Preparation method and preparation device of succinic acid

Abstract

The invention relates to the technical field of electrochemical synthesis, in particular to a preparation method and device of succinic acid, and the preparation method of succinic acid comprises the following steps: mixing an electrolyte and furfural to obtain a raw material electrolyte; and assembling the raw material electrolyte, an anode and a cathode into an electrolysis device, electrically connecting the anode and the cathode, carrying out an oxidation reaction on the anode, oxidizing the furfural into maleic acid, carrying out a reduction reaction on the cathode, and reducing the maleic acid into succinic acid, the anode is made of a first titanium substrate and a lead-manganese-platinum composite oxide loaded on the first titanium substrate, and the cathode is made of a second titanium substrate and a lead-manganese-platinum composite loaded on the second titanium substrate. The method has the advantages of high succinic acid yield and high current efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of electrochemical synthesis, and in particular to a method and device for preparing succinic acid. Background Art

[0002] Succinic acid is an important "C4 platform compound" that can undergo a variety of reactions such as halogenation, dehydration, esterification, sulfonation, acylation, oxidation and reduction. Downstream products include succinic anhydride, succinimide and its derivatives, and 1,4-butanediol. It can also be used as a monomer to synthesize biodegradable plastics such as polybutylene succinate and polyhexane succinate.

[0003] The global demand for succinic acid is 70,000 tons in 2022 and is expected to reach 135,000 tons in 2032. The industrial synthesis methods of succinic acid include biological fermentation, chemical hydrogenation and electrolysis. The biological fermentation method has the problems of low product concentration and high cost. The chemical hydrogenation method has a mature process, high yield and few by-products, but it involves dangerous processes, and the catalyst is expensive and the equipment investment is high. The electrolysis method produces less wastewater, the process is greener, and the equipment investment is less, but the succinic acid yield and current efficiency of the electrolysis method are low. Summary of the invention

[0004] Based on this, the first aspect of the present application provides a method for preparing succinic acid, and its technical scheme is as follows:

[0005] A method for preparing succinic acid comprises the following steps:

[0006] mixing the electrolyte and furfural to obtain a raw electrolyte;

[0007] The raw electrolyte, anode and cathode are assembled into an electrolysis device, the anode and the cathode are electrically connected, an oxidation reaction occurs at the anode to oxidize the furfural into maleic acid, and a reduction reaction occurs at the cathode to reduce the maleic acid into succinic acid, wherein the anode includes a first titanium substrate and a lead-manganese-platinum composite oxide supported on the first titanium substrate, and the cathode includes a second titanium substrate and a lead-manganese-platinum composite supported on the second titanium substrate.

[0008] Compared with the traditional solution, this application has the following beneficial effects:

[0009] The present application mixes furfural in the electrolyte, cooperates with the modified anode and cathode, and through electrochemical reaction, oxidizes furfural at the anode to generate maleic acid, relays catalysis, reduces maleic acid at the cathode to generate succinic acid, and prepares succinic acid through paired electrolysis. The above method has a high succinic acid yield and a high current efficiency. At the same time, the above electrochemical reaction process is green and environmentally friendly, generates less wastewater, requires less equipment investment, is suitable for industrial production of succinic acid, and has great industrial prospects.

[0010] In the present application, the anode includes a first titanium substrate and a lead-manganese-platinum composite oxide supported on the first titanium substrate. The anode can be prepared by hydrothermal reaction and calcination.

[0011] Optionally, the method for preparing the anode comprises the following steps:

[0012] S11, immersing the first titanium substrate in a precursor aqueous solution to perform a hydrothermal reaction to obtain a first titanium composite intermediate, wherein the precursor aqueous solution includes lead salt, manganese salt and platinum salt.

[0013] Optionally, the lead salt includes one or more of lead acetate and lead nitrate.

[0014] Optionally, the manganese salt includes one or more of manganese sulfate, manganese nitrate, manganese chloride and manganese acetate.

[0015] Optionally, the platinum salt includes one or more of chloroplatinic acid and platinum chloride.

[0016] Optionally, the mass percentage of the lead salt in the precursor aqueous solution is 10% to 25%. For example, the mass percentage is 10%, 15%, 18%, 20%, 23%, 25%. Preferably, the mass percentage is 15% to 25%.

