Preparation method and application of lignin-metal ion photocatalyst
Patent Information
- Application Number
- CN202611205174.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-10
- Publication Date
- 2026-10-09
AI Technical Summary
[0003]本发明解决了现有技术合成5-羟甲基糠醛过程中热催化体系稳定性差、易发生缩合、氧化等副反应的问题，提出了一种木质素-金属离子光催化剂的制备方法及其应用，本发明以木质素与金属盐为原料，经水热反应制备木质素-金属离子光催化剂，该催化剂成本低廉，制备工艺简单，在温和条件下能高效催化糖合成5-羟甲基糠醛
[0020]本发明与现有技术相比，具有如下优点：本发明提出的木质素-金属离子光催化剂组分简单、廉价，制备工艺简单，该催化剂可以在温和条件下光催化糖合成5-羟甲基糠醛，所得目标产品产率高，具有很好的工业化应用前景。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical engineering technology, specifically to a method for preparing a lignin-metal ion photocatalyst and its application. Background Technology
[0002] 5-Hydroxymethylfurfural (HMF) is an important biomass platform compound obtained from sugar dehydration. Its molecule contains both aldehyde and hydroxymethyl reaction sites, allowing it to be derived into various high-value-added chemicals and liquid fuels through oxidation and hydrogenation reactions, showing broad application prospects in energy, chemical, and pharmaceutical fields. However, current industrial production of HMF mainly relies on fructose dehydration, which is expensive and has poor product separation efficiency, resulting in high production costs. Traditional thermocatalytic synthesis of HMF typically requires harsh conditions such as high temperature and high pressure. Furthermore, HMF contains active structures such as furan rings, hydroxymethyl groups, and carbonyl groups, leading to poor stability during synthesis and susceptibility to side reactions such as condensation and oxidation. Large-scale production suffers from prominent problems such as low yield (<50%) and high cost (>50,000 RMB / ton). Photocatalysis technology can utilize light energy to drive the reaction, achieving the conversion of sugars to HMF under mild conditions, effectively reducing reaction energy barriers and minimizing side reactions. Therefore, developing efficient and green photocatalytic systems for the conversion of sugars to HMF is of great significance for promoting the high-value utilization of biomass resources. Summary of the Invention
[0003] This invention solves the problems of poor stability of the thermocatalytic system and easy occurrence of side reactions such as condensation and oxidation in the synthesis of 5-hydroxymethylfurfural in the prior art. It proposes a method for preparing lignin-metal ion photocatalyst and its application. The invention uses lignin and metal salt as raw materials to prepare lignin-metal ion photocatalyst through hydrothermal reaction. The catalyst is low in cost, simple in preparation process, and can efficiently catalyze the synthesis of 5-hydroxymethylfurfural from sugar under mild conditions.
[0004] This invention is achieved through the following technical solutions:
[0005] A method for preparing a lignin-metal ion photocatalyst includes the following steps: adding lignin and a metal salt to dimethyl sulfoxide, then reacting the resulting solution in a water bath at 25 ℃-80 ℃ for 5-60 minutes, whereby lignin and metal ions undergo a coordination reaction to form a lignin-metal ion chelate. After the reaction is complete, the solution is dropped into water to obtain a solid precipitate, which is then separated and dried to obtain the lignin-metal ion photocatalyst.
[0006] Preferably, the lignin is lignin isolated from coniferous wood, broadleaf wood and / or herbaceous plants, and the metal salt is selected from any one or more of calcium chloride, magnesium chloride, aluminum chloride, tin chloride, ferric chloride, copper chloride, zinc chloride, chromium chloride, aluminum nitrate and aluminum sulfate.
[0007] More preferably, the metal salt is a mixture of aluminum nitrate and tin chloride, ferric chloride or chromium chloride, wherein the mass ratio of aluminum nitrate to tin chloride, ferric chloride or chromium chloride is 1:1.
[0008] Preferably, the mass ratio of lignin to metal salt is 1:3-3:1.
[0009] Further preferably, the mass ratio of lignin to metal salt is 1:2-2:1.
[0010] Preferably, lignin and metal salt are added to dimethyl sulfoxide, and the mass concentration of lignin in the resulting solution is 1-20 g / L.
[0011] Further optimization yielded a solution with a lignin concentration of 15 g / L.
[0012] This invention also protects a lignin-metal ion photocatalyst, obtained by the aforementioned preparation method. This lignin-metal ion photocatalyst is a lignin-metal ion chelate photocatalyst.
[0013] This invention also protects the application of the lignin-metal ion photocatalyst in the catalytic synthesis of 5-hydroxymethylfurfural from sugars, comprising the following steps: adding the lignin-metal ion photocatalyst and sugar to dimethyl sulfoxide, purging the air in the solution with nitrogen, and performing a photocatalytic reaction at 50 ℃-100 ℃ for 1-20 h. After the reaction is completed, the product 5-hydroxymethylfurfural is obtained. The reaction solution is diluted with DMSO and used for high performance liquid chromatography to analyze the yield of 5-hydroxymethylfurfural and the sugar conversion rate.
