Copper-nickel alloy catalytic electrode and preparation method and application thereof

Abstract

The invention provides a copper-nickel alloy catalytic electrode and a preparation method and application thereof. The copper-nickel alloy catalytic electrode comprises a foamed nickel substrate and a copper-nickel alloy vertically loaded on the surface of the foamed nickel substrate, the molecular formula of the copper-nickel alloy is Cu < 0.81 > Ni < 0.19 >, and the copper-nickel alloy is of a dendritic nanostructure. The preparation method comprises the following steps: adding copper sulfate, nickel sulfate and ammonium sulfate into water, and uniformly stirring to obtain an electrolyte; taking a foamed nickel substrate as a working electrode, taking a saturated silver-silver chloride electrode as a reference electrode, taking a platinum sheet or a graphite rod electrode as a counter electrode, and applying constant current density to the working electrode to obtain a preset electrode; and alternately cleaning the preset electrode by using ethanol and distilled water, and carrying out vacuum drying to obtain the copper-nickel alloy catalytic electrode. According to the prepared copper-nickel alloy catalytic electrode, the copper-nickel alloy is in a dendritic morphology, has abundant active sites and a high specific surface area, and has excellent catalytic activity and stability in hydrogen preparation by coupling hydrogen evolution reaction for synthesizing adipic acid through electro-catalysis of cyclohexanone.

Description

Technical Field

[0001] The invention relates to the technical field of nano material synthesis and electrocatalysis, and in particular to a copper-nickel alloy catalytic electrode and a preparation method and application thereof. Background Art

[0002] In the field of electrocatalysis, non-precious metals such as iron, cobalt, nickel, and copper are valued for their abundant reserves, low cost, and good corrosion resistance. In particular, nickel-based and copper-based materials, which are not only abundant in reserves but also have easily adjustable electronic structures, occupy an important position in the synthesis of electrocatalysts.

[0003] Traditional methods for preparing nickel-copper-based alloy materials, such as co-reduction, mechanical ball milling, pyrolysis reduction and thermal diffusion, can successfully prepare alloy materials, but these methods are often time-consuming and costly, which is not conducive to large-scale production. In order to solve this problem, electrodeposition technology has become an effective alternative. By selecting a suitable working electrode and an electrolyte containing a soluble metal salt and applying a certain current, alloy catalysts can be quickly and easily deposited on the substrate material. However, technical improvements are still needed to prepare three-dimensional alloy catalytic electrodes with high loading and good structural stability.

[0004] In the chemical production process, adipic acid is a key industrial raw material and is widely used in the production of nylon-66, polyurethane and plasticizers. Traditionally, the production of adipic acid relies on the use of concentrated nitric acid as an oxidant and a thermal catalytic reaction under high temperature and high pressure conditions. This process is not only energy-intensive, but also produces tail gas that causes serious environmental pollution. In order to achieve a more environmentally friendly production method, the electrocatalytic oxidation of cyclohexanone / cyclohexanol to synthesize adipic acid has emerged. This method uses water as an oxidant and can produce adipic acid efficiently and cleanly. In the electrocatalytic process, nickel-based materials form NiOOH during the oxidation process, which is the key active site for the oxidation of cyclohexanone to produce adipic acid. However, the utilization efficiency of nickel-based materials in electrocatalytic cathode reactions still needs to be improved. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a copper-nickel alloy catalytic electrode and a preparation method and application thereof, which solve the problems raised in the above-mentioned background technology.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] According to a first aspect of the present invention, a copper-nickel alloy catalytic electrode is provided, comprising a nickel foam substrate and a copper-nickel alloy vertically loaded on the surface of the nickel foam substrate, wherein the molecular formula of the copper-nickel alloy is Cu 0.81 Ni 0.19 , the copper-nickel alloy is a nanostructure with a dendritic morphology.

[0010] The copper-nickel alloy catalytic electrode of the present invention is a copper-nickel alloy directly generated in situ on the surface of the nickel foam to have a morphology with a high specific surface area, and has good stability and excellent catalytic activity during the catalytic synthesis process.