[0017] Optionally, the mass percentage of the manganese salt in the precursor aqueous solution is 9% to 12%. For example, the mass percentage is 9%, 10%, 11%, 12%. Preferably, the mass percentage is 9% to 10%.

[0018] Optionally, the mass percentage of the platinum salt in the precursor aqueous solution is 1% to 3%. For example, the mass percentage is 1%, 1.5%, 2%, 2.5%, 3%. Preferably, the mass percentage is 2% to 3%.

[0019] Optionally, the temperature of the hydrothermal reaction is 100°C to 200°C. For example, the temperature is 100°C, 120°C, 140°C, 160°C, 180°C, or 200°C.

[0020] Optionally, the hydrothermal reaction time is 4 h to 8 h, for example, 4 h, 5 h, 6 h, 7 h, or 8 h.

[0021] After the hydrothermal reaction is completed, the product is taken out, rinsed and dried to obtain the first titanium composite intermediate product.

[0022] S12, calcining the first titanium composite intermediate product in an atmosphere containing oxygen.

[0023] Optionally, the heating rate of the calcination is 1°C / min to 5°C / min, for example, the heating rate is 1°C / min, 2°C / min, 3°C / min, 4°C / min, or 5°C / min.

[0024] Optionally, the calcination is carried out at a holding temperature of 500°C to 800°C. For example, the holding temperature is 500°C, 600°C, 700°C or 800°C.

[0025] Optionally, the calcination holding time is 1 h to 4 h. For example, the holding time is 1 h, 2 h, 3 h, or 4 h.

[0026] The above-mentioned preparation process of preparing the anode by hydrothermal reaction and calcination is simple and low in cost. The component content of the lead-manganese-platinum complex supported on the first titanium substrate can be regulated by controlling the composition of the precursor solution, the temperature and time of the hydrothermal reaction, and the calcination conditions.

[0027] In the present application, the cathode includes a second titanium substrate and a lead-manganese-platinum complex supported on the second titanium substrate. The cathode can also be prepared by hydrothermal reaction and calcination.

[0028] Optionally, the method for preparing the cathode comprises the following steps:

[0029] S21, immersing the second titanium substrate in a precursor aqueous solution to perform a hydrothermal reaction to obtain a second titanium composite intermediate, wherein the precursor aqueous solution includes lead salt, manganese salt and platinum salt.

[0030] Optionally, the lead salt includes one or more of lead acetate and lead nitrate.

[0031] Optionally, the manganese salt includes one or more of manganese sulfate, manganese nitrate, manganese chloride and manganese acetate.

[0032] Optionally, the platinum salt includes one or more of chloroplatinic acid and platinum chloride.

[0033] Optionally, the mass percentage of the lead salt in the precursor aqueous solution is 10% to 25%. For example, the mass percentage is 10%, 15%, 18%, 20%, 23%, 25%. Preferably, the mass percentage is 15% to 25%.

[0034] Optionally, the mass percentage of the manganese salt in the precursor aqueous solution is 9% to 12%. For example, the mass percentage is 9%, 10%, 11%, 12%. Preferably, the mass percentage is 9% to 10%.

[0035] Optionally, the mass percentage of the platinum salt in the precursor aqueous solution is 1% to 3%. For example, the mass percentage is 1%, 1.5%, 2%, 2.5%, 3%. Preferably, the mass percentage is 2% to 3%.

[0036] Optionally, the temperature of the hydrothermal reaction is 100°C to 200°C. For example, the temperature is 100°C, 120°C, 140°C, 160°C, 180°C, or 200°C.

[0037] Optionally, the hydrothermal reaction time is 4 h to 8 h, for example, 4 h, 5 h, 6 h, 7 h, or 8 h.

[0038] After the hydrothermal reaction is completed, the product is taken out, rinsed and dried to obtain a second titanium composite intermediate product.

[0039] S22, calcining the second titanium composite intermediate product in an atmosphere isolated from oxygen;

[0040] Different from the anode preparation process, the first titanium composite intermediate is calcined in an atmosphere containing oxygen, and the lead-manganese-platinum composite oxide is loaded on the first titanium substrate. In the cathode preparation process, the second titanium composite intermediate is calcined in an atmosphere isolated from oxygen, and the lead-manganese-platinum composite is loaded on the second titanium substrate.

