Foam nickel loaded nitrogen-carbon coated copper oxide electrocatalyst and application thereof
By coating a nitrogen-carbon layer onto a nickel foam, the problem of high cost and easy deactivation of electrocatalysts was solved, achieving efficient synthesis of 1,2,3,4-tetrahydroquinoline, reducing production costs and improving catalytic activity and selectivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHEAST GASOLINEEUM UNIV
- Filing Date
- 2026-02-26
- Publication Date
- 2026-05-29
AI Technical Summary
Existing electrocatalysts are expensive and easily poisoned by halogens in the synthesis of 1,2,3,4-tetrahydroquinoline compounds, and there is limited research on their application in electrocatalytic hydrogenation-debromination reactions.
Using nickel foam as a substrate, a nitrogen-carbon layer is formed by coating copper oxide with a modified polymer and then pyrolyzing it. Nitrogen and carbon atoms diffuse into the copper oxide lattice, and defect sites are constructed by plasma treatment to optimize catalytic activity.
It improves the activity and stability of the catalyst, reduces production costs, and exhibits high catalytic activity and selectivity in the hydrogenation and debromination of 8-bromoquinoline.
Smart Images
Figure CN122105460A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of catalyst technology, specifically to a nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst and its application in the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline. Background Technology
[0002] Quinolines and their derivatives are important organic synthetic intermediates, widely used in pharmaceutical intermediates, dyes, pesticides, and organic functional materials. 8-Bromoquinoline is an important quinoline derivative and an intermediate in the synthesis of many drug molecules. Since bromine atoms often act as directing or protecting groups in drug synthesis and require selective removal in the final product, debromination is a crucial transformation process for quinoline derivatives. Quinoline hydrogenation products are important precursors for pharmaceutical intermediates and organic functional materials; for example, 1,2,3,4-tetrahydroquinolines can be used to prevent and treat hyperlipidemia, arteriosclerosis, and other diseases, and can also be used in dye synthesis. Currently, the preparation of 1,2,3,4-tetrahydroquinolines mainly involves Diels-Alder reactions and thermocatalytic hydrogenation reactions. Thermocatalytic hydrogenation is the mainstream reaction for the industrial synthesis of 1,2,3,4-tetrahydroquinoline compounds. It can hydrogenate quinoline compounds to obtain the target product through a relatively simple reaction route under solvent-free conditions. However, it also has disadvantages such as harsh reaction conditions (200-400 ºC, 2-10 MPa H2), the need to use precious metals to catalyze the reaction, high production costs, and large equipment investment.
[0003] In recent years, electrocatalytic organic synthesis technology has become a hot topic in academia and industry due to its advantages such as mild reaction conditions, the use of electrons as a green reducing agent, and the ability to precisely control the reaction process by adjusting the applied electric field parameters. Regarding the selection of electrocatalysts, noble metal catalysts (such as Pd and Pt) have high reactivity, but they suffer from high cost and are easily poisoned and deactivated by halogens. Currently, research on the synthesis of 1,2,3,4-tetrahydroquinoline compounds is relatively limited, mainly focusing on the electrocatalytic hydrogenation to produce 1,2,3,4-tetrahydroquinoline compounds, while reactions that simultaneously achieve electrocatalytic hydrogenation and debromination are rarely reported. Therefore, developing non-noble metal catalysts that simultaneously achieve hydrogenation and debromination for the directed synthesis of 1,2,3,4-tetrahydroquinoline compounds has become an urgent problem to be solved. Summary of the Invention
[0004] One object of the present invention is to provide a nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst, which solves the problems of existing electrocatalysts being expensive and easily poisoned and deactivated by halogens; another object of the present invention is to provide the application of the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst.
[0005] The technical solution adopted by this invention to solve its technical problem is as follows: This nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst uses nickel foam as a substrate and copper oxide as an active component. The nitrogen-carbon coated copper oxide is obtained by coating with a modified polymer and then pyrolyzing. In the nitrogen-carbon coated copper oxide, nitrogen atoms and carbon atoms penetrate into the surface lattice of copper oxide and cause lattice distortion. The chemical valence state and electronic structure of the copper oxide surface are also changed accordingly. Then, the defect sites of the nitrogen-carbon coated copper oxide are constructed by plasma treatment to regulate the catalytic activity of copper oxide, optimize the thickness of the nitrogen-carbon layer, and enhance the charge and mass transfer efficiency.
