Method for alkaline-free catalytic oxidation of 5-hydroxymethylfurfural and applications thereof
By using a combination of persulfate and catalyst under alkaline conditions, highly efficient catalytic oxidation of HMF is achieved, solving the corrosion and safety issues that exist under high alkaline conditions, and improving reaction efficiency and product selectivity.
Patent Information
- Application Number
- CN202410969747.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2044-07-19
AI Technical Summary
Existing HMF catalytic oxidation technology suffers from numerous side reactions, strong equipment corrosion, severe catalyst damage, high cost, and poor safety under high alkaline conditions.
Persulfate is used as an oxidant, which combines with a catalyst under alkaline-free conditions and is activated by heating or light to achieve the catalytic oxidation reaction of HMF.
This method enables efficient conversion of HMF into target products under mild conditions, reducing corrosion risks, lowering costs, and improving safety and product selectivity.
Smart Images
Figure CN118908917B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of catalysis of 5-hydroxymethylfurfural, and in particular to a method for catalyzing 5-hydroxymethylfurfural without alkali and application thereof. BACKGROUND
[0002] 5-hydroxymethylfurfural (HMF) is an organic compound generated by dehydration of sugars under acidic conditions, and is widely concerned as a potential bio-based platform chemical because it can be further converted into a variety of useful chemicals and fuels. Oxidation derivatives of HMF include 5-formyl-2-furoic acid (FFCA), 2,5-furandicarboxaldehyde (DFF), 5-hydroxymethyl-2-furoic acid (HMFCA), 2,5-furandicarboxylic acid (FDCA), etc.
[0003] In the prior art, catalytic oxidation of HMF is generally carried out under high-alkali conditions (for example, by adding alkali substances such as sodium hydroxide or potassium hydroxide) to promote the conversion of HMF into its oxidation derivatives. However, this catalytic condition has the following problems: high-alkali environment is prone to cause side reactions, and the selectivity of the product is not high; high-alkali environment has strong corrosiveness to equipment materials, resulting in shortened equipment life and increased maintenance cost; in a high-alkali environment, some catalysts sensitive to pH may be damaged, resulting in changes in the structure of the catalyst or the active center, thereby reducing the catalytic efficiency and the reusability of the catalyst; the use of high-alkali conditions increases the consumption of chemical raw materials, especially in the case where a large amount of alkali is needed to maintain the reaction environment; in addition, more stringent safety measures and higher-level waste treatment technology are required, which may lead to an increase in production cost. SUMMARY
[0004] In view of the deficiencies of the prior art, the purpose of the present application is to develop a technology for efficiently catalyzing the oxidation of HMF under alkali-free conditions.
[0005] To achieve the above-mentioned purpose, the present application provides, in a first aspect, a method for catalyzing the oxidation of 5-hydroxymethylfurfural (HMF) without alkali, comprising the following steps: adding persulfate (PMS) as an oxidizing agent in an aqueous solution of 5-hydroxymethylfurfural, adding a catalyst, and heating or applying light to the mixed solution to make 5-hydroxymethylfurfural undergo catalytic oxidation reaction under alkali-free conditions.
[0006] The present application uses PMS as an oxidizing agent, which can realize efficient oxidation of HMF under alkali-free conditions. Since strong alkali is avoided, this process reduces the risk of corrosion during operation, improves safety, and has a simple process flow, requires less chemical raw materials, and the persulfate can be decomposed by a simple method after the reaction, and the by-products produced are relatively friendly to the environment.
[0007] Further, the molar ratio of the catalyst to the persulfate in the mixed solution is 1:1-1:5.
[0008] Further, the molar ratio of the persulfate to 5-hydroxymethylfurfural in the mixed solution is 1:1-1:10.
[0009] Further, the concentration of 5-hydroxymethylfurfural in the mixed solution is 0.5-10 mol / L.
[0010] By limiting the ratio and concentration of per-HMF, PMS and catalyst, the conversion rate of the reaction and the selectivity of the product can be improved.
[0011] Further, the persulfate is selected from one or more of potassium persulfate, sodium persulfate and ammonium persulfate.
[0012] Further, the temperature for heating the mixed solution is 30-150°C. The addition of persulfate in the reaction system can realize high-rate oxidation of HMF under mild reaction conditions.
