Actinide-graphene aerogel composite material and preparation method and application thereof

Abstract

The present invention discloses an actinide-graphite aerogel composite material and a preparation method and application thereof, in the field of catalyst material technology. The actinide-graphite aerogel composite material comprises actinide ions, iodide ions and graphite aerogel, and the graphite aerogel is a porous mesh structure, and the actinide ions and iodide ions are present on the surface of the graphite aerogel in the form of nanoclusters; the actinide ions are selected from one of Th, Pa, U, Np, Pu, and Am ions. The actinide-graphite aerogel composite material can be used as a catalyst to achieve efficient thermal catalytic ammonia production under mild conditions, and the thermal catalytic ammonia production performance of the composite material can be regulated by changing the monomer structure of the graphite aerogel, and even the thermal catalytic ammonia production of the graphite aerogel material can be achieved without metal loading, and is expected to become a new generation of high-performance thermal catalytic ammonia production catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst materials, and in particular to the preparation of an actinide-graphene aerogel composite material and its application in thermal catalytic ammonia production under mild conditions. Background Art

[0002] Ammonia is an important chemical raw material, and the synthetic ammonia industry has laid the foundation for modern agriculture. In recent years, the application of ammonia in the energy field has also attracted widespread attention. Due to the high hydrogen content and high safety of ammonia molecules, ammonia can be used as an excellent energy storage medium. Green ammonia is produced by electrolyzing water with renewable energy such as wind power and photovoltaics, and then preparing synthetic ammonia with nitrogen in the air. Since it produces nitrogen and water after combustion and does not produce carbon dioxide, green ammonia is considered to be a "zero-carbon" fuel, one of the important clean energy sources in the future, and one of the main means for the global transportation industry to achieve carbon neutrality in the future. Due to the high cost of green hydrogen, the current cost price of green ammonia is much higher than the traditional gray ammonia route. In order to make up for the problems caused by the high cost of green hydrogen, it is necessary to prepare high-performance catalysts to achieve efficient thermal catalytic ammonia production under mild conditions.

[0003] At present, the mainstream ammonia synthesis process used in industry is still the Haber-Bosch cycle proposed in the early twentieth century. The first generation of iron-based catalysts needs to catalyze the production of ammonia at 400-500°C and 150-200 atm. This process not only causes huge energy consumption, but also emits a large amount of greenhouse gases such as CO2. The ruthenium-based catalysts born at the end of the 20th century are considered to be the second generation of ammonia synthesis catalysts. Compared with the first generation of iron-based catalysts, they have higher catalytic activity and relatively lower reaction temperature. However, due to its relatively high cost and shortcomings such as hydrogen poisoning on the surface of metal ruthenium, it is still difficult for ruthenium-based catalysts to completely replace iron-based catalysts to date (VS Marakatti, et al. , Recent advances in heterogeneous catalysis for ammonia synthesis [J]. ChemCatChem 2020,12: 5838-5857).

[0004] Actinides have 5 f Track and 6 d The orbital energies are similar, so they can be converted between various chemical valence states. Based on the variable chemical valence states of light actinides and the strong covalent binding ability of ligands, light actinides represented by uranium show excellent activation performance after combining with functional ligands (Q. Zhu, et al., Heterometallic clusters with uranium–metal bonds supported by double-layer nitrogen–phosphorus ligands. Acc. Chem. Res. 2022, 55 (12): 1718-1730). As early as the last century, before Fe-based catalysts were used in the Haber-Bosch cycle to catalyze ammonia production, Haber discovered that uranium had a strong activation effect on N2, but due to the lack of suitable carrier materials, this catalyst was not used in industrial production. In recent years, the activation of nitrogen has been achieved by combining uranium with functional ligands, but the catalytic cycle of artificial ammonia synthesis has not yet been realized. So far, no uranium-based heterogeneous catalysts have been reported. Due to the characteristics of light weight and large specific surface area, heterogeneous catalysts have great advantages in catalytic environments involving gas adsorption.