[0041] Optionally, the oxygen-isolating atmosphere includes a mixed atmosphere of hydrogen and nitrogen.

[0042] Optionally, the heating rate of the calcination is 1°C / min to 5°C / min, for example, the heating rate is 1°C / min, 2°C / min, 3°C / min, 4°C / min, or 5°C / min.

[0043] Optionally, the calcination is carried out at a holding temperature of 500°C to 800°C. For example, the holding temperature is 500°C, 600°C, 700°C or 800°C.

[0044] Optionally, the calcination holding time is 1 h to 4 h. For example, the holding time is 1 h, 2 h, 3 h, or 4 h.

[0045] The preparation process of preparing the cathode by hydrothermal reaction and calcination is simple and low in cost. The component content of the lead-manganese-platinum complex supported on the second titanium substrate can be regulated by controlling the composition of the precursor solution, the temperature and time of the hydrothermal reaction, and the calcination conditions.

[0046] It is understandable that before preparing the anode and cathode by hydrothermal reaction and calcination, the first titanium substrate and the second titanium substrate may be pre-treated, such as pickling, grinding, degreasing, etc. The first titanium substrate and the second titanium substrate may be titanium plates.

[0047] The above-mentioned anode and cathode are used for preparing succinic acid by electrolysis in pairs, and the raw electrolyte, anode and cathode are assembled into an electrolysis device. Among them, the raw electrolyte includes furfural, furfural is biomass, and the raw material is green and environmentally friendly. With furfural as the raw material, in combination with the above-mentioned anode and cathode, in the absence of a diaphragm, furfural is oxidized to maleic acid at the anode, and maleic acid is reduced to succinic acid at the cathode. Optionally, the mass percentage of furfural in the raw electrolyte is 1% to 20%. For example, the mass percentage of furfural in the raw electrolyte is 1%, 5%, 10%, 15%, and 20%.

[0048] Optionally, the electrolyte includes an acid. The acid includes one or more of hydrochloric acid, nitric acid, sulfuric acid and acetic acid. Optionally, the electrolyte is an aqueous solution of the acid.

[0049] Optionally, the concentration of the acid in the raw electrolyte is 0.1 mol / L to 2 mol / L, and may be 0.1 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, or 2 mol / L.

[0050] Optionally, after electrically connecting the anode and the cathode, the current density is controlled to be ≥3000A / m 2 For example, the current density is 3000A / m 2 ~6000A / m 2 . It can be 3000A / m 2 、3500A / m 2 、4000A / m 2 、4500A / m 2 、5000A / m 2 、6000A / m 2 .

[0051] Optionally, after the anode and the cathode are electrically connected, the temperature of the raw electrolyte is controlled to be 10°C to 50°C, and may be 10°C, 15°C, 20°C, 30°C, 40°C, or 50°C.

[0052] The above-mentioned method for preparing succinic acid by paired electrolysis not only has a high yield of succinic acid and high current efficiency, but also can generate hydrogen and oxygen as by-products, making the process safer and the industrialization prospect brighter.

[0053] The second aspect of the present application provides a device for preparing succinic acid, and its technical solution is as follows:

[0054] A device for preparing succinic acid, see Figure 1 , including an anode 10, a cathode 20 and an electrolytic cell 30, wherein the electrolytic cell 30 is used to contain a raw electrolyte, one end of the anode 10 and the cathode 20 is placed in the electrolytic cell to contact the raw electrolyte, and the other end is used to connect the two poles of a power source.

[0055] The raw electrolyte includes electrolyte and furfural, the anode includes a first titanium substrate and a lead-manganese-platinum composite oxide loaded on the first titanium substrate, and the cathode includes a second titanium substrate and a lead-manganese-platinum composite loaded on the second titanium substrate.

