Novel lignin-based copper catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of catalyst preparation, and particularly relates to a novel lignin-based copper catalyst and a preparation method and application thereof. The preparation method comprises the following steps: mixing lignin with cyanuric chloride, heating for reaction, and carrying out suction filtration and washing to obtain cyanuric chloride functionalized lignin; mixing the cyanuric chloride functionalized lignin with benzylamine, reacting, and carrying out suction filtration and washing to obtain benzylamine functionalized lignin; and adding the benzylamine functionalized lignin and cuprous iodide into a solvent, reacting, carrying out suction filtration, and washing to obtain the lignin-based copper catalyst. The lignin-based copper catalyst prepared by the method is low in preparation cost, can be recycled, and has the advantages of mild catalytic conditions, high catalytic efficiency and high yield.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst preparation, and in particular relates to a novel lignin-based copper catalyst and a preparation method and application thereof. Background Art

[0002] In recent years, the use of renewable biomass resources to prepare supported catalysts has become a research hotspot in the field of green chemistry.

[0003] Lignin is a substance extracted through pulping and papermaking and biorefining processes. It is low-cost and renewable. At the same time, lignin molecules contain rich active groups such as phenolic hydroxyl, methoxy and thiol groups, which can serve as natural ligands or carrier matrices for metal ions and have important potential in the field of green chemistry.

[0004] There are two methods for loading metal ions on lignin that are widely used at present: (1) directly loading metal ions on lignin, for example, mixing lignin with a metal salt solution, and preparing a lignin-loaded catalyst by ion exchange or physical adsorption of metal ions (Scheme 1, the preparation process is as follows Figure 1 (2) First, the lignin is modified, and active groups are loaded on the lignin by sulfonation, amination and other steps, and then mixed with a metal salt solution to load metal ions, thereby preparing a lignin-supported catalyst (Scheme 2, the preparation process is as follows Figure 2 shown).

[0005] Patent application number 202111003515.3 discloses the use of an amine-functionalized lignin-based catalyst in the carbon dioxide cycloaddition reaction. Addressing the shortcomings of current heterogeneous catalysts for CO2 cycloaddition reactions, such as low stability, low activity, non-renewability, and environmental unfriendliness, this invention provides an amine-functionalized lignin-based catalyst obtained by grafting polyethyleneimine onto lignin. The catalyst preparation method is simple and easy to operate, with low production costs and high catalytic activity and selectivity. However, the catalyst requires a certain pressure and a catalytic time of more than 8 hours, which is long and inefficient.

[0006] The existing lignin-based catalyst synthesis methods and catalytic processes have the following three main shortcomings: (1) The use of organic reagents as reaction solvents violates the principles of green chemistry. (2) The reaction conditions are harsh and cannot be easily prepared. (3) The catalyst cannot be recycled multiple times, resulting in high synthesis costs and low utilization. Summary of the Invention

[0007] Based on the above technical background, the main purpose of the present invention is to provide a novel lignin-based copper catalyst and its preparation method and application, so as to overcome the shortcomings of the existing technology.

[0008] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include: The first aspect of the present invention is to provide a method for preparing a novel lignin-based copper catalyst, such as Figure 1 As shown, the preparation method comprises the following steps: Step 1: mixing lignin and cyanuric chloride, heating to react, filtering and washing to obtain cyanuric chloride functionalized lignin; Step 2: mixing the cyanuric chloride functionalized lignin and benzylamine, reacting the mixture, filtering and washing the mixture to obtain benzylamine functionalized lignin; Step 3: adding benzylamine functionalized lignin and cuprous iodide into a solvent, reacting, filtering and washing, and obtaining a lignin-based copper catalyst.

[0009] The above steps are described in detail below.

[0010] In step 1, the mass ratio of the lignin to cyanuric chloride is 1:(3-5).

[0011] Preferably, the mass ratio of the lignin to cyanuric chloride is 1:4.

[0012] Add lignin and cyanuric chloride into the solvent and heat it to 75-80 o C reaction for 45 to 50 hours.

[0013] Preferably, lignin and cyanuric chloride are added to a solvent and the temperature is raised to 78 o C for 48 h.

[0014] The solvent is selected from one or more of anhydrous acetonitrile, anhydrous ethanol, and water, preferably anhydrous acetonitrile.