[0005] In the special structure of graphdiyne (GDY for short), its electron-rich cavity can effectively anchor dispersed metal atoms, reduce metal agglomeration during the catalytic process, and help improve the cycle stability. Its inherent intrinsic band gap can enhance the charge transfer between metal and GDY and improve the catalytic activity of the catalyst. In recent years, the catalytic conversion of N2 by GDY has attracted people's attention. The current research on the catalytic ammonia production of GDY materials focuses on catalysts formed by the combination of transition metals or precious metals with GDY, and mainly focuses on electrocatalysis and photocatalysis systems. CN116809052A and CN118268008A used copper foil as the substrate material to prepare a few-layer GDY and bulk GDY with nanowall structure, respectively, and loaded uranium to prepare U-GDY composite materials. The above materials can produce ammonia efficiently under mild conditions (150 ° C, 14-15 bar). However, further studies have found that at higher temperatures, the surface morphology of GDY materials with nanowall structures will collapse due to thermal stress. Summary of the invention

[0006] The object of the present invention is to provide an actinide-graphite aerogel composite material, which can achieve thermal catalytic ammonia production under mild conditions. In order to overcome the disadvantage of the collapse of the physical morphology of the surface of the GDY material prepared by the prior art, the present invention uses a one-pot method to prepare a GDY aerogel with a porous mesh structure to avoid the collapse of the physical structure of the material. Moreover, compared with the GDY material prepared with copper foil as the substrate, the aerogel structure has a higher specific surface area. For catalysis, a large specific surface area can provide more adsorption binding sites, which is conducive to the improvement of catalytic efficiency. In addition, by rationally regulating the monomer structure of the preparation of GDY aerogel (for example, introducing different substituents into the monomer skeleton structure to change the local coordination environment and charge density), the catalytic ability of the actinide-graphite aerogel composite material can be effectively regulated, and the catalytic ability can even be reflected under the condition of no metal loading. The present invention is also an exploration of the research on the thermal catalytic ammonia production of metal-free GDY catalysts, which has great theoretical significance and research value.

[0007] Specifically, the first aspect of the present invention provides an actinide-graphite aerogel composite material, comprising actinide ions, iodide ions and graphite aerogel, wherein the graphite aerogel is a porous network structure, and the actinide ions and iodide ions exist on the surface of the graphite aerogel in the form of nanoclusters; the actinide ions are selected from at least one of thorium (Th), protactinium (Pa), uranium (U), neptunium (Np), plutonium (Pu), and americium (Am) ions, and the actinide ions have a quasi-tetravalent valence.

[0008] Furthermore, the graphyne aerogel is a porous network structure material prepared from 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomers, and the substituents (R) at positions 2,4,6 on the 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomers can be at least one of hydrogen atoms, fluorine atoms, chlorine atoms, methyl groups, methoxy groups, cyano groups, hydroxyl groups, amino groups and the like.

[0009] In some embodiments of the present invention, the Graphene aerogel can be prepared by the following method: dissolving 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomer and copper salt in a pyridine solution, sealing it, and heating it at 40-80°C for 2-4 days. The obtained product is subjected to solvent replacement, impurity removal and freeze drying to obtain the Graphene aerogel material.

[0010] Preferably, the copper salt is one or more of anhydrous copper acetate, cuprous chloride, cuprous iodide and the like.

[0011] In one embodiment of the present invention, the Graphdine aerogel is a porous network structure containing a variety of pore structures such as micropores, mesopores and macropores.

[0012] In one embodiment of the present invention, the actinide ions are uranium ions.

[0013] In some embodiments of the present invention, the valence of the actinide ions is in a quasi-tetravalent state, and the loading amount thereof is 0.5 wt% to 5 wt%.

[0014] The second aspect of the present invention provides a method for preparing the above-mentioned actinide-graphite aerogel composite material, comprising: immersing the graphite aerogel in a solution containing actinide ion iodide under the condition of isolating water, oxygen and nitrogen, and after standing for a period of time, draining the solvent to obtain the actinide-graphite aerogel composite material.

[0015] Preferably, the actinide ion iodide is uranium triiodide.

[0016] Preferably, the solvent used in the solution containing actinide ion iodides is selected from one or more of tetrahydrofuran, diethyl ether, dioxane and toluene.

[0017] In one embodiment of the present invention, the solution containing actinide ion iodide is a uranium triiodide tetrahydrofuran solution, wherein the uranium content of the solution is 0.1%-5% of the mass of the graphyne aerogel, and the graphyne aerogel is allowed to stand in the solution at room temperature for 12-24 hours.

[0018] The third aspect of the present invention provides the use of the above-mentioned actinide-graphene aerogel composite material in thermal catalytic ammonia production.

