Laser solid-phase synthesis of atomic-level catalysts and preparation method and application thereof

Abstract

The application discloses a kind of laser solid-phase synthesis atomic level catalyst and its preparation method and application.The preparation method includes: forming solid-phase reaction system, the solid-phase reaction system includes carbon-based material with multiple anchor points on surface and metal salt precursor loaded on the carbon-based material, the metal salt precursor is combined with the anchor point;The solid-phase reaction system is irradiated by laser, so that the metal salt precursor is reduced to form atomic level catalyst.The atomic level catalyst prepared by the application has various types, including single atom, diatomic, single atom alloy, diatomic alloy, atomic cluster, etc.The preparation method has simple process, strong universality, is suitable for various carbon-based materials containing anchor points and metal elements with catalytic activity, and can mass-produce atomic level catalyst, to meet the demand of various catalysts in chemical industry, petroleum processing industry, energy, pharmaceutical industry and environmental protection, etc.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalysts, and particularly relates to a laser solid-phase synthesized atomic-level catalyst and a preparation method and application thereof. BACKGROUND

[0002] Catalysts play an important role in many industries such as chemical industry, medical treatment, agriculture and environmental protection. Hydrogen energy is a high-calorific secondary clean energy, and a catalyst is one of the most critical materials in the hydrogen production industry. However, there are still two major bottlenecks in the preparation and application of the catalyst, one of which is the lack of batch production means in technology, and the other is that the huge amount of use leads to a cost of 38 yuan per kilogram for water electrolysis hydrogen production in China. In order to solve the above problems, atomic-level catalytic materials have developed rapidly. Atomic-level catalytic materials include single atoms, double atoms, atomic clusters, and single- and double-atom alloys. They can improve the atomic utilization rate of catalysts by reducing the size of traditional nanoparticle catalysts, thereby reducing the cost of materials. When the size of the catalyst is reduced to the atomic level, the atomic utilization rate is maximized, and the strong interaction between the metal and the carrier can bring high stability. At present, the methods for obtaining atomic-level catalysts efficiently and quickly include carbon thermal shock method, fast moving bed pyrolysis method, microwave heating method and joule rapid heating method. However, these methods have specific requirements for the carrier, and it is difficult to expand the production.

[0003] In the preparation of atomic-level catalytic materials, patent documents CN112221528A and CN113430540A disclose a method for synthesizing single-atom catalysts by using a conventional hydrothermal method. The preparation process requires a reaction kettle, high-temperature hydrothermal treatment and multi-step temperature rising, which is not conducive to batch production. The pulsed laser liquid-phase ablation technology was first proposed by Czech and German scientists in the 1990s, and has unique advantages in the preparation and modification of functional nanomaterials. Patent document CN114029505A discloses a method for obtaining atomic-level catalysts by using laser ablation of a precursor in a liquid phase. The reaction process needs to rely on a specific liquid phase environment. Therefore, how to simply and efficiently produce atomic-level catalysts in batches is a problem that needs to be solved. SUMMARY

[0004] The main purpose of the present application is to provide a laser solid-phase synthesized atomic-level catalyst and a preparation method and application thereof to overcome the shortcomings of the prior art.

[0005] To achieve the above-mentioned purposes, the technical solutions adopted by the present application include:

[0006] One aspect of the present application provides a method for preparing an atomic-level catalyst by laser solid synthesis, comprising: forming a solid-phase reaction system, the solid-phase reaction system comprising a carbon-based material having a plurality of anchor points on the surface and a metal salt precursor loaded on the carbon-based material, the metal salt precursor being combined with the anchor points; and irradiating the solid-phase reaction system with a laser to reduce the metal salt precursor to form an atomic-level catalyst.

[0007] Another aspect of the present application provides an atomic-level catalyst prepared by the aforementioned method. The atomic-level catalyst comprises any one of a monoatomic catalyst, a diatomic catalyst, a monoatomic alloy catalyst, a diatomic alloy catalyst, and a cluster catalyst.

[0008] Another aspect of the present application provides an application of the aforementioned atomic-level catalyst in a catalytic reaction.

[0009] Further, the application includes an application in hydrogen production, oxygen production, industrial organic energy product, energy conversion, medical treatment, agriculture, or environmental protection.

[0010] Compared with the prior art, the present application has at least the following beneficial effects:

[0011] (1) Simple process: in the present application, the laser spot contacts the carrier material, and the photothermal / photochemical effect occurs instantaneously to reduce the metal salt precursor loaded on the carrier, thereby efficiently preparing an atomic-level dispersed material.

[0012] (2) Strong universality: the synthesis method of the present application is not dependent on a specific reaction environment, and is applicable to various carbon-based materials containing anchor points and metal elements having catalytic activity. The atomic-level catalyst can be designed and prepared according to the active center required by the catalytic reaction.

