A supported NiM-OOH electrocatalytic material on nickel foam and a preparation method and application thereof

Abstract

The application belongs to the technical field of electrocatalytic materials, and provides a NiM-OOH electrocatalytic material loaded on foamed nickel, a preparation method and application thereof, and the preparation method comprises the following steps: treating the cut foamed nickel with nitric acid, ethanol and deionized water in sequence; dissolving nickel chloride hexahydrate, M chloride and diammonium hydrogen phosphate in deionized water, then adding the treated foamed nickel, heating and reacting, cooling to room temperature after the reaction is completed, collecting the product, washing with ethanol and deionized water, and drying again; activating the dried product in a potassium hydroxide solution to obtain the NiM-OOH electrocatalytic material loaded on foamed nickel. The NiM-OOH electrocatalytic material loaded on foamed nickel is synthesized by heating using simple and readily available raw materials, the preparation method is simple, easy to obtain and repeat, the cost is easy to control in industrial production, and the material is suitable for large-scale production, stable in quality, and can make the polylactic acid waste produce high-value-added products, such as potassium acetate and hydrogen.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic materials technology, and particularly relates to a NiM-OOH electrocatalytic material supported on nickel foam, its preparation method, and its application. Background Technology

[0002] Polylactic acid (PLA) is a representative renewable polymer material that plays a crucial role in the chemical industry. However, the post-treatment of PLA waste is receiving increasing attention. Current treatment methods include natural decomposition, composting, and incineration, but these generate large amounts of carbon dioxide, resulting in carbon emissions and resource waste. Therefore, how to treat PLA waste while producing high-value-added products is of great significance for environmental protection and resource utilization.

[0003] Electrocatalytic oxidation of small molecules is a promising method for treating polylactic acid (PLA) waste. However, research on the electrooxidation of potassium lactate is still in its early stages. The insufficient selectivity of the target product and the strongly alkaline environment of the reaction make product separation and purification challenging, thus limiting the production of high-purity target products and preventing these reactions from being scaled up industrially. Furthermore, subsequent processing must not only ensure the high purity of the final product, potassium acetate, but also minimize the economic costs of the process, posing a significant challenge to implementing this process on an industrial scale. Summary of the Invention

[0004] The purpose of this invention is to provide a NiM-OOH electrocatalytic material supported on nickel foam, aiming to solve the problems mentioned in the background art.

[0005] The present invention is implemented as follows: a NiM-OOH electrocatalytic material supported on nickel foam, wherein M is one of Co, Mn, Fe, Zn, and Cr.

[0006] Another objective of this invention is to provide a method for preparing NiM-OOH electrocatalytic material supported on nickel foam, comprising the following steps:

[0007] The cut nickel foam was treated sequentially with nitric acid, ethanol, and deionized water.

[0008] Nickel chloride hexahydrate, M chloride, and diammonium hydrogen phosphate were dissolved in deionized water, wherein M is one of Co, Mn, Fe, Zn, and Cr. Then, the treated nickel foam was added, and the mixture was heated to carry out the reaction. After the reaction was completed, the mixture was cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried.

[0009] The dried product was activated in potassium hydroxide solution to obtain NiM-OOH electrocatalytic material supported on nickel foam.

[0010] Preferably, in the step of treating the cut nickel foam sequentially with nitric acid, ethanol and deionized water, the concentration of the nitric acid is 1-1.2 mol / L, and the treatment is ultrasonic treatment for 10-15 min.

[0011] Preferably, in the step of heating the reaction, an oil bath heating method is used, with a temperature of 65-75 ℃ and a time of 2.5-3.5 h.

[0012] Preferably, in the step of activating the dried product in a potassium hydroxide solution, the concentration of the potassium hydroxide solution is 1-1.2 mol / L.

[0013] Another objective of this invention is to provide an application of NiM-OOH electrocatalytic material supported on nickel foam in the electrooxidation of potassium lactate to prepare potassium acetate.

[0014] Preferably, the electro-oxidation of potassium lactate to prepare potassium acetate is carried out in an H-type electrolytic cell, with the NiM-OOH electrocatalytic material supported on the nickel foam as the working electrode, a platinum sheet as the counter electrode, a mercury / mercury oxide electrode as the reference electrode, potassium hydroxide and potassium lactate as the anolyte, and potassium hydroxide as the cathode electrolyte, driving the potassium lactate to undergo an electro-oxidation reaction under energized conditions.