[0056] During electrolysis, furfural is oxidized to maleic acid at the anode 10, and maleic acid is reduced to succinic acid at the cathode 20, thereby preparing succinic acid. The above-mentioned succinic acid preparation device can prepare succinic acid with high yield and high current efficiency through paired electrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application and to more completely understand the present application and its beneficial effects, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0058] Figure 1 This is a schematic diagram of the structure of a device for preparing succinic acid. DETAILED DESCRIPTION

[0059] The present application will be further described in detail below in conjunction with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0061] the term

[0062] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0063] In the present application, "plurality", "multiple", "multiple times", "plurality", etc., unless otherwise specified, refer to a number greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0064] In this application, "optionally", "optional" and "optional" refer to optional, that is, to any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0065] In this application, in the "first aspect", "second aspect", "third aspect", "fourth aspect", etc., the terms "first", "second", "third", "fourth", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0066] In the present application, when referring to a numerical interval (i.e., a numerical range), unless otherwise specified, the optional numerical distribution within the above numerical interval is deemed to be continuous and includes the two numerical endpoints of the numerical range (i.e., the minimum value and the maximum value), and every numerical value between the two numerical endpoints.

[0067] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0068] The following is further described in conjunction with specific examples and comparative examples. The raw materials involved in the following specific examples and comparative examples, unless otherwise specified, can all be commercially available, for example, purchased from Aladdin Reagent Company, with a purity of >98.0wt%. The instruments used, unless otherwise specified, can all be commercially available, and the processes involved, unless otherwise specified, are all routinely selected by those skilled in the art.

[0069] Example 1

[0070] This embodiment provides a method and device for preparing succinic acid, and the steps are as follows:

[0071] Step 1: Preparation of PbMnPtOx / Ti anode

[0072] 1) Cut the titanium plate into 2cm×2cm size and boil it in 15wt% oxalic acid aqueous solution for 2h. After taking it out, polish it with 150 mesh, 300 mesh, 600 mesh and metallographic sandpaper to remove the surface oxide layer. Finally, ultrasonically treat it in acetone, ethanol, and pure water for 30min to remove the surface oil and obtain the pretreated titanium plate.

[0073] 2) Dissolve 8 g of lead nitrate, 4 g of manganese nitrate, and 0.8 g of chloroplatinic acid in 27.2 g of water and stir thoroughly to obtain a precursor aqueous solution.

[0074] 3) Transfer the precursor aqueous solution to a 50mL polytetrafluoroethylene liner, then vertically place the pretreated titanium plate, and then place the polytetrafluoroethylene liner in a stainless steel high-pressure reactor. Hydrothermal reaction was performed at 160°C for 6 hours. After the reaction was completed, rinsed with ethanol and dried with nitrogen to obtain a titanium composite intermediate.

[0075] 4) Place the titanium composite intermediate in a tubular furnace, heat the temperature to 600°C at a rate of 3°C / min in an air atmosphere, keep the temperature for 3 hours, cool naturally, load lead, manganese, and platinum composite oxides on the pretreated titanium plate, and obtain a PbMnPtOx / Ti anode.

[0076] Step 2: Preparation of PbMnPt / Ti cathode

[0077] The titanium composite intermediate obtained in step 1 (3) is placed in a tubular furnace, heated to 600°C at a rate of 3°C / min in a mixed atmosphere of hydrogen and nitrogen, and kept warm for 3 hours, cooled naturally, and a lead-manganese-platinum composite is loaded on a pretreated titanium plate to obtain a PbMnPt / Ti cathode.

[0078] Step 3: Assemble the electrolysis device

[0079] 1) Mix furfural and aqueous sulfuric acid solution to obtain a raw electrolyte, wherein the mass percentage of furfural in the raw electrolyte is 10%, and the concentration of sulfuric acid in the raw electrolyte is 1 mol / L, and pass the raw electrolyte into an electrolytic cell.

[0080] 2) Insert one end of the PbMnPtOx / Ti anode and PbMnPt / Ti cathode into the electrolytic cell to contact with the raw electrolyte, and connect the other end to the positive and negative electrodes of the power supply respectively.

[0081] Step 4: Electrolysis

[0082] Turn on the power supply, connect the PbMnPtOx / Ti anode and PbMnPt / Ti cathode, and 2 The electrolysis was carried out at a current density of 1.50 Å and the temperature of the raw electrolyte was maintained at 40° C. During electrolysis, an oxidation reaction occurred at the anode to oxidize furfural to maleic acid, and a reduction reaction occurred at the cathode to reduce maleic acid to succinic acid.

[0083] During the electrolysis process, samples were taken every 2 h to calculate the yield and current efficiency of succinic acid. The yield and current efficiency for 8 h were recorded and summarized in Table 1.

