Metallic monoatomic catalyst, method for preparing the same and use thereof

Abstract

The application belongs to the field of catalysis technology, and provides a metal monatomic catalyst, a preparation method and use thereof.The preparation method uses modified boron nitride as a carrier, and uses ALD atomic layer deposition technology to deposit a metal monatomic active component on the modified boron nitride, thereby obtaining the metal monatomic catalyst.The application optimizes the loading effect of the metal monatomic catalyst through the ALD atomic layer deposition technology, so that the metal monatomic catalyst has more advantages than a monatomic catalyst obtained by using conventional means such as a mixed reaction, the hydrogenation catalytic performance on a nitroaromatic hydrocarbon is improved by more than twice under the same loading amount, the obtained metal monatomic catalyst better realizes high conversion of nitroaromatic hydrocarbon hydrogenation and high selectivity on aromatic amine, the hydrogenation catalytic reaction can more effectively inhibit the generation of by-products, reduce catalyst deactivation, and is more gentle and green without introducing an alkaline additive.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalysis, and relates to a catalyst, in particular to a metal monatomic catalyst and a preparation method and application thereof. BACKGROUND

[0002] Aromatic amine compounds have extremely important applications in the chemical industry, are important chemical raw materials and intermediates, and have been widely used in multiple industries.

[0003] Aromatic amines refer to amines with an aromatic substituent, i.e., -NH2, -NH or a nitrogen-containing group connected to an aromatic hydrocarbon. The structure of the aromatic hydrocarbon usually contains one or more benzene rings, i.e., the nitrogen atom and the benzene ring carbon atom are directly connected by a chemical bond. Aniline is the simplest example of such compounds. Aromatic amines are generally high-boiling liquids or low-melting solids, have a special odor, and are relatively toxic.

[0004] The preparation of aromatic amines cannot be directly obtained by introducing an amino group (-NH2) onto an aromatic ring, but is obtained by indirect methods. Since aromatic nitro compounds are easily obtained by nitration, the reduction of aromatic nitro compounds is a common method for preparing primary aromatic amines.

[0005] The conversion of aromatic nitro compounds to aromatic amines by reduction reaction usually involves the selection and use of catalysts, aiming to efficiently and selectively break the N-O bond and perform hydrogenation, and in this process, attention should be paid to avoiding excessive reduction of the aromatic ring or the occurrence of other side reactions. Traditional reduction methods, such as iron powder / hydrochloric acid system or tin / hydrochloric acid system, although simple to operate and relatively low in cost, have limitations such as slow reaction rate, low selectivity, and serious environmental pollution. In the iron powder reduction method, the oxidation products of iron powder easily form difficult-to-handle sludge, causing environmental burden; while the tin hydrochloric acid system, although the reaction rate is faster in some cases, the potential toxicity problem of tin metal limits its wide application.

[0006] Therefore, it is necessary to research and develop hydrogenation schemes for aromatic nitro compounds to solve the problems existing in the existing schemes. SUMMARY

[0007] In view of the problems in the prior art, the purpose of the present application is to provide a metal monatomic catalyst, a preparation method and use thereof, the preparation method uses modified boron nitride as a carrier, and uses ALD atomic layer deposition technology to deposit a metal monatomic active component on the modified boron nitride, thereby obtaining a metal monatomic catalyst. The present application optimizes the loading effect of metal monatomic through ALD atomic layer deposition technology, so that the metal monatomic catalyst obtained by the present application has more advantages than the monatomic catalyst obtained by conventional means such as mixed reaction, the catalytic performance of the metal monatomic catalyst for the hydrogenation of nitroaromatic hydrocarbons is improved by more than twice under the same loading amount, the metal monatomic catalyst obtained by the present application better realizes high conversion rate of nitroaromatic hydrocarbons and high selectivity of aromatic amines, and the hydrogenation catalytic reaction can more effectively inhibit the generation of by-products, reduce catalyst deactivation, and is more gentle and green without introducing alkaline additives.

[0008] To achieve this purpose, the present application adopts the following technical solutions:

[0009] In a first aspect, the present application provides a preparation method of a metal monatomic catalyst, comprising:

[0010] Providing modified boron nitride, using ALD atomic layer deposition technology to prepare a metal monatomic active component on the modified boron nitride, and obtaining a metal monatomic catalyst.