[0015] Preferably, the potential applied during energization is 1.2-1.6 V compared to the standard hydrogen electrode.

[0016] Another objective of this invention is to provide an electrosynthetic system for converting polylactic acid waste into potassium acetate, comprising:

[0017] An alkali treatment device is used to treat polylactic acid waste to obtain potassium lactate solution;

[0018] An electrolysis device is connected to an alkali treatment device. The electrolysis device is equipped with NiM-OOH electrocatalytic material loaded on the nickel foam. Potassium lactate solution is used as the electrolyte to oxidize potassium lactate solution to potassium acetate at the anode and generate hydrogen gas at the cathode.

[0019] An acid treatment device and a drying device are connected to the electrolysis device to adjust the pH of the electrolyte and then dry the electrolyte to obtain solid potassium acetate.

[0020] Another objective of this invention is to provide an electrosynthesis method for an electrosynthesis system that converts polylactic acid waste into potassium acetate, comprising the following steps:

[0021] Polylactic acid waste is added to the reaction tank of an alkali treatment device and treated with potassium hydroxide solution to obtain potassium lactate solution;

[0022] Potassium lactate solution was passed into an electrolysis device as the electrolyte. Under the catalytic action of NiM-OOH electrocatalytic material loaded on nickel foam, it was oxidized to potassium acetate at the anode and hydrogen gas was generated at the cathode.

[0023] The electrolyte is adjusted to a certain pH using an acid treatment device, and then dried using a drying device to obtain solid potassium acetate.

[0024] The present invention uses readily available raw materials to synthesize nickel foam loaded with NiM-OOH by heating. The preparation method is simple, the required equipment and raw materials are abundant and inexpensive, easy to obtain and easy to repeat, and the cost is easy to control in industrial production. It is suitable for large-scale production and the material quality is stable.

[0025] The NiM-OOH loaded on the nickel foam prepared in this embodiment of the invention can be used as a working electrode to drive the electro-oxidation reaction of potassium lactate to generate potassium acetate under energized conditions. Furthermore, it can be applied in an industrial-grade electrosynthesis system, which can generate high-value-added products potassium acetate and hydrogen from polylactic acid waste. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an electrosynthesis system for converting polylactic acid waste into potassium acetate, provided in an embodiment of the present invention.

[0027] Figure 2 This is a comparison of the linear sweep voltammetry curves of the samples prepared in Example 1 and Comparative Example 1 of this invention in a mixed electrolyte of potassium hydroxide and potassium lactate.

[0028] Figure 3 This is a physical image of an industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product from polylactic acid waste, as provided in Embodiment 6 of the present invention.

[0029] Figure 4 This is a physical diagram of the electrolysis apparatus provided in Embodiment 6 of the present invention;

[0030] Figure 5 This is a graph showing the changes in the concentrations of potassium lactate, potassium acetate, and potassium pyruvate over time during the reaction period, as provided in Example 6 of the present invention. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] A NiM-OOH electrocatalytic material supported on nickel foam is prepared by the following steps:

[0033] S1. Cut the nickel foam NF into pieces of 25-100 cm. 2 To meet the specifications, the cut nickel foam was ultrasonicated in 1 mol / L nitric acid for 10 min, in ethanol for 10 min, and in deionized water for 10 min in sequence.

[0034] S2. Dissolve nickel chloride hexahydrate, M chloride, and diammonium hydrogen phosphate in deionized water. The range is: nickel chloride hexahydrate (7.92-31.68 g), M chloride (M is one of Co, Mn, Fe, Zn, or Cr) (1.14-8.88 g), diammonium hydrogen phosphate (6.58-26.33 g), and water (0.5-2 L). Add the treated nickel foam to the beaker solution and heat. After the reaction is complete and cooled to room temperature, collect the product, wash it with ethanol and deionized water, and then dry it.

[0035] S3. The product was activated in a 1 mol / L potassium hydroxide solution to obtain NiM-OOH electrocatalytic material supported on nickel foam;

[0036] The application of the above-mentioned electrocatalytic material in the electrocatalytic oxidation of potassium lactate specifically includes the following steps: setting up an H-type electrolytic cell as the electrochemical reaction cell, adopting a three-electrode system, using NiM-OOH electrocatalytic material loaded on nickel foam as the working electrode, a mercury-mercury oxide electrode as the reference electrode, a platinum sheet as the counter electrode, and 1 mol / L potassium hydroxide solution and 0.4 mol / L potassium lactate solution as the electrolyte. The potential applied when energized is 1.2-1.6 V compared to the standard hydrogen electrode.