[0015] In the present invention, anhydrous acetonitrile is the optimal reaction solvent. On the one hand, the reaction effect is good. On the other hand, lignin is basically insoluble in anhydrous acetonitrile. Anhydrous ethanol is the second best solvent, but the effect is far worse than anhydrous acetonitrile. Although water is more effective than anhydrous ethanol, lignin is easily soluble in water. Using water as a solvent will cause a large amount of lignin to be lost.

[0016] In step 2, cyanuric chloride lignin and benzylamine are mixed according to 1 g: (5-15) mmol.

[0017] Preferably, cyanuric chloride lignin and benzylamine are mixed at a ratio of 1 g:10 mmol.

[0018] The reaction is carried out in an ice-water bath, and the reaction time is 40-50 h.

[0019] Preferably, the reaction time is 48 h.

[0020] The reaction can be carried out in an ice-water bath, and the reaction conditions are mild.

[0021] In step 3, the ratio of the added amount of benzylamine lignin to cuprous iodide is 1 g: 0.3~0.7 mmol.

[0022] Preferably, the ratio of the added amount of the benzylamine lignin to cuprous iodide is 1 g:0.5 mmol.

[0023] The amount of cuprous iodide selected in the present invention during the loading process is 0.3-0.7 mmol. It is found that the loading amount can reach the optimal amount when it is 0.5 mmol. The functionality of the benzylamine copper lignin loaded with cuprous iodide is 0.2240 mmol / g after ICP testing.

[0024] The reaction is carried out at 20 to 30 o C reaction for 20~30 hours.

[0025] Preferably, the reaction is carried out at 25 o C for 24 h.

[0026] The reaction does not require high-temperature heating and can be carried out at room temperature, which has the advantages of low energy consumption and low cost.

[0027] The second aspect of the present invention is to provide a novel lignin-based copper catalyst prepared according to the preparation method described in the first aspect of the present invention.

[0028] The third aspect of the present invention is to provide an application of the novel lignin-based copper catalyst described in the second aspect of the present invention, wherein the novel lignin-based copper catalyst can be used as a catalyst.

[0029] Preferably, the novel lignin-based copper catalyst can be used as a catalyst to catalyze the reaction of benzyl bromide, phenylacetylene and sodium azide to generate 1,2,3-triazole compounds under a mild environment.

[0030] More preferably, the step of using the novel lignin-based copper catalyst as a catalyst for the catalytic reaction comprises: Benzyl bromide, phenylacetylene, sodium azide and lignin-based copper catalyst are added to water, and the temperature is raised under stirring to react. After the reaction is completed, the product is purified by extraction, drying column chromatography and the like to obtain the product.

[0031] The molar ratio of benzyl bromide, phenylacetylene and sodium azide is (1-1.3):1:(1.1-1.3).

[0032] Preferably, the molar ratio of benzyl bromide, phenylacetylene and sodium azide is 1.1:1:1.1-1.3.

[0033] The ratio of the amount of the lignin-based copper catalyst added to the amount of phenylacetylene added is 0.7 mol%~1 mol%:1mmol, that is, for every 1 mmol of phenylacetylene reacted as a substrate, 0.7 mol%~1 mol% of the lignin-based copper catalyst is added. Preferably, the ratio of the amount of the lignin-based copper catalyst added to the amount of phenylacetylene added is 1 mol%:1 mmol, and approximately 0.0446 g of catalyst is added.

[0034] The catalyst of the present invention can achieve high catalytic efficiency and yield with a relatively small addition amount, and the reaction solvent is water, which is not only highly safe but also simple in post-processing, thus avoiding the step of complicated post-processing of organic solvents.

[0035] The temperature is raised to 75-85°C and the reaction is carried out for 1-2 hours. Preferably, the temperature is raised to 80°C and the reaction is carried out for 1.5 hours.

[0036] The catalyst of the present invention can be used to carry out the reaction at a lower temperature, and the reaction time can be shortened to less than 2 hours, indicating that the catalyst of the present invention has mild catalytic conditions, high catalytic efficiency, and high product yield. After the catalyst is recycled five times, the yield of the obtained product is above 86%.