[0013] Further, the catalyst is selected from one or more of combinations of cobalt tetroxide (Co3O4), iron oxide (Fe2O3), manganese tetroxide (Mn3O4), manganese dioxide (MnO2) and palladium-carbon (Pd / C). The above catalysts can effectively activate PMS under heating conditions, and then efficiently catalyze the oxidation reaction of HMF.
[0014] Further, the intensity of light applied to the mixed solution is 100-800 mW / cm 2 .
[0015] Further, the catalyst is selected from one or more of combinations of titanium dioxide (TiO2), tungsten trioxide (WO3), zinc oxide (ZnO), vanadium oxide (V2O5), copper oxide (CuO) and cerium oxide (CeO2). The above catalysts can effectively activate PMS under visible light irradiation, generate strong oxidizing free radicals, and promote the oxidation reaction of HMF.
[0016] The second aspect of the present application provides an application of the above method for catalytic oxidation of 5-hydroxymethylfurfural to generate target products selected from one or more of 5-formyl-2-furan carboxylic acid (FFCA), 2,5-furan dicarboxylic acid (DFF), 5-hydroxymethyl-2-furan carboxylic acid (HMFCA) and 2,5-furan dicarboxylic acid (FDCA). HMF oxidation can generate various high-value derivatives, and by controlling the reaction conditions, the selectivity of the product can be adjusted.
[0017] Further, the reaction time required for catalytic oxidation of 5-hydroxymethylfurfural to generate target products is 0.5-12 h.
[0018] Compared with the prior art, the present application has the following beneficial effects:
[0019] The present application adopts the PMS activated alkali-free process, which is used for the photocatalytic and thermal catalytic oxidation of HMF, can be efficiently converted into target products under mild conditions, has the advantages of simple operation, environmental friendliness, cost-effectiveness and the like. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is the chemical reaction diagram of HMF conversion into target products in the specific embodiment of the present application.
[0021] Figure 2 is the HMF photocatalytic effect diagram in Example 1 of the present application.
[0022] Figure 3 is the HMF photocatalytic effect diagram in Example 2 of the present application.
[0023] Figure 4 is the HMF photocatalytic effect diagram in Example 3 of the present application.
[0024] Figure 5 is the HMF photocatalytic effect diagram in Example 4 of the present application.
[0025] Figure 6 is the HMF photocatalytic effect diagram in Example 5 of the present application.
[0026] Figure 7 is the HMF photocatalytic effect diagram in Example 6 of the present application.
[0027] Figure 8 is the HMF thermal catalytic effect diagram in Example 7 of the present application.
[0028] Figure 9 is the HMF thermal catalytic effect diagram in Example 8 of the present application.
[0029] Figure 10 is the HMF thermal catalytic effect diagram in Example 9 of the present application.
[0030] Figure 11 is the HMF thermal catalytic effect diagram in Example 10 of the present application.
[0031] Figure 12 is the HMF thermal catalytic effect diagram in Example 11 of the present application. DETAILED DESCRIPTION
[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings.
[0033] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for a range of values of, for example, concentration, thickness or the like, an intermediate value of the range can be specifically recited; however, it is intended to include all values including the intermediate value between any other value in the range. The upper and lower limits of these smaller ranges can independently be included or excluded in the range.
[0034] Many modifications and variations of the present application described herein will be apparent to those of ordinary skill in the art from the foregoing description. Accordingly, it is to be understood that the application, in its broadest form, is not to be limited to the specific embodiments foreseen as illustrative herein. Rather, the specific embodiments are included by way of example only and any other embodiment, including combinations of features from different embodiments, are intended to be within the scope of the application.
[0035] The specific embodiments of the present application provide a method for catalytic oxidation of 5-hydroxymethylfurfural without alkali, in which a persulfate salt is added as an oxidant in an aqueous solution of 5-hydroxymethylfurfural, and a catalyst is added to allow the 5-hydroxymethylfurfural to undergo catalytic oxidation under an alkali-free condition, thereby converting the 5-hydroxymethylfurfural into a target product. Figure 1 As shown, the target product includes FFCA, DFF, HMFCA, FDCA, etc.
