Anti-CO poisoning catalyst for fuel cell, preparation method thereof and fuel cell

Abstract

The invention provides an anti-CO poisoning catalyst of a fuel cell, a preparation method of the anti-CO poisoning catalyst and the fuel cell. The anti-CO poisoning catalyst comprises a monatomic catalyst base material and Pt nanoparticles loaded on the surface of the monatomic catalyst base material, the monatomic catalyst base material comprises a nitrogen-doped carbon material and Rh monatomic active sites loaded on the nitrogen-doped carbon material. In the anti-CO poisoning catalyst provided by the invention, when the monatomic catalyst base material is also modified with the S element, the modified S element can enhance regulation and control on the Pt nano-particles and reduce the d band center of Pt, so that the CO adsorption of the Pt nano-particles is weakened, and the CO poisoning resistance is improved; furthermore, the modified S element can also form a synergistic effect with an Rh monatomic active site, so that the CO adsorption of the Pt nano-particles is further reduced, and the CO poisoning resistance is further improved.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, and relates to an anti-CO poisoning catalyst for fuel cells, and more particularly to an anti-CO poisoning catalyst for fuel cells, its preparation method, and the fuel cell itself. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) are considered the best technological route for achieving a dual-carbon strategy due to their zero-pollution, long driving range, and excellent low-temperature performance, especially in the commercial vehicle and heavy-duty truck sectors. However, in the operation of PEMFCs, CO acts as a "poison" to platinum catalysts: even trace amounts (ppm level) of CO in the fuel will strongly adsorb onto the platinum active sites, leading to the "poisoning" of these sites and a sharp decline in battery performance.

[0003] In existing technologies, to avoid CO poisoning, PEMFCs require the use of extremely high-purity hydrogen (typically requiring CO content below 0.2 ppm or even 0.1 ppm). This necessitates complex and expensive fuel purification systems (such as pressure swing adsorption and membrane separation) or the use of precious metal-based preferential oxidation (PROX) reactors for deep CO removal. However, these approaches lead to high fuel cell costs, increased energy consumption, and increased overall complexity and maintenance difficulty.

[0004] Based on this, existing technologies have developed CO-resistant catalysts. These catalysts enable batteries to operate stably and efficiently in hydrogen containing trace amounts of CO (such as reformed gas or industrial by-product hydrogen), significantly improving the actual performance and long-term operational stability of the battery. They can simplify or even eliminate expensive deep purification units, significantly reducing the cost and complexity of the entire fuel cell system. Furthermore, they enable more economical and efficient utilization of a wider range of lower-cost "non-pure hydrogen" fuels, such as hydrogen-rich gas (inevitably containing 0.5%-1% or even higher CO) produced through the reforming of fossil fuels (natural gas, methanol, gasoline, diesel), and industrial by-product hydrogen (such as hydrogen from chlor-alkali and steel industry waste gases, which typically contain impurities). This helps reduce the pressure on hydrogen refueling stations to provide ultra-high purity hydrogen, promotes the construction and development of hydrogen energy infrastructure, and improves the flexibility and energy efficiency of fuel utilization.

[0005] CN101436669A discloses a CO-resistant catalyst for proton exchange membrane fuel cells and its preparation method. The method involves depositing a metal-organic compound onto a conductive support using supercritical CO2 fluid, followed by reduction to obtain the catalyst of this invention. The PtM / C catalyst prepared in this document can be used as a CO-resistant catalyst for proton exchange membrane fuel cells.

[0006] CN118073580A discloses a highly CO-resistant and highly anti-reverse-polarity proton exchange membrane fuel cell catalyst and its preparation method. The preparation method is as follows: a CO-resistant catalyst and an anti-reverse-polarity catalyst are mixed and then calcined in an argon atmosphere to obtain the highly CO-resistant and highly anti-reverse-polarity proton exchange membrane fuel cell catalyst. The CO-resistant catalyst comprises the following components in parts by weight: 0.1-50 parts carbon material, 1-100 parts deionized water, 0.1-25 parts non-precious metal precursor A of catalytically active particles, 1-200 parts reducing agent, and 0.1-25 parts precious metal precursor A of catalytically active particles. The anti-reverse-polarity catalyst comprises the following components in parts by weight: 0.1-25 parts non-precious metal precursor B of catalytically active particles, 1-100 parts dimethylformamide, 1-100 parts propylene oxide, and 0.1-25 parts precious metal precursor B of catalytically active particles.

[0007] CN118553938A discloses a poison-resistant fuel cell anode catalyst and its preparation method, as well as a fuel cell. The catalyst comprises a support and an alloy nanoparticle cluster supported on the support. The alloy nanoparticle cluster comprises ruthenium, platinum, and an optional third metal. The third metal is selected from one or more of palladium, molybdenum, cobalt, tin, and tungsten. The particle size of the alloy nanoparticle cluster is 1~2.5 nm.

[0008] However, existing CO poisoning resistant catalysts all have certain drawbacks, and their CO poisoning resistance cannot meet the requirements of practical applications. Therefore, developing and designing a novel CO poisoning resistant catalyst for fuel cells and its preparation method is crucial for fuel cells. Summary of the Invention

[0009] To address the shortcomings of existing technologies, the present invention aims to provide an anti-CO poisoning catalyst for fuel cells, its preparation method, and the fuel cell itself. In the anti-CO poisoning catalyst provided by the present invention, when the single-atom catalyst substrate is further modified with sulfur (S), the modified S element can enhance the regulation of Pt nanoparticles, reduce the d-band center of Pt, thereby weakening the adsorption of CO by Pt nanoparticles and improving the anti-CO poisoning performance. Furthermore, the modified S element can also form a synergistic effect with Rh single-atom active sites, further reducing the adsorption of CO by Pt nanoparticles, thereby further improving the anti-CO poisoning performance.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides an anti-CO poisoning catalyst for fuel cells, the anti-CO poisoning catalyst comprising a single-atom catalyst substrate and Pt nanoparticles supported on the surface of the single-atom catalyst substrate.

[0012] The single-atom catalyst substrate includes a nitrogen-doped carbon material and Rh single-atom active sites supported on the nitrogen-doped carbon material.

[0013] The CO poisoning resistant catalyst provided by this invention comprises a single-atom catalyst substrate and Pt nanoparticles. The Rh single-atom active sites (active sites for CO oxidation) in the single-atom catalyst substrate are in close contact with the Pt nanoparticles, which can not only effectively reduce the adsorption of CO on Pt, but also remove the strongly adsorbed CO on Pt in a timely manner, thereby improving the CO poisoning resistant performance of the catalyst and enabling the fuel cell to maintain high energy density output even in the presence of a small amount of CO.

[0014] Preferably, the single-atom catalyst substrate is further modified with sulfur (S) element.

[0015] In the CO poisoning catalyst provided by this invention, when the single-atom catalyst substrate is further modified with S element, the modified S element can enhance the regulation of Pt nanoparticles, reduce the d-band center of Pt, thereby weakening the adsorption of CO by Pt nanoparticles and improving the CO poisoning resistance. Furthermore, the modified S element can also form a synergistic effect with the Rh single-atom active site, further reducing the adsorption of CO by Pt nanoparticles, thereby further improving the CO poisoning resistance.

[0016] Preferably, the D50 particle size of the Pt nanoparticles is 2nm to 3nm, for example, it can be 2.0nm, 2.1nm, 2.2nm, 2.3nm, 2.4nm, 2.5nm, 2.6nm, 2.7nm, 2.8nm, 2.9nm or 3.0nm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] Preferably, the mass fraction of Rh element in the anti-CO poisoning catalyst is 0.5 tw% to 2 wt%, based on the mass of the anti-CO poisoning catalyst. For example, it can be 0.5 wt%, 0.7 wt%, 0.9 wt%, 1.0 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, or 2.0 wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, the mass fraction of Pt nanoparticles in the anti-CO poisoning catalyst is 30wt% to 60wt%, for example, it can be 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt% or 60wt%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Secondly, the present invention provides a method for preparing the CO poisoning resistant catalyst described in the first aspect, the method comprising:

[0020] (1) Mix Rh source, Zn source, nitrogen-containing organic ligand and solvent, and react to obtain Rh-loaded Zn-MOF material; then heat treat the obtained Rh-loaded Zn-MOF material in a reducing atmosphere to obtain a single-atom catalyst substrate.

[0021] (2) Mix the single-atom catalyst substrate, Pt source and solvent obtained in step (1), and react to obtain a precursor; then heat-treat the obtained precursor in a reducing atmosphere to obtain an anti-CO poisoning catalyst.

