Preparation and application of a supported ultrafine AgCu nanocrystalline catalyst

Abstract

The present invention discloses the preparation and application of a supported ultrafine AgCu nanocrystal catalyst. The present invention uses a simple co-reduction method to prepare ultrafine AgCu nanocrystals with an average size of about 2.7 nm. The nanocrystals are loaded onto calcined ZIF-8 (expressed as C-ZIF-8) to obtain a supported AgCu / C-ZIF-8 catalyst. The catalyst can efficiently catalyze click reactions under mild reaction conditions, and has good stability and can be recycled multiple times with almost unchanged activity. In addition, the catalyst has a wide substrate universality for catalyzing click reactions and has good practicality.

Description

Technical Field

[0001] The invention relates to the preparation of a supported ultrafine AgCu nanocrystalline catalyst and application thereof in a click reaction. Background Art

[0002] The study of 1,2,3-triazoles has attracted much attention in the field of medicinal chemistry, especially in polymer synthesis, antibacterial and anti-HIV drugs. The copper-catalyzed azide-alkyne [3+2] cycloaddition reaction (CuAAC) is one of the main methods for synthesizing 1,2,3-triazoles. In the past, many copper salts have been widely used as homogeneous catalysts in CuAAC reactions, and these copper salt catalysts have shown excellent catalytic activity and selectivity. However, homogeneous catalysts have problems such as difficult catalyst recovery and metal residue contamination of the target product, which limits their application on a practical scale.

[0003] Fortunately, the development of heterogeneous catalysts has provided a feasible solution to this problem. In recent years, many heterogeneous copper-based catalysts have been reported. For example, the Ramasamy Anandhan team reported a CuMOFs material. The CuMOFs catalyst is easy to recycle and reuse, and there is no significant loss of activity after multiple cycles. It is very promising for selective organic transformations in pharmaceutical and industrial formulations (ACS Appl. Mater. Interfaces 2020, 12, 56004-56016). Mahesh Madasu and his colleagues successfully synthesized Au-Cu core-shell nanotubes with a size of about 78 nm using a hydrothermal method. The nanotubes exhibited excellent click reaction catalytic activity at 50°C. In addition, the large-particle alloy catalyst makes it easy to separate the catalyst from the target product, further improving its practicality (Nanoscale, 2017, 9, 6970). In addition, the polymer CuNi alloy nanochains synthesized by the Tarun K. Mandal team showed good catalytic activity for the click reaction of various alkynyl azides in a mixed solution of water and DMF. In addition, the nano-alloy catalyst can still maintain its catalytic activity after three cycles (J.Phys.Chem.C 2014, 118, 22156-22165). Lin and his colleagues reported a nanoporous membrane made of AuCu alloy nanowires, which can effectively catalyze click reactions under flow conditions (ACSAppl.Mater.

[0004] Interfaces2018,10,25930-25935).

[0005] Despite this, current catalytic systems for this reaction still have many problems, such as high reaction temperatures, high catalyst loadings and usage, reaction solvents that are not compatible with green chemistry development, long reaction times, and poor catalyst recyclability. Therefore, the preparation of highly active catalysts has become an urgent issue that needs to be addressed. Summary of the Invention

[0006] The present invention addresses the deficiencies in the above-mentioned prior art and provides a method for preparing a supported ultrafine AgCu nanocrystal catalyst and its application. The present invention employs a simple co-reduction method to prepare ultrafine AgCu nanocrystals having an average size of approximately 2.7 nm. The nanocrystals are then loaded onto calcined ZIF-8 (denoted as C-ZIF-8) to obtain a supported AgCu / C-ZIF-8 catalyst. The catalyst can efficiently catalyze click reactions under mild reaction conditions, has good stability, and can be recycled multiple times with virtually unchanged activity. Furthermore, the catalyst exhibits a wide substrate universality for catalyzing click reactions and exhibits excellent practicality.