[0036] In the specific embodiments, the concentration of the 5-hydroxymethylfurfural is 0.5-10 mol / L, the molar ratio of the persulfate salt to the 5-hydroxymethylfurfural is 1:1-1:10, and the molar ratio of the catalyst to the persulfate salt is 1:1-1:5. By adjusting the proportions and concentrations of the raw materials, the reaction efficiency and selectivity can be improved.
[0037] The persulfate salt can be potassium persulfate, sodium persulfate, ammonium persulfate, etc. Depending on the catalytic reaction conditions, different catalysts can be selected. For thermal catalytic oxidation, Co3O4, Fe2O3, Mn3O4, MnO2, Pd / C, etc. are selected as the thermal catalysts, and the preferred heating temperature is 30-150°C. For photocatalytic oxidation, TiO2, WO3, ZnO, V2O5, CuO, CeO2, etc. are selected as the photocatalysts, and the preferred light intensity is 100-800 mW / cm 2 The reaction conditions are mild.
[0038] The reaction time required for the catalytic oxidation of the 5-hydroxymethylfurfural to generate the target product is 0.5-12 h, and the target product can be efficiently converted under mild conditions. The method has the advantages of simple operation, environmental friendliness, and cost-effectiveness, etc.
[0039] The technical effects of the present application are described below in conjunction with specific embodiments. Unless otherwise specified, the raw materials in the embodiments of the present application are purchased through commercial channels.
[0040] Example 1
[0041] A reaction vessel was charged with 9 ml of 20 mmol aqueous HMF and 1 ml of 100 mmol aqueous potassium persulfate solution, and 50 mg of catalyst titanium dioxide (Ti02) was added. A 300 watt xenon lamp was used to provide 500 mW / cm2of full spectrum light. After the light source was turned on, the reaction was started and the time was recorded. Every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the sample was analyzed by liquid chromatography. The whole reaction process lasted for 2 hours.
[0042] The effect of the photocatalytic reaction in this example is shown in Table 1, and the conversion of HMF was 99.8% within 2 hours of catalytic reaction time, the yield of FFCA was 3.3%, the yield of FDCA was 30.4%, and the yield of HMFCA was 38.4%. Figure 2
[0043] Example 2
[0044] A reaction vessel was charged with 9 ml of 20 mmol aqueous HMF and 1 ml of 20 mmol aqueous potassium persulfate solution, and 50 mg of catalyst tungsten oxide (W03) was added. A 300 watt xenon lamp was used to provide 100 mW / cm2of full spectrum light. After the light source was turned on, the reaction was started and the time was recorded. Every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the sample was analyzed by liquid chromatography. The whole reaction process lasted for 2 hours.
[0045] The effect of the photocatalytic reaction in this example is shown in Table 2, and the conversion of HMF was 59.7% within 2 hours of catalytic reaction time, the yield of FFCA was 1.9%, the yield of FDCA was 1.3%, the yield of HMFCA was 18.1%, and the yield of DFF was 30.5% (selectivity was 51.1%). Figure 3 Example 3
[0046] A reaction vessel was charged with 9 ml of 20 mmol aqueous HMF and 1 ml of 50 mmol aqueous sodium persulfate solution, and 50 mg of catalyst zinc oxide (ZnO) was added. A 300 watt xenon lamp was used to provide 400 mW / cm2of full spectrum light. After the light source was turned on, the reaction was started and the time was recorded. Every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the sample was analyzed by liquid chromatography. The whole reaction process lasted for 2 hours.
[0047] The effect of the photocatalytic reaction in this example is shown in Table 3, and the conversion of HMF was 99.8% within 2 hours of catalytic reaction time, the yield of FFCA was 3.3%, the yield of FDCA was 30.4%, and the yield of HMFCA was 38.4%.
[0048] Figure 4 As shown in Table 1, within 2 hours of catalytic reaction time, the conversion of HMF was 91.0%, the yield of FFCA was 43.3%, the yield of FDCA was 28.6%, the yield of HMFCA was 3.5%, and the yield of DFF was 3.9%.
[0049] Example 4
[0050] A reaction vessel was charged with 9 ml of 20 mmol aqueous HMF solution and 1 ml of 120 mmol aqueous sodium persulfate solution, and 50 mg of vanadium oxide (V2O5) catalyst was added. A 300 watt xenon lamp was used to provide 400 mW / cm2of full spectrum light. After turning on the light source, the catalytic reaction was started and the time was recorded. Every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the sample was analyzed by liquid chromatography. The whole reaction process lasted for 2 hours.