[0022] In the preparation method provided by the present invention, the rich pore structure of Zn-MOF material is used to form a nitrogen-doped carbon material with Rh single-atom active sites that has CO oxidation ability. After loading Pt nanoparticles, the Rh single-atom active sites can effectively reduce the adsorption of CO on Pt and remove the CO strongly adsorbed on Pt, thereby preparing an anti-CO poisoning catalyst with better anti-CO poisoning performance.

[0023] The preparation method provided by this invention also has the advantages of simple and controllable preparation process, no need for complex equipment, easy mass production, and ability to meet the needs of the fuel cell industry for large-scale application of catalysts.

[0024] Preferably, in the mixing in step (1), the mass ratio of Rh source to Zn source is (0.15~0.3):1, for example, it can be 0.15:1, 0.18:1, 0.20:1, 0.22:1, 0.25:1, 0.28:1 or 0.30:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] Preferably, in the mixing in step (1), the molar ratio of Zn source to nitrogen-containing organic ligand is 1:(3~10), for example, it can be 1:3, 1:5, 1:7, 1:9 or 1:10, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] In this invention, by limiting the molar ratio of Zn source to nitrogen-containing organic ligand to 1:(3~10), it is beneficial to ensure the structural uniformity and crystal integrity of ZIF-8 precursor.

[0027] Preferably, the Rh source in step (1) includes any one or a combination of at least two of rhodium acetylacetonate, rhodium chloride, rhodium nitrate, or rhodium triphenylphosphine chloride. Typical but non-limiting combinations include a combination of rhodium acetylacetonate and rhodium chloride, a combination of rhodium nitrate and rhodium triphenylphosphine chloride, a combination of rhodium acetylacetonate, rhodium chloride, and rhodium nitrate, or a combination of rhodium chloride, rhodium nitrate, and rhodium triphenylphosphine chloride.

[0028] Preferably, the Zn source in step (1) includes any one or at least two combinations of Zn(NO3)2·6H2O, ZnCl2, ZnSO4·7H2O, and Zn(CH3COO)2·2H2O. Typical but non-limiting combinations include the combination of Zn(NO3)2·6H2O and ZnCl2, the combination of ZnSO4·7H2O and Zn(CH3COO)2·2H2O, the combination of Zn(NO3)2·6H2O, ZnCl2 and ZnSO4·7H2O, or the combination of ZnCl2, ZnSO4·7H2O and Zn(CH3COO)2·2H2O.

[0029] Preferably, the nitrogen-containing organic ligand in step (1) includes any one or a combination of at least two of 2-methylimidazole, imidazole, 4-methylimidazole or benzimidazole. Typical but non-limiting combinations include combinations of 2-methylimidazole and imidazole, combinations of 4-methylimidazole and benzimidazole, combinations of 2-methylimidazole, imidazole and 4-methylimidazole, or combinations of imidazole, 4-methylimidazole and benzimidazole.

[0030] Preferably, the solvent in step (1) includes any one or a combination of at least two of methanol, ethanol, N,N-dimethylformamide, water or propanol. Typical but non-limiting combinations include a combination of methanol and ethanol, a combination of N,N-dimethylformamide and water, a combination of ethanol, N,N-dimethylformamide and propanol, or a combination of methanol, water and propanol.

[0031] Preferably, the Zn-MOF material in the Rh-loaded Zn-MOF material in step (1) includes any one or a combination of at least two of ZIF-8, ZIF-8, ZIF-11 or Zn-MOF-74. Typical but non-limiting combinations include the combination of ZIF-8 and ZIF-11, the combination of ZIF-11 and Zn-MOF-74, and the combination of ZIF-8, ZIF-11 and Zn-MOF-74, with ZIF-8 being the most preferred.

[0032] Preferably, the mixing in step (1) includes: first mixing the Rh source, Zn source and a portion of the solvent to obtain a first mixed liquid; second mixing the nitrogen-containing organic ligand and a portion of the solvent to obtain a second mixed liquid; and third mixing the first mixed liquid and the second mixed liquid to obtain a mixed solution.

[0033] Preferably, the temperatures during the first mixing, the second mixing, and the third mixing are each independently between 5°C and 40°C, for example, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, or 40°C, but are not limited to the listed values. Other unlisted values ​​within this range are also applicable, and the method of mixing is independently included.

[0034] Preferably, in the first mixture, the solid-liquid ratio of the Zn source to part of the solvent is 3:(30~60), for example, it can be 3:30, 3:35, 3:40, 3:45, 3:50, 3:55 or 3:60, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable; the unit of the solid-liquid ratio is g / mL.

[0035] Preferably, in the second mixture, the solid-liquid ratio of the nitrogen-containing organic ligand to part of the solvent is 6.5:(70~90), for example, it can be 6.5:70, 6.5:75, 6.5:80, 6.5:85 or 6.5:90, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The unit of the solid-liquid ratio is g / mL.

[0036] Preferably, step (1) further includes solid-liquid separation and drying performed sequentially between the reaction and heat treatment.

[0037] Preferably, the reducing atmosphere in step (1) contains a reducing gas and a protective gas in a volume ratio of (5~30):(70~95), for example, it can be 5:95, 10:90, 15:85, 20:80, 25:75 or 30:70, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the reducing gas includes any one or a combination of at least two of hydrogen, carbon monoxide, or methane. Typical but non-limiting combinations include a combination of hydrogen and carbon monoxide, a combination of carbon monoxide and methane, a combination of hydrogen and methane, or a combination of hydrogen, carbon monoxide, and methane.

[0039] Preferably, the protective gas includes nitrogen and / or an inert gas.

[0040] Preferably, the heat treatment in step (1) includes a first heating and a first holding in sequence;

[0041] The first heating rate is 1℃ / min to 10℃ / min, and the final temperature is the temperature of the first heat preservation.

[0042] The first insulation temperature is 850℃~1050℃, and the time is 1h~3h.

[0043] In this invention, the first heating rate is 1℃ / min to 10℃ / min, for example, it can be 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min or 10℃ / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] In this invention, the temperature of the first heat preservation is 850℃~1050℃, for example, it can be 850℃, 875℃, 900℃, 925℃, 950℃, 975℃, 1000℃, 1025℃ or 1050℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] In this invention, the first heat preservation time is 1h to 3h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] Preferably, step (1) further includes cooling, pickling, washing with water and drying in sequence after the heat treatment.

[0047] Preferably, the final temperature of the cooling is 5°C to 40°C, for example, it can be 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] Preferably, the pickling temperature is 5℃~40℃, the pickling time is 8h~16h, and the pickling agent used includes 0.5mol / L~2mol / L HCl solution.

[0049] In this invention, the pickling temperature is 5℃~40℃, for example, it can be 5℃, 7℃, 10℃, 12℃, 15℃, 17℃, 20℃, 22℃, 25℃, 27℃, 30℃, 32℃, 35℃, 37℃ or 40℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0050] In this invention, the pickling time is 8h to 16h, for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0051] In this invention, the pickling agent used for pickling includes an HCl solution of 0.5 mol / L to 2 mol / L, for example, it can be 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L or 2.0 mol / L, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0052] Preferably, the drying temperature is 40℃~90℃ and the drying time is 8h~16h.

[0053] In this invention, the drying temperature is 40℃~90℃, for example, it can be 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0054] In this invention, the drying time is 8h to 16h, for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0055] Preferably, the preparation method further includes S modification and / or N enrichment between step (1) and step (2).

[0056] In the preparation method provided by the present invention, a single-atom catalyst substrate with Rh single-atom active sites is formed in step (1). After S modification and / or N enrichment, S element is introduced and / or N element is further enriched, thereby enhancing the regulation of Pt, reducing the d-band center of Pt, and improving the CO poisoning resistance of the anti-CO poisoning catalyst.

[0057] Preferably, the preparation method further includes S modification and N enrichment performed simultaneously between steps (1) and (2), and the method for performing the S modification and N enrichment simultaneously includes:

[0058] After activating the single-atom catalyst substrate obtained in step (1), the activated single-atom catalyst substrate is mixed with sulfur source, nitrogen source and solvent to obtain a fluffy powder. The fluffy powder is then pyrolyzed in a protective atmosphere to obtain a single-atom catalyst substrate modified with S and enriched with N.

[0059] Preferably, the activation method includes:

[0060] After dispersing the single-atom catalyst substrate obtained in step (1) in an activation solvent, an oxidant is added, followed by a hydrothermal reaction and solid-liquid separation to obtain the activated single-atom catalyst substrate.

