Novel surface-reconstructed CoZn oxygen phosphate electrode and application thereof in efficiently converting polylactic acid hydrolysate into acetic acid

Abstract

The invention belongs to the technical field of electrocatalysis, biomass value-added utilization, polymer recycling and green chemistry, and particularly relates to a novel surface reconstruction CoZn oxygen phosphate electrode and application of the novel surface reconstruction CoZn oxygen phosphate electrode in efficient conversion of polylactic acid hydrolysate into acetic acid. A CoZn precursor oxide is prepared through a coprecipitation method, then the CoZnOP catalyst is obtained through phosphating treatment, the CoZnOP catalyst has a unique stacked three-dimensional nano-structure, the synergistic effect of Co and Zn and surface reconstruction induced by doping of the P element, the high specific surface area and rich active sites are provided, and the CoZnOP catalyst has a good application prospect in preparation of acetic acid through electrocatalytic oxidation of lactic acid. The selectivity, the yield, the energy consumption and the stability of the method are obviously superior to those of the prior art, and the method is an ideal technical scheme for realizing high-value utilization of the polylactic acid hydrolysate.

Description

Technical Field

[0001] This invention belongs to the fields of electrocatalysis, biomass valorization, polymer recycling, and green chemistry, specifically involving a novel surface-reconstructed CoZn oxyphosphate electrode and its application in the efficient conversion of polylactic acid hydrolysis products into acetic acid. Background Technology

[0002] Against the backdrop of increasingly severe global plastic pollution and energy challenges, the recycling of polylactic acid (PLA) has received widespread attention. PLA is a biodegradable and biocompatible polymer derived from renewable resources such as corn starch and sugarcane, and is considered a promising alternative to traditional petroleum-based plastics. The main hydrolysis product of PLA is lactic acid, a key platform chemical. Converting lactic acid into more valuable products, particularly acetic acid, is a crucial step in the biomass value-added utilization chain. Electrocatalytic oxidation, as an emerging technology, offers a sustainable and efficient method for the value-added utilization of biomass-derived feedstocks due to its operation under mild conditions (near room temperature and atmospheric pressure), its use of renewable electricity, and its tunable selectivity through precise potential control.

[0003] Existing technologies have significant limitations in converting lactic acid (a hydrolysis product of polylactic acid) into acetic acid, a high-value chemical. Specifically, traditional catalytic methods (such as thermal or chemical oxidation) often produce complex and diverse products when oxidizing lactic acid, such as mixtures of pyruvic acid, acetic acid, and propionic acid, making it difficult to achieve a single, highly selective conversion to the target product, acetic acid. A key challenge in the electrocatalytic oxidation of lactic acid lies in the need to break stable C-C bonds. This process typically requires a very high overpotential, demanding extremely high catalyst activity to overcome the high energy barrier and effectively reduce the reaction's onset potential. Currently, many non-precious metal catalysts lack long-term stability in harsh electrochemical reaction environments, easily undergoing structural changes or deactivation, thus failing to meet the stability and durability requirements of industrial applications.

[0004] Therefore, there is a need to develop an electrocatalyst and electrode that can convert lactic acid to acetic acid with high yield, high selectivity, and long-term stability. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a novel surface-reconstructed CoZn oxyphosphate electrode and its application in the efficient conversion of polylactic acid hydrolysis products to acetic acid. This invention first prepares a CoZn precursor oxide via co-precipitation, followed by phosphating to obtain a CoZnOP catalyst. This catalyst possesses a unique stacked three-dimensional nanostructure, and the synergistic effect of Co and Zn, along with surface reconstruction induced by P doping, provides a high specific surface area and abundant active sites. In the electrocatalytic oxidation of lactic acid to acetic acid, it effectively reduces the high energy barrier of C / C bond breaking and lowers the overpotential required for lactic acid oxidation, achieving long-term stable conversion of lactic acid to acetic acid. Its selectivity, yield, energy consumption, and stability are significantly superior to existing technologies, making it an ideal technical solution for the high-value utilization of polylactic acid hydrolysis products.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a method for preparing a surface-reconstructed CoZn oxyphosphate electrocatalyst, comprising the following steps: (1) Preparation of CoZn precursor oxide: The metal nitrate precursors Co(NO3)2·6H2O and Zn(NO3)2·6H2O were dissolved in deionized water with sodium citrate. After stirring, NaOH solution was added dropwise. The metal ions were precipitated by co-precipitation to form a precursor suspension. After centrifugation, washing, and vacuum drying, the precursors of Co and Zn oxides CoZnO were obtained. (2) Phosphating treatment and synthesis of CoZn oxyphosphate electrocatalyst: CoZn precursor oxide and reducing agent sodium hypophosphite are ground and mixed. The mixture is heated under an inert atmosphere to carry out solid phosphating reaction. After natural cooling to room temperature, it is washed and vacuum dried to obtain the target catalyst CoZnOP.