[0006] The preparation method of the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam in the above scheme includes the following steps: Step 1: Clean the nickel foam sequentially with hydrochloric acid, deionized water, and ethanol under ultrasonic conditions. Step 2: Mix the nickel foam obtained in Step 1 with copper salt, hexadecyltrimethylammonium bromide, and ethanol evenly and transfer the mixture to a hydrothermal synthesis reactor. React at 100–300 °C for 10–72 h. After the reaction is complete, cool to room temperature, rinse off any residual substances on the surface with deionized water, and dry under vacuum or inert gas at 50–200 °C to obtain the precursor. Step 3: The precursor obtained in Step 2 is calcined in air and then cooled naturally to room temperature to obtain nickel-supported copper oxide. Step 4: Prepare a mixed solution of dopamine hydrochloride, amino acids, ethylene glycol bis(2-aminoethyl ether)tetraacetic acid, and tris(hydroxymethyl)aminomethane. Adjust the pH of the solution to 8.5 with potassium hydroxide. Use a clamp to pick up the nickel foam-loaded copper oxide obtained in Step 3 and place it in the mixed solution. React for 6–24 h. After the reaction, rinse the catalyst surface with deionized water and dry it under vacuum or inert gas at 50–90 °C to obtain the modified polymer-coated precursor. Step 5: The modified polymer-coated precursor obtained in Step 4 is heated to 100-200 ºC under inert gas conditions at a heating rate of 1-10 ºC / min and cured for 1-6 h. Then, it is heated to 400-700 ºC at a heating rate of 1-10 ºC / min and heated for 1-6 h to obtain copper oxide coated with a nitrogen-carbon layer. Step 6: The copper oxide coated with the nitrogen-carbon layer obtained in Step 5 is treated with plasma under ammonia or vacuum conditions for 1-20 min on each side to obtain a nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam.
[0007] In the above scheme, the surface of the nitrogen-carbon coated copper oxide electrocatalyst supported by nickel foam has copper, oxygen, carbon and nitrogen elements, and there are C=C, CN and COC bonds.
[0008] In step one of the above scheme, the concentration of hydrochloric acid is 0.1–5 mol / L, and the ultrasonic time is 5–25 min.
[0009] In step two of the above scheme, the copper salt is selected from one of copper nitrate, copper chloride, copper sulfate, copper formate, copper acetate, copper acetylacetone, and copper bromide; the molar ratio of copper salt to hexadecyltrimethylammonium bromide is 2:1 to 20:1, and the mass ratio of ethanol to copper salt is 40:1 to 100:1.
[0010] The conditions for calcining the precursor in air in step three of the above scheme are as follows: calcining at 300-600 ºC for 1.5-6 h in an air atmosphere with a heating rate of 1-30ºC / min.
[0011] In step four of the above scheme, the concentration of dopamine hydrochloride in the mixed solution is 0.5–5 mmol / L, the concentration of amino acids is 0.01–0.1 mmol / L, the concentration of ethylene glycol bis(2-aminoethyl ether)tetraacetic acid is 0.01–0.1 mmol / L, and the concentration of tris(hydroxymethyl)aminomethane is 2.5–50 mmol / L.
[0012] The amino acids in step four of the above scheme are one or more of the following: glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, tyrosine, tryptophan, serine, threonine, asparagine, glutamine, aspartic acid, glutamic acid, lysine, arginine, and histidine.
[0013] The aforementioned nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst was used in the electrocatalytic debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline. Beneficial effects
[0014] 1. This invention uses nickel foam as a substrate and copper oxide as an active component. A modified polymer is used to coat and then pyrolyze the copper oxide to obtain a nitrogen-carbon layer coated copper oxide. Nitrogen and carbon atoms penetrate into the surface lattice of copper oxide and cause lattice distortion. The chemical valence state and electronic structure of the copper oxide surface are also changed accordingly. The material obtained in the previous step is subjected to plasma treatment to construct defect sites, further regulate the catalytic activity of copper oxide, effectively optimize the thickness of the nitrogen-carbon layer, enhance charge and mass transfer efficiency, and significantly improve the catalyst activity and stability.
[0015] 2. The present invention has the advantages of strong catalytic activity, high selectivity and high conversion rate in the reaction of hydrogenation and debromination of 8-bromoquinoline to produce 1,2,3,4-tetrahydroquinoline.
[0016] 3. The nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst provided by this invention has high catalytic activity and selectivity in the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline. In addition, the preparation of this catalyst does not require precious metals, which can significantly reduce production costs and has good potential for industrial application. Attached Figure Description
[0017] Figure 1 The Fourier transform infrared spectrum is that of the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst prepared in Example 1.
[0018] Figure 2 The X-ray diffraction pattern is shown for the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst prepared in Example 1.
[0019] Figure 3 The X-ray photoelectron spectroscopy (XPS) of the nickel foam-supported nitrogen-carbon-coated copper oxide electrocatalyst prepared in Example 1 is shown.