[0061] Preferably, in the activation, the solid-liquid ratio of the single-atom catalyst substrate obtained in step (1) to the activation solvent is 100:(30~100), for example, it can be 100:30, 100:40, 100:50, 100:60, 100:70, 100:80, 100:90 or 100:100, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The unit of the solid-liquid ratio is mg / mL.

[0062] Preferably, in the activation, the solid-liquid ratio of the single-atom catalyst substrate obtained in step (1) to the oxidant is 100:(0.1~1), for example, it can be 100:0.1, 100:0.2, 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9 or 100:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The unit of solid-liquid ratio is mg / mL.

[0063] Preferably, the activating solvent includes any one or a combination of at least two of water, ethanol, methanol, N,N-dimethylformamide or propanol. Typical but non-limiting combinations include a combination of water and ethanol, a combination of methanol and N,N-dimethylformamide, a combination of ethanol and propanol, or a combination of water, methanol and N,N-dimethylformamide.

[0064] Preferably, the oxidant includes hydrogen peroxide and / or potassium permanganate solution.

[0065] Preferably, the dispersion method includes ultrasonic treatment for 0.5h to 3h, for example, it can be 0.5h, 0.8h, 1.0h, 1.2h, 1.5h, 1.8h, 2.0h, 2.2h, 2.5h, 2.8h or 3.0h, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0066] Preferably, after adding the oxidant, magnetic stirring is performed for 5 to 30 minutes, for example, 5 minutes, 8 minutes, 10 minutes, 12 minutes, 15 minutes, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes or 30 minutes, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0067] Preferably, the hydrothermal reaction is carried out in a high-pressure reactor.

[0068] Preferably, the hydrothermal reaction is carried out at a temperature of 150°C to 300°C for a duration of 3 to 10 hours.

[0069] In this invention, the temperature of the hydrothermal reaction is 150℃~300℃, for example, it can be 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃ or 300℃, but it is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0070] In this invention, the hydrothermal reaction time is 3h to 10h, for example, it can be 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h or 10h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0071] Preferably, the hydrothermal reaction and solid-liquid separation further include cooling to 5°C to 40°C, for example, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C, but not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0072] Preferably, the activation further includes drying at 40°C to 90°C for 1 to 5 hours after the solid-liquid separation.

[0073] In this invention, the activation also includes drying at 40°C to 90°C after solid-liquid separation. For example, the temperature can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0074] In this invention, the activation also includes drying for 1 to 5 hours after the solid-liquid separation. For example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, or 5 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0075] Preferably, in the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:(2~10), for example, it can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0076] Preferably, in the mixture, the mass ratio of the activated single-atom catalyst substrate to the sulfur source is 1:(1~5), for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0077] Preferably, in the mixture, the mass ratio of the activated single-atom catalyst substrate to the nitrogen source is 1:(1~5), for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0078] Preferably, in the mixture, the solid-liquid ratio of the activated single-atom catalyst substrate to the solvent is 1:(0.5~2), for example, it can be 1:0.5, 1:0.7, 1:0.9, 1:1.1, 1:1.3, 1:1.5, 1:1.7, 1:1.9 or 1:2, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable, and the unit is mg / mL.

[0079] Preferably, the sulfur source includes any one or a combination of at least two of thiols, thioureas, or cysteine. Typical but non-limiting combinations include combinations of thiols and thioureas, combinations of thioureas and cysteine, combinations of thiols and cysteine, or combinations of thiols, thioureas, and cysteine.

[0080] Preferably, the nitrogen source includes any one or a combination of at least two of urea, melamine, dicyandiamide or ethylenediamine. Typical but non-limiting combinations include a combination of urea and melamine, a combination of dicyandiamide and ethylenediamine, a combination of melamine and ethylenediamine, or a combination of urea, dicyandiamide and ethylenediamine.

[0081] Preferably, the solvent in the mixture includes any one or a combination of at least two of water, ethanol, methanol, N,N-dimethylformamide or propanol. Typical but non-limiting combinations include a combination of water and ethanol, a combination of methanol and N,N-dimethylformamide, a combination of ethanol and propanol, or a combination of water, methanol and N,N-dimethylformamide.

[0082] Preferably, the mixing method includes: ultrasonic treatment for 0.5h to 3h, magnetic stirring for 1h to 4h, and then freeze drying.

[0083] In this invention, the mixture includes ultrasonic treatment for 0.5h to 3h, for example, it can be 0.5h, 0.8h, 1.0h, 1.2h, 1.5h, 1.8h, 2.0h, 2.2h, 2.5h, 2.8h or 3.0h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0084] In this invention, the mixing process includes magnetic stirring for 1 to 4 hours, for example, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours, 2.0 hours, 2.2 hours, 2.5 hours, 2.8 hours, 3.0 hours, 3.2 hours, 3.5 hours, 3.8 hours, or 4.0 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0085] Preferably, the protective atmosphere includes nitrogen and / or an inert gas.

[0086] Preferably, the pyrolysis temperature is 800℃~1100℃ and the time is 0.5h~2h.

[0087] In this invention, the pyrolysis temperature is 800℃~1100℃, for example, it can be 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃ or 1100℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0088] In this invention, the pyrolysis time is 0.5h to 2h, for example, it can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0089] Preferably, in the mixing described in step (2), the mass ratio of the single-atom catalyst substrate obtained in step (1) to the Pt element in the Pt source is 30:(2.5~5), for example, it can be 30:2.5, 30:3.0, 30:3.5, 30:4.0, 30:4.5 or 30:5.0, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0090] Preferably, the Pt source in step (2) includes an H2PtCl6 solution.

[0091] Preferably, the solvent in step (2) includes any one or a combination of at least two of methanol, ethanol, N,N-dimethylformamide, water or propanol. Typical but non-limiting combinations include a combination of methanol and ethanol, a combination of N,N-dimethylformamide and water, a combination of ethanol and propanol, or a combination of methanol, water and propanol.

[0092] Preferably, the mixing in step (2) includes: mixing the single-atom catalyst substrate obtained in step (1) with a solvent to obtain a fourth mixture; and mixing the fourth mixture obtained in the fifth mixing with a Pt source to obtain a mixed solution.

[0093] Preferably, the fourth mixing method includes ultrasound for a duration of 10 min to 50 min, for example, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min or 50 min, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0094] Preferably, the fifth mixing method includes stirring for a time of 8h to 16h, for example, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0095] Preferably, the solid-liquid ratio of the single-atom catalyst substrate obtained in step (1) of the fourth mixing to the solvent is 30:(30~50), for example, it can be 30:30, 30:35, 30:40, 30:45 or 30:50, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable; the unit is mg / mL.

[0096] Preferably, step (2) further includes rotary evaporation between the reaction and the heat treatment.

[0097] Preferably, the reducing atmosphere in step (2) contains a reducing gas and a protective gas in a volume ratio of (5~30):(70~95), for example, it can be 5:95, 10:90, 15:85, 20:80, 25:75 or 30:70, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0098] Preferably, the reducing gas includes any one or a combination of at least two of hydrogen, carbon monoxide, or methane. Typical but non-limiting combinations include a combination of hydrogen and carbon monoxide, a combination of carbon monoxide and methane, a combination of hydrogen and methane, or a combination of hydrogen, carbon monoxide, and methane.

[0099] Preferably, the protective gas includes nitrogen and / or an inert gas.

[0100] Preferably, the heat treatment in step (2) includes a third heating and a third holding in sequence;

[0101] The third heating rate is 1℃ / min to 10℃ / min, and the endpoint temperature is the temperature of the third heat preservation.

[0102] The third insulation temperature is 600℃~800℃, and the time is 1h~3h.

[0103] In this invention, the third heating rate is 1℃ / min to 10℃ / min, for example, it can be 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min or 10℃ / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0104] In this invention, the temperature of the third insulation is 600℃~800℃, for example, it can be 600℃, 625℃, 650℃, 675℃, 700℃, 725℃, 750℃, 775℃ or 800℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0105] In this invention, the third heat preservation time is 1h to 3h, for example, it can be 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h, 2.8h or 3h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0106] Preferably, step (2) further includes cooling, pickling, washing with water and drying in sequence after the heat treatment.

[0107] Preferably, the final temperature of the cooling is 5°C to 40°C, for example, it can be 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C or 40°C, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0108] Preferably, the pickling temperature is 5℃~40℃, the pickling time is 8h~16h, and the pickling agent used includes an HNO3 solution with a concentration of 0.2mol / L~1.5mol / L.