[0011] Preferably, the length of the copper-nickel alloy catalytic electrode is 1 to 2 cm, and the width of the copper-nickel alloy catalytic electrode is 1 to 2 cm.

[0012] According to a second aspect of the present invention, there is provided a method for preparing a copper-nickel alloy catalytic electrode, comprising the following steps:

[0013] a) adding copper sulfate, nickel sulfate and ammonium sulfate into water and stirring to obtain an electrolyte;

[0014] b) using a nickel foam substrate as a working electrode, a saturated silver-silver chloride electrode as a reference electrode, and a platinum sheet or graphite rod electrode as a counter electrode, placing the working electrode, the reference electrode and the counter electrode in the electrolyte respectively, applying a constant current density to the working electrode, and obtaining a copper-nickel alloy preset electrode;

[0015] c) using ethanol and distilled water to alternately clean the copper-nickel alloy pre-set electrode, and vacuum drying to obtain the copper-nickel alloy catalytic electrode.

[0016] The present invention adopts a simple and fast electrodeposition synthesis method to prepare a self-supporting three-dimensional copper-nickel alloy catalytic material in one step. Ammonium sulfate is added to the electrolyte. During the electrodeposition process, not only the conductivity and complexation are enhanced, but also the corrosion resistance of the coating is effectively enhanced. The pH value in the electrolyte is effectively maintained, and a certain negative current density is applied to the working electrode, so that copper ions and nickel ions are reduced on the electrode surface to form an alloy, and the loading amount is high and the alloy has excellent stability.

[0017] Preferably, in step a), the concentration of copper sulfate in the electrolyte is 12.5 to 37.5 mM;

[0018] The concentration of nickel sulfate in the electrolyte is 12.5-37.5 mM;

[0019] The concentration of the ammonium sulfate is 50-60 mM.

[0020] Further preferably, the molar ratio of nickel sulfate to copper sulfate in the electrolyte is 1:1.5-2;

[0021] The concentration of ammonium sulfate is 60 mM.

[0022] Preferably, in step b), the constant current density applied to the working electrode is -150 to -50 mA cm -2 ;

[0023] The constant current density is applied for a time of 2 to 15 minutes.

[0024] Further preferably, in step b), the constant current density applied to the working electrode is -100 mA cm -2 ;

[0025] The constant current density is applied for 10 min.

[0026] Preferably, in step c), the number of alternating cleanings is 3 to 5 times;

[0027] The vacuum drying temperature is 80-100°C.

[0028] According to a third aspect of the present invention, a copper-nickel alloy catalytic electrode or a copper-nickel alloy catalytic electrode obtained according to the above preparation method is used in the electrocatalytic synthesis of adipic acid from cyclohexanone coupled with hydrogen evolution reaction to produce hydrogen.

[0029] (III) Beneficial effects

[0030] The present invention provides a copper-nickel alloy catalytic electrode and a preparation method and application thereof, which has the following beneficial effects:

[0031] (1) The present invention provides a copper-nickel alloy catalytic electrode, in which the copper-nickel alloy is vertically loaded on a nickel foam substrate and has a dendritic morphology. It has abundant active sites and a high specific surface area, and thus has excellent catalytic activity and stability. In addition, the copper-nickel alloy catalytic electrode of the present invention does not require any conductive material and auxiliary adhesive material and can be quickly assembled into an electrode device for application.

[0032] (2) The present invention provides a method for preparing a copper-nickel alloy catalytic electrode. First, an electrolyte is prepared. Ammonium sulfate is added to the electrolyte to improve the conductivity, complexation and corrosion resistance of the electrolyte. The pH value of the electrolyte is effectively maintained. During the electrodeposition process, a certain negative current density is applied to the working electrode so that copper ions and nickel ions are reduced on the electrode surface to form an alloy. The alloy has a high loading capacity and excellent stability.

[0033] (3) The present invention provides a method for preparing a copper-nickel alloy catalytic electrode. The preparation method is simple and convenient. The electrodeposition equipment has a simple structure. The chemical raw materials used are common and easy to obtain. The product is easy to collect and can be mass-produced.