[0020] Figure 4 The image shows the 8-hour gas chromatogram of the debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline catalyzed by the nitrogen-carbon-coated copper oxide electrocatalyst supported on nickel foam prepared in Example 1. Detailed Implementation
[0021] The present invention will be further described below with reference to the accompanying drawings: Example 1:
[0022] This nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst uses nickel foam as a substrate and copper oxide as the active component. The nitrogen-carbon coated copper oxide is obtained by coating with a modified polymer and then pyrolyzing it. In the nitrogen-carbon coated copper oxide, nitrogen and carbon atoms diffuse into the surface lattice of copper oxide and cause lattice distortion. The chemical valence state and electronic structure of the copper oxide surface are also changed accordingly. Then, the defect sites of the nitrogen-carbon coated copper oxide are constructed by plasma treatment to regulate the catalytic activity of copper oxide, optimize the thickness of the nitrogen-carbon layer, and enhance the charge and mass transfer efficiency.
[0023] The preparation method of this supported nitrogen-carbon coated copper oxide electrocatalyst is as follows: Step 1, cleaning of nickel foam: Take nickel foam (2 cm × 2 cm) and clean it with 3 mol / L hydrochloric acid, deionized water and ethanol in sequence for 10 min by ultrasonic cleaning. When changing the solvent, clean the nickel foam with deionized water.
[0024] Step 2, hydrothermal synthesis: Weigh 0.4832 g of copper nitrate trihydrate and 0.25 g of hexadecyltrimethylammonium bromide, and sonicate them in 30 mL of ethanol. Transfer the resulting mixed solution, along with the cleaned nickel foam, to a hydrothermal synthesis reactor. React at 180 ºC for 24 h. After the reaction, allow it to cool naturally to room temperature. Rinse the surface with deionized water to remove any residual substances, and vacuum dry at 80 ºC to obtain precursor A.
[0025] Step 3, calcination under air conditions: Place precursor A in a tube furnace and heat it to 400 ºC at a heating rate of 5 ºC / min under air atmosphere. Maintain the temperature at 400 ºC for 3 h and allow it to cool naturally to room temperature to obtain precursor B.
[0026] Step 4: Modified Polymer Coating: Prepare a mixed solution of 1.6 mmol / L dopamine hydrochloride, 0.02 mmol / L glycine, and 0.02 mmol / L ethylene glycol bis(2-aminoethyl ether)tetraacetic acid in 50 mL. Prepare a 10 mL solution of 50 mmol / L tris(hydroxymethyl)aminomethane. Add the prepared tris(hydroxymethyl)aminomethane solution dropwise to the 50 mL mixed solution under stirring. Adjust the pH of the mixed solution to 8.5 with potassium hydroxide solution. When the solution turns yellow, insert precursor B into the solution and stir for 12 h. Remove the precursor, rinse the surface with deionized water, and vacuum dry at 80 ºC to obtain precursor C.
[0027] Step 5: Construction of the charge transport highway – the nitrogen-carbon layer: Precursor C was heated to 120 ºC at a heating rate of 5 ºC / min under argon protection and held at 120 ºC for 1 h. Then, it was heated to 500 ºC at a heating rate of 2 ºC / min and held at 500 ºC for 2 h to obtain precursor D.
[0028] Step 6: Plasma treatment: Precursor D is treated with plasma under vacuum conditions for 10 minutes on each side to obtain a nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst.
[0029] The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 1 was characterized by Fourier transform infrared spectroscopy. The results are shown in [Figure 1]. Figure 1 The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 1 was characterized by X-ray diffraction. The results are shown in [Figure 1]. Figure 2 The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 1 was characterized by X-ray photoelectron spectroscopy. The full spectrum is shown in [image missing]. Figure 3 .Depend on Figure 1 It can be seen that the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 1 has a performance at 3435 cm⁻¹ -1 The broad peaks around 1625 cm⁻¹ originate from adsorbed water on the material surface. -1 The moderate-intensity spikes on the left and right originate from the stretching vibration of C=C, 1385 cm. -1 The sharp peaks on the left and right originate from the stretching vibration of CN, 1065 cm -1 The sharp peaks on the left and right originate from the stretching and contracting vibrations of the COC. Figure 2 As can be seen, the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 1, compared with the PDF card, only has peaks of copper oxide and nickel, without other impurity peaks. However, the peak of copper oxide is slightly shifted compared to the standard PDF card, indicating that the prepared catalyst has high purity, and nitrogen and carbon elements were successfully introduced into the copper oxide lattice, causing distortion. Figure 3 It can be seen that the surface of the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst obtained in Example 1 contains carbon, nitrogen, oxygen and copper elements.