[0109] In this invention, the pickling temperature is 5℃~40℃, for example, it can be 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃ or 40℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0110] In this invention, the pickling time is 8h to 16h, for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0111] In this invention, the pickling agent used for pickling includes an HNO3 solution with a concentration of 0.2 mol / L to 1.5 mol / L, for example, it can be 0.2 mol / L, 0.4 mol / L, 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.4 mol / L or 1.5 mol / L, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0112] Preferably, the drying temperature is 40℃~90℃ and the drying time is 8h~16h.

[0113] In this invention, the drying temperature is 40℃~90℃, for example, it can be 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0114] In this invention, the drying time is 8h to 16h, for example, it can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0115] As a preferred embodiment of the preparation method of the present invention, the preparation method includes:

[0116] (I) A first mixed solution is obtained by stirring a first mixed Rh source (rhodium acetylacetone, rhodium chloride, rhodium nitrate or triphenylphosphine rhodium chloride), a Zn source (Zn(NO3)2·6H2O, ZnCl2, ZnSO4·7H2O, Zn(CH3COO)2·2H2O) and a portion of the solvent (methanol, ethanol, N,N-dimethylformamide, water or propanol) at 5℃~40℃; a second mixed solution is obtained by stirring a second mixed nitrogen-containing organic ligand (2-methylimidazole, imidazole, 4-methylimidazole or benzimidazole) and a portion of the solvent (methanol, ethanol, N,N-dimethylformamide, water or propanol) at 5℃~40℃; a third mixed solution is obtained by stirring the first mixed solution and the second mixed solution obtained by stirring at 5℃~40℃ to obtain a mixed solution. After the reaction, solid-liquid separation and drying are performed sequentially to obtain the Rh-loaded Zn-MOF material (ZIF-8).

[0117] In a reducing atmosphere containing a reducing gas (hydrogen, carbon monoxide, or methane) and a protective gas (nitrogen and / or inert gas) in a volume ratio of (5~30):(70~95), the obtained Rh-loaded Zn-MOF material is heated to 850~1050℃ at a rate of 1℃ / min~10℃ / min and held at that temperature for 1h~3h. Then it is cooled to 5℃~40℃ and acid-washed with 0.5mol / L~2mol / L HCl solution at 5℃~40℃ for 8h~16h. After washing with water, it is dried at 40℃~90℃ for 8h~16h to obtain a single-atom catalyst substrate (a single-atom catalyst substrate with the ability to catalyze CO oxidation can be obtained).

[0118] The mass ratio of Rh source to Zn source is (0.15~0.3):1, and the molar ratio of Zn source to nitrogen-containing organic ligand is 1:(3~10); in the first mixture, the solid-liquid ratio of Zn source to a portion of the solvent is 3:(30~60), and the unit of solid-liquid ratio is g / mL; in the second mixture, the solid-liquid ratio of nitrogen-containing organic ligand to a portion of the solvent is 6.5:(70~90), and the unit of solid-liquid ratio is g / mL.

[0119] (II) After dispersing the single-atom catalyst substrate obtained in step (I) in an activation solvent (water, ethanol, methanol, N,N-dimethylformamide or propanol) by ultrasonic treatment for 0.5h to 3h, an oxidant (hydrogen peroxide) is added and the mixture is magnetically stirred for 5min to 30min. Then, the mixture is subjected to hydrothermal reaction in a high-pressure reactor at a temperature of 150℃ to 300℃ for 3h to 10h, and then cooled to 5℃ to 40℃. After solid-liquid separation, the mixture is dried at 40℃ to 90℃ for 1h to 5h to obtain the activated single-atom catalyst substrate.

[0120] The activated single-atom catalyst substrate was mixed with a sulfur source (thiol, thiourea, or cysteine), a nitrogen source (urea, melamine, dicyandiamide, or ethylenediamine), and a solvent (water, ethanol, methanol, N,N-dimethylformamide, or propanol) by sequential ultrasonic treatment for 0.5 to 3 hours, magnetic stirring for 1 to 4 hours, and freeze drying to obtain a fluffy powder. The fluffy powder was then pyrolyzed in nitrogen and / or inert gas at a temperature of 800°C to 1100°C for 0.5 to 2 hours to obtain the S-modified and N-enriched single-atom catalyst substrate.

[0121] In step (I), the solid-liquid ratio of the single-atom catalyst substrate to the activation solvent is 100:(30~100), and the solid-liquid ratio of the substrate to the oxidant is 100:(0.1~1). The unit of the solid-liquid ratio is mg / mL.

[0122] In the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:(2~10), the mass ratio to the sulfur source is 1:(1~5), the mass ratio to the nitrogen source is 1:(1~5), and the solid-liquid ratio to the solvent is 1:(0.5~2), with units of mg / mL.

[0123] (III) The S-modified and N-enriched single-atom catalyst substrate obtained in step (II) of the fourth mixing step by ultrasonication for 10 min to 50 min is mixed with a solvent (methanol, ethanol, N,N-dimethylformamide, water or propanol) to obtain a fourth mixture; the fourth mixture obtained by stirring for 8 h to 16 h is mixed with a Pt source (H2PtCl6 solution) to obtain a mixed solution, and after the reaction, rotary evaporation is performed to obtain the precursor;

[0124] In a reducing atmosphere containing a reducing gas (hydrogen, carbon monoxide, or methane) and a protective gas (nitrogen and / or inert gas) in a volume ratio of (5~30):(70~95), the obtained precursor is heated to 600~800℃ at a rate of 1℃ / min~10℃ / min and held at that temperature for 1h~3h. Then it is cooled to 5℃~40℃, and then acid-washed at 5℃~40℃ with a HNO3 solution of concentration of 0.2mol / L~1.5mol / L for 8h~16h. After washing with water, it is dried at 40℃~90℃ for 8h~16h to obtain the CO-resistant catalyst.

[0125] In the fourth mixing step (II), the solid-liquid ratio of the S-modified and N-enriched single-atom catalyst substrate to the solvent is 30:(30~50), with units of mg / mL; the mass ratio of the S-modified and N-enriched single-atom catalyst substrate to the Pt element in the Pt source is 30:(2.5~5).

[0126] Thirdly, the present invention provides a fuel cell comprising the CO-poisoning catalyst described in the first aspect.

[0127] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0128] Compared with the prior art, the present invention has the following beneficial effects:

[0129] In the preparation method provided by the present invention, the rich pore structure of Zn-MOF material is used to form a nitrogen-doped carbon material with Rh single-atom active sites that has CO oxidation ability. After loading Pt nanoparticles, the Rh single-atom active sites can effectively reduce the adsorption of CO on Pt and remove the CO strongly adsorbed on Pt, thereby preparing an anti-CO poisoning catalyst with better anti-CO poisoning performance. Attached Figure Description

[0130] Figure 1 This is a spherical aberration electron microscope image of the single-atom catalyst substrate after S modification and N enrichment in Example 1.

[0131] Figure 2 This is a TEM image of the CO-poisoning resistant catalyst in Example 1.

[0132] Figure 3 The curves show the current density versus voltage of the working electrodes prepared using the anti-CO poisoning catalysts provided in Example 1 and Comparative Example 2.

[0133] Figure 4 The curves show the change in current density over time for the working electrodes prepared using the anti-CO poisoning catalysts provided in Examples 1 and 6 and Comparative Examples 1 and 2. Detailed Implementation

[0134] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0135] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0136] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0137] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0138] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0139] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0140] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0141] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0142] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0143] Example 1

[0144] This embodiment provides a CO poisoning resistant catalyst for a fuel cell, the CO poisoning resistant catalyst comprising a single-atom catalyst substrate and Pt nanoparticles with a D50 particle size of 2.5 nm supported on the surface of the single-atom catalyst substrate;

[0145] The single-atom catalyst substrate includes a nitrogen-doped carbon material and Rh single-atom active sites supported on the nitrogen-doped carbon material, and the single-atom catalyst substrate is modified with S element.

[0146] Based on the mass percentage of the CO poisoning resistant catalyst, the mass fraction of Rh element in the CO poisoning resistant catalyst is 1.2 wt%, and the mass fraction of Pt nanoparticles is 30 wt%.

[0147] The preparation method of the CO poisoning resistant catalyst is as follows:

[0148] (I) A first mixture was obtained by stirring a first mixture of Rh source (rhodium acetylacetone), Zn source (Zn(NO3)2·6H2O) and a portion of solvent (methanol) at 25°C; a second mixture was obtained by stirring a second mixture of nitrogen-containing organic ligand (2-methylimidazole) and a portion of solvent (methanol) at 25°C; a mixed solution was obtained by stirring the first mixture and the second mixture obtained by a third mixture at 25°C. After the reaction, solid-liquid separation and drying were performed sequentially to obtain Rh-loaded Zn-MOF material (ZIF-8).