[0007] The preparation method of the supported ultrafine AgCu nanocrystalline catalyst of the present invention comprises the following steps:

[0008] Step 1: One-pot synthesis of AgCu nanocrystals

[0009] First, at 7°C, 15 mL of CH2Cl2 was added to a 50 mL round-bottom flask, 0.2 mmol of AgNO3 was dissolved in 2 mL of methanol and transferred to the above round-bottom flask, and then 0.66 mmol of 2,4-dimethylthiophenol was added; after 2 minutes, 10 mg of CuCl2·2H2O was dissolved in 2 mL of ethanol and added to the reaction system, and stirring was continued for 10 minutes. The solution was light yellow; then 6 mg of PPh4Br methanol solution was added to the above mixed solution; after 7 minutes, 0.5 mL of 0.8 mmol / mL NaBH4 aqueous solution was added to the reaction system. The color of the reaction mixture changed from yellow to brown, and the solution was kept under stirring for 6 hours; finally, the dark solution was centrifuged, the supernatant was evaporated, and the precipitate was washed with about 5 mL of methanol for more than 3 times.

[0010] Step 2: First, ZIF-8 is synthesized, and then a certain amount of ZIF-8 is calcined in a tubular furnace to obtain C-ZIF-8.

[0011] Step 3: Ultrasonic dispersion of the C-ZIF-8 obtained in step 2 in toluene to obtain suspension A; then dissolve the AgCu nanocrystals prepared in step 1 in dichloromethane solution and add it dropwise to A, continue stirring for 60 minutes, centrifuge, wash, and naturally dry to obtain an AgCu / C-ZIF-8 composite material.

[0012] In step 2, the calcination temperature is 300° C., the calcination time is 180 minutes under a nitrogen atmosphere, the heating rate is 5° C. / min, and the mass of ZIF-8 is 100-300 mg.

[0013] In step 3, the amount of AgCu nanocrystals is 1-3 mg, and the amount of dichloromethane solution is 0.5-1.5 mL.

[0014] In step 3, the loading amount of AgCu in the AgCu nanocrystalline catalyst AgCu / C-ZIF-8 is 0.1-0.5 wt.%.

[0015] The application of the supported ultrafine AgCu nanocrystals prepared by the present invention is to use the supported ultrafine AgCu nanocrystals as catalysts to catalyze click reactions.

[0016] The specific steps are as follows: AgCu / C-ZIF-8 catalyst, water, terminal alkyne, and benzyl azide are added sequentially to a 10 mL Schlenk reaction flask, and the reaction is carried out at 30-50°C in an argon atmosphere for 12 hours. After the reaction is completed, the reaction liquid temperature is cooled to room temperature, the product is extracted with dichloromethane, and the catalyst is removed by centrifugation (9000 rpm) to obtain the target product.

[0017] The terminal alkyne is selected from phenylacetylene, m-aminophenylacetylene, p-methoxyphenylacetylene, m-chlorophenylacetylene, p-fluorophenylacetylene, p-pentylphenylacetylene, p-methylphenylacetylene, p-bromophenylacetylene or p-methylformatephenylacetylene.

[0018] During the catalytic reaction, the amount of the terminal alkyne as the reaction substrate is 0.1-0.5 mmol, the amount of benzyl azide is 0.1-0.5 mmol, and the amount of catalyst added is 20-40 mg. The specific reaction route is as follows:

[0019]

[0020] The supported ultrafine AgCu nanocrystal AgCu / C-ZIF-8 prepared by the invention has high activity and high stability in click reaction under mild conditions and can be reused multiple times.

[0021] The beneficial effects of the present invention are embodied in:

[0022] 1. The material of the present invention is simple to prepare and has good catalytic material performance.

[0023] 2. The catalyst of the present invention has high catalytic activity for click reaction under relatively mild reaction conditions.

[0024] 3. The catalyst of the present invention uses water as a solvent in the catalytic click reaction, which meets the requirements of green chemistry.

[0025] 4. The present invention has excellent recyclability. The catalyst can be recycled more than 7 times without significant decrease in catalytic activity, and has a wide range of applicability to substrates with different substituents. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be noted that these drawings do not limit the scope of the present invention, but are only used as an explanation of the technical solution of the present invention.