[0019] In one embodiment of the present invention, the actinide-graphene aerogel composite material is used as a catalyst to produce ammonia by thermal catalysis using a nitrogen-hydrogen mixed gas.

[0020] Preferably, the nitrogen content in the nitrogen-hydrogen mixed gas is 25-90 vol%, more preferably 10-40 vol%; the temperature for catalytic production of ammonia is 90-180° C.; the pressure required for catalytic production of ammonia is 1-20 bar, more preferably 15-18 bar.

[0021] In some embodiments of the present invention, the amount of the actinide-graphite aerogel composite material is as follows: 20 to 40 mg of the actinide-graphite aerogel composite material is added to a reactor with a volume of 100 to 250 mL.

[0022] Beneficial effects of the present invention:

[0023] The actinide-graphene aerogel composite material provided by the present invention is a graphene aerogel material with actinide ions loaded thereon, which is used as a catalyst to achieve efficient thermal catalytic ammonia production under mild conditions. By changing the monomer structure of the graphene aerogel, the thermal catalytic ammonia production performance of the composite material can be effectively regulated, and even the thermal catalytic ammonia production of the graphene aerogel material can be achieved without metal loading. The present invention is of great significance for the development of new actinide-graphene composite catalysts and metal-free graphene catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to explain the technical solutions in the embodiments of the present invention more clearly and in detail, the drawings related to the embodiments of the present invention are briefly introduced.

[0025] Figure 1 Schematic diagram of the monomer structure and synthesis route for preparing graphyne aerogel.

[0026] Figure 2 The scanning electron microscope (SEM) images of the graphyne aerogels prepared in Example 1 and Example 4. Among them, (a) is a trifluoro-substituted graphyne aerogel (3F-GDY), and (b) is a trihydro-substituted graphyne aerogel (3H-GDY).

[0027] Figure 3 The high-resolution transmission electron microscopy (HRTEM) images of the Graphdine aerogels prepared in Example 1 and Example 4 are shown in Figure 1. (a) is 3F-GDY, and (b) is 3H-GDY.

[0028] Figure 4 The X-ray photoelectron spectroscopy (XPS) spectra of the Graphdine aerogels prepared in Example 1 and Example 4. Among them, (a) is 3F-GDY, and (b) is 3H-GDY.

[0029] Figure 5 C 1 of the Graphdiyne aerogel prepared in Example 1 and Example 4 s X-ray photoelectron spectroscopy (XPS) spectra. (a) is 3F-GDY, and (b) is 3H-GDY.

[0030] Figure 6 These are SEM images of the uranium-graphene aerogel composite materials prepared in Example 1 and Example 4 after catalytic ammonia production, wherein (a) is 0.5% U / 3F-GDY, and (b) is 0.5% U / 3H-GDY. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below in conjunction with specific experiments and drawings, but the present invention is not limited thereto. Other embodiments obtained by those skilled in the art based on the present invention all belong to the scope of protection of the present invention.

[0032] Experimental Materials:

[0033] 2,4,6-Trifluoro-1,3,5-tris(trimethylsilylethynyl)benzene, 1,3,5-tris(trimethylsilylethynyl)benzene and uranium triiodide were prepared according to the method reported in the literature; pyridine (99%), acetone (99%), ultra-dry dioxane (99%, water and oxygen content were less than 50 ppm), tetrahydrofuran (99%), diethyl ether (99%) and other solvents were purchased from Beijing Inokai Technology Co., Ltd. Among them, dioxane, tetrahydrofuran and diethyl ether were dehydrated and deoxygenated by solvent purification system and then dried with activated molecular sieves in a glove box for 1 week before use; anhydrous cupric acetate (99.9%) was purchased from Shanghai Titan Technology Co., Ltd.; concentrated sulfuric acid (concentration of 98%), hydrochloric acid (99%), dichloromethane (99%) and anhydrous ethanol (99%) were purchased from Xilong Science Co., Ltd.

[0034] Experimental instruments:

[0035] XPS analysis of Al-K α X-ray (λ=1.3371Å); ion chromatography was performed on an INTEGRION ion chromatograph produced by Thermo Electron (USA), and quantitative analysis was performed using the standard curve method; scanning electron microscopy (SEM) images were taken on a field emission scanning electron microscope (ZEISS, Germany); low-resolution and high-resolution transmission electron microscopy images were taken on a JEM-2100F field emission high-resolution transmission electron microscope (JEOL, Japan).