[0034] (4) This scheme provides an application of a copper-nickel alloy catalytic electrode. The copper-nickel alloy catalytic electrode can not only make full use of the original nickel-based material to efficiently and cleanly produce adipic acid, but also can be coupled to produce green hydrogen energy, thereby improving the utilization rate of the cathode reaction. In addition, it has excellent working stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A process flow chart of a copper-nickel alloy catalytic electrode provided by the present invention;

[0036] Figure 2 The XRD diagram of a copper-nickel alloy catalytic electrode prepared in the present invention, wherein a is the XRD diagram of the copper-nickel alloy catalytic electrode prepared in Example 1; b is the XRD diagram of the Ni sample prepared in Comparative Example 1; c is the XRD diagram of the Cu-CuO sample prepared in Comparative Example 2;

[0037] Figure 3 The present invention provides a scanning electron microscope image of a copper-nickel alloy catalytic electrode prepared in accordance with the present invention, wherein: Figure a is a SEM image of the copper-nickel alloy catalytic electrode prepared in Example 1 at 2 μm; Figure b is a SEM image of the Ni sample prepared in Comparative Example 1 at 2 μm; Figure c is a SEM image of the Cu-CuO sample prepared in Comparative Example 2 at 2 μm; Figure d is a SEM image of the copper-nickel alloy catalytic electrode prepared in Example 1 at 200 nm; Figure e is a SEM image of the Ni sample prepared in Comparative Example 1 at 200 nm; Figure f is a SEM image of the Cu-CuO sample prepared in Comparative Example 2 at 200 nm;

[0038] Figure 4 The Cu prepared in Example 1 of the present invention 0.81 Ni 0.19 XPS test graphs of the Ni / NF catalytic electrode prepared in Comparative Example 1, the Ni / NF catalytic electrode prepared in Comparative Example 2, wherein Figure a is the XPS spectrum of Cu 2p; Figure b is the XPS spectrum of Ni 2p;

[0039] Figure 5 The performance test of the catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention under 1M KOH alkaline conditions, wherein Figure a is a linear voltammetric curve of the hydrogen evolution reaction (HER) of the catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2; Figure b is the Faraday efficiency of hydrogen production of the catalytic electrode prepared in Example 1 under different time tests;

[0040] Figure 6 The Cu prepared in Example 1 of the present invention 0.81 Ni 0.19HER chronovoltage curve of the NF catalytic electrode obtained by electrochemical three-electrode test under 1M KOH alkaline conditions;

[0041] Figure 7 The HER linear voltammetric curve of the copper-nickel alloy catalytic electrode synthesized by the present invention with different ratios of copper salt and nickel salt measured under 1M KOH alkaline conditions;

[0042] Figure 8 Figure a is a linear voltammogram of cyclohexanone oxidation (COR) of the catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2 tested in 1M KOH and 0.4M cyclohexanone solution; Figure b is the yield of adipic acid produced by the catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2 in 1M KOH and 0.4M cyclohexanone solution; Figure c is the Faraday efficiency of adipic acid produced by the catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2 in 1M KOH and 0.4M cyclohexanone solution;

[0043] Fig. 9 Figure a shows the Cu prepared in Example 1 0.81 Ni 0.19 The cyclohexanone conversion rate and the yield of oxalic acid at different reaction times in cyclohexanone oxidation (COR) to adipic acid using Cu / NF catalytic electrode in 1M KOH and 0.4M cyclohexanone solution; b is the Cu / NF catalytic electrode prepared in Example 1. 0.81 Ni 0.19 H NMR spectra of cyclohexanone oxidation (COR) to adipic acid on the / NF catalytic electrode in 1M KOH and 0.4M cyclohexanone solution ( 1 H NMR);