[0149] In a reducing atmosphere containing a reducing gas (hydrogen) and a protective gas (argon) in a volume ratio of 10:90, the obtained Rh-loaded Zn-MOF material was heated to 950℃ at a rate of 5℃ / min and held at that temperature for 2h. Then it was cooled to 25℃ and acid-washed with a 1mol / L HCl solution at 25℃ for 12h. After washing with water, it was dried at 55℃ for 12h to obtain a single-atom catalyst substrate (a single-atom catalyst substrate with the ability to catalyze CO oxidation was obtained).

[0150] The mass ratio of Rh source to Zn source is 0.22:1, and the molar ratio of Zn source to nitrogen-containing organic ligand is 1:6. In the first mixture, the solid-liquid ratio of Zn source to a portion of the solvent is 3:40, and the unit of solid-liquid ratio is g / mL. In the second mixture, the solid-liquid ratio of nitrogen-containing organic ligand to a portion of the solvent is 6.5:80, and the unit of solid-liquid ratio is g / mL.

[0151] (II) After dispersing the single-atom catalyst substrate obtained in step (I) in an activation solvent (a mixed solution of water and ethanol in a volume ratio of 1:1) by ultrasonic treatment for 1 hour, an oxidant (hydrogen peroxide) was added and magnetically stirred for 10 minutes. Then, a hydrothermal reaction was carried out in a high-pressure reactor at a temperature of 200°C for 6 hours, followed by cooling to 25°C. After solid-liquid separation, the substrate was dried at 50°C for 2 hours to obtain the activated single-atom catalyst substrate.

[0152] The activated single-atom catalyst substrate was mixed with a sulfur source (thiol), a nitrogen source (urea), and a solvent (a 1:1 volume mixture of water and ethanol) by sequentially performing 1 hour of ultrasonic treatment, 2 hours of magnetic stirring, and freeze drying to obtain a fluffy powder. The fluffy powder was then pyrolyzed at 900°C for 1 hour in an argon atmosphere to obtain the S-modified and N-enriched single-atom catalyst substrate.

[0153] In step (I), the solid-liquid ratio of the single-atom catalyst substrate to the activation solvent is 100:50, and the solid-liquid ratio of the substrate to the oxidant is 100:0.5. The unit of the solid-liquid ratio is mg / mL.

[0154] In the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:4, the mass ratio to the sulfur source is 1:2, the mass ratio to the nitrogen source is 1:2, and the solid-liquid ratio to the solvent is 1:1, with units of mg / mL.

[0155] (III) The S-modified and N-enriched single-atom catalyst substrate obtained in the fourth mixing step (II) by ultrasonication for 30 min is mixed with solvent (ethanol) to obtain the fourth mixture; the fourth mixture obtained by stirring for 12 h is mixed with Pt source (1.5 mg Pt / mL H2PtCl6 solution) to obtain a mixed solution, and after reaction, rotary evaporation is performed to obtain the precursor;

[0156] In a reducing atmosphere containing a reducing gas (hydrogen) and a protective gas (argon) in a volume ratio of 10:90, the obtained precursor was heated to 700℃ at a rate of 5℃ / min and held at that temperature for 2h. Then it was cooled to 25℃ and acid-washed with a 0.5mol / L HNO3 solution at 25℃ for 12h. After washing with water, it was dried at 55℃ for 12h to obtain the CO-resistant catalyst.

[0157] In the fourth mixing step (II), the solid-liquid ratio of the S-modified and N-enriched single-atom catalyst substrate to the solvent is 30:40, with units of mg / mL; the mass ratio of the S-modified and N-enriched single-atom catalyst substrate to the Pt element in the Pt source is 30:3.6.

[0158] Example 2

[0159] This embodiment provides an anti-CO poisoning catalyst for a fuel cell, the anti-CO poisoning catalyst comprising a single-atom catalyst substrate and Pt nanoparticles with a D50 particle size of 2 nm supported on the surface of the single-atom catalyst substrate.

[0160] The single-atom catalyst substrate includes a nitrogen-doped carbon material and Rh single-atom active sites supported on the nitrogen-doped carbon material, and the single-atom catalyst substrate is modified with S element.

[0161] Based on the mass percentage of the CO poisoning resistant catalyst, the mass fraction of Rh element in the CO poisoning resistant catalyst is 1.5 wt%, and the mass fraction of Pt nanoparticles is 45 wt%.

[0162] The preparation method of the CO poisoning resistant catalyst is as follows:

[0163] (I) A first mixture was obtained by stirring a first mixture of Rh source (rhodium acetylacetone), Zn source (ZnCl2), and a portion of solvent (methanol) at 20°C; a second mixture was obtained by stirring a second mixture of nitrogen-containing organic ligand (2-methylimidazole) and a portion of solvent (methanol) at 5°C to 40°C; a mixed solution was obtained by stirring the first mixture obtained by a third mixture and the second mixture obtained at 20°C. After the reaction, solid-liquid separation and drying were performed sequentially to obtain Rh-loaded Zn-MOF material (ZIF-8).

[0164] In a reducing atmosphere containing a reducing gas (hydrogen) and a protective gas (nitrogen) in a volume ratio of 5:95, the obtained Rh-loaded Zn-MOF material was heated to 850°C at a rate of 1°C / min and held at that temperature for 3 hours. Then it was cooled to 20°C and acid-washed with a 0.5 mol / L HCl solution at 20°C for 16 hours. After washing with water, it was dried at 90°C for 8 hours to obtain a single-atom catalyst substrate (a single-atom catalyst substrate with the ability to catalyze CO oxidation was obtained).

[0165] The mass ratio of Rh source to Zn source is 0.25:1, and the molar ratio of Zn source to nitrogen-containing organic ligand is 1:5. In the first mixture, the solid-liquid ratio of Zn source to a portion of the solvent is 3:30, and the unit of solid-liquid ratio is g / mL. In the second mixture, the solid-liquid ratio of nitrogen-containing organic ligand to a portion of the solvent is 6.5:70, and the unit of solid-liquid ratio is g / mL.

[0166] (II) After dispersing the single-atom catalyst substrate obtained in step (I) in an activation solvent (water) by ultrasonic treatment for 0.5 h, an oxidant (hydrogen peroxide) was added and magnetically stirred for 30 min. Then, a hydrothermal reaction was carried out in a high-pressure reactor at a temperature of 150 °C for 10 h, followed by cooling to 20 °C. After solid-liquid separation, the substrate was dried at 90 °C for 1 h to obtain the activated single-atom catalyst substrate.

[0167] The activated single-atom catalyst substrate was mixed with a sulfur source (thiol), a nitrogen source (urea), and a solvent (water) by sequentially performing ultrasonic treatment for 3 hours, magnetic stirring for 1 hour, and freeze drying to obtain a fluffy powder; the fluffy powder was then pyrolyzed in nitrogen and / or inert gas at 1100℃ for 0.5 hours to obtain a single-atom catalyst substrate modified with S and enriched with N.

[0168] In step (I), the solid-liquid ratio of the single-atom catalyst substrate to the activation solvent is 100:100, and the solid-liquid ratio of the substrate to the oxidant is 100:0.1. The unit of the solid-liquid ratio is mg / mL.

[0169] In the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:2, the mass ratio to the sulfur source is 1:1, the mass ratio to the nitrogen source is 1:1, and the solid-liquid ratio to the solvent is 1:0.5, with units of mg / mL.

[0170] (III) The S-modified and N-enriched single-atom catalyst substrate obtained in the fourth mixing step (II) by ultrasonication for 10 min is mixed with a solvent (methanol) to obtain a fourth mixture; the fourth mixture obtained by stirring for 16 h is mixed with a Pt source (H2PtCl6 solution) to obtain a mixed solution, and after the reaction, rotary evaporation is performed to obtain the precursor;

[0171] In a reducing atmosphere containing a reducing gas (hydrogen) and a protective gas (nitrogen) in a volume ratio of 5:95, the obtained precursor was heated to 800℃ at a rate of 10℃ / min and held at that temperature for 1h. Then it was cooled to 20℃ and acid-washed with a 0.2mol / L HNO3 solution at 20℃ for 16h. After washing with water, it was dried at 90℃ for 8h to obtain the CO-resistant catalyst.

