, washed with ethanol more than 5 times, and the washed product was dried in a vacuum oven at 60 °C for 18 h to obtain the catalyst PtFe / C.

[0118] Figure 4 is the HOR polarization curve of the transition metal-doped Pt nanoclusters / single atom catalyst in Example 1 of the present invention and commercial Pt / C under acidic conditions. It can be seen from the figure that the half-wave potentials (E 1 / 2 ) of Co-doped Pt nanoclusters / single atoms and Fe-doped Pt nanoclusters / single atoms are both 14 mV, which are 1 mV and 2 mV lower than those of Pt / C and Ni-doped Pt nanoclusters / single atoms respectively, indicating that Co-doped Pt nanoclusters / single atoms and Fe-doped Pt nanoclusters / single atoms have better HOR activity than Pt / C and Ni-doped Pt nanoclusters / single atoms.

[0119] The catalysts of Examples 1-13 and Comparative Examples 1-4 were tested for HOR performance in 0.1 M HClO4. The half-wave potentials (E 1 / 2) All are 14 mV, which are 1 mV and 2 mV lower than Pt / C and Ni-doped Pt nanoclusters / single atoms respectively. Meanwhile, the HOR performance tests were carried out in 0.1 M HClO4 saturated with H2 / 50 ppm CO. The limiting current densities of Co-doped Pt nanoclusters / single atoms, Ni-doped Pt nanoclusters / single atoms, and Fe-doped Pt nanoclusters / single atoms in 0.1 M HClO4 saturated with H2 / 50 ppm CO decreased by 1.79%, 1.95%, and 1.58% respectively compared with the H2-saturated condition. All these decreases were significantly lower than 4.65% of Pt / C. The half-wave potentials of the remaining transition metal-doped Pt nanocluster / single atom catalysts and the decrease rates of the limiting current densities in 0.1 M HClO4 saturated with H2 / 50 ppm CO compared with the H2-saturated condition are shown in Table 1. To quantitatively compare the Pt utilization rates of different catalysts, the amount of Pt used on the working electrode was normalized and compared, and the mass activity (MA) of Examples 1-13 and Comparative Examples 1-3 was calculated using the Koutecky-Levich equation. The results are shown in Figure 1.

[0120] Table 1

[0121]

[0122] In summary, from Examples 1-13, it can be seen that the Fe-doped Pt nanocluster / single atom catalyst in Example 1 was synthesized by the method described in this patent and had the highest HOR activity and the best anti-CO poisoning performance. In Comparative Example 2, due to the addition of sodium hydride, the prepared catalyst only contained nanoclusters and did not contain Pt single atoms. In the present invention, some metals exist in the form of single atoms, which not only improves the utilization rate of metals but also reduces the adsorption energy with CO, greatly enhancing the HOR activity and anti-CO poisoning ability of the catalyst. In Comparative Example 3, no transition metal was added. Although the MA of the catalyst increased, its anti-CO performance was greatly reduced, indicating that transition metal doping can effectively regulate the electronic structure of Pt, thereby enhancing its anti-CO poisoning performance. In Comparative Example 4, the molar ratios of the metal precursor, transition metal precursor, and carbon support were changed, and the nanocluster / single atom catalyst could not be successfully prepared, indicating that the appropriate ratio of metal to carbon support is the key to preparing the nanocluster / single atom catalyst.

[0123] Figure 5 It is the stability polarization curve of the transition metal-doped Pt nanocluster / single atom catalyst and commercial Pt / C in Example 1 of the present invention in a 0.1 M HClO4 solution saturated with H2. At a potential of 0.1 V, the HOR stability of the catalyst was evaluated by chronoamperometry (CA) in a 0.1 M HClO4 solution saturated with H2. The results are as Figure 5As shown. After 30,000 s of CA testing, the current decays of Co-doped Pt nanoclusters / single atoms, Ni-doped Pt nanoclusters / single atoms, and Fe-doped Pt nanoclusters / single atoms were 9.7%, 11.4%, and 10.2% respectively, significantly lower than 28.5% of Pt / C, indicating that the transition metal-doped Pt nanocluster / single atom catalysts have excellent stability.