[0037] After the catalytic reaction, the lignin-based copper catalyst can be easily separated by filtration. After testing, the separated lignin-based copper catalyst can be recycled 5 times or more. After 5 cycles, the catalytic yield of the catalyst only dropped from 99% to 86%. The experimental efficiency is high, indicating that the prepared lignin-based copper catalyst can reduce experimental costs and is suitable for industrial production.

[0038] The beneficial effects of the present invention are: (1) The preparation method of the novel lignin-based copper catalyst of the present invention is simple and does not require high temperature and high pressure preparation conditions. The reaction conditions are mild and can be industrialized and scaled up for production.

[0039] (2) The lignin-based copper catalyst prepared by the present invention can catalyze the reaction of benzyl bromide, phenylacetylene and sodium azide to produce 1,2,3-triazole compounds under a mild environment. The catalyst usage is low, only 1 mol% (about 0.0446 g). The catalyst has high catalytic efficiency and can achieve a higher yield under the premise of using a small amount. In addition, a high-purity product can be obtained through a simple column chromatography process, which greatly saves post-processing time. At the same time, after the catalytic reaction, the lignin-based copper catalyst can be easily separated by filtration. The separated lignin-based copper catalyst can be recycled multiple times. After multiple recycling, the catalytic yield of the catalyst is still above 86%, and the catalytic efficiency can still be maintained at a high level.

[0040] (3) The lignin-based copper catalyst prepared by the present invention is used as a catalyst for the reaction, which reduces the preparation cost and the pressure of post-reaction treatment, and enhances sustainability while reducing energy consumption.

[0041] (4) The lignin-based copper catalyst prepared by the present invention can be used as a solvent for catalytic reactions. Compared with traditional organic solvents, it is less expensive and conforms to the principles of green chemistry. In addition, the addition of organic solvents makes product post-processing more difficult and more dangerous. The use of water as a solvent improves the safety of the reaction, and water as a solvent provides a better solution for sustainable synthetic chemistry. It can be seen that the catalyst prepared by the present invention can improve the safety of the catalytic reaction, shorten the post-processing process and time, and improve the preparation efficiency.

[0042] The lignin-based copper catalyst prepared by the present invention can optimize the reaction conditions so that the catalytic reaction can be carried out at about 80°C, which not only reduces the energy consumption of preparation and meets the requirements of green chemistry, but also makes the catalytic reaction more suitable for industrial production.

[0043] (5) When the lignin-based copper catalyst prepared by the present invention is used for catalytic reaction, green reagent water can be used as a solvent, the reaction temperature is low, the reaction conditions are mild, and the characteristics of high reactant conversion rate and high product yield can be achieved when the catalyst usage is low. In addition, the post-reaction treatment is simple and the catalyst can be recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention shows the preparation process of lignin-supported catalyst by ion exchange or physical adsorption of metal ions; Figure 2 The preparation process of the lignin-supported catalyst is shown in which active groups are first loaded on lignin and then mixed and stirred with a metal salt solution; Figure 3 The reaction process of preparing the lignin-based copper catalyst by the preparation method of the present invention is shown; Figure 4 The H NMR spectrum of the product 1-benzyl-4-phenyl-1H-1,2,3-triazole prepared using the lignin-based copper catalyst of the present invention is shown; Figure 5 The infrared spectra of various lignins during the modification process are shown; Figure 6 The XPS graph of the lignin-based copper catalyst AL-Cu prepared in Example 1 is shown. DETAILED DESCRIPTION

[0045] The present invention will be described in detail below, and the characteristics and advantages of the present invention will become clearer and more distinct with the following description.

[0046] Example The present invention is further described below by way of specific examples, which are intended to illustrate the present invention but not to limit the scope of the present invention. The raw materials used in the examples of the present invention were all purchased.

[0047] Example 1 Lignin and cyanuric chloride were mixed in a mass ratio of 1:4 and added into a round-bottom flask. Anhydrous acetonitrile was added as solvent and heated at 78 o C for 48 h, and then filtered and washed to obtain cyanuric chloride lignin; The above-mentioned cyanuric chloride lignin and benzylamine were mixed in a ratio of 1 g:10 mmol and added to a round-bottom flask. Anhydrous acetonitrile was added as solvent and reacted in an ice-water bath for 48 h. The benzylamine lignin was obtained by filtration and washing. 1 g of the above benzylamine lignin and 0.5 mmol of cuprous iodide were added to a round-bottom flask, and anhydrous acetonitrile was added as solvent. o C) for 24 h, and then filtered and washed to obtain the lignin-based copper catalyst. Figure 3 shown.