[0013] (3) Batch production: the synthesis parameters are stable during the laser solid synthesis process, and the parameters of the laser can be adjusted to produce the atomic-level catalyst in batches, thereby meeting the demand for various catalysts in the fields of chemical industry, petroleum processing industry, energy, pharmaceutical industry, and environmental protection. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0015] Figure 1 is an electron microscope image of a Pt monoatomic catalyst prepared in Example 1 of the present application;

[0016] Figure 2a This is an electron microscope image of the Fe single-atom catalyst prepared in Example 4 of this invention;

[0017] Figure 2b These are the stability test results of the Fe single-atom catalyst prepared in Example 4 of this invention in a zinc-air battery;

[0018] Figure 3 This is an electron microscope image of the Co single-atom catalyst prepared in Example 8 of this invention;

[0019] Figure 4 This is an electron microscope image of the Ni single-atom catalyst prepared in Example 10 of the present invention;

[0020] Figure 5a This is a microscope image of the spherical aberration electrons of the Pt1Co single-atom alloy catalyst particles prepared in Example 16 of this invention;

[0021] Figure 5b This is a microscopic image of the spherical aberration electrons of the (PtRu)1Co diatomic alloy catalyst particles prepared in Example 25 of this invention;

[0022] Figure 5c The figure shows the chronovoltaic curve of the (PtRu)1Co diatomic alloy catalyst prepared in Example 25 of this invention during the hydrogen evolution reaction. Detailed Implementation

[0023] In view of the problems existing in the prior art, the inventors of this invention have conducted extensive and in-depth research and have provided a laser solid-state synthesis method for atomic-level catalysts and its preparation and application. The method mainly uses a one-step laser irradiation of a carbon support for a metal salt precursor. The carbon support is a carbon-based material with sufficient anchoring points, which directly yields atomic-level catalysts. The synthesis method is simple, efficient, and does not require special equipment or high-temperature and high-pressure environments, and can be mass-produced.

[0024] The following will provide a further explanation of the technical solution, its implementation process, and its principles.

[0025] As one aspect of the technical solution of the present invention, a method for preparing an atomic-level catalyst by laser solid-state synthesis includes: forming a solid-state reaction system, the solid-state reaction system including a carbon-based material having multiple anchoring points on its surface and a metal salt precursor supported on the carbon-based material, the metal salt precursor being bonded to the anchoring points; and irradiating the solid-state reaction system with a laser to reduce the metal salt precursor to form an atomic-level catalyst.

[0026] In some embodiments, the formation process of the solid-phase reaction system specifically includes: contacting or mixing a liquid-phase system containing a metal salt precursor with the carbon-based material; removing the solvent from the liquid-phase system to obtain the solid-phase reaction system.

[0027] Further, the carbon-based material is used as a filter to filter the liquid phase system to form the solid phase reaction system.

[0028] Further, the carbon-based material is dispersed in the liquid phase system and dried into a film to form the solid phase reaction system.

[0029] Further, the carbon-based material and the liquid phase system are both dissolved in an organic solvent, and after freeze-drying, the solid phase reaction system is formed.

[0030] In the present application, the anchor points on the carbon-based material form chemical bonds with metal atoms in the metal salt precursor, the metal salt precursor is randomly distributed on the carbon-based material before laser irradiation, and the metal salt is reduced into single atoms and bonded to the anchor points during laser irradiation. The anchor points bond with the metal atoms, fixing the metal atoms at these positions, and these metal atoms remain stable on the anchor points during subsequent laser irradiation, ultrasonic, and electrochemical testing. In addition, the process of sudden heating and cooling of the precursor during laser irradiation retains a large number of anchor points, and the number of anchor points is sufficient.

[0031] In some embodiments, for the graphene oxide carrier, the precursor ions are dispersed on the negatively charged graphene oxide sheets after freeze-drying of the uniformly mixed liquid phase precursor; then laser irradiation, the reduction of graphene oxide while retaining a large number of oxygen-containing functional groups on the surface will produce an anchoring effect on metal atoms. For the ZIF carrier, a large number of N atoms retained on the surface of the material after carbonization will produce an anchoring effect on metal atoms.

[0032] In some embodiments, in the solid phase reaction system, the mass ratio of the carbon-based material to the metal salt precursor ranges from 20:1 to 50:1.

[0033] In some embodiments, the mass fraction of the metal salt precursor in the liquid phase system is 30% to 70%.

[0034] In some embodiments, the wavelength of the laser ranges from 248 nm to 10.6 μm.

[0035] In some embodiments, the scanning speed of the laser is 500 to 2000 mm / s.

[0036] In some embodiments, the power of the laser is 0.5 to 200 W.

[0037] In some embodiments, the frequency of the laser is 1 to 1000 kHz.

[0038] In some embodiments, the spot diameter of the laser is 20 μm to 1 cm.

[0039] In some embodiments, the pulse width of the laser is 10 ps to 10 ms.

[0040] In some embodiments, the irradiation time is 10 to 60 min, wherein the laser irradiation time is related to the amount of the support of the carbon-based material.

[0041] In some embodiments, the type of the laser includes any one of, but not limited to, an excimer laser, a fiber laser, a carbon dioxide laser, a solid-state laser, and the like.