[0172] In the fourth mixing step (II), the solid-liquid ratio of the S-modified and N-enriched single-atom catalyst substrate to the solvent is 30:30, with units of mg / mL; the mass ratio of the S-modified and N-enriched single-atom catalyst substrate to the Pt element in the Pt source is 30:4.2.

[0173] Example 3

[0174] This embodiment provides an anti-CO poisoning catalyst for a fuel cell, the anti-CO poisoning catalyst comprising a single-atom catalyst substrate and Pt nanoparticles with a D50 particle size of 3 nm supported on the surface of the single-atom catalyst substrate.

[0175] The single-atom catalyst substrate includes a nitrogen-doped carbon material and Rh single-atom active sites supported on the nitrogen-doped carbon material, and the single-atom catalyst substrate is modified with S element.

[0176] Based on the mass of the CO poisoning resistant catalyst, the mass fraction of Rh element in the CO poisoning resistant catalyst is 2 wt%, and the mass fraction of Pt nanoparticles is 50 wt%.

[0177] The preparation method of the CO poisoning resistant catalyst is as follows:

[0178] (I) A first mixture was obtained by stirring a first mixture of Rh source (rhodium chloride), Zn source (ZnSO4·7H2O) and a portion of solvent (ethanol) at 30°C; a second mixture was obtained by stirring a second mixture of nitrogen-containing organic ligand (2-methylimidazole) and a portion of solvent (ethanol) at 5°C to 40°C; a mixed solution was obtained by stirring the first mixture obtained by a third mixture and the second mixture obtained at 30°C. After the reaction, solid-liquid separation and drying were performed sequentially to obtain Rh-loaded Zn-MOF material (ZIF-8).

[0179] In a reducing atmosphere containing a reducing gas (carbon monoxide) and a protective gas (argon) in a volume ratio of 30:70, the obtained Rh-loaded Zn-MOF material was heated to 1050℃ at a rate of 10℃ / min and held for 1h. Then it was cooled to 30℃, acid-washed with 2mol / L HCl solution at 30℃ for 8h, washed with water, and dried at 40℃ for 16h to obtain a single-atom catalyst substrate (a single-atom catalyst substrate with the ability to catalyze CO oxidation was obtained).

[0180] The mass ratio of Rh source to Zn source is 0.3:1, and the molar ratio of Zn source to nitrogen-containing organic ligand is 1:3. In the first mixture, the solid-liquid ratio of Zn source to a portion of the solvent is 3:60, and the unit of solid-liquid ratio is g / mL. In the second mixture, the solid-liquid ratio of nitrogen-containing organic ligand to a portion of the solvent is 6.5:90, and the unit of solid-liquid ratio is g / mL.

[0181] (II) After dispersing the single-atom catalyst substrate obtained in step (I) in an activation solvent (water) by ultrasonic treatment for 3 hours, an oxidant (hydrogen peroxide) is added and magnetically stirred for 5 minutes. Then, a hydrothermal reaction is carried out in a high-pressure reactor at a temperature of 300°C for 3 hours, followed by cooling to 30°C. After solid-liquid separation, the substrate is dried at 40°C for 5 hours to obtain the activated single-atom catalyst substrate.

[0182] The activated single-atom catalyst substrate was mixed with a sulfur source (thiol), a nitrogen source (urea), and a solvent (water) by sequentially performing ultrasonic treatment for 0.5 h, magnetic stirring for 4 h, and freeze drying to obtain a fluffy powder; the fluffy powder was then pyrolyzed in nitrogen and / or inert gas at 800 °C for 2 h to obtain a single-atom catalyst substrate modified with S and enriched with N.

[0183] In step (I), the solid-liquid ratio of the single-atom catalyst substrate to the activation solvent is 100:30, and the solid-liquid ratio of the substrate to the oxidant is 100:1. The unit of the solid-liquid ratio is mg / mL.

[0184] In the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:10, the mass ratio to the sulfur source is 1:5, the mass ratio to the nitrogen source is 1:5, and the solid-liquid ratio to the solvent is 1:2, with units of mg / mL.

[0185] (III) The S-modified and N-enriched single-atom catalyst substrate obtained in the fourth mixing step (II) by ultrasonication for 50 min is mixed with a solvent (methanol) to obtain a fourth mixture; the fourth mixture obtained by stirring for 8 h is mixed with a Pt source (H2PtCl6 solution) to obtain a mixed solution, and after the reaction, rotary evaporation is performed to obtain the precursor;

[0186] In a reducing atmosphere containing a reducing gas (hydrogen) and a protective gas (nitrogen) in a volume ratio of 30:70, the obtained precursor was heated to 600℃ at a rate of 1℃ / min and held at that temperature for 3h. Then it was cooled to 30℃ and acid-washed with a 1.5mol / L HNO3 solution at 30℃ for 8h. After washing with water, it was dried at 40℃ for 16h to obtain the CO-resistant catalyst.

[0187] In the fourth mixing step (II), the solid-liquid ratio of the S-modified and N-enriched single-atom catalyst substrate to the solvent is 30:50, with units of mg / mL; the mass ratio of the S-modified and N-enriched single-atom catalyst substrate to the Pt element in the Pt source is 30:5.

[0188] Example 4

[0189] This embodiment provides a CO-poisoning resistant catalyst for a fuel cell, except that the S element modified on the single-atom catalyst substrate is omitted;

[0190] That is, except for the sulfur source (thiol) added during mixing in step (II) of the preparation method of the anti-CO poisoning catalyst, the rest is the same as in Example 1.

[0191] Example 5

[0192] This embodiment provides an anti-CO poisoning catalyst for fuel cells. Except for omitting the nitrogen source (urea) added during mixing in step (II) of the preparation method of the anti-CO poisoning catalyst, the rest is the same as in Example 1.

[0193] Example 6

[0194] This embodiment provides a CO-poisoning resistant catalyst for a fuel cell, except that the S element modified on the single-atom catalyst substrate is omitted;

[0195] That is, step (II) of the preparation method of the anti-CO poisoning catalyst is omitted, and the single-atom catalyst substrate with S modification and N enrichment obtained in step (II) is replaced with the same mass of single-atom catalyst substrate obtained in step (I) during the fourth mixing in step (III). Otherwise, it is the same as in Example 1.

[0196] Example 7

[0197] This embodiment provides a CO poisoning resistant catalyst for a fuel cell, wherein the mass fraction of Rh element in the CO poisoning resistant catalyst is 0.5 tw%~2 wt%, based on the mass of the catalyst.

[0198] In step (I) of the preparation method of the anti-CO poisoning catalyst, the mass ratio of Rh source to Zn source is (0.15~0.3):1, and all other steps are the same as in Example 1.

[0199] Example 8

[0200] This embodiment provides a CO poisoning resistant catalyst for a fuel cell, wherein the mass fraction of Rh element in the CO poisoning resistant catalyst is 0.5 tw%~2 wt%, based on the mass of the catalyst.

[0201] In step (I) of the preparation method of the anti-CO poisoning catalyst, the mass ratio of Rh source to Zn source is (0.15~0.3):1, and all other steps are the same as in Example 1.

[0202] Example 9

[0203] This embodiment provides a CO-poisoning resistant catalyst for a fuel cell, except that the D50 particle size of the Pt nanoparticles is 1 nm;

[0204] In step (III) of the preparation method of the anti-CO poisoning catalyst, except for heating the obtained precursor to 600℃~800℃ at a rate of 1℃ / min~10℃ / min and holding it at that temperature for 1h~3h in a reducing atmosphere, the rest is the same as in Example 1.

[0205] Example 10

[0206] This embodiment provides a CO-poisoning resistant catalyst for a fuel cell, except that the D50 particle size of the Pt nanoparticles is 6 nm;

[0207] In step (III) of the preparation method of the anti-CO poisoning catalyst, except for heating the obtained precursor to 600℃~800℃ at a rate of 1℃ / min~10℃ / min and holding it at that temperature for 1h~3h in a reducing atmosphere, the rest is the same as in Example 1.

[0208] Comparative Example 1

[0209] This embodiment provides a CO-poisoning resistant catalyst for a fuel cell, except that the Rh single-atom active sites supported on the nitrogen-doped carbon material are omitted;

[0210] That is, except for the Rh source (rhodium acetylacetonate) mixed in during the first mixing in step (Ⅰ) of the preparation method of the anti-CO poisoning catalyst, the rest is the same as in Example 1.