[0014] Preferably, the specific conditions for the photocatalytic reaction are: 70 ℃-90 ℃ for 12-18 h.
[0015] Preferably, the mass ratio of lignin-metal ion photocatalyst to sugar is 1:6-6:1.
[0016] Further optimization yielded a lignin-metal ion photocatalyst with a sugar mass ratio of 1:1.25.
[0017] Preferably, the sugar is selected from one or more of fructose, glucose, and sucrose, and the sugar concentration in the solution obtained by adding the sugar to dimethyl sulfoxide is 1-20 g / L.
[0018] Further preferred, the sugar concentration in the solution obtained by adding sugar to dimethyl sulfoxide is 10 g / L.
[0019] Preferably, the light intensity of the photocatalytic reaction is 0.1-1.0 W / cm². 2 .
[0020] Compared with the prior art, the present invention has the following advantages: the lignin-metal ion photocatalyst proposed in this invention has simple and inexpensive components and a simple preparation process. The catalyst can photocatalyze the synthesis of 5-hydroxymethylfurfural from sugars under mild conditions, and the yield of the target product is high, which has good prospects for industrial application. Attached Figure Description
[0021] Figure 1 It is the lignin and lignin-Al in Example 1 3+ XPS spectra of photocatalysts, including: (a) overall elemental spectrum of XPS analysis, and (b) XPS spectrum of Al 2p characteristic peaks.
[0022] Figure 2 This is a process flow diagram for the photocatalytic synthesis of 5-hydroxymethylfurfural from lignin-metal ion photocatalysts.
[0023] Figure 3 This is the ultraviolet absorption spectrum of the lignin-metal ion prepared in Examples 1-2. Detailed Implementation
[0024] The following embodiments are further illustrations of the present invention, but not limitations thereof.
[0025] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental materials and reagents used herein are commercially available products conventionally available in this technical field. Lignin CAS No.: 9005-53-2. The lignin described in the following examples or comparative examples may be commercially available or isolated from coniferous, broadleaf, and / or herbaceous plants.
[0026] Example 1
[0027] Lignin-Al 3+ The preparation method of the photocatalyst includes the following steps: 0.3 g of lignin and 0.15 g of aluminum nitrate nonahydrate are added to 20 mL of dimethyl sulfoxide. The resulting solution is then reacted in a 70 ℃ water bath for 15 minutes. After the reaction is complete, the solution is dropped into water to obtain a solid precipitate. After centrifugation and drying, lignin-Al is obtained. 3+ Chelate photocatalysts, XPS analysis of photocatalyst structure as follows Figure 1 As shown.
[0028] like Figure 2 As shown, lignin-Al 3+ A method for photocatalytic synthesis of 5-hydroxymethylfurfural from sugars using a photocatalyst includes the following steps:
[0029] 0.16 g of lignin-Al 3+ The photocatalyst and 0.2 g of glucose were added to 20 mL of dimethyl sulfoxide. Air in the solution was removed using nitrogen gas, and the reaction was carried out in a photocatalytic reactor at 80 °C for 18 h. The light intensity was 1.0 W / cm². 2 After the reaction was completed, the final product 5-hydroxymethylfurfural (HMF) was obtained. The yield of HMF was 83.0%, and the glucose conversion rate was 99.9%.
[0030] Example 2
[0031] Similar to Example 1, except that the metal salt is replaced with calcium chloride, magnesium chloride, tin chloride, ferric chloride, copper chloride, zinc chloride, or chromium chloride, respectively, to obtain lignin-Ca 2+ Photocatalyst, lignin-Mg 2+ Photocatalyst, lignin-Sn 4+ Photocatalyst, lignin-Fe 3+ Photocatalyst, lignin-Cu 2+ Photocatalyst, lignin-Zn 2+ Photocatalyst, lignin-Cr 3+ Photocatalyst.
[0032] The ultraviolet absorption spectra of the photocatalysts obtained in Examples 1-2 are as follows: Figure 3 As shown.
[0033] The above catalysts were used to photocatalyze the synthesis of HMF from glucose. The yields of HMF were 1.18%, 1.01%, 43.4%, 1.13%, 0.77%, 0.16%, and 11.15%, respectively, and the glucose conversion rates were 27.6%, 25.5%, 57.4%, 94.4%, 50.1%, 59.9%, 30.2%, and 48.8%, respectively.
[0034] Comparative Example 1
[0035] Same as Example 1, except that the metal salt was nickel chloride. The resulting substance was used to synthesize 5-hydroxymethylfurfural, with an HMF yield of 0% and a glucose conversion rate of 5.4%.
[0036] Example 3
[0037] Similar to Example 1, except that the metal salt is a mixture of aluminum nitrate nonahydrate and tin chloride in a mass ratio of 1:1, yielding lignin-Al. 3+ / Sn 4+ The photocatalyst achieved a HMF yield of 86.5% and a glucose conversion rate of 99.9%.
[0038] Example 4
[0039] Similar to Example 1, except that the metal salt is a mixture of aluminum nitrate nonahydrate and ferric chloride in a mass ratio of 1:1, yielding lignin-Al. 2+ / Fe 3+ The photocatalyst achieved an HMF yield of 84.8% and a glucose conversion rate of 99.9%.