[0036] Example 1

[0037] (1) Preparation of trifluorosubstituted graphyne aerogel (3F-GDY)

[0038] A 10 mL sample bottle was used as a reaction container, 18 mg of anhydrous copper acetate and 2 mL of pyridine were added, and the copper salt was dissolved by ultrasonication for 10 min. After the ultrasonication, 42 mg (0.1 mmol) of 2,4,6-trifluoro-1,3,5-tris(trimethylsilylethynyl)benzene was added to the sample bottle, and the ultrasonication was continued for 10 min. The sample bottle was heated at 40 °C for three days. It can be observed that as the reaction proceeded, a brown gel grew at the bottom of the sample bottle. After the reaction, the product was solvent replaced with pyridine, dichloromethane, ethanol, 0.1 M dilute hydrochloric acid and ultrapure water in turn. Each solvent was replaced at least twice, and each time for no less than 12 hours. After the final water replacement was completed, the sample was frozen with liquid nitrogen, and the trifluoro-substituted graphyne aerogel was obtained after freeze-drying. The synthesized aerogel material was characterized by SEM, TEM and XPS.

[0039] (2) Preparation of low-valent uranium-graphene aerogel composites

[0040] The preparation of low-valent uranium-graphite aerogel composite material was carried out in an argon glove box. 20 mg of trifluoro-substituted graphite aerogel was transferred to the glove box, and 1 mL of uranium triiodide tetrahydrofuran solution was added to the graphite aerogel, and the amount of trivalent uranium in the solution was 0.5% of the mass of the graphite aerogel. The system was allowed to stand at room temperature for 12 hours, and after the solvent was drained, a low-valent uranium-graphite aerogel composite material 0.5%U / 3F-GDY loaded with 0.5% low-valent uranium was obtained.

[0041] (3) Catalytic production of ammonia by low-valent uranium-graphene aerogel composites

[0042] The low-valent uranium-graphene aerogel composite loaded with 0.5% low-valent uranium was added to a 20 mL sample bottle and transferred to a 100 mL stainless steel high-pressure reactor with a polytetrafluoroethylene liner in an argon glove box. The reactor was sealed and transferred out of the glove box. The reactor was gas-displaced using a vacuum pump and a nitrogen-hydrogen mixture with a nitrogen content of 25 vol%. After more than three gas replacements, a nitrogen-hydrogen mixture with an initial pressure of 10 bar was flushed into the reactor at room temperature. After the gas filling was completed, the reactor valve was closed and the system was heated to 150°C (after reaching the set temperature, the system pressure was 14 bar). The heating was stopped after the reaction for 24 hours. After the reactor was cooled to room temperature, the gas in the reactor was slowly introduced into 1 mL of a dilute sulfuric acid solution with a concentration of 0.005 M (mol / L) to absorb the ammonia produced by the reaction. After the solution was diluted 3 times, the ammonium ions in the solution were analyzed by ion chromatography and quantified by the standard curve. The analysis conditions were as follows: the chromatographic column was a Dionex IonPac 4 μm ion chromatography column, the column temperature was constant at 25°C, the system was isocratic eluted at a flow rate of 1 mL / min, and the eluent was 0.01 M methanesulfonic acid solution.

[0043] Example 2

[0044] Except that the uranium loading in step (2) of Example 1 was changed to 1%, the rest was the same as in Example 1 to obtain the corresponding ammonia production of 1%U / 3F-GDY.

[0045] Example 3

[0046] Except that the uranium loading in step (2) of Example 1 was changed to 1.5%, the rest was the same as in Example 1, and the corresponding ammonia production of 1.5% U / 3F-GDY was obtained.

[0047] Example 4

[0048] Except that the monomer in step (1) of Example 1 was changed to 37 mg 1,3,5-tris(trimethylsilylethynyl)benzene (0.1 mmol), the rest was the same as in Example 1 to prepare a trihydrogen-substituted graphyne aerogel material (3H-GDY), and loaded with trivalent uranium to obtain a low-valent uranium-graphyne aerogel composite material 0.5%U / 3H-GDY with a loading amount of 0.5%. The corresponding ammonia production was obtained through catalytic experiments.