[0011] The preparation method of the present application obtains a metal monatomic catalyst, which utilizes the characteristics of single active site of homogeneous catalyst and stability, easy separation and reusability of heterogeneous catalyst of the monatomic catalyst, effectively improves the atomic utilization rate, and provides a green and efficient new way for the conversion of nitroaromatic hydrocarbons to prepare aromatic amine compounds, and does not use inorganic alkali in the reaction process, thereby avoiding the common environmental pollution problem in the hydrogenation process of nitroaromatic hydrocarbons.

[0012] The present application realizes the deposition and loading of metal monatomic on a specific modified boron nitride carrier through ALD atomic layer deposition technology, on the one hand, the modified boron nitride has a higher specific surface area and more abundant nitrogen active sites, so that it can form more coordination with the active component, and promote the formation of atomic-level dispersion of the active component on the surface of the specific carrier; on the other hand, and more importantly, the ALD atomic layer deposition technology realizes and improves the loading of metal monatomic, the metal monatomic catalyst prepared by the ALD atomic layer deposition technology is more stable and has a more definite structure, and through adjusting the program, the design of clusters and nanoparticles can be realized, so that the active sites on the carrier can be better matched to realize better directional anchoring of the metal monatomic active component.

[0013] Compared with a single-atom catalyst obtained by a conventional method such as a mixing reaction, the metal single-atom catalyst obtained by the ALD atomic layer deposition technology and the specific carrier has more advantages, the catalytic performance of hydrogenation of a nitro aromatic hydrocarbon is improved by more than twice under the same loading, the obtained metal single-atom catalyst better realizes high conversion of nitro aromatic hydrocarbon hydrogenation and high selectivity of aromatic amine, the hydrogenation catalytic reaction does not introduce an alkaline additive, subsequent separation operation is not needed, production cost is greatly reduced, and high-activity and high-selectivity one-step hydrogenation of nitrobenzene to aniline is realized under the condition of normal temperature and low pressure.

[0014] The following is a preferred technical solution of the present application, but is not a limitation of the technical solution provided by the present application. Through the following technical solution, the technical purpose and beneficial effects of the present application can be better achieved and realized.

[0015] As a preferred technical solution of the present application, the modified boron nitride includes a defective boron nitride.

[0016] Preferably, the metal single-atom active component includes a metal single atom of at least one of Pd, Ir, Co, Ni, Rh, Pt or Ru.

[0017] The surface of the defective boron nitride has rich nitrogen active sites, defect sites and alkaline sites, which can promote the single-atom dispersion of the active component and improve the utilization rate of the active component; the nitrogen active sites and the defect sites can simultaneously act as alkaline sites to enhance the alkalinity, so that the catalyst can effectively inhibit the generation of by-products dicyclohexylamine and cyclohexylamine without adding an alkaline additive, thereby reducing the catalyst deactivation caused by the by-products. Without introducing an alkaline additive, the reaction can be carried out under relatively mild temperature and pressure, high conversion of nitro aromatic hydrocarbon hydrogenation and high selectivity of aromatic amine can be realized, subsequent separation operation is not needed, production cost is greatly reduced, and the discharge of waste liquid and waste residue is reduced.

[0018] As a preferred technical solution of the present application, the ALD atomic layer deposition technology includes placing the modified boron nitride in a chamber, after the conditions of the deposition reaction are reached, sequentially performing a metal single-atom active component precursor pulse, an inert gas first purge, a reactant pulse and an inert gas second purge to complete one cycle period, repeating the cycle period until the deposition reaction is completed, and obtaining a metal single-atom catalyst.

[0019] As a preferred technical solution of the present application, the conditions of the deposition reaction include a temperature of 80-200℃.

[0020] As a preferred technical solution of the present application, the conditions of the deposition reaction include a background vacuum degree of 9-11Pa, such as 9Pa, 9.3Pa, 9.5Pa, 9.8Pa, 10Pa, 10.2Pa, 10.5Pa, 10.8Pa or 11Pa, etc.