[0042] In some embodiments, the metal element in the metal salt precursor includes any one or a combination of two or more of, but not limited to, copper, nickel, iron, cobalt, palladium, platinum, ruthenium, iridium, titanium, manganese, chromium, and the like.

[0043] In some embodiments, the carbon-based material containing the anchor point includes any one of, but not limited to, a carbon-based material containing a non-metal element, a carbon-based material containing a material defect, and the like. The anchor point can be formed on the carbon-based material by a chemical method. The non-metal element includes any one or a combination of two or more of, but not limited to, N, O, S, P elements, and the like. The material defect includes any one of, but not limited to, a vacancy, an interstitial atom, a substitutional atom, and the like.

[0044] In some embodiments, the carbon-based material includes any one or a combination of two or more of, but not limited to, a carbon-nitrogen material without carbonization, a carbon nanotube material, and the like. The carbon-nitrogen material includes any one of, but not limited to, g-C3N4, C3N2, C2N, CN, and the like.

[0045] In some embodiments, the carbon-based material further includes any one or a combination of two or more of, but not limited to, graphene oxide, a metal organic framework material, natural wood, and the like, which need to be carbonized. The carbonization method includes any one of, but not limited to, a tube furnace heating, a microwave heating, a laser heating, and the like.

[0046] In some typical embodiments, the preparation method of the laser solid-phase synthesized single / dual-atomic alloy catalyst specifically includes the following steps:

[0047] (1) mixing a metal organic framework ZIF-67, a polybenzimidazole PBI, and dimethylacetamide DMAC to obtain a solution A, which is uniformly stirred; coating the solution A on a glass plate, soaking in deionized water, and then taking out and drying; using a laser to irradiate the material on the glass plate, and collecting a powder A;

[0048] (2) mixing a metal salt precursor and DMAC to obtain a solution B, which is uniformly mixed;

[0049] (3) mixing the powder A, the solution B and the polybenzimidazole PBI to obtain a solution C;

[0050] (4) coating the solution C on a support, soaking in deionized water, and then taking out and drying;

[0051] (5) using laser irradiation on the material on the support to collect the powder B.

[0052] Wherein, the DMAC is in liquid phase as a solvent, and after being immersed in water, the water replaces the DMAC solvent to promote the PBI to form a solid-phase porous organic framework. Similarly, a kind of wholly aromatic polyamide obtained through the polycondensation reaction of DADS and CBSI can be dissolved in NMP to form a film, and form a solid-phase porous organic framework under the action of water.

[0053] Further, the concentration of the ZIF-67 in the solution in step (1) is 10-30 g / L.

[0054] Further, the mass concentration of the polybenzimidazole in the solution A in step (1) is 10-30%.

[0055] Further, the thickness coated on the glass plate in step (1) is 20-100 μm.

[0056] Further, the concentration of the metal salt precursor in the solution B in step (2) is 0.001-0.2 M.

[0057] Further, the concentration of the powder A in the solution C in step (3) is 10-30 g / L.

[0058] Further, steps (1)-(3) are combined into one step: mixing the metal organic framework ZIF-67, the metal salt precursor, the polybenzimidazole PBI and the dimethylacetamide DMAC to obtain a solution C.

[0059] Further, the mass ratio of the metal organic framework ZIF-67, the metal salt precursor, the polybenzimidazole PBI and the dimethylacetamide DMAC ranges from 10:1:1:1 to 10:3:3:3.

[0060] Further, the support in step (5) is any one of quartz glass plate, nickel mesh, carbon paper, carbon felt and carbon cloth, but is not limited thereto.

[0061] In some typical embodiments, the preparation method of the laser solid-phase synthesized single-atom catalyst specifically comprises the following steps:

[0062] (1) mixing and grinding ZIF-8 and NaCl to obtain a powder A, and carbonizing in a tube furnace;

[0063] (2) mixing and stirring powder A with metal salt precursor and methanol to obtain solution A;

[0064] (3) vacuum filtering solution A onto PTFE membrane through filter and drying;

[0065] (4) collecting powder B after irradiating the material on the PTFE membrane with laser.

[0066] Further, the mass ratio of ZIF-8 to NaCl in step (1) ranges from 1:2 to 2:1.

[0067] Further, the grinding time in step (1) ranges from 10 to 50 min.

[0068] Further, the mass ratio of powder A to metal salt precursor and methanol in step (2) ranges from 2:1 to 1:1.

[0069] In some embodiments, the metal salt precursor provides a metal element capable of forming a catalytically active metal element, which includes any one of copper, nickel, iron, cobalt, palladium, platinum, ruthenium, iridium, titanium, manganese, chromium, but is not limited thereto.

[0070] The laser solid-phase synthesis atomic-level catalyst method provided by the present application can instantaneously reduce metal salt precursors through laser irradiation to produce a large number of single atoms, double atoms, single-atom alloys, double-atom alloys and atomic clusters loaded on the surface of carbon-based carriers, and the metal element types are various, and the preparation method is innovative.