[0049] Example 5

[0050] Except that the uranium loading in step (2) of Example 4 was changed to 1.5%, the rest was the same as in Example 5, and the corresponding ammonia production of 1.5% U / 3H-GDY was obtained.

[0051] Comparative Example 1

[0052] A blank experiment was carried out with a 100 mL empty reactor, and the other experimental conditions were the same as those in Example 1 to obtain the corresponding catalytic ammonia production.

[0053] Comparative Example 2

[0054] Without the trivalent uranium loading, the other experimental conditions were the same as those in Example 1, and the corresponding catalytic ammonia production of 3F-GDY was obtained.

[0055] Comparative Example 3

[0056] Without the trivalent uranium loading, the other experimental conditions were the same as those in Example 4, and the corresponding catalytic ammonia production of 3H-GDY was obtained.

[0057] Experimental results:

[0058] Figure 1 The figure shows the monomer structure and synthetic route for preparing graphene aerogel. Figure 1 As shown, the monomer used in the preparation of Graphene aerogel material is 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomer, and the substituent (R) at the 2,4,6 position can be at least one of hydrogen atom, fluorine atom, chlorine atom, methyl, methoxy, cyano, hydroxyl, amino and other substituents. The solvent used in the reaction is pyridine, and the copper salt used for catalysis is anhydrous copper acetate. After heating the reaction at 40°C for 3 days, Graphene aerogel material can be grown.

[0059] Figure 2 Graphene aerogel prepared in Example 1 and Example 4 is a SEM image. Figure 2 As shown, a large number of pore structures can be observed on the surface of the prepared 3F-GDY and 3H-GDY materials, which is a typical structural feature of aerogel materials.

[0060] Figure 3HRTEM images of the Graphene aerogels prepared in Example 1 and Example 4. Figure 3 As shown in (a), a clear lattice fringe phase can be observed in HRTEM of 3F-GDY, which indicates that the material has good crystallinity. Its interplanar spacing d value is 0.34nm, which corresponds to the interplanar spacing of 3F-GDY in the (10-1) direction. Figure 3 The lattice fringe phase of 3H-GDY can also be observed in (b), with a d value of 0.37 nm, corresponding to the crystal plane spacing in the (10-1) direction.

[0061] Figure 4 This is the full XPS spectrum of the Graphene aerogel prepared in Example 1 and Example 4. Figure 4 As shown in (a), the XPS spectrum of 3F-GDY mainly contains four elements: C, O, N, and F. The O element comes from the adsorbed oxygen in the air and the oxygen-containing functional groups on the surface of the material, and the N element comes from the pyrrole N signal in the material skeleton. Figure 4 As shown in (b), the XPS spectrum of 3H-GDY mainly contains three elements: C, O, and N. The O element also comes from the adsorbed oxygen in the air and the oxygen-containing functional groups on the surface of the material, and the N element comes from the pyrrole N signal in the material skeleton.

[0062] Figure 5 C1 of the Graphene aerogel prepared in Example 1 and Example 4 s XPS fine spectrum. Figure 5 As shown in (a), C1 of 3F-GDY s The signal can be divided into four types of species at 284.6 eV, 285.9 eV, 288.6 eV, and 289.2 eV, corresponding to sp 2 carbon, sp Carbon, carbon-oxygen double bonds, and carbon-fluorine single bonds. Figure 5 As shown in (b), C1 of 3H-GDY s The signal can be fitted to 284.5 eV, 285.0 eV, 287.8 eV, and 289.5 eV, corresponding to sp 2 carbon, sp Carbon, carbon-oxygen single bonds, and carbon-oxygen double bonds.

[0063] Figure 6 The following is a SEM image of the uranium-graphene aerogel prepared in Example 1 and Example 4 after the catalytic reaction. Figure 6As shown in the figure, after 0.5%U / 3F-GDY and 0.5%U / 3H-GDY catalyzed the ammonia production reaction, the surface of the material was still a porous structure, and the morphology of the material did not change significantly, which shows that the prepared uranium-graphyne aerogel composite material has good thermal stability.