[0040] Example 5
[0041] Similar to Example 1, except that the metal salt is a mixture of aluminum nitrate nonahydrate and chromium chloride in a mass ratio of 1:1, yielding lignin-Al. 2+ / Cr 3+ The photocatalyst achieved an HMF yield of 83.7% and a glucose conversion rate of 99.9%.
[0042] Example 6
[0043] Similar to Example 1, except that: lignin and aluminum nitrate nonahydrate were added to dimethyl sulfoxide, the mass concentration of lignin in the solution was 1 g / L, the mass ratio of lignin to aluminum nitrate nonahydrate was 1:3, the solution was reacted in a water bath at 25 °C for 60 minutes, after the reaction was completed, the solution was dropped into water to obtain a solid precipitate, which was separated and dried to obtain lignin-Al. 3+ Photocatalyst.
[0044] Lignin - Al 3+ A method for photocatalytic synthesis of 5-hydroxymethylfurfural from sugars includes the following steps: adding lignin-metal ion photocatalyst and fructose to dimethyl sulfoxide, resulting in a solution with a fructose concentration of 1 g / L, and lignin-Al... 3+ The mass ratio of photocatalyst to fructose was 6:1. The photocatalytic reaction was carried out at 50 °C for 20 h, and the light intensity of the photocatalytic reaction was 0.1 W / cm². 2 After the reaction was completed, the product HMF was obtained. The yield of HMF was 67.8%, and the fructose conversion rate was 99.5%.
[0045] Example 7
[0046] Similar to Example 1, except that: lignin and aluminum nitrate nonahydrate were added to dimethyl sulfoxide, the mass concentration of lignin in the solution was 20 g / L, the mass ratio of lignin to metal salt was 3:1, the solution was reacted in an 80 °C water bath for 5 minutes, after the reaction was completed, the solution was dropped into water to obtain a solid precipitate, which was separated and dried to obtain lignin-Al. 3+ Photocatalyst.
[0047] Lignin-Al 3+ A method for photocatalytic synthesis of 5-hydroxymethylfurfural from sugars using a photocatalyst includes the following steps: reacting lignin-Al... 3+Photocatalyst and sucrose were added to dimethyl sulfoxide, resulting in a solution with a sucrose concentration of 20 g / L, and lignin-Al 3+ The mass ratio of photocatalyst to sucrose was 1:6. The photocatalytic reaction was carried out at 100 °C for 1 h, and the light intensity of the photocatalytic reaction was 1.0 W / cm². 2 After the reaction was completed, the product HMF was obtained. The yield of HMF was 63.5%, and the sucrose conversion rate was 99.8%.
[0048] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims
1. A method for preparing a lignin-metal ion photocatalyst, comprising the following steps: Lignin and metal salt were added to dimethyl sulfoxide, and the resulting solution was reacted in a water bath at 25 ℃-80 ℃ for 5-60 minutes. After the reaction was completed, the solution was dropped into water to obtain a solid precipitate. After separation and drying, the lignin-metal ion photocatalyst was obtained.
2. The preparation method according to claim 1, characterized in that, The lignin is lignin isolated from coniferous wood, broad-leaved wood and / or herbaceous plants, and the metal salt is selected from any one or more of calcium chloride, magnesium chloride, aluminum chloride, tin chloride, ferric chloride, copper chloride, zinc chloride, chromium chloride, aluminum nitrate and aluminum sulfate.
3. The preparation method according to claim 1, characterized in that, The mass ratio of lignin to metal salt is 1:3-3:
1.
4. The preparation method according to claim 1, characterized in that, When lignin and metal salts are added to dimethyl sulfoxide, the resulting solution contains lignin at a concentration of 1-20 g / L.
5. A lignin-metal ion photocatalyst, characterized in that, It is obtained by the preparation method according to any one of claims 1-4.
6. The application of the lignin-metal ion photocatalyst according to claim 5 in the catalytic synthesis of 5-hydroxymethylfurfural from sugars, characterized in that, The lignin-metal ion photocatalyst and sugar were added to dimethyl sulfoxide, and the air in the solution was removed by nitrogen gas. The photocatalytic reaction was carried out at 50 ℃-100 ℃ for 1-20 h. After the reaction was completed, the product 5-hydroxymethylfurfural was obtained.
7. The application according to claim 6, characterized in that, The specific conditions for the photocatalytic reaction are: 70 ℃-90 ℃ for 12-18 h.
8. The application according to claim 6 or 7, characterized in that, The mass ratio of lignin-metal ion photocatalyst to sugar is 1:6-6:
1.
9. The application according to claim 6 or 7, characterized in that, The sugar is selected from one or more of fructose, glucose, and sucrose, and the sugar concentration in the solution obtained by adding the sugar to dimethyl sulfoxide is 1-20 g / L.
10. The application according to claim 6 or 7, characterized in that, The light intensity of the photocatalytic reaction is 0.1-1.0 W / cm². 2 .