[0051] The effect of photocatalytic reaction in this example is shown in Table 1. Figure 5 As shown in Table 1, within 2 hours of catalytic reaction time, the conversion of HMF was 91.2%, the yield of FFCA was 10.2%, the yield of FDCA was 27.9%, and the yield of HMFCA was 26.3%.
[0052] Example 5
[0053] A reaction vessel was charged with 9 ml of 20 mmol aqueous HMF solution and 1 ml of 90 mmol aqueous ammonium persulfate solution, and 50 mg of copper oxide (CuO) catalyst was added. A 300 watt xenon lamp was used to provide 800 mW / cm2of full spectrum light. After turning on the light source, the catalytic reaction was started and the time was recorded. Every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the sample was analyzed by liquid chromatography. The whole reaction process lasted for 2 hours.
[0054] The effect of photocatalytic reaction in this example is shown in Table 1. Figure 6 As shown in Table 1, within 2 hours of catalytic reaction time, the conversion of HMF was 82.4%, the yield of FFCA was 0.8%, the yield of FDCA was 18.1%, and the yield of HMFCA was 54.3% (selectivity was 65.9%).
[0055] Example 6
[0056] A reaction vessel was charged with 9 ml of 20 mmol aqueous HMF solution and 1 ml of 40 mmol aqueous ammonium persulfate solution, and 50 mg of cerium oxide (CeO2) catalyst was added. A 300 watt xenon lamp was used to provide 300 mW / cm2of full spectrum light. After turning on the light source, the catalytic reaction was started and the time was recorded. Every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the sample was analyzed by liquid chromatography. The whole reaction process lasted for 2 hours.
[0057] The effect of the photocatalytic reaction in this embodiment is as follows: Figure 7 As shown, within a catalytic reaction time of 2 hours, the conversion rate of HMF was 63.2%, the yield of FFCA was 0.4%, the yield of FDCA was 0.6%, the yield of HMFCA was 13.2%, and the yield of DFF was 43.5% (selectivity was 68.7%).
[0058] Example 7
[0059] 9 mL of 20 mmol HMF aqueous solution and 1 mL of 100 mmol potassium persulfate aqueous solution were added to the reaction vessel, followed by 50 mg of cobalt tetroxide (Co3O4) catalyst. The temperature inside the reaction vessel was controlled at 50°C. After reaching the set temperature, samples were taken every 30 minutes, and 10 μL of the reaction solution was diluted and filtered. The samples were analyzed using liquid chromatography. The entire reaction process lasted for 2 hours.
[0060] The effect of the thermocatalytic reaction in this embodiment is as follows: Figure 8 As shown, within a catalytic reaction time of 2 hours, the conversion rate of HMF was 98.6%, the yield of FFCA was 34.4%, the yield of FDCA was 13.9%, the yield of HMFCA was 38.1%, and the yield of DFF was 0.63%.
[0061] Example 8
[0062] 9 mL of 20 mmol HMF aqueous solution and 1 mL of 20 mmol potassium persulfate aqueous solution were added to the reaction vessel, followed by 50 mg of ferric oxide (Fe2O3) catalyst. The temperature inside the reaction vessel was controlled at 30°C. After reaching the set temperature, samples were taken every 30 minutes, and 10 μL of the reaction solution was diluted and filtered. The samples were analyzed using liquid chromatography. The entire reaction process lasted for 2 hours.
[0063] The effect of the thermocatalytic reaction in this embodiment is as follows: Figure 9 As shown, within a catalytic reaction time of 2 hours, the conversion rate of HMF was 47.7%, the yield of FDCA was 6.9%, the yield of HMFCA was 7.3%, and the yield of DFF was 31.4% (with a selectivity of 65.8%).
[0064] Example 9
[0065] A reaction vessel was charged with 9 mL of a 20 mmol aqueous solution of HMF and 1 mL of a 50 mmol aqueous solution of sodium persulfate, and 50 mg of the catalyst manganese tetroxide (Mn3O4) was added. The temperature in the reaction vessel was controlled at 80 degrees Celsius, and after reaching the set temperature, samples were taken every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the samples were analyzed using liquid chromatography. The entire reaction process lasted 2 hours.