[0064] Table 1 shows the ammonium ion concentrations measured in Examples 1-5 and Comparative Examples 1-3. As shown in Table 1, the ammonium ion concentration measured in Example 1 is 3.01 ppm; the ammonium ion concentration measured in Example 2 is 3.42 ppm; the ammonium ion concentration measured in Example 3 is 3.94 ppm; the ammonium ion concentration measured in Example 4 is 1.90 ppm; the ammonium ion concentration measured in Example 5 is 3.69 ppm; the ammonium ion concentration measured in Comparative Example 1 is 0.12 ppm; the ammonium ion concentration measured in Comparative Example 2 is 2.19 ppm; the ammonium ion concentration measured in Comparative Example 3 is 0.12 ppm. The above results show that under mild conditions, the uranium-graphite aerogel composite material exhibits obvious catalytic ammonia production performance in a closed ammonia production experiment using a 100 mL closed reactor. The results of Examples 1-5 show that under the same U loading conditions, the catalytic performance of 3F-GDY is better than that of 3H-GDY. It is worth noting that 3F-GDY has shown catalytic ability without uranium loading, which is mainly due to the introduction of different substituents that can effectively regulate the surface coordination environment of GDY and the electronic structure of the material, thereby reducing the activation energy of the catalytic reaction. The above results show that the catalytic activity of the synthesized Graphene aerogel material can be effectively regulated by regulating the monomer structure.

[0065] In summary, the present invention provides an actinide-graphene aerogel composite material and a preparation method thereof, which can effectively regulate the catalytic ability of the material through the monomer structure, and even exhibit catalytic performance without metal loading. This type of catalyst material is expected to become a new generation of thermal catalytic ammonia production catalyst.

[0066]

[0067] *The ammonium concentration in the table is the ammonium concentration detected in the solution after 1 mL of 0.005 M sulfuric acid solution absorbs the generated ammonia.

Claims

1. An actinide-graphene aerogel composite material for thermal catalytic ammonia production, comprising actinide ions, iodide ions and graphene aerogel, characterized in that: The graphyne aerogel is a porous network structure prepared from 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomer by the following method: dissolving the 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomer and copper salt in a pyridine solution, sealing it, heating it at 40-80°C for 2-4 days, then removing impurities from the obtained product by solvent replacement, and freeze-drying it to obtain the graphyne aerogel; actinide ions and iodide ions exist on the surface of the graphyne aerogel in the form of nanoclusters; wherein the actinide ions are selected from at least one of thorium, protactinium, uranium, neptunium, plutonium, and americium ions, and the valence of the actinide ions is quasi-tetravalent; the substituents at the 2,4,6 positions on the 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomer are selected from fluorine atoms or chlorine atoms.

2. The actinide-graphene aerogel composite material according to claim 1, characterized in that: The 2,4,6-trisubstituted 1,3,5-(trimethylsilylethynyl)benzene monomer is 2,4,6-trifluoro-1,3,5-tris(trimethylsilylethynyl)benzene.

3. The actinide-graphene aerogel composite material according to claim 1, characterized in that: The loading amount of actinide ions in the actinide-graphene aerogel composite material is 0.5 wt% to 5 wt%.

4. The method for preparing the actinide-graphene aerogel composite material according to any one of claims 1 to 3, characterized in that: Under the condition of isolating water, oxygen and nitrogen, the graphyne aerogel is immersed in a solution containing actinide ion iodide, and after standing for a period of time, the solvent is drained to obtain the actinide-graphyne aerogel composite material.

5. The preparation method according to claim 4, characterized in that: The actinide ion iodide is uranium triiodide; and / or the solvent used in the solution containing actinide ion iodide is selected from one or more of tetrahydrofuran, ether, dioxane and toluene.

6. The preparation method according to claim 4, characterized in that: The solution containing actinide ion iodide is a uranium triiodide tetrahydrofuran solution, and the uranium content of the solution is 0.1% to 5% of the mass of the graphyne aerogel. The graphyne aerogel is placed in the solution at room temperature for 12 to 24 hours.

7. Use of the actinide-graphene aerogel composite material according to any one of claims 1 to 3 in thermal catalytic ammonia production.

8. The use according to claim 7, characterized in that The actinide-graphene aerogel composite material is used as a catalyst, and a nitrogen-hydrogen mixed gas is used for thermal catalysis to produce ammonia.

9. The use according to claim 8, characterized in that The nitrogen content of the nitrogen-hydrogen mixed gas is 25 vol% to 90 vol%, the temperature of the catalytic ammonia production is 90° C. to 180° C., and the pressure is 1 bar to 20 bar.

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