[0211] Comparative Example 2

[0212] This embodiment provides a CO-poisoning resistant catalyst for fuel cells, except that the Rh single-atom active sites supported on the nitrogen-doped carbon material are omitted, and the S element modified on the single-atom catalyst substrate is also omitted.

[0213] That is, the Rh source (rhodium acetylacetonate) mixed in step (I) of the preparation method of the anti-CO poisoning catalyst is omitted, and step (II) of the preparation method of the anti-CO poisoning catalyst is omitted. Except for replacing the single-atom catalyst substrate modified with S and enriched with N in step (III) with the same mass of the single-atom catalyst substrate obtained in step (I), everything else is the same as in Example 1.

[0214] Comparative Example 3

[0215] This embodiment provides a CO-poisoning resistant catalyst for fuel cells, except that nitrogen-doped carbon material is replaced with undoped carbon material;

[0216] In step (I) of the preparation method of the anti-CO poisoning catalyst, the nitrogen-containing organic ligand (2-methylimidazole) is replaced with an equal mass of nitrogen-free organic ligand (terephthalic acid), and the nitrogen source (urea) added during mixing in step (II) of the preparation method of the anti-CO poisoning catalyst is omitted. All other steps are the same as in Example 1.

[0217] The S-modified and N-enriched single-atom catalyst substrate prepared in step (II) of the preparation method provided in Example 1 was tested using spherical aberration electron microscopy. The resulting spherical aberration electron microscopy image of the S-modified and N-enriched single-atom catalyst substrate in Example 1 is shown below. Figure 1 As shown.

[0218] Depend on Figure 1 As can be seen, in Example 1, there are no metal particles in the single-atom catalyst substrate after S modification and N enrichment, and Rh is distributed in single-atom form (as Rh single-atom active sites). The Rh single-atom active sites have the ability to catalyze CO oxidation.

[0219] The CO poisoning resistant catalyst prepared in step (III) of the preparation method provided in the example was tested using transmission electron microscopy. The TEM image of the CO poisoning resistant catalyst in Example 1 is shown below. Figure 2 As shown.

[0220] Depend on Figure 2 As can be seen, in Example 1, with the introduction and pyrolysis of the Pt source, the Pt source successfully formed highly active Pt nanoparticles.

[0221] The electrochemical performance of the anti-CO poisoning catalysts provided in the above embodiments and comparative examples was tested using the following methods:

[0222] (1) Preparation of catalyst ink: Weigh 5.0 mg of the anti-CO poisoning catalyst and place it in a sample bottle. Add ultrapure water (400 μL), isopropanol (550 μL) and Nafion solution (5 wt%, 50 μL) and mix. Disperse by ultrasonication to obtain a uniformly dispersed catalyst ink.

[0223] (2) Preparation of working electrode: The rotation speed of the rotating ring electrode was set to 500 rpm. An appropriate amount of catalyst ink was accurately transferred with a pipette and dropped onto the glassy carbon surface of the electrode. The rotation speed was maintained until the ink was completely dry to obtain the working electrode to be tested. By controlling the amount of ink, the Pt loading on the working electrode to be tested was precisely controlled at 20 μgPt / cm³. 2 Before testing, rinse the working electrode under test with deionized water to eliminate air bubble interference.

[0224] (3) Perform oxidation test and constant voltage test under CO respectively:

[0225] The oxidation test method was as follows: linear sweep voltammetry was used in a 0.5 mol / L H2SO4 solution with a CO concentration of 100% (i.e., saturated state). The test was conducted at a scan rate of 50 mV / s within a potential range of 0 V to 1.2 V (vs. RHE). The potential values ​​corresponding to the CO oxidation peaks are shown in Table 1. The current density versus voltage curves of the working electrodes prepared using the anti-CO poisoning catalysts provided in Example 1 and Comparative Example 2 are shown in Table 1. Figure 3 As shown;

[0226] The method for constant voltage testing under CO is as follows: The working electrode to be tested is placed in a 0.5 mol / L H2SO4 solution with a CO concentration of 0.1%, and tested for 2000 s under a constant voltage of 0.6 V (vs. RHE). The change in current density is monitored. The current density of the working electrode after 2000 s is shown in Table 1. Among them, the curves of current density change with time for the working electrodes prepared with the anti-CO poisoning catalysts provided in Examples 1 and 6 and Comparative Examples 1 and 2 are shown in Table 1. Figure 4 As shown.

[0227] Table 1

[0228]

[0229] From Table 1 and Figure 3 and Figure 4 We can obtain:

[0230] (1) The working electrode prepared with the anti-CO poisoning catalyst provided in Examples 1-3 has a low potential value corresponding to the CO oxidation peak, indicating that CO is successfully oxidized at a low potential. The working electrode prepared with the anti-CO poisoning catalyst provided in Examples 1-3 still shows a high working current density after running for 2000s, which indicates that the anti-CO poisoning catalyst has excellent anti-CO poisoning performance.

[0231] (2) By comparing Example 1 with Examples 4-6, it can be seen that in the preparation method provided by the present invention, when the single-atom catalyst substrate is modified with S element, the modified S element can enhance the regulation of Pt nanoparticles, reduce the d-band center of Pt, thereby weakening the adsorption of CO by Pt nanoparticles and improving the anti-CO poisoning performance; furthermore, the modified S element can also form a synergistic effect with Rh single-atom active sites, further reducing the adsorption of CO by Pt nanoparticles, thereby further improving the anti-CO poisoning performance;

[0232] (3) By comparing Example 1 with Examples 7 and 8, it can be seen that in the preparation method provided by the present invention, when the mass fraction of Rh element in the anti-CO poisoning catalyst is 0.5tw%~2wt%, the anti-CO poisoning catalyst exhibits better overall performance. This is because the Rh content at this level is at the optimal balance point between electronic effects and bifunctional synergistic effects: On the one hand, an appropriate amount of Rh causes the d-band center of Pt to shift downward through electronic effects, effectively weakening the CO adsorption intensity for easy removal, avoiding weak modification due to too low Rh content (<0.5wt%) or excessive dilution of Pt active sites due to too high Rh content (>2wt%); on the other hand, at this ratio, Rh can form a "synergistic rescue network" around Pt in a highly dispersed form, providing sufficient hydroxyl groups to assist CO oxidation at adjacent Pt sites through a bifunctional mechanism, while avoiding the invasion of the main active sites of the hydrogen oxidation reaction (HOR) by excessive Rh.

[0233] (4) By comparing Example 1 with Examples 9 and 10, it can be seen that in the preparation method provided by the present invention, when the D50 particle size of Pt nanoparticles in the anti-CO poisoning catalyst is 2nm~3nm, the anti-CO poisoning catalyst exhibits better overall performance. This is because this particle size range causes a sharp increase in the specific surface area of ​​Pt, exposing a large number of active sites, ensuring that it still has a high current retention rate when some sites are poisoned by CO. At the same time, the significant quantum confinement effect and the increase in the proportion of high-index crystal planes (such as steps and corner atoms) at the 2nm~3nm scale lead to the downward shift of the d-band center of Pt and the change of coordination environment, effectively weakening the adsorption intensity of CO and making it easier to be oxidized and desorbed. In addition, this size also shortens the reaction mass transfer path and enhances the electronic interaction with the support, thereby synergistically improving the intrinsic activity and anti-poisoning ability of the catalyst.

[0234] (5) From Figure 3 It can be seen that the CO peak in Example 1 shifts significantly to the left compared to Comparative Example 2, from 0.82V in Comparative Example 2 to 0.7V. This is because the CO adsorbed by Pt is successfully oxidized at a lower potential, which can effectively enhance the anti-CO poisoning ability of Pt.

[0235] from Figure 4 It can be seen that the current density of Example 1 > the current density of Comparative Example 1 > the current density of Comparative Example 2. Comparative Example 2 showed almost no performance due to the strong poisoning of Pt. From the comparison between Example 6 and Comparative Example 2, it can be seen that the introduction of S and N in the carbon support modulates the d-band center of Pt and also reduces the adsorption of CO.

[0236] (6) By comparing Example 1 with Comparative Examples 1 to 3, it can be seen that in the preparation method provided by the present invention, the rich pore structure of Zn-MOF material is used to form a nitrogen-doped carbon material with Rh single-atom active sites that has CO oxidation ability. After loading Pt nanoparticles, the Rh single-atom active sites can effectively reduce the adsorption of CO on Pt and remove the CO strongly adsorbed on Pt, thereby preparing an anti-CO poisoning catalyst with better anti-CO poisoning performance.

