A method for preparing DS by catalyzing a foamed iron-nickel electrode in series with a chemical reactor
By catalyzing a series chemical reactor with iron-nickel foam electrodes and combining electrolysis and chemical reactions, CO2 can be converted into dimethyl succinate efficiently and at low cost under mild conditions, solving the problems of high carbon emissions and high costs in existing technologies and improving reaction activity and yield.
Patent Information
- Application Number
- CN202411028509.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-30
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2044-07-30
AI Technical Summary
The existing technology for preparing dimethyl succinate (DS) has problems of high carbon emissions and high production costs, and the cost of biological fermentation production is high. How to use the electrocatalytic CO2 reduction reaction to directly convert CO2 into stable dimethyl succinate is an urgent problem that needs to be solved.
Foamed iron-nickel electrodes are used to catalyze a series chemical reactor. By adding an electrolyte and a CO2 gas mixture into the electrolytic cell, an electrocarboxylation reaction is carried out under the application of a reducing voltage to generate a carboxylic acid compound, which is then methylated through a chemical reactor to ultimately obtain dimethyl succinate.
Efficient and low-cost DS preparation was achieved under mild conditions without producing greenhouse gases, which improved the reaction activity and yield and simplified the synthesis route.
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Figure CN118773624B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of electrochemical reduction, and particularly relates to a method for preparing DS by using a foamed iron-nickel electrode catalyzed in series with a chemical reactor. Background Art
[0002] Succinic acid (SA) has a wide range of uses in medicine, surfactants, additives, polymers, and succinate substrates. Dimethyl succinate (DS), its esterification product, has better solubility and chemical stability, so methyl esterification of SA can better maintain its stability.
[0003] There are currently two methods for preparing SA: petrochemical synthesis and bio-based synthesis. The preparation of SA by catalytic hydrogenation of maleic acid (petrochemical synthesis) will result in high carbon emissions and non-renewable energy consumption, and the production cost is as high as US$2,715 / ton; compared with the traditional petrochemical synthesis method, the production of SA by biological fermentation (bio-based synthesis) provides another method to reduce greenhouse gas emissions by more than 60%, but the production cost is also high, estimated at US$1,111 / ton.
[0004] The rapid development of electrocatalytic CO2 reduction reaction (CO2RR) has led to the research on the conversion of CO2 into multi-carbon (C 2+ ) chemicals are gaining interest.
[0005] How to use the electrocatalytic CO2 reduction reaction to directly convert CO2 into stable dimethyl succinate is an urgent problem that needs to be solved. Summary of the Invention
[0006] In order to solve the above problems, the present invention provides a method for preparing DS by catalyzing an iron-nickel foam electrode in series with a chemical reactor, comprising: using the iron-nickel foam as a cathode material and an active metal as an anode material; adding an electrolyte to an electrolytic cell, and then introducing an organic substrate and a CO2 gas mixture into the electrolyte; conducting an electrocarboxylation reaction under the condition of applying a reducing voltage, so that the organic substrate and CO2 undergo a carboxylation reaction to generate a carboxylic acid compound; methylating the carboxylation product in a chemical reactor, and then extracting, washing, drying and evaporating to obtain the corresponding ester compound.
[0007] In one embodiment of the present invention, the active metal is one or more of magnesium, aluminum, zinc, and nickel.
[0008] In one embodiment of the present invention, the organic substrate is one or more compounds containing carbon-carbon double bonds, specifically C2H4.
[0009] In one embodiment of the present invention, the electrolyte is a mixture of tetra-n-butylammonium hexafluorophosphate and N,N-dimethylformamide.
[0010] In one embodiment of the present invention, the electrolytic cell is a single-chamber electrolytic cell, a double-chamber electrolytic cell, or a flow electrolytic cell.
[0011] In one embodiment of the present invention, the mixed gas is introduced at a flow rate of 20 to 25 mL / min.
[0012] In one embodiment of the present invention, the electrocarboxylation reaction time is 5 to 6 hours.
[0013] In one embodiment of the present invention, the volume ratio of the organic substrate to CO2 in the gas mixture is 1:1.