[0084] Example 2

[0085] This embodiment provides a method and device for preparing succinic acid, and the steps are as follows:

[0086] Step 1: Preparation of PbMnPtOx / Ti anode

[0087] 1) Same as Example 1.

[0088] 2) Dissolve 7.2 g of lead acetate, 4 g of manganese sulfate, and 0.4 g of chloroplatinic acid in 28.4 g of water and stir thoroughly to obtain a precursor aqueous solution.

[0089] 3) Transfer the precursor aqueous solution to a 50mL polytetrafluoroethylene liner, then vertically place the pretreated titanium plate, and then place the polytetrafluoroethylene liner in a stainless steel high-pressure reactor. Hydrothermal reaction was performed at 180°C for 4 hours. After the reaction was completed, rinsed with ethanol and dried with nitrogen to obtain a titanium composite intermediate.

[0090] 4) Place the titanium composite intermediate in a tubular furnace, heat the temperature to 700°C at a rate of 2.5°C / min in an air atmosphere, keep the temperature for 3 hours, cool naturally, load lead, manganese, and platinum composite oxide on the pretreated titanium plate, and obtain a PbMnPtOx / Ti anode.

[0091] Step 2: Preparation of PbMnPt / Ti cathode

[0092] The titanium composite intermediate obtained in step 1 (3) is placed in a tubular furnace, heated to 700°C at a rate of 2.5°C / min in a mixed atmosphere of hydrogen and nitrogen, and kept warm for 3 hours, then cooled naturally, and a lead-manganese-platinum composite is loaded on a pretreated titanium plate to obtain a PbMnPt / Ti cathode.

[0093] Step 3: Assemble the electrolysis device

[0094] 1) Mix furfural and aqueous sulfuric acid solution to obtain a raw electrolyte, wherein the mass percentage of furfural in the raw electrolyte is 15%, and the concentration of sulfuric acid in the raw electrolyte is 1 mol / L, and pass the raw electrolyte into an electrolytic cell.

[0095] 2) Same as Example 1.

[0096] Step 4: Electrolysis

[0097] Turn on the power supply, connect the PbMnPtOx / Ti anode and PbMnPt / Ti cathode, and 2The electrolysis was carried out at a current density of 1.50 Å and the temperature of the raw electrolyte was maintained at 30° C. During electrolysis, an oxidation reaction occurred at the anode to oxidize furfural to maleic acid, and a reduction reaction occurred at the cathode to reduce maleic acid to succinic acid.

[0098] During the electrolysis process, samples were taken every 2 h to calculate the yield and current efficiency of succinic acid. The yield and current efficiency for 8 h were recorded and summarized in Table 1.

[0099] Example 3

[0100] This embodiment provides a method and device for preparing succinic acid, and the steps are as follows:

[0101] Step 1: Preparation of PbMnPtOx / Ti anode

[0102] 1) Same as Example 1.

[0103] 2) Dissolve 4 g of lead acetate, 3.6 g of manganese chloride, and 0.4 g of platinum chloride in 32 g of water and stir thoroughly to obtain a precursor aqueous solution.

[0104] 3) Transfer the precursor aqueous solution to a 50mL polytetrafluoroethylene liner, then vertically place the pretreated titanium plate, and then place the polytetrafluoroethylene liner in a stainless steel high-pressure reactor. Hydrothermal reaction was performed at 190°C for 4 hours. After the reaction was completed, rinsed with ethanol and dried with nitrogen to obtain a titanium composite intermediate.

[0105] 4) Place the titanium composite intermediate in a tubular furnace, heat the temperature to 800°C at a rate of 2.5°C / min in an air atmosphere, keep the temperature for 2 hours, cool naturally, load lead, manganese, and platinum composite oxide on the pretreated titanium plate, and obtain a PbMnPtOx / Ti anode.

[0106] Step 2: Preparation of PbMnPt / Ti cathode

[0107] The titanium composite intermediate obtained in step 1 (3) is placed in a tubular furnace, heated to 800°C at a rate of 2.5°C / min in a mixed atmosphere of hydrogen and nitrogen, and kept warm for 2 hours, then cooled naturally, and a lead-manganese-platinum composite is loaded on a pretreated titanium plate to obtain a PbMnPt / Ti cathode.