[0237] The applicant declares that the above description is only a specific embodiment 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 conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A CO-poisoning resistant catalyst for fuel cells, characterized in that, The anti-CO poisoning catalyst includes a single-atom catalyst substrate and Pt nanoparticles supported on the surface of the single-atom catalyst substrate. The single-atom catalyst substrate includes a nitrogen-doped carbon material and Rh single-atom active sites supported on the nitrogen-doped carbon material.

2. The CO-poisoning resistant catalyst according to claim 1, characterized in that, The single-atom catalyst substrate is also modified with sulfur.

3. The CO-resistant catalyst according to claim 1, characterized in that, The D50 particle size of the Pt nanoparticles is 2nm~3nm.

4. The CO-poisoning resistant catalyst according to claim 1, characterized in that, Based on the mass of the CO poisoning resistant catalyst, the mass fraction of Rh element in the CO poisoning resistant catalyst is 0.5 tw%~2 wt%; Preferably, the mass fraction of Pt nanoparticles in the anti-CO poisoning catalyst is 30wt% to 60wt%, based on the mass of the anti-CO poisoning catalyst.

5. A method for preparing the anti-CO poisoning catalyst according to any one of claims 1 to 4, characterized in that, The preparation method includes: (1) Mix Rh source, Zn source, nitrogen-containing organic ligand and solvent, and react to obtain Rh-loaded Zn-MOF material; then heat treat the obtained Rh-loaded Zn-MOF material in a reducing atmosphere to obtain a single-atom catalyst substrate. (2) Mix the single-atom catalyst substrate, Pt source and solvent obtained in step (1), and react to obtain a precursor; then heat-treat the obtained precursor in a reducing atmosphere to obtain an anti-CO poisoning catalyst.

6. The preparation method according to claim 5, characterized in that, In the mixing process described in step (1), the mass ratio of Rh source to Zn source is (0.15~0.3):1; Preferably, in the mixing in step (1), the molar ratio of Zn source to nitrogen-containing organic ligand is (3~10):1; Preferably, the reducing atmosphere in step (1) contains a reducing gas and a protective gas in a volume ratio of (5~30):(70~95); Preferably, the heat treatment in step (1) includes a first heating and a first holding in sequence; The first heating rate is 1℃ / min to 10℃ / min, and the final temperature is the temperature of the first heat preservation. The first insulation temperature is 850℃~1050℃, and the time is 1h~3h.

7. The preparation method according to claim 5, characterized in that, The preparation method further includes S modification and / or N enrichment between steps (1) and (2); Preferably, the preparation method further includes S modification and N enrichment performed simultaneously between steps (1) and (2), and the method for performing the S modification and N enrichment simultaneously includes: After activating the single-atom catalyst substrate obtained in step (1), the activated single-atom catalyst substrate is mixed with sulfur source, nitrogen source and solvent to obtain fluffy powder. The fluffy powder is then pyrolyzed in a protective atmosphere to obtain S-modified and N-enriched single-atom catalyst substrate. Preferably, the activation method includes: After dispersing the single-atom catalyst substrate obtained in step (1) in an activation solvent, an oxidant is added, followed by a hydrothermal reaction and solid-liquid separation to obtain the activated single-atom catalyst substrate. Preferably, the hydrothermal reaction is carried out at a temperature of 150°C to 300°C for a duration of 3 hours to 10 hours. Preferably, in the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:(2~10); Preferably, in the mixture, the mass ratio of the activated single-atom catalyst substrate to the sulfur source is 1:(1~5); Preferably, in the mixture, the mass ratio of the activated single-atom catalyst substrate to the nitrogen source is 1:(1~5); Preferably, the pyrolysis temperature is 800℃~1100℃ and the time is 0.5h~2h.

8. The preparation method according to claim 5, characterized in that, In the mixing described in step (2), the mass ratio of the single-atom catalyst substrate obtained in step (1) to the Pt element in the Pt source is 30:(2.5~5); Preferably, the reducing atmosphere in step (2) contains a reducing gas and a protective gas in a volume ratio of (5~30):(70~95); Preferably, the heat treatment in step (2) includes a third heating and a third holding in sequence; The third heating rate is 1℃ / min to 10℃ / min, and the endpoint temperature is the temperature of the third heat preservation. The third insulation temperature is 600℃~800℃, and the time is 1h~3h.

9. The preparation method according to claim 5, characterized in that, The preparation method includes: (I) A first mixture of Rh source, Zn source and part of solvent is obtained by stirring at 5℃~40℃; a second mixture of nitrogen-containing organic ligand and part of solvent is obtained by stirring at 5℃~40℃; a mixed solution is obtained by stirring the first mixture and the second mixture obtained by a third mixture at 5℃~40℃. After the reaction, solid-liquid separation and drying are performed sequentially to obtain Rh-loaded Zn-MOF material. In a reducing atmosphere containing a reducing gas and a protective gas in a volume ratio of (5~30):(70~95), the obtained Rh-loaded Zn-MOF material is heated to 850℃~1050℃ at a rate of 1℃ / min~10℃ / min and held for 1h~3h, then cooled to 5℃~40℃, and then acid-washed with 0.5mol / L~2mol / L HCl solution at 5℃~40℃ for 8h~16h, then washed with water and dried at 40℃~90℃ for 8h~16h to obtain a single-atom catalyst substrate; The mass ratio of Rh source to Zn source is (0.15~0.3):1, and the molar ratio of Zn source to nitrogen-containing organic ligand is 1:(3~10); in the first mixture, the solid-liquid ratio of Zn source to a portion of the solvent is 3:(30~60), and the unit of solid-liquid ratio is g / mL; in the second mixture, the solid-liquid ratio of nitrogen-containing organic ligand to a portion of the solvent is 6.5:(70~90), and the unit of solid-liquid ratio is g / mL. (II) After dispersing the single-atom catalyst substrate obtained in step (I) in the activation solvent by ultrasonic treatment for 0.5h to 3h, an oxidant (hydrogen peroxide) is added and magnetically stirred for 5min to 30min. Then, a hydrothermal reaction is carried out in a high-pressure reactor at a temperature of 150℃ to 300℃ for 3h to 10h, and then cooled to 5℃ to 40℃. After solid-liquid separation, the substrate is dried at 40℃ to 90℃ for 1h to 5h to obtain the activated single-atom catalyst substrate. The activated single-atom catalyst substrate was mixed with sulfur source, nitrogen source and solvent by sequential ultrasonic treatment for 0.5h~3h, magnetic stirring for 1h~4h and freeze drying to obtain a fluffy powder; the fluffy powder was then pyrolyzed in nitrogen and / or inert gas at a temperature of 800℃~1100℃ for 0.5h~2h to obtain the S-modified and N-enriched single-atom catalyst substrate. In step (I), the solid-liquid ratio of the single-atom catalyst substrate to the activation solvent is 100:(30~100), and the solid-liquid ratio of the substrate to the oxidant is 100:(0.1~1). The unit of the solid-liquid ratio is mg / mL. In the mixture, the mass ratio of the activated single-atom catalyst substrate to the total mass of the sulfur source and nitrogen source is 1:(2~10), the mass ratio to the sulfur source is 1:(1~5), the mass ratio to the nitrogen source is 1:(1~5), and the solid-liquid ratio to the solvent is 1:(0.5~2), with units of mg / mL. (III) The S-modified and N-enriched single-atom catalyst substrate obtained in the fourth ultrasonic mixing step (II) and the solvent are mixed to obtain the fourth mixture; the fourth mixture obtained by the fifth mixing step of stirring for 8h to 16h is mixed with the Pt source (H2PtCl6 solution) to obtain a mixed solution. After the reaction, the precursor is obtained by rotary evaporation. In a reducing atmosphere containing a reducing gas and a protective gas in a volume ratio of (5~30):(70~95), the obtained precursor is heated to 600℃~800℃ at a rate of 1℃ / min~10℃ / min and held at that temperature for 1h~3h. Then it is cooled to 5℃~40℃ and then acid-washed with HNO3 solution at a concentration of 0.2mol / L~1.5mol / L at 5℃~40℃ for 8h~16h. After washing with water, it is dried at 40℃~90℃ for 8h~16h to obtain the CO-resistant catalyst. In the fourth mixing step (II), the solid-liquid ratio of the S-modified and N-enriched single-atom catalyst substrate to the solvent is 30:(30~50), with units of mg / mL; the mass ratio of the S-modified and N-enriched single-atom catalyst substrate to the Pt element in the Pt source is 30:(2.5~5).

10. A fuel cell, characterized in that, The fuel cell includes the CO-resistant catalyst as described in any one of claims 1 to 4.

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