[0021] As a preferred technical solution of the present invention, the metal single-atom active component precursor includes at least one of [Pd(NH3)4](NO3)2, [Pd(NH3)]4SO4, (NH4)2PdCl6, K2PdCl4, Na2PdCl4, Pd(AcAc)2, Pd(OAc)2, PdCl2, H2IrCl6, CoCl3·nH2O, Pd(NO3)2, RuCl3·nH2O, Ru2Cl4(CO)6, RuI3, K2RuCl, (NH)4RuCl6, cyclopentadienylpalladium, bis(cyclopentadienyl)nickel, (methylcyclopentadienyl)trimethylplatinum, cobalt β-diketone, or platinum acetylacetonate.

[0022] Preferably, the reactants include at least one of formaldehyde, ozone, or oxygen, with formaldehyde being the most preferred.

[0023] The metal single-atom catalyst prepared by the method described in this invention has advantages over single-atom catalysts in the prior art. Under the same loading, the catalytic performance is greatly improved. Therefore, it is suitable for loading non-metallic components and can obtain better actual catalytic effects. Alternatively, when loading noble metal components, the target catalytic effect can be obtained with a significantly reduced loading, greatly reducing costs.

[0024] As a preferred embodiment of the present invention, the loading amount of the metal single-atom active component is 0.1 to 0.5 wt%, for example, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, or 0.5 wt%.

[0025] As a preferred embodiment of the present invention, the pulse duration of the metal single-atom active component precursor is 8–15 s, for example, 8 s, 9 s, 10 s, 11 s, 12 s, 13 s, 14 s, or 15 s, and the purging time of the inert gas is 100–150 s, for example, 100 s, 105 s, 110 s, 115 s, 120 s, 125 s, 130 s, 135 s, 140 s, 145 s, or 150 s, etc. The reactant pulse duration is 50–120 s, for example, 50 s, 55 s, 60 s, 65 s, 70 s, 75 s, 80 s, 85 s, 90 s, 95 s, 100 s, 105 s, 110 s, 115 s, or 120 s, etc., and the inert gas secondary purging duration is 20–120 s, for example, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s, 110 s, or 120 s, etc.

[0026] The cycle is performed 1 to 8 times, for example, 1 time, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times or 8 times.

[0027] As a preferred technical solution of the present invention, the method for preparing the modified boron nitride includes mixing and reacting boron nitride with a modifier to obtain modified boron nitride.

[0028] Preferably, the modifier includes amino-containing compounds and / or hydroxyl-containing compounds.

[0029] Preferably, the amino-containing compound includes at least one of ammonia, urea, ethylenediamine, aniline, or naphthylamine.

[0030] Preferably, the hydroxyl-containing compound includes at least one of sodium hydroxide, hydrogen peroxide, potassium hydroxide, or lithium hydroxide.

[0031] Preferably, the mass ratio of boron nitride to the modifier is 1:(5-100), for example 1:5, 1:10, 1:20, 1:30, 1:40, 1:50, 1:60, 1:70, 1:80, 1:90 or 1:100, and more preferably 1:(10-50).

[0032] Preferably, the method for the mixing reaction includes ball milling.

[0033] Preferably, the ball milling includes liquid-phase ball milling using water as the medium.

[0034] Preferably, the rotational speed of the ball mill is 400 to 1500 rpm, such as 400 rpm, 500 rpm, 600 rpm, 700 rpm, 800 rpm, 900 rpm, 1000 rpm, 1100 rpm, 1200 rpm, 1300 rpm, 1400 rpm or 1500 rpm, and more preferably 500 to 1000 rpm.

[0035] Preferably, the ball milling time is 2 to 50 hours, such as 2 hours, 5 hours, 8 hours, 10 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, 40 hours, 45 hours or 50 hours, and more preferably 5 to 30 hours.

[0036] As a preferred technical solution of the present invention, the method for preparing the boron nitride includes reacting a boron source with a nitrogen source to obtain boron nitride.

[0037] Preferably, the temperature of the reaction is 700–2000℃, such as 700℃, 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, 1800℃, 1900℃, or 2000℃, and the time is 3–10h, such as 3h, 4h, 5h, 6h, 7h, 8h, 9h, or 10h.