[0048] Example 2 Lignin and cyanuric chloride were mixed in a mass ratio of 1:4 and added into a round-bottom flask. Anhydrous acetonitrile was added as solvent and heated at 75 o C was reacted for 50 h, and cyanuric chloride lignin was obtained by filtration and washing; The above-mentioned cyanuric chloride lignin and benzylamine were mixed in a ratio of 1 g:10 mmol and added to a round-bottom flask. Anhydrous acetonitrile was added as solvent and reacted in an ice-water bath for 48 h. The benzylamine lignin was obtained by filtration and washing. 1 g of the above benzylamine lignin and 0.5 mmol of cuprous iodide were added to a round-bottom flask, and anhydrous acetonitrile was added as solvent. o C) for 24 h, and then filtered and washed to obtain the lignin-based copper catalyst. Figure 3 shown.

[0049] Example 3 Lignin and cyanuric chloride were mixed in a mass ratio of 1:4 and added into a round-bottom flask. Anhydrous acetonitrile was added as solvent and heated at 80 o C was reacted for 45 h, and cyanuric chloride lignin was obtained by filtration and washing; The above-mentioned cyanuric chloride lignin and benzylamine were mixed in a ratio of 1 g:10 mmol and added to a round-bottom flask. Anhydrous acetonitrile was added as solvent and reacted in an ice-water bath for 48 h. The benzylamine lignin was obtained by filtration and washing. 1 g of the above benzylamine lignin and 0.5 mmol of cuprous iodide were added to a round-bottom flask, and anhydrous acetonitrile was added as solvent.o C) for 24 h, and then filtered and washed to obtain the lignin-based copper catalyst. Figure 3 shown.

[0050] Example 4 Lignin and cyanuric chloride were mixed in a mass ratio of 1:3 and added into a round-bottom flask. Anhydrous acetonitrile was added as solvent and heated at 78 o C for 48 h, and then filtered and washed to obtain cyanuric chloride lignin; The above-mentioned cyanuric chloride lignin and benzylamine were mixed in a ratio of 1 g:10 mmol and added to a round-bottom flask. Anhydrous acetonitrile was added as solvent and reacted in an ice-water bath for 48 h. The benzylamine lignin was obtained by filtration and washing. 1 g of the above benzylamine lignin and 0.5 mmol of cuprous iodide were added to a round-bottom flask, and anhydrous acetonitrile was added as solvent. o C) for 24 h, and then filtered and washed to obtain the lignin-based copper catalyst. Example 5 Lignin and cyanuric chloride were mixed in a mass ratio of 1:5 and added into a round-bottom flask. Anhydrous acetonitrile was added as solvent and heated at 78 o C for 48 h, and then filtered and washed to obtain cyanuric chloride lignin; The above-mentioned cyanuric chloride lignin and benzylamine were mixed in a ratio of 1 g:10 mmol and added to a round-bottom flask. Anhydrous acetonitrile was added as solvent and reacted in an ice-water bath for 48 h. The benzylamine lignin was obtained by filtration and washing. 1 g of the above benzylamine lignin and 0.5 mmol of cuprous iodide were added to a round-bottom flask, and anhydrous acetonitrile was added as solvent. o C) for 24 h, and then filtered and washed to obtain the lignin-based copper catalyst.

[0051] Example 6 The catalyst was prepared in a manner similar to Example 1, except that the above-mentioned cyanuric chloride lignin and benzylamine were mixed at a ratio of 1 g:5 mmol and added to a round-bottom flask, anhydrous acetonitrile was added as a solvent, and the mixture was reacted in an ice-water bath for 40 h. Example 7 The catalyst was prepared in a manner similar to Example 1, except that the above-mentioned cyanuric chloride lignin and benzylamine were mixed at a ratio of 1 g:15 mmol and added to a round-bottom flask, anhydrous acetonitrile was added as a solvent, and the mixture was reacted in an ice-water bath for 50 h.