[0071] In addition, the laser reduction of metal salt and the laser irradiation of the un-carbonized carrier in the carbonization process do not change the characteristics of the anchor points, and the atomic-level catalyst material is directly formed after laser irradiation, and has good stability.

[0072] As another aspect of the technical solution of the present application, an atomic-level catalyst prepared by the aforementioned preparation method is provided. The atomic-level catalyst includes any one of a single-atom catalyst, a double-atom catalyst, a single-atom alloy catalyst, a double-atom alloy catalyst and an atomic cluster catalyst.

[0073] As another aspect of the technical solution of the present application, it also provides the application of the aforementioned atomic-level catalyst in a catalytic reaction.

[0074] Further, the application includes the application in hydrogen production, oxygen production, industrial organic energy products, energy conversion, medical treatment, agriculture or environmental protection.

[0075] The atomic level catalyst involved in the present application can accelerate various catalytic reactions, is beneficial to hydrogen production, oxygen production and various industrial organic energy products, has shown significant advantages in the field of energy conversion, and has shown a trend of replacing traditional products in many industries such as medical treatment, agriculture and environmental protection.

[0076] In summary, the present application provides a preparation method of laser solid-phase synthesis of atomic level catalyst, which directly obtains atomic level catalyst by one-step laser irradiation of carbon carrier loaded with metal salt precursor, and has the advantages of simple synthesis method, high efficiency, no need for special equipment and high temperature and high pressure environment, batch production, and can meet the demand for various catalysts in the fields of chemical industry, petroleum processing industry, energy, pharmaceutical industry and environmental protection.

[0077] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with examples and comparative examples. It should be understood that the specific examples and comparative examples described herein are only used to explain the present application, and are not used to limit the present application. Those skilled in the art can modify or replace equivalently on the basis of understanding the technical scheme of the present application, without departing from the spirit and scope of the technical scheme of the present application, which should be covered within the protection scope of the present application.

[0078] The specific experimental steps or conditions not mentioned in the examples can be carried out according to the operation or conditions of the conventional experimental steps described in the literature in the art. The reagents or instruments used are not marked with the manufacturer, which are conventional products that can be obtained by market purchase.

[0079] Example 1

[0080] A method for laser solid-phase synthesis of Pt monatomic catalyst, the specific steps are as follows:

[0081] (1) First, 4 mL of 7 mg mL -1 The graphene oxide aqueous dispersion is filtered through a 0.2 μm pore size polytetrafluoroethylene filter membrane, and freeze-dried;

[0082] (2) 2 mL of 1 mmol L -1 After the 2 mL of 1 mmol L H2PtCl6 metal precursor solution passes through the polytetrafluoroethylene membrane containing the above graphene oxide, freeze-drying is carried out to obtain a Pt precursor-graphene film, and the mass ratio of carbon-based material to metal precursor is 35:1; During freeze-drying, solid ice directly sublimates into water vapor, and [PtCl6] 2- Anions are dispersed on the negatively charged graphene sheets, and the oxygen-containing functional groups on the graphene are anchor points.

[0083] (3) using a solid-state laser, an infrared laser with a wavelength of 1064 nm, a pulse width of 5 ns, a repetition frequency of 30 kHz, and an average power of 3-10 W is focused to a spot size of about 1 mm, and then irradiated at a scanning speed of 1000 mm / s once on the above-mentioned thin film; during the laser irradiation process, the graphene oxide is reduced at the same time, a large number of oxygen-containing functional groups are retained as anchor points to form chemical bonding with the Pt atoms formed by the laser-reduced metal salt, and a Pt single-atom catalyst is obtained.

[0084] Figure 1 is an electron microscope image of the Pt single-atom catalyst prepared in Example 1 of the present application.

[0085] Example 2

[0086] The difference between this example and Example 1 is that 4 mL of 7 mg / mL graphene oxide aqueous dispersion solution is replaced by 4 mL of 4.1 mg / mL graphene oxide aqueous dispersion solution. -1 The difference between this example and Example 1 is that 4 mL of 7 mg / mL graphene oxide aqueous dispersion solution is replaced by 4 mL of 4.1 mg / mL graphene oxide aqueous dispersion solution. -1 The difference between this example and Example 1 is that 4 mL of 7 mg / mL graphene oxide aqueous dispersion solution is replaced by 4 mL of 4.1 mg / mL graphene oxide aqueous dispersion solution.

[0087] Example 3

[0088] The difference between this example and Example 1 is that 4 mL of 7 mg / mL graphene oxide aqueous dispersion solution is replaced by 4 mL of 10 mg / mL graphene oxide aqueous dispersion solution. -1 The difference between this example and Example 1 is that 4 mL of 7 mg / mL graphene oxide aqueous dispersion solution is replaced by 4 mL of 10 mg / mL graphene oxide aqueous dispersion solution. -1 The difference between this example and Example 1 is that 4 mL of 7 mg / mL graphene oxide aqueous dispersion solution is replaced by 4 mL of 10 mg / mL graphene oxide aqueous dispersion solution.