[0027] Figure 1 Transmission electron microscopy (TEM) image (a), size distribution (b), UV absorption spectrum (c) and XRD (d) of AgCu nanocrystals.

[0028] Figure 2 This is the TEM of AgCu / C-ZIF-8.

[0029] Figure 3 is the X-ray diffraction pattern (XRD) of AgCu / C-ZIF-8.

[0030] Figure 4 This is the relationship curve between the conversion rate of the click reaction catalyzed by AgCu / C-ZIF-8 and time.

[0031] Figure 5 It is a cyclic performance test of the click reaction catalyzed by AgCu / C-ZIF-8. DETAILED DESCRIPTION

[0032] The technical solutions of the present invention are further described below in conjunction with specific embodiments. It should be noted that the specific description of the embodiments below is only used to illustrate the synthesis, characterization and performance of the catalyst and should not be understood as limiting the present invention. Those embodiments not directly mentioned in this article may still be obtained by combining these technical solutions.

[0033] The present invention will be further described below in conjunction with specific embodiments:

[0034] Example 1: Preparation of AgCu nanocrystals

[0035] First, at 7°C, 15 mL of CHCl was added to a 50 mL round-bottom flask. 0.2 mmol of AgNO₃ was dissolved in 2 mL of methanol and transferred to the glass bottle described above. Then, 0.66 mmol of 2,4-dimethylthiophenol was added to this solution. Next, 10 mg of CuCl₂·2H₂O was dissolved in 2 mL of ethanol and added to the solution. Stirring continued for 10 minutes, leaving the solution light yellow. A methanol solution of 6 mg of PPh₄Br was then added to the mixture. After 7 minutes, 0.5 mL of a 0.8 mmol / mL aqueous solution of NaBH₄ was added to the reaction mixture. The color of the reaction mixture changed from yellow to brown. The solution was stirred for 6 hours. Finally, the dark solution was centrifuged, the supernatant was removed by rotary evaporation, and the precipitate was washed three more times with approximately 5 mL of methanol.

[0036] Figure 1 In the figure, (a) and (c) are the TEM images and UV characterizations of the nanocrystals prepared in Example 1. The prepared AgCu nanocrystals have two obvious absorption peaks; (b) shows that the size of the nanocrystals is about 2.7 nm; (d) is the XRD of the AgCu nanocrystals prepared in Example 1, indicating the successful synthesis of the AgCu nanocrystals.

[0037] Example 2: Preparation of C-ZIF-8 and AgCu / C-ZIF-8

[0038] First, ZIF-8 was synthesized according to the literature (JAm Chem Soc 2018, 140(5), 1812-1823), and a certain amount of ZIF-8 was calcined in a tube furnace to obtain C-ZIF-8. The obtained C-ZIF-8 was then ultrasonically dispersed in toluene to obtain suspension A. The AgCu nanocrystals prepared in Example 1 were dissolved in dichloromethane solution and added dropwise to A. The mixture was stirred for 60 minutes, centrifuged, washed, and dried naturally to obtain an AgCu / C-ZIF-8 composite material with a loading amount of 0.42 wt%.

[0039] Figure 2 This is the TEM of AgCu / C-ZIF-8. AgCu nanocrystals can be successfully loaded onto C-ZIF-8, indicating the successful preparation of AgCu / C-ZIF-8 composite materials.

[0040] Figure 3 This is the XRD of AgCu / C-ZIF-8, which also shows the successful preparation of AgCu / C-ZIF-8 composite material.

[0041] Example 3: AgCu / C-ZIF-8 catalyzes the reaction of phenylacetylene and benzyl azide in ethanol solution.

[0042] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of ethanol, 0.3 mmol of phenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-phenyl-1H-1,2,3-triazole with a conversion rate of 4.3%.

[0043] Example 4: AgCu / C-ZIF-8 catalyzes the reaction of phenylacetylene and benzyl azide in N,N-dimethylformamide solution.

[0044] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of N,N-dimethylformamide, 0.3 mmol of phenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35°C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-phenyl-1H-1,2,3-triazole with a conversion rate of 4.1%.