[0014] In one embodiment of the present invention, a method for preparing DS by catalyzing a foamed iron-nickel electrode in series with a chemical reactor specifically comprises the following steps:
[0015] (1) Carboxylation reaction of C2H4 and CO2
[0016] a) The nickel-iron foam material was used as the cathode, the Ni plate and the Ag wire were used as the anode and quasi-reference electrode, respectively;
[0017] b) adding an electrolyte to an electrolytic cell, wherein tetra-n-butylammonium hexafluorophosphate is dissolved in N,N-dimethylformamide to form a 0.5 mM tetra-n-butylammonium hexafluorophosphate solution as the electrolyte, and then introducing a mixed gas of 50% C2H4 and 50% CO2;
[0018] c) applying a negative voltage to the foamed iron-nickel material electrode, and reacting C2H4 with CO2 to obtain a carboxylated product;
[0019] (2) Methylation of carboxylation products
[0020] The reaction solution is subjected to methyl esterification, extraction, washing, drying and evaporation to obtain the corresponding ester compound.
[0021] Beneficial effects of the present invention
[0022] 1. The present invention can realize the electrocarboxylation reaction of CO2 and organic matter under mild experimental conditions (normal temperature and pressure), and the preparation method is simple and the production cost is low;
[0023] 2. Combining electrochemical and chemical reactors allows for complex synthesis pathways (CO2-SA-DS) to be achieved within the same system, with high yields and product stability.
[0024] 3. Compared with the synthesis method of carboxylic acid compounds catalyzed by other materials, the present invention uses foamed iron nickel as the cathode material in the electrocarboxylation process of C2H4, achieving higher reaction activity;
[0025] 4. The electrocarboxylation reaction of C2H4 and CO2 of the present invention can produce DS without generating any greenhouse gases. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 The DS yield bar graph of the electrocarboxylation reaction of C2H4 and CO2 at different mixed gas flow rates in Examples 1, 2 and Comparative Example 4 is shown;
[0027] Figure 2 The DS yield bar graph of the electrocarboxylation reaction of C2H4 and CO2 under different cathode materials in Example 1 and Comparative Examples 1-3 is shown;
[0028] Figure 3 The DS yield bar graph of the electrocarboxylation reaction of C2H4 and CO2 at different electrocarboxylation reaction times in Examples 1, 3, and Comparative Example 5 is shown;
[0029] Figure 4 is the H NMR spectrum of the target product DS;
[0030] Figure 5 This is the mass spectrometry-gas chromatography-mass spectrometry of the target product DS;
[0031] Figure 6 The possible mechanism diagram of the electrocarboxylation reaction of C2H4 and CO2;
[0032] Figure 7 Schematic diagram of the preparation of DS by tandem catalysis. DETAILED DESCRIPTION
[0033] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention.
[0034] The nickel-iron foam used in the following examples and comparative examples was purchased from Kunshan Lvchuang Electronic Technology Co., Ltd.
[0035] Example 1
[0036] A method for preparing DS using a foamed nickel electrode catalyzed in series with a chemical reactor comprises: using the foamed nickel as the cathode of a single-chamber electrolytic cell, a Ni plate and an Ag wire as the anode and a quasi-reference electrode, respectively; mixing N,N-dimethylformamide and tetra-n-butylammonium hexafluorophosphate to form an electrolyte; introducing a gas mixture consisting of 50% CO2 and 50% C2H4 (percentages by volume) at a flow rate of 20 mL / min; and electrocarboxylation at a constant voltage of -5 V (vs. Ag). After 5 hours, the carboxylation product is methylated in a chemical reactor, and then extracted, washed, dried, and evaporated. The specific operation is carried out according to the following steps:
[0037] (1) Preparation of electrolyte
[0038] Tetra-n-butylammonium hexafluorophosphate is dissolved in N,N-dimethylformamide to form a 0.5 mM tetra-n-butylammonium hexafluorophosphate solution as an electrolyte, which is then placed in a single-chamber electrolytic cell with iron-nickel foam as a cathode and a Ni plate as an anode; the N,N-dimethylformamide and tetra-n-butylammonium hexafluorophosphate are of analytical grade, and the tetra-n-butylammonium hexafluorophosphate is used as a supporting electrolyte;
[0039] (2) Electrocarboxylation reaction
[0040] Under normal pressure, a mixed gas consisting of 50% CO2 and 50% C2H4 was introduced into the electrolytic cell at a flow rate of 20 mL / min, and then a constant voltage of -5 V (vs. Ag) was applied to the foamed iron-nickel electrode to carry out the electrocarboxylation reaction. The introduced mixed gas was continued until the electrolysis was completed.