[0037] An electrosynthetic system for converting polylactic acid waste into potassium acetate, such as... Figure 1 As shown, it includes the following structure:

[0038] Alkali treatment unit, including a reaction tank; electrolysis unit, including an alkali water electrolysis tank, a gas-liquid separator, and a heating and temperature control system; acid treatment unit, including a reaction tank; and drying unit, employing a spray dryer.

[0039] The specific steps are as follows:

[0040] In an industrial-grade electrosynthesis system, polylactic acid waste is added to the reaction tank of an alkali treatment device, treated with potassium hydroxide solution to obtain potassium lactate solution, and then passed into an electrolysis device. Under the action of NiM-OOH electrocatalytic material loaded on nickel foam, it is oxidized to potassium acetate at the anode and hydrogen is generated at the cathode. The acidity and alkalinity are then adjusted by an acid treatment device, and the solid potassium acetate is obtained by spray drying.

[0041] The electrolysis unit, an industrial-scale electrolytic cell, is the core component of this industrial-grade electrosynthesis system. It comprises 18 independent electrolytic cells with a total electrolyte volume of 10 L. Furthermore, the working areas for both the anode and cathode are 1386 cm². 2 The anode was NiM-OOH electrocatalytic material supported on nickel foam, and the cathode was commercially available nickel wire mesh.

[0042] During the system's circulation process (current density 2000 A / m) 2 320 g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 h to obtain 232 L of hydrogen gas. The pH of the electrolyte was then adjusted with acetic acid, and finally spray-dried to obtain 1200 g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 97%. In this process, the system processes 500 L of potassium lactate solution to generate 11.6 standard mg / L of potassium acetate. 3 The hydrogen produced reaches an industrial-scale production rate. Furthermore, the electrocatalytic material exhibits extremely high stability at 2000 A / m³. 2 Maintain for more than 50 cycles (100 h).

[0043] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0044] Example 1: A NiM-OOH (M=Co) electrocatalytic material supported on nickel foam, the specific preparation method of which is as follows:

[0045] Cut the 78.5 cm 2 The circular nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. The raw materials selected were analytical grade nickel chloride hexahydrate (24.87 g), cobalt chloride hexahydrate (6.21 g), and diammonium hydrogen phosphate (20.67 g), dissolved in deionized water (1.57 L). The treated nickel foam was added to the solution and heated in an oil bath at 70 °C for 3 h. After the reaction was completed and cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried to obtain the final product. The product was activated in a 1 mol / L potassium hydroxide solution to obtain a NiM-OOH (M=Co) electrocatalyst supported on the nickel foam.

[0046] Example 2: A NiM-OOH (M=Mn) electrocatalytic material supported on nickel foam, the specific preparation method of which is as follows:

[0047] Cut the 78.5 cm 2Circular nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. The raw materials were selected from analytical grade nickel chloride hexahydrate (24.87 g), manganese chloride tetrahydrate (5.17 g), and diammonium hydrogen phosphate (20.67 g), dissolved in deionized water (1.57 L). The treated nickel foam was added to the solution and heated in an oil bath at 70 °C for 3 h. After the reaction was completed and cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried to obtain the final product. The product was activated in a 1 mol / L potassium hydroxide solution to obtain a NiM-OOH (M=Mn) electrocatalytic material supported on the nickel foam.

[0048] Example 3: A NiM-OOH (M=Fe) electrocatalytic material supported on nickel foam, the specific preparation method of which is as follows:

[0049] Cut the 78.5 cm 2 The circular nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. The raw materials were selected from analytical grade nickel chloride hexahydrate (24.87 g), ferrous chloride tetrahydrate (5.21 g), and diammonium hydrogen phosphate (20.67 g), dissolved in deionized water (1.57 L). The treated nickel foam was added to the solution and heated in an oil bath at 70 °C for 3 h. After the reaction was completed and cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried to obtain the final product. The product was activated in a 1 mol / L potassium hydroxide solution to obtain a NiM-OOH (M=Fe) electrocatalyst supported on the nickel foam.

[0050] Example 4: A NiM-OOH (M=Zn) electrocatalytic material supported on nickel foam, the specific preparation method of which is as follows:

[0051] Cut the 78.5 cm 2 The circular nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. The raw materials selected were analytical grade nickel chloride hexahydrate (24.87 g), anhydrous zinc chloride (3.57 g), and diammonium hydrogen phosphate (20.67 g), dissolved in deionized water (1.57 L). The treated nickel foam was added to the solution and heated in an oil bath at 70 °C for 3 h. After the reaction was completed and cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried to obtain the final product. The product was activated in a 1 mol / L potassium hydroxide solution to obtain a NiM-OOH (M=Zn) electrocatalytic material supported on the nickel foam.