[0038] Preferably, the boron source includes at least one of boric acid, borax, elemental boron, sodium metaborate, boron chloride, or boron bromide.

[0039] Preferably, the nitrogen source includes at least one of cyanamide, dicyandiamide, melamine, thiourea, urea, or guanidine hydrochloride.

[0040] Preferably, the molar ratio of the boron source to the nitrogen source is 1:(10-30), for example, 1:10, 1:15, 1:20, 1:25 or 1:30.

[0041] In a second aspect, the present invention provides a metal single-atom catalyst, obtained according to the preparation method described in the first aspect.

[0042] Thirdly, the present invention provides an use of the metal single-atom catalyst described in the second aspect, the use of which includes hydrogenation reactions.

[0043] As a preferred embodiment of the present invention, the hydrogenation reaction includes the hydrogenation of nitroaromatic hydrocarbons to produce aromatic amines.

[0044] Preferably, in the reaction of hydrogenating nitroaromatic hydrocarbons to produce aromatic amines, the mass of the metal single-atom catalyst is 1% to 25% of the mass of the nitroaromatic hydrocarbon, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%.

[0045] Preferably, the temperature for the hydrogenation reaction of nitroaromatic hydrocarbons to produce aromatic amines is 20 to 60°C, such as 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, or 60°C.

[0046] Preferably, the initial pressure for the hydrogenation reaction of nitroaromatic hydrocarbons to produce aromatic amines is 0.1 (atmospheric pressure) to 2 MPa, for example, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.8 MPa, 1 MPa, 1.2 MPa, 1.4 MPa, 1.6 MPa, 1.8 MPa or 2 MPa.

[0047] Preferably, the reaction time for the hydrogenation of nitroaromatic hydrocarbons to produce aromatic amines is 10 to 60 minutes, such as 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, or 60 minutes.

[0048] Preferably, the nitroaromatic hydrocarbon includes nitrobenzene.

[0049] Preferably, the hydrogenation reaction of nitroaromatic hydrocarbons to produce aromatic amines is carried out in a solvent medium.

[0050] Preferably, the solvent medium includes at least one of tetrahydrofuran, methanol, isopropanol, ethanol, cyclohexane, cyclohexylamine, n-butanol, toluene, N-methylpyrrolidone, or tert-butanol.

[0051] Compared with existing technical solutions, the present invention has at least the following beneficial effects:

[0052] This invention utilizes ALD (Atomic Layer Deposition) technology to achieve the deposition and loading of metal single atoms on a specific modified boron nitride support. On one hand, it leverages the higher specific surface area and abundant nitrogen active sites of modified boron nitride, enabling it to form more coordination sites with the active components and promoting atomic-level dispersion of the active components on the specific support surface. On the other hand, ALD technology achieves and improves the loading of metal single atoms. The metal single-atom catalyst prepared by ALD is more stable and has a more defined structure. By adjusting the program, clusters and nanoparticles can be designed, allowing for better matching of active sites on the support and achieving better directional anchoring of the metal single-atom active components. The resulting metal single-atom catalyst has significant advantages; at the same loading, its catalytic performance for the hydrogenation of nitroaromatic hydrocarbons is more than doubled. The obtained metal single-atom catalyst better achieves high conversion rates for the hydrogenation of nitroaromatic hydrocarbons and high selectivity for aromatic amines. Furthermore, the hydrogenation catalytic reaction does not introduce alkaline promoters, eliminating the need for subsequent separation operations and significantly reducing production costs. Under ambient temperature and low pressure conditions, it achieves highly active and selective hydrogenation of nitrobenzene to aniline. Attached Figure Description

[0053] Figure 1 This is a spherical aberration electron microscopy characterization of the metal single-atom catalyst obtained in Example 1. Detailed Implementation

[0054] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0055] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0056] Example 1

[0057] This embodiment provides a method for preparing a metal single-atom catalyst, including:

[0058] (1) Boron source borax and nitrogen source urea were mixed at a molar ratio of 1:20 and calcined at 900℃ for 5h to carry out the formation reaction and obtain hexagonal boron nitride.