[0066] The effect of the thermal catalytic reaction in this example is shown in Table 1, and the results are shown in Figure 1. Within the 2 hours of catalytic reaction time, the conversion of HMF was 32.6%, the yield of FFCA was 2.5%, the yield of FDCA was 2.6%, the yield of HMFCA was 1.6%, and the yield of DFF was 25.2% (selectivity 77.4%). Figure 10
[0067] Example 10
[0068] A reaction vessel was charged with 9 mL of a 20 mmol aqueous solution of HMF and 1 mL of a 150 mmol aqueous solution of sodium persulfate, and 50 mg of the catalyst manganese dioxide (MnO2) was added. The temperature in the reaction vessel was controlled at 60 degrees Celsius, and after reaching the set temperature, samples were taken every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the samples were analyzed using liquid chromatography. The entire reaction process lasted 2 hours.
[0069] The effect of the thermal catalytic reaction in this example is shown in Table 1, and the results are shown in Figure 1. Within the 2 hours of catalytic reaction time, the conversion of HMF was 32.6%, the yield of FFCA was 2.5%, the yield of FDCA was 2.6%, the yield of HMFCA was 1.6%, and the yield of DFF was 25.2% (selectivity 77.4%). Figure 11 Example 11
[0070] A reaction vessel was charged with 9 mL of a 20 mmol aqueous solution of HMF and 1 mL of a 100 mmol aqueous solution of ammonium persulfate, and 50 mg of the catalyst palladium on carbon (Pd / C) was added. The temperature in the reaction vessel was controlled at 50 degrees Celsius, and after reaching the set temperature, samples were taken every 30 minutes, 10 microliters of the reaction solution was taken for dilution and filtration, and the samples were analyzed using liquid chromatography. The entire reaction process lasted 2 hours.
[0071] The effect of the thermal catalytic reaction in this example is shown in Table 1, and the results are shown in Figure 1. Within the 2 hours of catalytic reaction time, the conversion of HMF was 32.6%, the yield of FFCA was 2.5%, the yield of FDCA was 2.6%, the yield of HMFCA was 1.6%, and the yield of DFF was 25.2% (selectivity 77.4%).
[0072] Figure 12
[0073] Although the present disclosure has been disclosed with reference to the above embodiments, the scope of protection of the present disclosure is not limited to the above. Those skilled in the art, without departing from the spirit and scope of the present disclosure, can make various changes and modifications, and these changes and modifications will fall within the scope of protection of the present disclosure.
Claims
1. A method for the base-free catalytic oxidation of 5-hydroxymethylfurfural, characterized in that, The method comprises the following steps: adding a persulfate salt as an oxidizing agent to an aqueous 5-hydroxymethylfurfural solution, adding a catalyst selected from one or more combinations of titanium dioxide, tungsten trioxide, zinc oxide, vanadium oxide, copper oxide, cerium oxide, and subjecting the mixed solution to light application at an intensity of 100 to 800 mW / cm 2 catalytic oxidation of 5-hydroxymethylfurfural under alkali-free conditions.
2. The method of base-free catalytic oxidation of 5-hydroxymethylfurfural according to claim 1, characterized in that, The molar ratio of persulfate to 5-hydroxymethylfurfural in the mixed solution is 1:1-1:10, and the molar ratio of catalyst to persulfate is 1:1-1:
5.
3. The method of base-free catalytic oxidation of 5-hydroxymethylfurfural according to claim 2, characterized by, The concentration of 5-hydroxymethylfurfural in the mixed solution is 0.5-10 mol / L.
4. The method of base-free catalytic oxidation of 5-hydroxymethylfurfural according to claim 1, characterized by that, The persulfate is selected from one or more of potassium persulfate, sodium persulfate, and ammonium persulfate.
5. An application according to claim 4, characterized in that The method according to any one of claims 1-4 is used to catalytically oxidize 5-hydroxymethylfurfural to generate a target product selected from one or more of 5-formyl-2-furan carboxylic acid, 2,5-furan dicarboxylic acid, 5-hydroxymethyl-2-furan carboxylic acid, and 2,5-furan dicarboxylic acid.
6. Use according to claim 5, characterized in that, The reaction time required for catalytically oxidizing 5-hydroxymethylfurfural to generate a target product is 0.5-12 h.