[0007] Further, in step (1), the molar ratio of Co(NO3)2·6H2O and Zn(NO3)2·6H2O is 1:1.

[0008] Further, in step (1), the stirring refers to magnetic stirring for 20 min.

[0009] Furthermore, in step (1), the concentration of the NaOH solution is 0.5 M.

[0010] Furthermore, in step (1), the washing refers to repeated washing with deionized water and ethanol.

[0011] Furthermore, in step (2), the temperature for heating is 300 °C, and the time for the solid phosphating reaction is 4 h.

[0012] A second aspect of the present invention provides a surface-reconstructed CoZn oxyphosphate electrocatalyst prepared by the above-described preparation method.

[0013] A third aspect of the present invention provides a surface-reconstructed CoZn oxyphosphate electrode comprising the above-described surface-reconstructed CoZn oxyphosphate electrocatalyst, wherein the preparation method of the electrode comprises the following steps: CoZn oxyphosphate electrocatalyst, carbon black and Nafion solution are mixed, and isopropanol is added for ultrasonic treatment to obtain catalyst slurry. The catalyst slurry is coated on a conductive substrate and dried to obtain CoZn oxyphosphate electrode.

[0014] Furthermore, the mass ratio of the CoZn oxyphosphate electrocatalyst, carbon black, and Nafion solution is 8:1:1.

[0015] The fourth aspect of the present invention provides an application of the above-mentioned surface-reconstructed CoZn oxyphosphate electrode in the conversion of polylactic acid hydrolysis products into acetic acid, wherein the surface-reconstructed CoZn oxyphosphate electrode converts polylactic acid hydrolysis products into acetic acid through an electrocatalytic oxidation reaction.

[0016] Furthermore, in the electrocatalytic oxidation process, a 1 M KOH alkaline aqueous solution is used as the electrolyte.

[0017] Furthermore, the applied potential for the electrocatalytic oxidation reaction is 1.6 V vs. RHE.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a novel surface-reconstructed CoZn oxyphosphate electrode and its application in the efficient conversion of polylactic acid hydrolysis products to acetic acid. The invention first prepares a CoZn precursor oxide via co-precipitation, followed by phosphating to obtain a CoZnOP catalyst. This catalyst possesses a unique stacked three-dimensional nanostructure, and the synergistic effect of Co and Zn, along with surface reconstruction induced by P doping, provides a high specific surface area and abundant active sites. In the electrocatalytic oxidation of lactic acid to acetic acid, it effectively reduces the high energy barrier of C / C bond breaking and lowers the overpotential required for lactic acid oxidation, achieving long-term stable conversion of lactic acid to acetic acid. Its selectivity, yield, energy consumption, and stability are significantly superior to existing technologies, making it an ideal technical solution for the high-value utilization of polylactic acid hydrolysis products. Specifically, the present invention has the following beneficial effects: (1) First, the catalyst has extremely high acetic acid selectivity and Faraday efficiency (FE). At the preferred potential (1.6 V vs. RHE), the FE of acetic acid can reach up to 94%, and it can maintain a high selectivity of 70% to 90% over a wide potential range, which is far superior to the conversion level of existing technologies.

[0019] (2) Secondly, the catalyst exhibits high yield, with an acetic acid production rate of up to 328 mmol / h. -1 g -1 More importantly, the introduction of the CoZnOP catalyst significantly reduced the reaction overpotential. Compared with the oxygen evolution reaction (OER), the onset potential of the lactic acid oxidation reaction shifted negatively by 225 mV, indicating that it can effectively reduce the energy input required for lactic acid oxidation.

[0020] (3) Furthermore, thanks to its optimized charge transfer performance (charge transfer resistance Rct is only 0.24 Ω), the present invention exhibits excellent reaction kinetics.