[0041] (3) Methylation
[0042] The electrolyzed liquid was transferred to a round-bottom flask, 0.138 g of K2CO3 and 1 mL of CH3I were added to the flask, and the mixture was placed in a 60°C water bath and stirred for 5 h.
[0043] (4) Extraction, washing, drying and evaporation
[0044] The reaction mixture was acidified with 2M HCl, extracted three times with ethyl acetate (3×8 mL), and the organic phase was washed three times with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , and finally filtered and evaporated to obtain the product dimethyl succinate.
[0045] The yield of DS of the above product was determined by gas chromatography-mass spectrometry, and the yield of dimethyl succinate was 103.7 μmol at a flow rate of 20 mL / min of a mixed gas of 50% CO 2 and 50% C 2 H 4 and a reaction time of 5 h.
[0046] Comparative Example 1
[0047] The preparation method is the same as that of Example 1, except that only the foamed iron-nickel cathode material is replaced by foamed nickel.
[0048] The yield of DS was determined by gas chromatography-mass spectrometry and was 21.85 μmol.
[0049] Comparative Example 2
[0050] The preparation method is the same as that of Example 1, except that only the foamed iron-nickel cathode material is replaced by foamed iron.
[0051] The yield of DS was determined by gas chromatography-mass spectrometry and was 42.30 μmol.
[0052] Comparative Example 3
[0053] The preparation method is the same as that of Example 1, except that only the foamed iron-nickel cathode material is replaced by foamed copper.
[0054] The yield of DS was determined by gas chromatography-mass spectrometry and was 70.79 μmol.
[0055] Example 2
[0056] The preparation method is consistent with that in Example 1, except that the flow rate of the mixed gas is 25 mL / min.
[0057] The yield of DS was determined by gas chromatography-mass spectrometry and was 162.5 μmol.
[0058] Comparative Example 4
[0059] The preparation method is consistent with that in Example 1, except that the flow rates of the mixed gas are 5 mL / min, 10 mL / min, and 15 mL / min, respectively.
[0060] The yields of DS at flow rates of 5 mL / min, 10 mL / min, and 15 mL / min were determined by gas chromatography-mass spectrometry to be 6.6 μmol, 12.5 μmol, and 75.5 μmol, respectively.
[0061] Example 3
[0062] The preparation method is consistent with that of Example 1, except that the electrocarboxylation reaction time is 6 h.
[0063] The yield of DS was determined by gas chromatography-mass spectrometry and was 127.5 μmol.
[0064] Comparative Example 5
[0065] The preparation method is consistent with that in Example 1, except that the electrocarboxylation reaction time is 1 h, 2 h, 3 h, and 4 h, respectively.
[0066] The yields of DS were determined by gas chromatography-mass spectrometry, which were 25 μmol, 34.8 μmol, 61.2 μmol and 92.1 μmol, respectively.
[0067] Comparative Example 6
[0068] A method for preparing DS using a foamed nickel electrode catalyzed in series with a chemical reactor comprises: using the foamed nickel as the cathode of a single-chamber electrolytic cell, a Ni plate and an Ag wire as the anode and a quasi-reference electrode, respectively; mixing N,N-dimethylformamide and tetra-n-butylammonium hexafluorophosphate to form an electrolyte; introducing a gas mixture consisting of 5% CO2, 10% C2H4, and 85% Ar (percentages are by volume) at a flow rate of 25 mL / min; and electrocarboxylation at a constant voltage of -5 V (vs. Ag). After 6 hours, the carboxylation product is methylated in a chemical reactor, and then extracted, washed, dried, and evaporated. The specific application is carried out according to the following steps:
[0069] (1) Preparation of electrolyte
[0070] Tetra-n-butylammonium hexafluorophosphate is dissolved in N,N-dimethylformamide to form a 0.5 mM tetra-n-butylammonium hexafluorophosphate solution as an electrolyte, which is then placed in a single-chamber electrolytic cell with iron-nickel foam as a cathode and a Ni plate as an anode; the N,N-dimethylformamide and tetra-n-butylammonium hexafluorophosphate are of analytical grade, and the tetra-n-butylammonium hexafluorophosphate is used as a supporting electrolyte;
[0071] (2) Electrocarboxylation reaction
[0072] Under normal pressure, a mixed gas consisting of 5% CO2, 10% C2H4 and 85% Ar was introduced into the electrolytic cell at a flow rate of 25 mL / min, and then an electrocarboxylation reaction was carried out at a constant voltage of -5 V (vs. Ag) until the electrolysis was completed;
[0073] (3) Methylation
[0074] The electrolyzed liquid was transferred to a round-bottom flask, 0.138 g of K2CO3 and 1 mL of CH3I were added to the flask, and the mixture was placed in a 60°C water bath and stirred for 5 h.