[0089] However, it is found through comparison that the Pt single-atom catalyst can also be obtained in this example, but the Pt single-atom concentration of the Pt single-atom catalyst in Example 1 is higher.

[0090] Example 4

[0091] A method for laser solid-phase synthesis of Fe single-atom catalyst, the specific steps are as follows:

[0092] (1) First, 10 mmol Zn(NO3)2·6H2O is dissolved in 100 mL methanol solution and 50 mmol 2-methyl imidazole is dissolved in 100 mL methanol solution to form a solution mixture, and then stirred, centrifuged after 24 hours, and the precipitate is washed several times, dried at 60℃ overnight, and then collected ZIF-8;

[0093] (2) 2.0 g of ZIF-8 and 2.0 g of NaCl are gently ground with a motor and a pestle for 10 minutes, and then carbonized. By pyrolyzing at 1000℃ under flowing Ar gas for 2 hours. Finally, porous carbon is obtained by washing with deionized water three times to remove NaCl and drying at 60℃ for 12 hours. The porous carbon contains a large amount of N element, which is an anchor point.

[0094] (3) 200 mg porous carbon and 10 mg FeCl3·6H2O powder were added into 100 mL methanol, constant stirring at room temperature for 12 hours, freeze-drying to obtain Fe 3+ - porous carbon precursor, and coated on a glass plate, the mass ratio of carbon-based material to metal precursor was 20:1.

[0095] (4) a pulsed laser with a wavelength of 355 nm, a power of 3 W, a spot size of 0.45 mm, a laser energy density of 50 mJ cm −2 -2, a pulse repetition rate of 20 kHz, a pulse duration of 8 ns, a scanning speed of 500 mm / s, and a scanning distance of 0.01 mm to ablate Fe 3+ - porous carbon precursor, to obtain a Fe single-atom dispersed material. The chemical bond formed by Fe and the anchor point can be represented by Fe-N4.

[0096] Figure 2a is an electron microscope image of the Fe single-atom catalyst prepared in Example 4 of the present application, Figure 2b is the stability test result of the Fe single-atom catalyst prepared in Example 4 of the present application in a zinc air battery, showing that the single-atom catalyst has better stability than the commercial catalyst.

[0097] Example 5

[0098] The difference between this example and Example 4 is that in this example, 10 mg FeCl3·6H2O is increased to 50 mg FeCl3·6H2O to obtain a Fe atomic cluster catalyst, and the rest is the same as Example 4.

[0099] Example 6

[0100] The difference between this example and Example 4 is that in this example, 200 mg of porous carbon is replaced by 350 mg of porous carbon.

[0101] Example 7

[0102] The difference between this example and Example 4 is that in this example, 200 mg of porous carbon is replaced by 500 mg of porous carbon.

[0103] However, through comparison, it is found that Examples 6 and 7 can also obtain Fe single-atom catalysts, but the Fe single-atom concentration of the Fe single-atom catalyst of Example 4 is higher.

[0104] Example 8

[0105] The difference between this embodiment and embodiment 4 is only that 10 mg FeCl3·6H2O powder is replaced by 10 mg CoCl3·6H2O powder to obtain a Co monatomic catalyst, and the rest is the same as embodiment 4.

[0106] Figure 3 is the electron microscope image of the Co monatomic catalyst prepared in embodiment 8 of the present application.

[0107] Embodiment 9

[0108] The difference between this embodiment and embodiment 4 is only that 10 mg FeCl3·6H2O powder is replaced by 50 mg CoCl3·6H2O powder to obtain a Co atomic cluster catalyst, and the rest is the same as embodiment 4.

[0109] Embodiment 10

[0110] The difference between this embodiment and embodiment 4 is only that 10 mg FeCl3·6H2O powder is replaced by 10 mg NiCl3·6H2O powder to obtain a Ni monatomic catalyst, and the rest is the same as embodiment 4.

[0111] Figure 4 is the electron microscope image of the Ni monatomic catalyst prepared in embodiment 10 of the present application.

[0112] Embodiment 11

[0113] The difference between this embodiment and embodiment 4 is only that 10 mg FeCl3·6H2O powder is replaced by 50 mg NiCl3·6H2O powder to obtain a Ni atomic cluster catalyst, and the rest is the same as embodiment 4.