[0045] Example 5: AgCu / C-ZIF-8 catalyzes the reaction of phenylacetylene and benzyl azide in acetonitrile solution.

[0046] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of acetonitrile, 0.3 mmol of phenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-phenyl-1H-1,2,3-triazole with a conversion rate of 5.1%.

[0047] Example 6: AgCu / C-ZIF-8 catalyzes the reaction of phenylacetylene and benzyl azide in tetrahydrofuran solution.

[0048] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of tetrahydrofuran, 0.3 mmol of phenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35°C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-phenyl-1H-1,2,3-triazole with a conversion rate of 5.4%.

[0049] Example 7: AgCu / C-ZIF-8 catalyzes the reaction of phenylacetylene and benzyl azide in aqueous solution.

[0050] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of phenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-phenyl-1H-1,2,3-triazole with a conversion rate of 98.2%.

[0051] Example 8: Changes in the conversion rate of phenylacetylene and benzyl azide catalyzed by AgCu / C-ZIF-8 over time.

[0052] 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of phenylacetylene, and 0.27 mmol of benzyl azide were added to a 10 mL Schlenk reaction bottle in sequence and reacted at 35 °C in an argon atmosphere. Samples were taken at 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, and 14 h to detect the conversion rate ( Figure 4 ), Figure 4 It can be seen that the reaction conversion rate gradually increases with the extension of the reaction time. After 12 hours, the conversion rate of the target product 1-benzyl-4-phenyl-1H-1,2,3-triazole reaches 98.2%. After that, it maintains at a high conversion rate and hardly increases. Therefore, the optimal reaction time is set to 12 hours.

[0053] Example 9: Cyclic performance test of AgCu / C-ZIF-8 catalyzing phenylacetylene and benzyl azide.

[0054] To a 10 mL Schlenk reaction flask, 40 mg AgCu / C-ZIF-8 catalyst, 2 mL water, 0.3 mmol phenylacetylene, and 0.27 mmol benzyl azide were added in sequence and reacted at 35 ° C for 12 h in an argon atmosphere. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). Figure 5 It can be seen from the data that after the catalyst was recycled 7 times, there was no obvious decrease in its yield.

[0055] Example 10: AgCu / C-ZIF-8 catalyzes the reaction of m-aminophenylacetylene and benzyl azide.

[0056] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of m-aminophenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35°C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(3-aminophenyl)-1H-1,2,3-triazole with a conversion rate of 96.3%.

[0057] Example 11: AgCu / C-ZIF-8 catalyzes the reaction of p-methoxyphenylacetylene and benzyl azide.

[0058] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of p-methoxyphenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C in an argon atmosphere for 12 hours. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(4-methoxyphenyl)-1H-1,2,3-triazole with a conversion rate of 98.4%.

[0059] Example 12: AgCu / C-ZIF-8 catalyzes the reaction of m-chlorophenylacetylene and benzyl azide.

[0060] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of m-chlorophenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C in an argon atmosphere for 12 hours. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(3-chlorophenyl)-1H-1,2,3-triazole with a conversion rate of 85.3%.

[0061] Example 13: AgCu / C-ZIF-8 catalyzes the reaction of p-fluorophenylacetylene and benzyl azide.

[0062] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of p-fluorophenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35°C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(4-fluorophenyl)-1H-1,2,3-triazole with a conversion rate of 95.9%.

[0063] Example 14: AgCu / C-ZIF-8 catalyzes the reaction of p-pentylphenylacetylene and benzyl azide.

[0064] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of p-pentylphenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35°C in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(4-pentylphenyl)-1H-1,2,3-triazole with a conversion rate of 85.4%.

[0065] Example 15: AgCu / C-ZIF-8 catalyzes the reaction of p-methylphenylacetylene and benzyl azide.

[0066] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of p-methylphenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C. in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(4-methylphenyl)-1H-1,2,3-triazole with a conversion rate of 99.2%.

[0067] Example 16: AgCu / C-ZIF-8 catalyzes the reaction of p-bromophenylacetylene and benzyl azide.