[0021] (4) Finally, continuous cycle tests confirmed that the CoZnOP catalyst has excellent long-term electrochemical stability, providing a reliable guarantee for industrial application.

[0022] In summary, the present invention is significantly superior to the prior art in terms of selectivity, yield, energy consumption and stability, and is an ideal technical solution for realizing the high-value utilization of polylactic acid hydrolysis products. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating the preparation process of the surface-reconstructed CoZn oxyphosphate electrocatalyst of the present invention.

[0024] Figure 2 The images shown are: a scanning electron microscope image (A) of the CoZn oxyphosphate electrocatalyst prepared in Example 1, its corresponding energy dispersive spectroscopy elemental mapping image (B), a transmission electron microscope image (C, D) of the CoZnOP catalyst, and a high-resolution transmission electron microscope image (E).

[0025] Figure 3 This is a comparison chart of the acetic acid Faradaic efficiency (FE) and acetic acid production rate for different electrocatalysts.

[0026] Figure 4 Comparison of LSV curves for CoZnOP catalyst under OER and LOR conditions.

[0027] Figure 5 The cyclic chronoampere (it) curve of the CoZnOP catalyst.

[0028] Figure 6 The graph shows the intensity variation of the characteristic peaks of 1H NMR at different charge points in the electrocatalytic lactic acid oxidation reaction of CoZnOP catalyst. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0031] Example 1: Preparation of CoZnOP electrode (1) Preparation of CoZn precursor oxide CoZnO (coprecipitation method) Accurately weigh 5 mmol of cobalt nitrate hexahydrate (AR grade) and 5 mmol of zinc nitrate hexahydrate (AR grade), ensuring a Co:Zn molar ratio of 1:1. Dissolve them together in 200 mL of deionized water, and add 0.1 g of sodium citrate. While stirring magnetically at 500 rpm, slowly add 40 mL of 0.5 mol / L sodium hydroxide solution, continuing stirring for 20 min. Centrifuge the suspension at 8000 rpm for 10 min to collect the precipitate. Wash the resulting solid three times each with deionized water and ethanol. Dry the precipitate in an oven at 60 ℃ for 12 h to obtain CoZnO oxide precursor powder.

[0032] (2) Phosphating synthesis of CoZnOP composite electrocatalyst (solid phosphating) Accurately weigh 50 mg of the CoZnO oxide precursor powder obtained in step (1), and place it in an agate mortar with 300 mg of sodium hypophosphite (analytical grade). Grind thoroughly for 30 min to ensure uniform mixing. Spread the mixture evenly in a quartz boat and transfer it into a tube furnace. Under continuous Ar atmosphere protection, raise the temperature to 300 ℃ at a heating rate of 2 ℃ / min and maintain the reaction for 4 h. After the reaction is complete, allow the tube furnace to cool naturally to room temperature. Collect the black solid product, wash it, and vacuum dry it at 60 ℃ for 6 h to obtain the target catalyst CoZnOP powder. The preparation flow chart is shown below. Figure 1 As shown.

[0033] SEM image of CoZnOP powder as shown below Figure 2 As shown, it can be seen that Figure 2 The SEM images in Figure A show that the CoZnOP material is constructed from irregularly aggregated, interlocked particles. These particles form large aggregates, resulting in a highly porous three-dimensional structure. Figure 2Image B is an elemental image of the CoZnOP material, clearly showing that cobalt (Co), zinc (Zn), phosphorus (P), and oxygen (O) are uniformly distributed throughout the nanoparticle aggregates. This indicates that the two metals were successfully and uniformly incorporated into the material during the synthesis process. Figure 2 The C-value is the TEM image of the CoZnOP material, showing that the catalyst was simply dispersed after 10 min of ultrasonic dispersion. The aggregates observed in the SEM image transformed into dispersed, irregularly shaped, approximately rectangular nanosheets and nanocrystals at the nanoscale. The sizes of the nanosheets and nanocrystals are 30–50 nm and ~5 nm, respectively. Figure 2 (D). Such morphological combinations and stackings facilitate the spatial composition for electrolyte diffusion between active substances. Figure 2 HRTEM images of the E-type confirmed the presence of crystalline domains, with the observed lattice edges showing a planar spacing of 0.212 nm, consistent with the (200) plane of cubic CoO. The 0.245 nm lattice spacing can be attributed to the (101) plane of hexagonal zinc oxide. Therefore, the nanosheet structure can be classified as zinc oxide, while the nanocrystalline particles are considered cobalt oxide. The CoZnOP material is a composite material of two cobalt oxides and zinc oxides after phosphating. This multiphase composite morphology provides abundant active sites and efficient mass transfer channels for electrocatalytic reactions.