[0114] Embodiment 12

[0115] A method for laser solid synthesis of S, N coordinated carbon-based Pt monatomic catalyst, the specific steps are as follows:

[0116] (1) First, 10 mmol Zn (NO3)2·6H2O is dissolved in 100 mL methanol solution and 50 mmol 2-methyl imidazole is dissolved in 100 mL methanol solution to form a solution mixture, and then stirred, centrifuged after 24 hours, and the precipitate is washed several times. After drying at 60 ℃ overnight, white powder ZIF-8 is collected;

[0117] (2) 50 mg of metal organic framework ZIF-8, 0.5 mL of 15% PBI, 12 mg of thiourea, and 0.2 mL of 20 mmol / L Pt precursor solution are mixed to obtain a precursor solution;

[0118] (3) Using a coater to apply 1.5 mL of precursor solution on a quartz glass plate with a thickness of 60 μm, soaked in deionized water for 2 h, and then taken out and dried;

[0119] (4) Using excimer ultraviolet laser to irradiate the precursor material on the quartz glass plate to obtain S, N-coordinated carbon-based Pt monatomic dispersion material, the mass ratio of carbon-based material to metal precursor is 25:1, wherein the laser wavelength is 355 nm, the spot size is 20 μm, the repetition frequency is 1000 kHz, the power is 2 W, and the scanning speed is 500 mm / s.

[0120] Example 13

[0121] The difference between this embodiment and example 12 is that thiourea in example 12 is replaced by potassium dihydrogen phosphate to obtain a laser solid-phase synthesized P, N-coordinated carbon-based Pt monatomic catalyst, and the rest is the same as example 12.

[0122] Example 14

[0123] The difference between this embodiment and example 12 is that the 0.2 ml of 20 mmol / L Pt precursor in example 12 is replaced by 0.3 ml of 20 mmol / L Pt precursor to obtain an S, N-coordinated Pt atomic cluster catalyst.

[0124] Example 15

[0125] The difference between this embodiment and example 12 is that the 0.2 ml of 20 mmol / L Pt precursor in example 12 is replaced by 0.1 ml of 20 mmol / L Pt precursor.

[0126] However, through comparison, it is found that this embodiment can also obtain S, N-coordinated carbon-based Pt monatomic, but the Pt monatomic concentration of the Pt monatomic catalyst in example 12 is higher.

[0127] Example 16

[0128] A method for laser solid-phase synthesis of Pt1Co monatomic alloy catalyst particles, the specific steps are as follows:

[0129] (1) First, 10 mmol of Co (NO3)2·6H2O is dissolved in 100 mL of methanol solution, and 50 mmol of 2-methyl imidazole is dissolved in 100 mL of methanol solution to form a solution mixture, and then stirred, centrifuged after 24 hours, and the precipitate is washed several times. After drying at 60 ℃ overnight, ZIF-67 is collected;

[0130] (2) 50 mg of metal-organic framework ZIF-67, 0.3 mL of 15% PBI, and 1.5 mL of dimethylacetamide (DMAC) are mixed to obtain a precursor solution;

[0131] (3) 1.5 mL of the precursor solution is coated on a quartz glass plate using a coater, with a thickness of 60 μm, soaked in deionized water for 2 h, and then taken out and dried;

[0132] (4) After laser irradiation of the precursor on the glass plate, the Co precursor supported on the porous carbon is reduced to Co atoms, and the porous carbon-supported ultra-small Co nanoparticles are collected as a base material, wherein the laser wavelength is 1064 nm, the spot size is 20 μm, the repetition frequency is 20 kHz, the power is 50 W, and the scanning speed is 2000 mm / s;

[0133] (6) 80 mg of porous carbon-supported ultra-small Co nanoparticles, 0.5 mL of 20 mmol / L chloroplatinic acid, 2 mL of DMAC, and 0.3 mL of 15% polybenzimidazole PBI are mixed;

[0134] (7) Step (3) is repeated;

[0135] (8) After irradiating the material on the glass plate with an ultraviolet laser, the powder is collected to obtain a Pt1Co single-atom alloy catalyst, the mass ratio of the carbon-based material to the metal precursor is 20:1, the laser wavelength is 355 nm, the spot size is 20 μm, the repetition frequency is 1000 kHz, the power is 2 W, and the scanning speed is 500 mm / s.

[0136] Figure 5a is a spherical aberration electron microscope image of a Pt1Co single-atom alloy catalyst particle prepared in Example 16.

[0137] Example 17

[0138] The difference between this example and Example 16 is that 0.5 mL of 20 mmol / L chloropalladic acid is used instead of 0.5 mL of 20 mmol / L chloroplatinic acid to obtain a Pd1Co single-atom alloy.

[0139] Example 18

[0140] The difference between this example and Example 16 is that 0.5 mL of 20 mmol / L chlororuthenic acid is used instead of 0.5 mL of 20 mmol / L chloroplatinic acid to obtain a Ru1Co single-atom alloy.

[0141] Example 19

[0142] The difference between this embodiment and embodiment 16 is that 0.5 mL of 20 mmol / L chloroiridic acid is used instead of 0.5 mL of 20 mmol / L chloroplatinic acid to obtain an Ir1Co monatomic alloy.

[0143] Embodiment 20

[0144] The difference between this embodiment and embodiment 16 is that 0.5 mL of 20 mmol / L titanium tetrachloride is used instead of 0.5 mL of 20 mmol / L chloroplatinic acid to obtain a Ti1Co monatomic alloy.