[0124] Figure 6 Figure 4 is the polarization curves of the transition metal-doped Pt nanocluster / single atom catalysts and commercial Pt / C in 0.1 M HClO4 saturated with H2 / 50 ppm CO in Example 1 of the present invention. As can be seen from the figure, at a voltage of 0.2 V, the limiting current densities of Co-doped Pt nanoclusters / single atoms, Ni-doped Pt nanoclusters / single atoms, and Fe-doped Pt nanoclusters / single atoms in 0.1 M HClO4 saturated with H2 / 50 ppm CO decreased by 1.79%, 1.95%, and 1.58% respectively compared with the H2-saturated condition. All of these decreases were significantly lower than 4.65% of Pt / C.

[0125] Figure 7 Figure 5 is the stability polarization curves of the transition metal-doped Pt nanocluster / single atom catalysts and commercial Pt / C in 0.1 M HClO4 saturated with H2 / 50 ppm CO in Example 1 of the present invention. At a potential of 0.1 V, the stability of the catalysts was evaluated for up to 20,000 s in a 0.1 M HClO4 solution saturated with H2 / 50 ppm CO using the CA method. After 20,000 s of testing, the currents of Co-doped Pt nanoclusters / single atoms and Fe-doped Pt nanoclusters / single atoms were lost by 12.6% and 8.6% respectively, significantly lower than the decay of Ni-doped Pt nanoclusters / single atoms (23.6%). In contrast, Pt / C had a decay of 41.9% after 10,000 s. These results all indicate that Co-doped Pt nanoclusters / single atoms and Fe-doped Pt nanoclusters / single atoms have excellent CO tolerance while maintaining high HOR activity.

[0126] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a transition metal-doped Pt nanocluster / single atom catalyst with high CO tolerance, characterized in that: The preparation method comprises: (1) mixing a platinum precursor, a transition metal precursor, a carbon support and a polyol to prepare a mixed solution; (2) reacting the mixed solution in step (1) in an inert gas atmosphere, and washing and drying after the reaction to obtain a transition metal-doped Pt nanocluster / single atom catalyst.

2. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 1, characterized in that: The molar ratio of the platinum precursor to the transition metal precursor is 1:0.1-10; the mass ratio of the platinum precursor to the carbon carrier is 1:0.5-4; and the molar ratio of the platinum precursor to the polyol is 1:1000-4000.

3. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 2, characterized in that: The reaction temperature is 120-190° C. and the reaction time is 0.5-5 h.

4. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 3, characterized in that: The drying temperature is 50-80° C. and the drying time is 12-24 hours.

5. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 1, characterized in that: The platinum precursor is chloroplatinic acid, platinum chloride or sodium chloroplatinate; the polyol is ethylene glycol, propylene glycol, glycerol or triethylene glycol.

6. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 5, characterized in that: The transition metal in the transition metal precursor is any one of cobalt, nickel, iron, zinc, manganese, cadmium, chromium, silver and molybdenum.

7. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 5, characterized in that: The transition metal precursor is cobalt acetate tetrahydrate, nickel acetate tetrahydrate, ferric acetate, zinc acetate dihydrate, silver acetate tetrahydrate, manganese acetate tetrahydrate, copper acetate monohydrate, cadmium acetate dihydrate, cobalt nitrate hexahydrate, copper nitrate trihydrate, manganese nitrate tetrahydrate, nickel nitrate hexahydrate, chromium nitrate nonahydrate, silver acetate tetrahydrate, molybdenum nitrate pentahydrate, iron nitrate nonahydrate, zinc nitrate hexahydrate, iron sulfate hydrate, cobalt sulfate heptahydrate, nickel sulfate heptahydrate, zinc sulfate heptahydrate or copper sulfate hexahydrate.

8. The method for preparing the transition metal-doped Pt nanocluster / single atom anode catalyst with high CO tolerance according to claim 1, characterized in that: The carbon carrier is carbon black; the carbon black is Vulcan XC-72, EC-300J, EC-600J, ECP-600JD, Blackpearls 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK40B2.

9. The transition metal-doped Pt nanocluster / single atom catalyst prepared by the preparation method according to any one of claims 1 to 8, characterized in that: Pt is distributed on the surface of carbon support in the form of nanoclusters and atoms, and transition metals are distributed on Pt nanoclusters and carbon support in the form of atoms.

10. The use of the transition metal-doped Pt nanocluster / single atom catalyst in a proton exchange membrane fuel cell according to claim 9, characterized in that: The anode of the proton exchange membrane fuel cell includes transition metal-doped Pt nanoclusters / single atom catalysts.

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