[0030] This nickel-supported nitrogen-carbon coated copper oxide electrocatalyst is used for the hydrogenation and debromination of bromoquinoline to 1,2,3,4-tetrahydroquinoline.
[0031] The performance of the nitrogen-carbon-coated copper oxide electrocatalyst supported on nickel foam obtained in Example 1 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested. The specific test method is as follows: Example 1 yielded a nickel-foamed, nitrogen-carbon-coated copper oxide electrocatalyst with dimensions of 1 cm × 1 cm, which served as the working electrode in the cathode chamber. A 1 cm × 1 cm platinum sheet electrode was used as the counter electrode in the anode chamber. Electrolysis was performed in an H-type electrolytic cell using an Ag / AgCl standard electrode as the reference electrode. The cathode chamber solution consisted of a mixture of 6 mL of 1 mol / L potassium hydroxide solution and 1 mL of 1,4-dioxane, with 20.8 mg of 8-bromoquinoline added as the reaction substrate. The mixture was ultrasonically mixed and a magnetic stirrer was added. The anode chamber solution consisted of 7 mL of 1 mol / L potassium hydroxide solution. The anode and cathode chambers were separated by a Nafion N117 ion-exchange membrane.
[0032] To ensure the electrolytic cell was kept at a constant temperature of 25 °C, the cathode chamber was magnetically stirred. An electrochemical workstation was used as the external power source to conduct a constant potential electrolysis experiment with an electrolysis potential of -1.2 V vs. Ag / AgCl and an electrolysis time of 8 h.
[0033] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. The reaction results are as follows: Figure 4 As shown, when the reaction time is 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline is 97.65% and the selectivity is 99%. Example 2:
[0034] The difference from Example 1 is that the raw materials in step two are adjusted to 0.4 g copper nitrate trihydrate, 0.4 g hexadecyltrimethylammonium bromide and 30 mL ethanol.
[0035] This nickel-supported nitrogen-carbon coated copper oxide electrocatalyst is used for the hydrogenation and debromination of bromoquinoline to 1,2,3,4-tetrahydroquinoline.
[0036] The performance of the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 2 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested using the same method as in Example 1.
[0037] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. Detection and calculation showed that when the reaction time was 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline was 95.74%, and the selectivity was 98%. Example 3:
[0038] The difference from Example 1 is that the reaction temperature in step three is adjusted to 500 ºC.
[0039] This nickel-supported nitrogen-carbon coated copper oxide electrocatalyst is used for the hydrogenation and debromination of bromoquinoline to 1,2,3,4-tetrahydroquinoline.
[0040] The performance of the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 3 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested using the same method as in Example 1.
[0041] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. Detection and calculation showed that when the reaction time was 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline was 94.31%, and the selectivity was 98%. Example 4:
[0042] The difference from Example 1 is that the reaction time in step four is adjusted to 16 h.
[0043] This nickel-supported nitrogen-carbon coated copper oxide electrocatalyst is used for the hydrogenation and debromination of bromoquinoline to 1,2,3,4-tetrahydroquinoline.
[0044] The performance of the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 4 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested using the same method as in Example 1.
[0045] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. Detection and calculation showed that when the reaction time was 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline was 97.31%, and the selectivity was 99%. Example 5:
[0046] The difference from Example 1 is that in step five, the plasma treatment time under vacuum conditions is 5 minutes per side.
[0047] This nickel-supported nitrogen-carbon coated copper oxide electrocatalyst is used for the hydrogenation and debromination of bromoquinoline to 1,2,3,4-tetrahydroquinoline.
[0048] The performance of the nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam obtained in Example 5 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested using the same method as in Example 1.
[0049] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. Detection and calculation showed that when the reaction time was 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline was 95.03%, and the selectivity was 96%.
[0050] Comparative Example 1: The difference from Example 1 is that only steps one, two, and three of Example 1 are performed to obtain the nickel foam-supported copper oxide electrocatalyst.
[0051] The performance of the nickel-supported copper oxide electrocatalyst obtained in Comparative Example 1 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested using the same method as in Example 1.
[0052] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. Detection and calculation showed that when the reaction time was 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline was 93.41%, and the selectivity was 98%.
[0053] Comparative Example 2: The difference from Example 1 is that step six in Example 1 is not performed, resulting in a nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst that has not undergone plasma treatment.
[0054] The performance of the untreated nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst obtained in Comparative Example 2 for the hydrogenation and debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline was tested using the same method as in Example 1.