[0052] Example 8 Catalytic three-component reaction In a 15 ml pressure tube, 1.1 mmol benzyl bromide, 1 mmol phenylacetylene, 1.1 mmol sodium azide, 1 mol% (about 0.0446 g) of the catalyst prepared in Example 1, and 5 ml of water were added. o C in an oil bath and stirred for 1.5 h. The reaction system was purified by extraction, drying, column chromatography, etc. to obtain a white solid product with a yield of 94%. The H NMR spectrum of the obtained product is shown in FIG. Figure 4 shown.

[0053] Figure 4 The single peak at 5.50 is the peak of 2 H on the methylene in the product, the multiple peaks at 7.16~7.38 are the peaks of 8 H on the benzene ring, the single peak at 7.59 is the peak of H on the triazole ring, and the double peak at 7.68~7.76 is the peak of two ortho-position H on the benzene ring connected to the triazole ring. From this spectrum, it can be determined that the product is 1-benzyl-4-phenyl-1 H -1,2,3-triazole.

[0054] Experimental example Experimental Example 1 Catalyst Cycle Performance Test The catalytic reaction was carried out under the conditions described in Example 8. After each reaction, 5 to 8 ml of ethyl acetate was added to the system and shaken. The system was separated into an aqueous phase, an organic phase, and insoluble residual lignin catalyst. The residual lignin was first filtered out by filtration and washed and dried for recovery. The aqueous phase and the organic phase were then separated by extraction. Since the lignin catalyst was easily soluble in water, the aqueous phase was recovered as the mother liquor for the next cycle reaction system. The organic phase was dried, rotary evaporated, column chromatographed, etc. to obtain the target product. The catalyst recovered by filtration was washed clean and then heated at 60 o After oven drying, C can be used directly for the next round of catalytic reaction.

[0055] Testing showed that the lignin-based copper catalyst prepared in Example 1 could be recycled up to five times, with product yields of 99%, 99%, 95%, 92%, and 86%, respectively. This indicates that the catalyst prepared by the preparation method of the present invention can be recycled, and when recycled, the product yield can still reach 86% or higher.

[0056] Experimental Example 2 Conversion rate and yield test The catalysts prepared in Examples 1 to 7 were subjected to catalytic reactions according to the catalytic conditions described in Example 8, and the conversion rates and yields were tested. The test results are shown in Table 1.

[0057] Table 1

[0058] As can be seen from Table 1, the conversion rates of the catalytic reactions of the catalysts prepared in Examples 1 to 7 were 94% to 97%, and the catalytic yields were 89% to 94%. These results demonstrate that the catalysts of the present invention have high conversion rates and yields, with conversion rates of 94% and above and yields of 89% and above.

[0059] Experimental Example 3 Functionality Test The functionality of each intermediate product and the lignin-based copper catalyst in the preparation process of Example 1 was detected. The functionality was estimated and calculated using the formula: [w% / [M(1+w%)]×1000, where M is the molecular weight of the functional fragment corresponding to each modification step, and w% is the weight increase of AL-Me (cyanuric chloride functionalized lignin) and AL-Ar (benzylamine functionalized lignin). The functionality of AL-Cu (lignin-based copper catalyst prepared in Example 1) was obtained by ICP testing by a professional institution. The test results are shown in Table 2: Table 2 Functionality of various lignins

[0060] Table 2 shows that the functionality of the intermediate product AL-Me (cyanuric chloride-functionalized lignin) prepared in Example 1 is approximately 2.06 mmol / g, the functionality of the intermediate product AL-Ar (benzylamine-functionalized lignin) is approximately 0.29 mmol / g, and the functionality of the lignin-based copper catalyst is approximately 0.22 mmol / g. This indicates that all groups were successfully loaded onto the lignin during the preparation process.

[0061] Experimental Example 4 Infrared Spectrum Test AL-Me (cyanuric chloride functionalized lignin, the intermediate product of Example 1), AL-Ar (benzylamine functionalized lignin, the intermediate product of Example 1), AL-Cu (lignin-based copper catalyst prepared in Example 1), AL (lignin) and AL-Cu-5 (catalyst obtained by recycling the lignin-based copper catalyst prepared in Example 1 for 5 times) were tested by infrared spectroscopy. The test results are as follows: Figure 5 shown.