[0059] (2) The obtained hexagonal boron nitride and the modifier sodium hydroxide were mixed at a mass ratio of 1:30 and dissolved in water. The mixture was ball-milled at 700 rpm for 40 h to obtain a mixture. The mixture was centrifuged, filtered, and washed until the pH of the filtrate was 7. The filter residue was placed in a forced-air drying oven and dried at 80°C for 12 h to obtain defective boron nitride as modified boron nitride.

[0060] (3) Prepare single-atom metal active components on the modified boron nitride using ALD atomic layer deposition technology:

[0061] Cyclopentadienylpalladium was used as the precursor of the single-atom active metal component; nitrogen was used as the inert gas; and formaldehyde was used as the reactant.

[0062] The modified boron nitride was placed in a chamber, and after the deposition reaction temperature reached 120°C, a cycle was completed by sequentially performing a 12s pulse of the metal single-atom active component precursor, a 120s inert gas purging, a 90s pulse of the reactants, and a 100s inert gas purging. The cycle was repeated 8 times until the deposition reaction was completed, yielding a 0.4wt% metal single-atom catalyst.

[0063] Examples 2-6

[0064] This embodiment provides a method for preparing a metal single-atom catalyst. In step (3) of the preparation method, the precursor of the metal single-atom active component is adjusted from cyclopentadienylpalladium to palladium acetylacetonate, platinum acetylacetonate, RuCl3, and Co(NO3)2, respectively. 3)2 K2PdCl4 was used to obtain metal single-atom catalysts with different active components but the same loading.

[0065] Examples 7-10

[0066] This embodiment provides a method for preparing a metal single-atom catalyst. In step (3), the total amount of the metal single-atom active component precursor and the amount of the modified boron nitride are adjusted so that the loading of the metal single-atom active component is adjusted from 0.4 wt% to 0.05 wt%, 0.1 wt%, 0.7 wt%, and 1.0 wt%, respectively. Except for the above, the other conditions are exactly the same as in Example 1.

[0067] Examples 11-14

[0068] This embodiment provides a method for preparing a metal single-atom catalyst. In step (3), the precursor of the metal single-atom active component is changed from cyclopentadienylpalladium to Co(NO3)2, and the total amount of the metal single-atom active component precursor and the amount of the modified boron nitride are adjusted so that the loading of the metal single-atom active component is adjusted from 0.4 wt% to 0.1 wt%, 0.5 wt%, 0.7 wt%, and 1.0 wt%, respectively, to obtain a non-noble metal single-atom catalyst in which both the metal single-atom active component and its loading are changed. Except for the above, the other conditions are exactly the same as in Example 1.

[0069] Comparative Example 1

[0070] This comparative example provides a method for preparing a metal single-atom catalyst, wherein the preparation method employs a ball milling mixing method to deposit the metal single-atom active component, i.e., step (3) is as follows:

[0071] Cyclopentadienylpalladium was used as a precursor of the single-atom active metal component. It was mixed with modified boron nitride and ball-milled at 700 rpm for 10 h to obtain an intermediate mixture. The obtained intermediate mixture was evenly spread on the surface of a magnetic boat, placed in a tube furnace, and calcined at 300 °C for 5 h with nitrogen gas to obtain a single-atom hydrogenation catalyst with a loading of 0.4 wt%.

[0072] Comparative Example 2

[0073] This comparative example provides a method for preparing a metal single-atom catalyst. In step (3) of the preparation method, the precursor of the metal single-atom active component is changed from cyclopentadienylpalladium to K2PdCl4. Except for the above, the other conditions are exactly the same as those in Comparative Example 1.

[0074] Comparative Example 3

[0075] This comparative example provides a method for preparing a metal single-atom catalyst. In step (3) of the preparation method, the precursor of the metal single-atom active component is changed from cyclopentadienylpalladium to Co(NO3)2, and the amounts of the metal single-atom active component precursor and modified boron nitride are adjusted. Other conditions are exactly the same as those in Comparative Example 1.

[0076] Characterization and testing:

[0077] I. Figure 1 This is a spherical aberration electron microscopy characterization image of the metal single-atom catalyst obtained in Example 1. As can be seen from the image, metal Pd is atomically dispersed on the surface of defective boron nitride, and the particle size of active metal Pd is 0.1 nm.