[0034] (3) Preparation of CoZnOP working electrode Weigh 1.5 mg of CoZnOP powder and place it in a mixed solvent of 10 μL Nafion solution and 1 mL ethanol. Sonicate the mixture for 30 min to obtain a homogeneous slurry. Evenly drop the slurry onto a 1 × 1 cm... 2 On a carbon paper substrate, the catalyst loading was controlled to be approximately 1.5 mg cm⁻¹. -2 Dry the electrodes at 60 ℃ for 1 h for later use.

[0035] Comparative Example 1: Preparation of CoOP Electrode This comparative example aims to demonstrate the critical role of Zn element introduction in the synergistic effect of CoZnOP, so as to prove that the high performance of CoZnOP is due to the synergistic effect of Co and Zn and the unique surface reconstruction, rather than being achieved by CoOP alone.

[0036] (1) Preparation of Co precursor CoO Accurately weigh 5 mmol of nitric acid hexahydrate and dissolve it in 200 mL of deionized water. Under magnetic stirring, add 0.1 g of sodium citrate, then slowly add 40 mL of 0.5 mol / L NaOH solution, stirring continuously for 20 min. Centrifuge the suspension at 8000 rpm for 10 min to collect the precipitate. Wash the obtained solid three times each with deionized water and ethanol. Dry the precipitate in an oven at 60 ℃ for 12 h to obtain CoO oxide precursor powder.

[0037] (2) Phosphating synthesis using CoOP catalyst Weigh 50 mg of the CoO oxide precursor powder obtained in step (1) and place it in an agate mortar with 300 mg of sodium hypophosphite (analytical grade). Grind thoroughly for 30 min to ensure homogeneity. Spread the mixture evenly in a quartz boat and transfer it into a tube furnace. Under a continuous Ar atmosphere, raise the temperature to 300 °C at a heating rate of 2 °C / min and maintain the reaction for 4 h. After the reaction is complete, allow the tube furnace to cool naturally to room temperature. Collect the black solid product, wash it, and vacuum dry it at 60 °C for 6 h to obtain the control catalyst CoOP powder.

[0038] (3) Preparation of CoOP working electrode Weigh 1.5 mg of CoOP powder and place it in a mixed solvent of 10 μL Nafion solution and 1 mL ethanol. Sonicate the mixture for 30 min to obtain a homogeneous slurry. Evenly drop the slurry onto a 1 × 1 cm... 2 On a carbon paper substrate, the catalyst loading was controlled to be approximately 1.5 mg cm⁻¹. -2 Dry the electrodes at 60 ℃ for 1 h for later use.

[0039] Comparative Example 2: Preparation of CoZnO Electrode This comparative example aims to demonstrate the importance of phosphating (i.e., the introduction of P element) for constructing highly efficient catalytic active sites, in order to distinguish the high activity of CoZnOP from its unique oxyphosphate structure and surface reconstruction, rather than a simple oxide structure.

[0040] (1) Preparation of CoZnO oxide catalyst Accurately weigh 5 mmol of cobalt nitrate hexahydrate (AR grade) and 5 mmol of zinc nitrate hexahydrate (AR grade), ensuring a Co:Zn molar ratio of 1:1. Dissolve them together in 200 mL of deionized water, and add 0.1 g of sodium citrate. While stirring magnetically at 500 rpm, slowly add 40 mL of 0.5 mol / L sodium hydroxide solution, continuing stirring for 20 min. Centrifuge the suspension at 8000 rpm for 10 min to collect the precipitate. Wash the resulting solid three times each with deionized water and ethanol. Dry the precipitate in an oven at 60 ℃ for 12 h to obtain CoZnO oxide precursor powder.

[0041] (2) Preparation of CoZnO working electrode Weigh 1.5 mg of CoZnO powder and place it in a mixed solvent of 10 μL Nafion solution and 1 mL ethanol. Sonicate the mixture for 30 min to obtain a homogeneous slurry. Evenly drop the slurry onto a 1 × 1 cm... 2 On a carbon paper substrate, the catalyst loading was controlled to be approximately 1.5 mg cm⁻¹. -2 Dry the electrodes at 60 ℃ for 1 h for later use.