[0108] Step 3: Assemble the electrolysis device

[0109] Same as Example 1.

[0110] Step 4: Electrolysis

[0111] Turn on the power supply, connect the PbMnPtOx / Ti anode and PbMnPt / Ti cathode, and 2The electrolysis was carried out at a current density of 1.50 Å and the temperature of the raw electrolyte was maintained at 30° C. During electrolysis, an oxidation reaction occurred at the anode to oxidize furfural to maleic acid, and a reduction reaction occurred at the cathode to reduce maleic acid to succinic acid.

[0112] Comparative Example 1

[0113] This comparative example provides a method and device for preparing succinic acid, which are basically the same as those of Example 1, with the main difference being that the anode is the pretreated titanium plate obtained in step 1).

[0114] Comparative Example 2

[0115] This comparative example provides a method and device for preparing succinic acid, which are basically the same as those of Example 1, with the main difference being that the cathode is the pretreated titanium plate obtained in step 1).

[0116] Comparative Example 3

[0117] This comparative example provides a method and device for preparing succinic acid, which are basically the same as those in Example 1, except that the preparation methods of the anode and cathode are different, specifically:

[0118] Step 1: Preparation of PbOx / Ti anode

[0119] 1) Same as Example 1.

[0120] 2) Dissolve 8 g of lead acetate in 32 g of water and stir thoroughly to obtain a precursor aqueous solution.

[0121] 3) Transfer the precursor aqueous solution to a 50mL polytetrafluoroethylene liner, then vertically place the pretreated titanium plate, and then place the polytetrafluoroethylene liner in a stainless steel high-pressure reactor. Hydrothermal reaction was performed at 160°C for 6 hours. After the reaction was completed, rinsed with ethanol and dried with nitrogen to obtain a titanium composite intermediate.

[0122] 4) Place the titanium composite intermediate in a tube furnace, heat the temperature to 600°C at a rate of 3°C / min in an air atmosphere, keep the temperature for 3 hours, cool naturally, load lead oxide on the pretreated titanium plate, and obtain a PbOx / Ti anode.

[0123] Step 2: Preparation of Pb / Ti cathode

[0124] The titanium composite intermediate obtained in step 1 (3) is placed in a tubular furnace, heated to 600°C at a rate of 3°C / min in a mixed atmosphere of hydrogen and nitrogen, and kept warm for 3 hours, cooled naturally, and lead is loaded on the pretreated titanium plate to obtain a Pb / Ti cathode.

[0125] Table 1

[0126]

[0127] It can be seen from the above that in each embodiment, using PbMnPtOx / Ti as the anode, PbMnPt / Ti as the cathode, and furfural as the raw material, the yield of succinic acid generated by the paired electrolysis method is ≥95%, and the current efficiency is ≥90, which has a high succinic acid yield and current efficiency.

[0128] In Comparative Example 1, relative to the use of PbMnPtOx / Ti, the use of titanium plate as the anode and the use of PbMnPt / Ti cathode affects the yield and current efficiency of succinic acid. In Comparative Example 2, relative to the use of PbMnPt / Ti, the use of titanium plate as the cathode and the use of PbMnPtOx / Ti anode also affects the yield and current efficiency of succinic acid. In Comparative Example 3, with PbOx / Ti as the anode and Pb / Ti as the cathode, the yield and current efficiency of succinic acid are both poor, indicating that PbMnPtOx / Ti and PbMnPt / Ti as electrodes have obvious advantages in generating succinic acid by paired electrolysis using furfural as raw material.

[0129] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0130] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A method for preparing succinic acid, characterized in that: The following steps are involved: mixing the electrolyte and furfural to obtain a raw electrolyte; The raw electrolyte, anode and cathode are assembled into an electrolysis device, the anode and the cathode are electrically connected, an oxidation reaction occurs at the anode to oxidize the furfural into maleic acid, and a reduction reaction occurs at the cathode to reduce the maleic acid into succinic acid, wherein the anode includes a first titanium substrate and a lead-manganese-platinum composite oxide supported on the first titanium substrate, and the cathode includes a second titanium substrate and a lead-manganese-platinum composite supported on the second titanium substrate.