[0078] II. The metal single-atom catalysts obtained in the examples and comparative examples were used to carry out the hydrogenation reaction of nitroaromatic hydrocarbons to produce aromatic amines. Nitrobenzene was mixed with 25% of the metal single-atom catalyst by mass in a solvent medium, and the hydrogenation reaction was carried out for 10 to 60 min at an initial pressure of 0.1 to 2 MPa and a temperature of 20 to 60 °C. The specific reaction conditions and reaction results are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] As can be seen from Table 1:

[0083] When using the metal single-atom catalyst obtained in this invention for the hydrogenation of nitroaromatic hydrocarbons to aromatic amines, the selectivity of the product aromatic amine is consistently around 99.9%. Therefore, the yield is calculated as yield = conversion * selectivity. To achieve the same yield, a shorter time is required, resulting in better catalytic performance. Thus, it can be seen that the catalyst prepared using ALD atomic layer deposition technology has a better catalytic effect than the catalyst prepared by ball milling. Under the same metal loading, the catalyst prepared by ALD atomic layer deposition technology exhibits better coordination between the active metal and defect sites on the support than that prepared by ball milling, demonstrating higher utilization of active metal atoms. The hydrogenation activity of noble metals is superior to that of non-noble metals, attributed to the metal's activation ability for hydrogen. The catalytic effect of the metal single-atom catalyst obtained in this invention is more than double that of single-atom catalysts obtained by existing methods, and the catalyst TOF value is doubled.

[0084] This invention illustrates the detailed process equipment and process flow through the above embodiments. However, this invention is not limited to the detailed process equipment and process flow described above, meaning that this invention does not necessarily depend on the detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

[0085] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0086] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0087] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. The use of a metal single-atom catalyst in the hydrogenation of nitrobenzene to aniline, characterized in that, The metal single-atom catalyst is prepared by the following method, the method comprising: A modified boron nitride is provided, and a single-atom metal active component is prepared on the modified boron nitride using ALD atomic layer deposition technology to obtain a single-atom metal catalyst; The loading amount of the single-atom metal active component is 0.1~0.5 wt%; The metal single-atom active component includes at least one metal single atom selected from Pd, Ir, Co, Ni, Rh, Pt, or Ru. The method for preparing the modified boron nitride includes mixing and reacting boron nitride with a modifier to obtain modified boron nitride; The modifier includes amino-containing compounds and / or hydroxyl-containing compounds; The amino-containing compound includes at least one of urea, ethylenediamine, aniline, or naphthylamine; The hydroxyl-containing compound includes at least one of sodium hydroxide, hydrogen peroxide, potassium hydroxide, or lithium hydroxide. The mass ratio of boron nitride to the modifier is 1:(5~100).

2. The use according to claim 1, characterized in that, The ALD atomic layer deposition technology includes placing the modified boron nitride in a chamber, and after the conditions for deposition reaction are met, sequentially performing a pulse of the metal single-atom active component precursor, a first purging with inert gas, a pulse of the reactants, and a second purging with inert gas to complete one cycle. The cycle is repeated until the deposition reaction is completed to obtain a metal single-atom catalyst.

3. The use according to claim 2, characterized in that, The deposition reaction is carried out at a temperature of 80~200℃.

4. The use according to claim 2, characterized in that, The pulse duration of the metal single-atom active component precursor is 8-15s, the first purging time of the inert gas is 100-150s, the pulse duration of the reactant is 50-120s, and the second purging time of the inert gas is 20-120s; the cycle is performed 1-8 times in total.

5. The use according to claim 2, characterized in that, The single-atom active component precursor includes at least one of [Pd(NH3)4](NO3)2, [Pd(NH3)]4SO4, (NH4)2PdCl6, K2PdCl4, Na2PdCl4, Pd(OAc)2, PdCl2, H2IrCl6, CoCl3·nH2O, Pd(NO3)2, RuCl3·nH2O, Ru2Cl4(CO)6, cyclopentadienylpalladium, bis(cyclopentadienyl)nickel, (methylcyclopentadienyl)trimethylplatinum, or platinum acetylacetonate.

6. The use according to claim 2, characterized in that, The reactants include at least one of formaldehyde, ozone, or oxygen.

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