[0068] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of p-bromophenylacetylene, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C. in an argon atmosphere for 12 h. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(4-bromophenyl)-1H-1,2,3-triazole with a conversion rate of 93.4%.

[0069] Example 17: AgCu / C-ZIF-8 catalyzes the reaction of methyl formate phenylacetylene and benzyl azide.

[0070] To a 10 mL Schlenk reaction flask, 40 mg of AgCu / C-ZIF-8 catalyst, 2 mL of water, 0.3 mmol of methyl phenylacetylene p-formate, and 0.27 mmol of benzyl azide were added in sequence, and the reaction was carried out at 35 ° C. in an argon atmosphere for 12 hours. After the reaction was completed, the reaction liquid temperature was cooled to room temperature, the product was extracted with dichloromethane, and the solid and liquid were separated by centrifugation (9000 rpm). The reaction was analyzed by GC to obtain the target product 1-benzyl-4-(4-methylformylphenyl)-1H-1,2,3-triazole with a conversion rate of 82.4%.

Claims

1. An application of supported ultrafine AgCu nanocrystals, characterized by: Using the supported ultrafine AgCu nanocrystals as catalysts to catalyze a click reaction; The supported ultrafine AgCu nanocrystals are prepared by a method comprising the following steps: Step 1: One-pot synthesis of AgCu nanocrystals First, CH2Cl2 was added to a round-bottom flask at 7°C. 0.2 mmol of AgNO3 was dissolved in methanol and transferred to the above round-bottom flask, followed by the addition of 0.66 mmol of 2,4-dimethylthiophenol. 10 mg of CuCl2·2H2O was dissolved in ethanol and added to the reaction system. Stirring continued until the solution turned light yellow. 6 mg of PPh4Br in methanol was then added to the above mixed solution. 0.5 mL of 0.8 mmol / mL aqueous NaBH4 was then added to the reaction system. The color of the reaction mixture changed from yellow to brown, and the solution was stirred for 6 hours. Finally, the dark solution was centrifuged, the supernatant was evaporated, and the precipitate was washed with methanol. Step 2: First, ZIF-8 is synthesized, and then ZIF-8 is calcined in a tube furnace to obtain C-ZIF-8; Step 3: Ultrasonic dispersion of the C-ZIF-8 obtained in step 2 in toluene to obtain suspension A; then dissolve the AgCu nanocrystals prepared in step 1 in dichloromethane solution and add dropwise to A, continue stirring for 60 minutes, centrifuge, wash, and dry naturally to obtain supported ultrafine AgCu nanocrystals.

2. The use according to claim 1, characterized in that: In step 1, the average size of the prepared AgCu nanocrystals is 2.7 nm.

3. The use according to claim 1, characterized in that: In step 2, calcination is carried out in a nitrogen atmosphere at a calcination temperature of 300° C. and a calcination time of 180 minutes.

4. The use according to claim 3, characterized in that: The heating rate is 5°C / min.

5. The use according to claim 1, characterized in that: In step 3, the loading amount of the AgCu nanocrystals in the supported ultrafine AgCu nanocrystals is 0.1-0.4 wt %.

6. The use according to claim 1, characterized in that: Catalyst-supported ultrafine AgCu nanocrystals, water, terminal alkynes, and benzyl azide were sequentially added to a Schlenk reaction flask and reacted at 30-50°C for 12 hours in an argon atmosphere. After the reaction was completed, the reaction liquid was cooled to room temperature, the product was extracted with dichloromethane, and the catalyst was removed by centrifugation to obtain the target product.

7. The use according to claim 6, characterized in that: During the catalytic reaction, the amount of the terminal alkyne as the reaction substrate is 0.1-0.5 mmol, the amount of benzyl azide is 0.1-0.5 mmol, and the amount of the added catalyst is 20-40 mg.

8. The use according to claim 6, characterized in that: The terminal alkyne is selected from phenylacetylene, m-aminophenylacetylene, p-methoxyphenylacetylene, m-chlorophenylacetylene, p-fluorophenylacetylene, p-pentylphenylacetylene, p-methylphenylacetylene, p-bromophenylacetylene or p-methylformatephenylacetylene.

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