[0145] Embodiment 21

[0146] The difference between this embodiment and embodiment 16 is that 0.5 mL of 20 mmol / L manganese chloride trihydrate is used instead of 0.5 mL of 20 mmol / L chloroplatinic acid to obtain a Mn1Co monatomic alloy.

[0147] Embodiment 22

[0148] The difference between this embodiment and embodiment 16 is that 0.5 mL of 20 mmol / L chromium chloride is used instead of 0.5 mL of 20 mmol / L chloroplatinic acid to obtain a Cr1Co monatomic alloy.

[0149] Embodiment 23

[0150] The difference between this embodiment and embodiment 16 is that 0.5 mL of 20 mmol / L chloroplatinic acid is replaced by 0.35 mL of 20 mmol / L chloroplatinic acid.

[0151] Embodiment 24

[0152] The difference between this embodiment and embodiment 16 is that 0.5 mL of 20 mmol / L chloroplatinic acid is replaced by 0.2 mL of 20 mmol / L chloroplatinic acid.

[0153] However, through comparison, it is found that the Pt1Co monatomic alloy catalyst can also be obtained in embodiments 23 and 24, but the Pt monatomic concentration in the Pt1Co monatomic alloy catalyst of embodiment 16 is higher.

[0154] Embodiment 25

[0155] A method for laser solid synthesis of (PtRu)1Co diatomic alloy catalyst particles, the specific steps of which are as follows:

[0156] (1) First, 10 mmol of Co (NO3)2·6H2O was dissolved in 100 mL of methanol solution and 50 mmol of 2-methylimidazole was dissolved in 100 mL of methanol solution to form a solution mixture, which was stirred for 24 hours, and then the precipitate was centrifuged and washed several times. After drying at 60 °C overnight, the purple powder metal organic framework ZIF-67 was collected;

[0157] (2) 50 mg of metal organic framework ZIF-67, 0.2 mL of 20 mmol / L chloroplatinic acid DMAC solution, 1 mL of 20 mmol / L DMAC solution containing chlororuthenium acid ammonia, and 0.3 mL of 15% PBI and dimethylacetamide DMAC were mixed to obtain solution A.

[0158] (3) Using a coater, 1.5 mL of solution A was coated on a quartz glass plate with a thickness of 60 μm, soaked in deionized water for 2 h, and then dried.

[0159] (4) After irradiating the material on the above support with an ultraviolet laser, the powder was collected to obtain a (PtRu)1Co bimetallic alloy catalyst, and the mass ratio of the carbon-based material to the metal precursor was 25:1, the laser wavelength was 355 nm, the pulse width was 16 ps, the spot size was 20 μm, the repetition frequency was 1000 kHz, the power was 2 W, and the scanning speed was 500 mm / s.

[0160] Figure 5b is a spherical aberration electron microscope image of (PtRu)1Co bimetallic alloy catalyst particles prepared according to Example 25 of the present application. Figure 5c is a chronoamperometric curve of a (PtRu)1Co bimetallic alloy catalyst prepared according to the present application in a hydrogen evolution reaction, which shows better stability than a commercial Pt / C catalyst.

[0161] Example 26

[0162] The difference between this example and Example 25 is that the laser irradiation parameters used in the preparation of (PtRu)1Co bimetallic alloy nanoparticles in this example are: laser wavelength 532 nm, pulse width 10 ns, repetition frequency 100 kHz, power 200 W, and scanning speed 1000 mm / s.

[0163] Example 27

[0164] The difference between this example and Example 25 is that the laser irradiation parameters used in the preparation of (PtRu)1Co bimetallic alloy nanoparticles in this example are: laser wavelength 1064 nm, pulse width 10 ns, repetition frequency 100 kHz, power 125 W, and scanning speed 1000 mm / s.

[0165] Example 26, 27 can also form (PtRu)1Co diatomic alloy nanoparticles, but by comparison, it is found that the (PtRu)1Co diatomic alloy nanoparticles formed by Example 25 are smaller in size and more uniform in distribution.

[0166] Example 28

[0167] The difference between this example and Example 25 is that the laser irradiation parameters used in this example to prepare (PtRu)1Co diatomic alloy nanoparticles are: laser wavelength 248 nm, spot size 1 cm, repetition frequency 0.1 kHz, power 0.5 W, and scanning speed 500 mm / s.

[0168] This example can also form (PtRu)1Co diatomic alloy nanoparticles, but by comparison, it is found that the (PtRu)1Co diatomic alloy nanoparticles formed by Example 25 have a higher yield.

[0169] Example 29

[0170] The difference between this example and Example 25 is that 0.2 ml of 20 mmol / L Pt precursor is replaced by 0.1 ml of 20 mmol / L Pt precursor in this example.

[0171] However, by comparison, it is found that (PtRu)1Co diatomic alloy nanoparticles can also be obtained in this example, but the Pt and Ru atomic concentrations in the (PtRu)1Co diatomic alloy nanoparticles of Example 25 are higher.