[0042] Comparative Example 3: Preparation of CoO Electrode (1) Preparation of CoO oxide catalyst Accurately weigh 5 mmol of cobalt nitrate hexahydrate (AR grade) and dissolve it in 200 mL of deionized water. Add 0.1 g of sodium citrate. While magnetically stirring at 500 rpm, slowly add 40 mL of 0.5 mol / L sodium hydroxide solution and continue stirring for 20 min. Centrifuge the suspension at 8000 rpm for 10 min to collect the precipitate. Wash the obtained solid three times each with deionized water and ethanol. Dry the precipitate in an oven at 60 ℃ for 12 h to obtain CoO oxide precursor powder.

[0043] (2) Preparation of CoO working electrode Weigh 1.5 mg of CoO powder and place it in a mixed solvent of 10 μL Nafion solution and 1 mL ethanol. Sonicate the mixture for 30 min to obtain a homogeneous slurry. Evenly drop the slurry onto a 1 × 1 cm... 2 On a carbon paper substrate, the catalyst loading was controlled to be approximately 1.5 mg cm⁻¹. -2 Dry the electrodes at 60 ℃ for 1 h for later use.

[0044] Comparative Example 4: Preparation of CP Electrode The CP electrode is made of hydrophilic carbon paper, purchased from GLS. It is used directly after ultrasonic cleaning with ethanol and drying.

[0045] Test Example 1: Acetic Acid Selectivity and Yield Test This test case demonstrates the high selectivity and high yield of acetic acid in the lactic acid oxidation reaction using the CoZnOP catalyst.

[0046] (1) Experimental methods and conditions Electrochemical testing: The tests were conducted using a Shanghai Chenhua CHI760E electrochemical workstation.

[0047] Electrolytic cell configuration: classic three-electrode system, working electrode (CoZnOP), counter electrode (platinum mesh) and reference electrode (mercury oxide electrode).

[0048] Electrolyte: Add a measured amount of polylactic acid hydrolysate to a 1 M KOH solution.

[0049] Potential setting: Perform timing ampere voltage for 2 hours under a certain constant voltage.

[0050] (2) Product analysis and results After electrolysis, a quantitative electrolyte sample was taken and analyzed using the internal standard method. 1 H and 13 24C NMR spectroscopy was used to analyze the type and yield of reaction products. The specific sample preparation steps are as follows: 600 μL of the electrolyzed liquid, 100 μL of heavy water (D₂O), and 2 μL of internal standard dimethyl sulfoxide (DMSO) were added to a standard NMR tube. NMR spectroscopy analysis showed that acetic acid was the main product of the electrolysis. A comparison of the acetic acid Faradaic efficiency (FE) and acetic acid production rate of different electrocatalysts is shown in the figure below. Figure 3 As shown, the CoZnOP catalyst in Example 1 exhibits an acetic acid Faradaic efficiency (FE) of 94%. The acetic acid production reaches 328 mmol / h. -1 g -1 .

[0051] Test Example 2: Overpotential, Kinetics and Stability Test (1) Overpotential reduction verification (LSV test) Linear sweep voltammetry (LSV) was performed on the CoZnOP electrode in pure 1 mol / L KOH solution (OER test) and 1 mol / L KOH solution containing polylactic acid hydrolysis (LOR test), respectively, at a scan rate of 5 mV / s. The LSV curves of the CoZnOP catalyst under OER and LOR conditions were compared as follows: Figure 4 As shown in the figure, the LSV curve indicates that at a value of 0.04 Acm... -2At the target current density, the potential corresponding to the LOR curve was 225 mV negatively shifted compared to the OER curve. This result indicates that the lactic acid oxidation reaction has significant kinetic advantages under CoZnOP catalysis, effectively reducing the energy input required for the reaction.

[0052] (2) Long-term stability test (cyclic timing ampere test) A constant potential of 1.6 V vs. RHE was applied to the CoZnOP electrode in 1 mol / L KOH containing polylactic acid hydrolysis solution for 6 cycles, each lasting 2 h, for a total of 12 h. The cyclic chronoamperotropic (it) curve of the obtained CoZnOP catalyst is shown in the figure. Figure 5 As shown in the curves, the current density and product FE remained stable during the continuous 12-hour electrolysis process, without significant decay. This demonstrates that the CoZnOP catalyst possesses excellent long-term electrochemical stability and durability.