[0055] After electrolysis, the electrolyte in the cathode chamber was removed, distilled under reduced pressure, and extracted with ethyl acetate. The extract was quantitatively analyzed by gas chromatography and compared with standard samples. Detection and calculation showed that when the reaction time was 8 h, the conversion rate of 1,2,3,4-tetrahydroquinoline was 93.56%, and the selectivity was 98%.
Claims
1. A nickel foam-supported, nitrogen-carbon-coated copper oxide electrocatalyst, characterized in that: The preparation method of this nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst is as follows: using nickel foam as a substrate and copper oxide as the active component, a modified polymer is used to coat and then pyrolyze to obtain a nitrogen-carbon coated copper oxide. In the nitrogen-carbon coated copper oxide, nitrogen and carbon atoms diffuse into the surface lattice of copper oxide and cause lattice distortion, and the chemical valence state and electronic structure of the copper oxide surface are also changed accordingly. Then, the defect sites of the nitrogen-carbon coated copper oxide are constructed by plasma treatment to obtain the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst.
2. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 1, characterized in that: The preparation method of the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst includes the following steps: Step 1: Clean the nickel foam sequentially with hydrochloric acid, deionized water, and ethanol under ultrasonic conditions. Step 2: Mix the nickel foam obtained in Step 1 with copper salt, hexadecyltrimethylammonium bromide, and ethanol evenly and transfer the mixture to a hydrothermal synthesis reactor. React at 100–300 °C for 10–72 h. After the reaction is complete, cool to room temperature, rinse off any residual substances on the surface with deionized water, and dry under vacuum or inert gas at 50–200 °C to obtain the precursor. Step 3: The precursor obtained in Step 2 is calcined in air and then cooled naturally to room temperature to obtain nickel-supported copper oxide. Step 4: Prepare a mixed solution of dopamine hydrochloride, amino acids, ethylene glycol bis(2-aminoethyl ether)tetraacetic acid, and tris(hydroxymethyl)aminomethane. Adjust the pH of the solution to 8.5 with potassium hydroxide. Use a clamp to pick up the nickel foam-loaded copper oxide obtained in Step 3 and place it in the mixed solution. React for 6–24 h. After the reaction, rinse the catalyst surface with deionized water and dry it under vacuum or inert gas at 50–90°C to obtain the modified polymer-coated precursor. Step 5: The modified polymer-coated precursor obtained in Step 4 is heated to 100-200 ºC under inert gas conditions at a heating rate of 1-10 ºC / min and cured for 1-6 h. Then, it is heated to 400-700 ºC at a heating rate of 1-10 ºC / min and heated for 1-6 h to obtain copper oxide coated with a nitrogen-carbon layer. Step 6: The copper oxide coated with the nitrogen-carbon layer obtained in Step 5 is treated with plasma under ammonia or vacuum conditions for 1-20 min on each side to obtain a nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam.
3. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 2, characterized in that: The surface of the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst contains copper, oxygen, carbon, and nitrogen elements, and also contains C=C, CN, and COC bonds.
4. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 3, characterized in that: The concentration of hydrochloric acid in step one is 0.1–5 mol / L, and the ultrasonic time is 5–25 min.
5. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 4, characterized in that: The copper salt in step two is selected from one of copper nitrate, copper chloride, copper sulfate, copper formate, copper acetate, copper acetylacetone, and copper bromide; the molar ratio of copper salt to hexadecyltrimethylammonium bromide is 2:1 to 20:1, and the mass ratio of ethanol to copper salt is 40:1 to 100:
1.
6. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 5, characterized in that: The conditions for calcining the precursor in air in step three are as follows: calcining at a heating rate of 1–30 ºC / min in an air atmosphere until reaching 300–600 ºC for 1.5–6 h.
7. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 6, characterized in that: In step four, the concentration of dopamine hydrochloride in the mixed solution is 0.5–5 mmol / L, the concentration of amino acids is 0.01–0.1 mmol / L, the concentration of ethylene glycol bis(2-aminoethyl ether)tetraacetic acid is 0.01–0.1 mmol / L, and the concentration of tris(hydroxymethyl)aminomethane is 2.5–50 mmol / L.
8. The nitrogen-carbon coated copper oxide electrocatalyst supported on nickel foam according to claim 7, characterized in that: The amino acid in step four is one or more of the following: glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, tyrosine, tryptophan, serine, threonine, asparagine, glutamine, aspartic acid, glutamic acid, lysine, arginine, and histidine.
9. The application of the nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst of claim 8, characterized in that: The nickel foam-supported nitrogen-carbon coated copper oxide electrocatalyst is used in the electrocatalytic debromination of 8-bromoquinoline to 1,2,3,4-tetrahydroquinoline.