[0052] Example 5: A NiM-OOH (M=Cr) electrocatalytic material supported on nickel foam, the specific preparation method of which is as follows:

[0053] Cut the 78.5 cm 2 The circular nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. The raw materials were selected as analytical grade nickel chloride hexahydrate (24.87 g), chromium chloride hexahydrate (6.97 g), and diammonium hydrogen phosphate (20.67 g), dissolved in deionized water (1.57 L). The treated nickel foam was added to the solution and heated in an oil bath at 70 °C for 3 h. After the reaction was completed and cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried to obtain the final product. The product was activated in a 1 mol / L potassium hydroxide solution to obtain a NiM-OOH (M=Cr) electrocatalytic material supported on the nickel foam.

[0054] Comparative Example 1: A Ni-OOH electrocatalytic material supported on nickel foam, the specific preparation method of which is as follows:

[0055] Cut the 78.5 cm 2 The circular nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. The raw materials were analytical grade nickel chloride hexahydrate (31.10 g) and diammonium hydrogen phosphate (20.67 g), dissolved in deionized water (1.57 L). The treated nickel foam was added to the solution and heated in an oil bath at 70 °C for 3 h. After the reaction was completed and cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried to obtain the final product. The product was activated in a 1 mol / L potassium hydroxide solution to obtain a Ni-OOH electrocatalytic material supported on the nickel foam.

[0056] Performance testing:

[0057] The samples prepared in Example 1 and Comparative Example 1 were cut to suitable specifications and used as electrocatalytic materials to test their performance in the electro-oxidation of potassium lactate to high-value potassium acetate. An H-type electrolytic cell was set up as the electrochemical reaction cell, employing a three-electrode system, with the anode and cathode chambers separated by anion exchange membranes. Two samples were used as working electrodes, with a platinum sheet as the counter electrode and a mercury / mercury oxide electrode as the reference electrode. Testing with an electrochemical workstation showed that the applied potential during energization was 1.2-1.6 V compared to the standard hydrogen electrode, yielding the following results: Figure 2 The linear sweep voltammetry curve shown indicates that the NiM-OOH electrocatalyst material supported on nickel foam prepared in this embodiment of the invention reaches 403 mA / cm² in 1 mol / L potassium hydroxide and 0.4 mol / L potassium lactate solutions. 2 The current density required is only 1.4 V (relative to the standard hydrogen electrode).

[0058] Example 6: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, such as... Figure 3As shown, the specific process is as follows:

[0059] Polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then electrolyzed in an electrolytic device (such as...). Figure 4 The anodic oxidation (as shown) produces potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0060] During the system's circulation process (current density 2000 A / m) 2 320 g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 h to obtain 232 L of hydrogen gas. The pH of the electrolyte was then adjusted with acetic acid, and finally, the electrolyte was spray-dried to obtain 1200 g of pure solid potassium acetate. Testing showed that the purity of the obtained potassium acetate product exceeded 97%. The changes in the concentrations of potassium lactate, potassium acetate, and potassium pyruvate over time during the reaction cycle are shown in the graph below. Figure 5 As shown.

[0061] Example 7: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, the specific process of which is as follows:

[0062] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0063] During the system's circulation process (current density 200 A / m) 2 32g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 hours to obtain 22 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 117g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 96%.

[0064] Example 8: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, the specific process of which is as follows:

[0065] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0066] During the system's circulation process (current density 500 A / m) 2 80g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 hours to obtain 55 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 295g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 96%.

[0067] Example 9: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, the specific process of which is as follows:

[0068] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0069] During the system's circulation process (current density 1000 A / m) 2 160g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 hours to obtain 115 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 602 g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 97%.

[0070] Example 10: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste. The specific process is as follows:

[0071] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0072] During the system's circulation process (current density 3000 A / m) 2 480g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 hours to obtain 350 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 1790g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 97%.

[0073] Example 11: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, the specific process of which is as follows:

[0074] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0075] During the system's circulation process (current density 4000 A / m) 2 640 g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 h to obtain 469 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 2430 g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 96%.