[0062] from Figure 5 It can be clearly seen that after being loaded with cyanuric chloride, AL-Me at 546 cm -1 There is an obvious peak at , which is caused by the stretching vibration of the triazine ring of cyanuric chloride, indicating that cyanuric chloride has been successfully loaded ( Figure 5 b); 488 cm in Al-Ar -1 The peak at is due to the CH stretching vibration on the benzene ring, proving that benzylamine has been successfully loaded ( Figure 5c); The infrared spectra of AL-Cu after loading with cuprous iodide did not change significantly compared with AL-Ar, indicating that the overall structure of lignin was not destroyed during the loading process ( Figure 5 c and d); Although the infrared spectrum of AL-Cu-5 after 5 cycles is different from that of other modified lignins, the characteristic peaks are still visible, indicating that the lignin-based copper catalyst has good tolerance and recyclability ( Figure 5 e). At the same time, infrared characterization confirmed that the target groups in the preparation process of the present invention have been successfully loaded onto lignin.

[0063] Experimental Example 5 XPS Test X-ray photoelectron spectroscopy (XPS) was performed on AL-Cu (lignin-based copper catalyst prepared in Example 1) to explore the chemical properties of the AL-Cu surface. The test results are as follows: Figure 6 shown.

[0064] from Figure 6 It can be seen that various elements of Cu, C, N, Cl and O can be significantly observed in the full spectrum, indicating that the nitrogen heterocycle, benzylamine and CuI are successfully fixed in the catalyst of the present invention ( Figure 6 a). The peak at 934.4 eV belongs to the 2p peak of Cu, which further confirms that CuI is successfully grafted onto the lignin surface ( Figure 6 b). In addition, the peaks at 284.4, 285.7, and 289.5 eV in the C 1s XPS spectrum belong to C=N, CH, and CN bonds, respectively, and the peaks at 400.0 and 401.4 eV in the N 1s XPS spectrum belong to CN and C=N, respectively, indicating that cyanuric chloride and benzylamine have been successfully loaded onto lignin ( Figure 6 c-6d). The corresponding Cl 2p spectrum shows a peak at 199.5 eV, which further proves the loading of cyanuric chloride ( Figure 6 e). In addition, the strong peak at 532.6 eV in the O 1s XPS spectrum is attributed to the CO bond in the Al-Cu ( Figure 6 f). The XPS spectrum verifies that the lignin-based copper catalyst AL-Cu of the present invention has been successfully prepared.

[0065] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing a novel lignin-based copper catalyst, characterized in that: The preparation method comprises the following steps: Step 1: mixing lignin and cyanuric chloride, heating to react, filtering and washing to obtain cyanuric chloride functionalized lignin; Step 2: mixing the cyanuric chloride functionalized lignin and benzylamine, reacting the mixture, filtering and washing the mixture to obtain benzylamine functionalized lignin; Step 3: adding benzylamine functionalized lignin and cuprous iodide into a solvent, reacting, filtering and washing, to obtain a lignin-based copper catalyst.

2. The preparation method according to claim 1, characterized in that In step 1, the mass ratio of the lignin to cyanuric chloride is 1:(3-5).

3. The preparation method according to claim 1, characterized in that In step 1, lignin and cyanuric chloride are added to the solvent and the temperature is raised to 75-80 o C reaction for 45~50 hours.

4. The preparation method according to claim 1, characterized in that In step 2, cyanuric chloride lignin and benzylamine are mixed according to 1 g: (5-15) mmol, and anhydrous acetonitrile is used as a solvent.

5. The preparation method according to claim 1, characterized in that In step 2, the reaction is carried out in an ice-water bath, and the reaction time is 40 to 50 h.

6. The preparation method according to claim 1, characterized in that In step 3, the ratio of the added amount of benzylamine lignin to cuprous iodide is 1 g:0.3-0.7 mmol, and anhydrous acetonitrile is used as the solvent.

7. The preparation method according to claim 1, characterized in that In step 3, the reaction is carried out at 20 to 30 o C reaction for 20~30 hours.

8. A novel lignin-based copper catalyst prepared according to the preparation method according to any one of claims 1 to 7.

9. Use of the novel lignin-based copper catalyst according to claim 8, characterized in that: The novel lignin-based copper catalyst can be used as a catalyst to catalyze the reaction of benzyl bromide, phenylacetylene and sodium azide to generate 1,2,3-triazole compounds.

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