[0053] (3) Verification of reaction pathway mechanism (NMR spectroscopy analysis) Electrolyte samples were collected at different charge levels during a constant-potential electrolysis process at 1.6 V vs. RHE. Deuterated water was used as the solvent, and NMR was performed using a Bruker Avance III 500 MHz NMR spectrometer. 1 1H NMR spectral analysis. The intensity variations of the characteristic peaks of the CoZnOP catalyst at different charge points in the electrocatalytic lactic acid oxidation reaction are shown in the figure below. Figure 6 As shown in the spectral results, at the beginning of the reaction, while the characteristic peak intensity of lactic acid decreased, the characteristic peak intensity of pyruvate rapidly increased. Subsequently, the peak intensity of pyruvate began to decrease, while the characteristic intensity of acetic acid continued to rise. This dynamic change directly confirms that the conversion process of the present invention follows a two-step tandem reaction pathway of "lactic acid--pyruvate--acetic acid," with pyruvate being the key intermediate in this efficient conversion pathway.

[0054] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for the preparation of a surface reconstructed CoZn oxyphosphate electrocatalyst, characterized in that, The method comprises the following steps: (1) Preparation of CoZn precursor oxide: metal nitrate precursors Co(NO3)2·6H2O and Zn(NO3)2·6H2O and sodium citrate are dissolved in deionized water, and after stirring, NaOH solution is added dropwise, metal ions are precipitated by coprecipitation to form a precursor suspension, which is centrifuged, washed, and vacuum dried to obtain Co and Zn oxide precursor CoZnO; (2) Phosphating treatment and synthesis of CoZn oxyphosphate electrocatalyst: CoZn precursor oxide is mixed with reducing agent sodium hypophosphite, and the mixture is heated for solid-state phosphating reaction under inert atmosphere protection, and then naturally cooled to room temperature, washed, and vacuum dried to obtain the target catalyst CoZnOP.

2. The method for preparing a surface reconstructed CoZn oxyphosphate electrocatalyst according to claim 1, characterized in that, In step (1), the molar ratio of Co(NO3)2·6H2O and Zn(NO3)2·6H2O is 1:

1.

3. The method for preparing a surface reconstructed CoZn oxyphosphate electrocatalyst according to claim 1, characterized in that, In step (1), the washing refers to repeated washing with deionized water and ethanol.

4. The method for preparing a surface reconstructed CoZn oxyphosphate electrocatalyst according to claim 1, characterized in that, In step (2), the temperature of heating is 300 ℃, and the time of solid-state phosphating reaction is 4 h.

5. A surface-reconstructed CoZn oxyphosphate electrocatalyst prepared by the preparation method of any one of claims 1-4.

6. A surface reconstructed CoZn oxyphosphate electrocatalyst electrode comprising the surface reconstructed CoZn oxyphosphate electrocatalyst of claim 5, characterized in that, The preparation method of the electrode comprises the following steps: CoZn oxyphosphate electrocatalyst, carbon black and Nafion solution are mixed, isopropanol is added for ultrasonic treatment to prepare a catalyst slurry, the catalyst slurry is coated on a conductive substrate, and then dried to obtain a CoZn oxyphosphate electrode.

7. A surface-reconstructed CoZn oxyphosphate electrode according to claim 6, characterized in that, The mass ratio of the CoZn oxyphosphate electrocatalyst, carbon black and Nafion solution is 8:1:

1.

8. Use of the surface-reconstructed CoZn oxyphosphate electrode according to claim 6 or 7 for the conversion of a poly-lactic acid hydrolysate into acetic acid, characterized in that, The surface-reconstructed CoZn oxyphosphate electrode converts the hydrolysis product of polylactic acid into acetic acid through an electrocatalytic oxidation reaction.

9. Use of a surface-reconstructed CoZn oxyphosphate electrode according to claim 8 for the conversion of a poly(lactic acid) hydrolysate into acetic acid, characterized in that, In the electrocatalytic oxidation reaction process, 1 M KOH alkaline aqueous solution is used as the electrolyte.

10. Use of a surface-reconstructed CoZn oxyphosphate electrode according to claim 9 for the conversion of a poly(lactic acid) hydrolysate into acetic acid, characterized in that, The applied potential of the electrocatalytic oxidation reaction is 1.6 V vs. RHE.

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