[0076] Example 12: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, the specific process of which is as follows:

[0077] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0078] During the system's circulation process (current density 5000 A / m) 2 800 g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 h to obtain 575 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 2990 g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 99%.

[0079] Example 13: An industrial-grade electrosynthesis system for producing potassium acetate, a high-value-added product, from polylactic acid waste, the specific process of which is as follows:

[0080] In an industrial-grade electrosynthesis system, polylactic acid is first treated with potassium hydroxide solution to obtain potassium lactate solution, and then anolyzed to potassium acetate, while hydrogen gas is generated at the cathode; after acid treatment and drying, pure solid potassium acetate is obtained.

[0081] During the system's circulation process (current density 6000 A / m) 2 960g of polylactic acid waste was treated with potassium hydroxide solution and electrolyzed for 2 hours to obtain 704 L of hydrogen gas. Then, the pH of the electrolyte was adjusted with acetic acid. Finally, the electrolyte was spray-dried to obtain 3615 g of pure solid potassium acetate. The purity of the obtained potassium acetate product exceeded 98%.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. The application of a NiM-OOH electrocatalytic material supported on nickel foam in the electrooxidation of potassium lactate to potassium acetate, characterized in that, M is one of Co, Mn, Fe, Zn, and Cr; the preparation method of the NiM-OOH electrocatalytic material supported on nickel foam includes the following steps: The cut nickel foam was treated sequentially with nitric acid, ethanol, and deionized water. Nickel chloride hexahydrate, M chloride, and diammonium hydrogen phosphate were dissolved in deionized water, wherein M is one of Co, Mn, Fe, Zn, and Cr. Then, the treated nickel foam was added, and the mixture was heated to carry out the reaction. After the reaction was completed, the mixture was cooled to room temperature, the product was collected, washed with ethanol and deionized water, and then dried. The dried product was activated in potassium hydroxide solution to obtain NiM-OOH electrocatalytic material supported on nickel foam.

2. The application according to claim 1, characterized in that, In the step of treating the cut nickel foam sequentially with nitric acid, ethanol and deionized water, the concentration of the nitric acid is 1-1.2 mol / L, and the treatment is ultrasonic treatment for 10-15 min.

3. The application according to claim 1, characterized in that, In the heating reaction step, an oil bath heating method is used, with a temperature of 65-75 ℃ and a time of 2.5-3.5 h.

4. The application according to claim 1, characterized in that, In the step of activating the dried product in a potassium hydroxide solution, the concentration of the potassium hydroxide solution is 1-1.2 mol / L.

5. The application according to claim 1, characterized in that, The electro-oxidation of potassium lactate to prepare potassium acetate is carried out in an H-type electrolytic cell. The NiM-OOH electrocatalytic material supported on the nickel foam is used as the working electrode, the platinum sheet is used as the counter electrode, the mercury / mercury oxide electrode is used as the reference electrode, the anolyte is potassium hydroxide and potassium lactate, and the catholyte is potassium hydroxide. Under the condition of energization, potassium lactate is driven to carry out the electro-oxidation reaction.

6. The application according to claim 5, characterized in that, The potential applied during energization is 1.2-1.6 V compared to the standard hydrogen electrode.

7. An electrosynthetic system for converting polylactic acid waste into potassium acetate, characterized in that, include: An alkali treatment device is used to treat polylactic acid waste to obtain potassium lactate solution; An electrolysis device is connected to an alkali treatment device. The electrolysis device is equipped with the NiM-OOH electrocatalytic material loaded on nickel foam as described in claim 1, and uses potassium lactate solution as the electrolyte to oxidize potassium lactate solution to potassium acetate at the anode and generate hydrogen gas at the cathode. An acid treatment device and a drying device are connected to the electrolysis device to adjust the pH of the electrolyte and then dry the electrolyte to obtain solid potassium acetate.

8. An electrosynthesis method for an electrosynthesis system for converting polylactic acid waste into potassium acetate as described in claim 7, characterized in that, The electrosynthesis method of the electrosynthesis system includes the following steps: Polylactic acid waste is added to the reaction tank of an alkali treatment device and treated with potassium hydroxide solution to obtain potassium lactate solution; Potassium lactate solution was passed into an electrolysis device as the electrolyte. Under the catalytic action of NiM-OOH electrocatalytic material loaded on nickel foam, it was oxidized to potassium acetate at the anode and hydrogen gas was generated at the cathode. The electrolyte is adjusted to a certain pH using an acid treatment device, and then dried using a drying device to obtain solid potassium acetate.

Images