2. The method for preparing succinic acid according to claim 1, characterized in that: The method for preparing the anode comprises the following steps: Immersing the first titanium substrate in a precursor aqueous solution for hydrothermal reaction to obtain a first titanium composite intermediate, wherein the precursor aqueous solution includes a lead salt, a manganese salt, and a platinum salt; The first titanium composite intermediate product is calcined in an atmosphere containing oxygen.

3. The method for preparing succinic acid according to claim 2, characterized in that: Includes at least one of the following features: (1) The lead salt includes one or more of lead acetate and lead nitrate; (2) The manganese salt includes one or more of manganese sulfate, manganese nitrate, manganese chloride and manganese acetate; (3) The platinum salt includes one or more of chloroplatinic acid and platinum chloride; (4) The mass percentage of the lead salt in the precursor aqueous solution is 10% to 25%, preferably 15% to 25%; (5) The mass percentage of the manganese salt in the precursor aqueous solution is 9% to 12%, preferably 10% to 12%; (6) The mass percentage of the platinum salt in the precursor aqueous solution is 1% to 3%, preferably 2% to 3%; (7) The temperature of the hydrothermal reaction is 100°C to 200°C; (8) The hydrothermal reaction time is 4h~8h; (9) The heating rate of the calcination is 1°C / min to 5°C / min; (10) The calcination holding temperature is 500°C to 800°C; (11) The calcination holding time is 1h~4h.

4. The method for preparing succinic acid according to claim 1, characterized in that: The preparation method of the cathode comprises the following steps: Immersing the second titanium substrate in a precursor aqueous solution for hydrothermal reaction to obtain a second titanium composite intermediate, wherein the precursor aqueous solution includes a lead salt, a manganese salt, and a platinum salt; The second titanium composite intermediate product is calcined in an atmosphere isolated from oxygen.

5. The method for preparing succinic acid according to claim 4, characterized in that: Includes at least one of the following features: (1) The lead salt includes one or more of lead acetate and lead nitrate; (2) The manganese salt includes one or more of manganese sulfate, manganese nitrate, manganese chloride and manganese acetate; (3) The platinum salt includes one or more of chloroplatinic acid and platinum chloride; (4) The mass percentage of the lead salt in the precursor aqueous solution is 10% to 25%, preferably 15% to 25%; (5) The mass percentage of the manganese salt in the precursor aqueous solution is 9% to 12%, preferably 10% to 12%; (6) The mass percentage of the platinum salt in the precursor aqueous solution is 1% to 3%, preferably 2% to 3%; (7) The temperature of the hydrothermal reaction is 100°C to 200°C; (8) The hydrothermal reaction time is 4h~8h; (9) The heating rate of the calcination is 1°C / min to 5°C / min; (10) The calcination holding temperature is 500°C to 800°C; (11) The calcination holding time is 1h~4h; (12) The oxygen-isolating atmosphere includes a mixed atmosphere of hydrogen and nitrogen.

6. The method for preparing succinic acid according to any one of claims 1 to 5, characterized in that: The mass percentage of furfural in the raw electrolyte is 1% to 20%.

7. The method for preparing succinic acid according to any one of claims 1 to 5, characterized in that: The electrolyte includes an acid, and the acid includes one or more of hydrochloric acid, nitric acid, sulfuric acid and acetic acid.

8. The method for preparing succinic acid according to claim 7, characterized in that: The concentration of the acid in the raw electrolyte is 0.1 mol / L to 2 mol / L.

9. The method for preparing succinic acid according to any one of claims 1 to 5 and 8, characterized in that: Includes at least one of the following features: (1) After electrically connecting the anode and the cathode, control the current density to be ≥3000A / m 2 ; (2) After electrically connecting the anode and the cathode, the temperature of the raw electrolyte is controlled to be 10° C. to 50° C.

10. A device for preparing succinic acid, characterized in that: It comprises an anode, a cathode and an electrolytic cell, wherein the electrolytic cell is used to contain a raw electrolyte, one end of the anode and the cathode are placed in the electrolytic cell for contacting the raw electrolyte, and the other end is used for mutual electrical connection; wherein the raw electrolyte comprises an electrolyte and furfural, the anode comprises a first titanium substrate and a lead-manganese-platinum composite oxide loaded on the first titanium substrate, and the cathode comprises a second titanium substrate and a lead-manganese-platinum composite loaded on the second titanium substrate.

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