[0172] Example 30

[0173] The difference between this example and Example 25 is that 0.2 ml of 20 mmol / L Pt precursor is replaced by 0.3 ml of 20 mmol / L Pt precursor in this example.

[0174] However, by comparison, it is found that (PtRu)1Co diatomic alloy nanoparticles can also be obtained in this example, but PtRuCo alloy nanoparticles are also present.

[0175] Comparative Example 1

[0176] This comparative example is generally the same as Example 1, with the main difference being:

[0177] The pulsed laser irradiation is replaced by continuous infrared lamp irradiation, with the average power being consistent with the pulsed laser irradiation.

[0178] Due to the inability to reach the reduction temperature of the precursor, the monatomic catalyst and atomic alloy catalyst cannot be ultimately formed.

[0179] Comparative Example 2

[0180] This comparative example is generally the same as Example 1, the main difference is that:

[0181] The pulsed laser irradiation is replaced by transient pulsed electric heating on the graphene film layer formed after the filtration and drying, the power remains the same, and the cooling speed of the latter is milliseconds, which is much longer than the microsecond cooling speed of the former. Longer temperature retention is not conducive to the retention of functional groups, i.e., atomic anchoring sites, and is also prone to atomic migration and agglomeration into nanoparticles.

[0182] Comparative Example 3

[0183] This comparative example is generally the same as Example 1, the main difference is that:

[0184] The graphene oxide is replaced by porous activated carbon with almost no active groups on the surface. Due to the lack of functional groups, the latter cannot provide a large number of single-atom anchoring sites, and lacks uniformly distributed single atoms. Further increasing the content of metal salt precursors is prone to generate nanoparticles.

[0185] Comparative Example 4

[0186] This comparative example is generally the same as Example 4, the main difference is that:

[0187] The metal-organic framework ZIF-8 is replaced by porous activated carbon, which also causes the lack of functional groups, i.e., atomic anchoring sites, and ultimately low single-atom loading.

[0188] Aspects, embodiments, features, and examples of the present application should be considered illustrative in all respects, and are not intended to limit the present application, the scope of which is defined only by the claims. Those skilled in the art will appreciate other embodiments, modifications, and uses without departing from the spirit and scope of the claimed application.

[0189] In addition, the present inventors have also carried out tests with other raw materials, process operations, and process conditions described in the present specification with reference to the foregoing examples, and have obtained relatively ideal results.

[0190] Although the present application has been described with reference to illustrative embodiments, those skilled in the art will appreciate that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the present application, and that elements of the described embodiments can be substituted with substantial equivalents. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present application without departing from the scope thereof. Therefore, the present application is not intended to be limited to the disclosed specific embodiments for carrying out the present application, but is intended to encompass all embodiments falling within the scope of the appended claims.

Claims

1. A method for preparing a laser solid synthesis atomic level catalyst, characterized in that, The application relates to a method for preparing an atomic-level catalyst. Mixing metal organic framework ZIF-67, polybenzimidazole and dimethylacetamide to obtain solution A, coating the solution A on a glass plate, soaking in deionized water, taking out and drying, then irradiating the material on the glass plate by laser to obtain powder A; Mixing metal salt precursor and dimethylacetamide to obtain solution B; Mixing the powder A, the solution B and polybenzimidazole to obtain solution C, coating the solution C on a support, soaking in deionized water, taking out and drying, then irradiating the material on the support by laser to prepare an atomic-level catalyst, wherein the concentration of the metal organic framework ZIF-67 in the solution A is 10-30 g / L, the mass concentration of polybenzimidazole is 10-30%, the thickness of the solution A coated on the glass plate is 20-100 mu m, the concentration of the metal salt precursor in the solution B is 0.001-0.2 mol / L, and the concentration of the powder A in the solution C is 10-30 g / L; Or, mixing metal organic framework ZIF-67, metal salt precursor, polybenzimidazole and dimethylacetamide, stirring uniformly, coating on a support, soaking in deionized water, taking out and drying, then irradiating the material on the support by laser to prepare an atomic-level catalyst, wherein the mass ratio of metal organic framework ZIF-67, metal salt precursor, polybenzimidazole and dimethylacetamide ranges from (10:1:1:1) to (10:3:3:3); The laser irradiation adopts a laser wavelength of 248 nm-10.6 mu m, a power of 0.5-200 W, a scanning speed of 500-2000 mm / s, a frequency of 1-1000 kHz, a spot diameter of 20 mu m-1 cm and a pulse width of 10 ps-10 ms, and the laser irradiation time is 10-60 min.

2. The method of claim 1, wherein: The metal element in the metal salt precursor includes any one or a combination of two or more of copper, nickel, iron, palladium, platinum, ruthenium, iridium, titanium, manganese and chromium.

3. The method of claim 1, wherein: The support is selected from at least any one of quartz glass plate, nickel mesh, carbon paper, carbon felt and carbon cloth.

4. An atomic scale catalyst produced by the method of any one of claims 1 to 3, characterized by: The atomic-level catalyst includes any one of single-atom alloy catalyst and double-atom alloy catalyst.

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