[0075] (4) Extraction, washing, drying and evaporation
[0076] The reaction mixture was acidified with 2M HCl, extracted three times with ethyl acetate (3×8 mL), and the organic phase was washed three times with saturated NaCl solution, dried over anhydrous Na 2 SO 4 , and finally filtered and evaporated to obtain the product.
[0077] The yield of DS of the above product was determined by gas chromatography-mass spectrometry, and the yield of dimethyl succinate was 0.57 μmol at a mixed gas flow rate of 5% CO2, 10% C2H4 and 85% Ar of 25 mL / min and a reaction time of 6 h.
[0078] Comparative Example 7
[0079] The preparation method is consistent with that of Comparative Example 6, except that the flow rates of the mixed gas are 15 mL / min, 20 mL / min, 25 mL / min, and 30 mL / min, respectively.
[0080] The yields of DS of the product under the above flow rate reaction were determined by gas chromatography-mass spectrometry at flow rates of 15 mL / min, 20 mL / min, 25 mL / min, and 30 mL / min, which were 0.54 μmol, 0.54 μmol, 0.56 μmol, and 0.56 μmol, respectively.
[0081] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.
Claims
1. A method for preparing DS by catalyzing a foamed iron-nickel electrode in series with a chemical reactor, characterized in that: Foamed iron-nickel is used as the cathode material, and active metal is used as the anode material. An electrolyte is added to the electrolytic cell, and then a mixture of organic substrates C2H4 and CO2 gas is introduced into the electrolyte. Under the condition of applying a reducing voltage, an electrocarboxylation reaction is carried out to generate a carboxylic acid compound. The carboxylation product is methylated in a chemical reactor, and then extracted, washed, dried and evaporated to obtain the corresponding ester compound dimethyl succinate DS; the volume ratio of the organic substrate and CO2 in the gas mixture is 1:
1.
2. The method for preparing DS by using a foamed iron-nickel electrode catalyzed in series chemical reactor according to claim 1, characterized in that: The active metal is one or more of magnesium, aluminum, zinc and nickel.
3. The method for preparing DS by using a foamed iron-nickel electrode catalyzed in series chemical reactor according to claim 1, characterized in that: The flow rate of the organic substrate and CO2 gas mixture into the electrolyte is 20-25 mL / min.
4. The method for preparing DS by using a foamed iron-nickel electrode catalyzed in series chemical reactor according to claim 1, characterized in that: The electrocarboxylation reaction time is 5 to 6 hours.
5. The method for preparing DS by using a foamed iron-nickel electrode catalyzed in series chemical reactor according to claim 1, characterized in that: The electrolyte is a mixture of tetra-n-butylammonium hexafluorophosphate and N,N-dimethylformamide.
6. The method for preparing DS by using a foamed iron-nickel electrode catalyzed in series chemical reactor according to claim 1, characterized in that: Tetra-n-butylammonium hexafluorophosphate was dissolved in N,N-dimethylformamide to form a tetra-n-butylammonium hexafluorophosphate solution with a concentration of 0.5 mM as an electrolyte.
7. The method for preparing DS by using a foamed iron-nickel electrode catalyzed in series chemical reactor according to claim 1, characterized in that: The electrolytic cell is a single-chamber electrolytic cell, a double-chamber electrolytic cell or a flow electrolytic cell.