[0044] Fig.10 The Cu prepared in Example 1 of the present invention 0.81 Ni 0.19 The yield and Faraday efficiency stability of cyclohexanone oxidation (COR) to synthesize adipic acid over the NF catalytic electrode in 1M KOH and 0.4M cyclohexanone solution were tested for 5 consecutive times without changing the catalyst;

[0045] Fig.11 The Cu prepared in Example 1 of the present invention 0.81 Ni 0.19 / NF catalytic electrode in a mixed solution of 1M KOH and 0.4M cyclohexanone / cyclohexanol (KA oil) in a flow electrolyzer to test the performance of the full decomposition system of KA oil oxidation and hydrogen evolution, wherein Figure a is the full decomposition performance diagram of oxidation and hydrogen evolution, Figure b is the Faraday efficiency and yield of adipic acid produced by the full decomposition system at different current densities, and Figure c is the Faraday efficiency and yield of hydrogen produced by the full decomposition system at different current densities;

[0046] Fig.12 The Cu prepared in Example 1 of the present invention 0.81 Ni 0.19 The catalytic electrode of / NF was used in a mixed solution of 1M KOH and 0.4M cyclohexanone / cyclohexanol (KA oil) to test the full decomposition system of KA oil oxidation and hydrogen evolution reaction in a flowable electrolyzer at 100mAcm -2 Stability curves at current density of . DETAILED DESCRIPTION

[0047] In order to better illustrate the content of the present invention, a detailed description is given below in conjunction with specific embodiments.

[0048] Example 1

[0049] A Cu 0.81 Ni 0.19 / NF catalytic electrode preparation method, the process flow is as follows Figure 1 As shown:

[0050] Step 1, preparing a mixed solution containing 0.03M nickel sulfate hexahydrate, 0.02M copper sulfate and 0.06M sulfuric acid to obtain a light blue electrolyte;

[0051] Step 2: Select a 1×2cm piece 2 The nickel foam was used as the working electrode, saturated silver chloride was used as the reference electrode, platinum was used as the counter electrode, and the mixed solution of step 1 was used as the electrode solution to construct an electrolytic cell with a three-electrode system. -100 mA cm was applied to the working electrode. -2 The surface of the nickel foam substrate will quickly turn black after applying a constant current density of 600s. 0.81 Ni 0.19 The alloy will tightly cover the surface of the metal foam nickel substrate to obtain a copper-nickel alloy pre-electrode;

[0052] Step 3: Clean the copper-nickel alloy pre-set electrode in step 2 with ethanol and distilled water alternately by ultrasonic cleaning for 5 minutes to remove the residue on the surface of the copper-nickel alloy pre-set electrode. Repeat this three times, take out the electrode, and put it into a vacuum oven and dry it at 80°C for 30 minutes to obtain a copper-nickel alloy catalytic electrode.

[0053] Example 2

[0054] The preparation method of this embodiment is the same as that of embodiment 1, except that in step 1, the molar ratio of nickel sulfate hexahydrate to copper sulfate in the electrolyte is 3:1.

[0055] Example 3

[0056] The preparation method of this embodiment is the same as that of embodiment 1, except that in step 1, the molar ratio of nickel sulfate hexahydrate to copper sulfate in the electrolyte is 1:1.

[0057] Example 4

[0058] The preparation method of this embodiment is the same as that of embodiment 1, except that in step 1, the molar ratio of nickel sulfate hexahydrate to copper sulfate in the electrolyte is 1:1.5.

[0059] Example 5

[0060] The preparation method of this embodiment is the same as that of embodiment 1, except that in step 1, the molar ratio of nickel sulfate hexahydrate to copper sulfate in the electrolyte is 1:3.

[0061] Comparative Example 1

[0062] A method for preparing a Ni / NF catalytic electrode comprises the following steps:

[0063] Step 1, preparing a mixed solution of 0.03M nickel sulfate hexahydrate and 0.06M ammonium sulfate to obtain a light green electrolyte;

[0064] Step 2: Select a 1×2cm piece 2 The nickel foam was used as the working electrode, saturated silver chloride was used as the reference electrode, platinum was used as the counter electrode, and the mixed solution of step 1 was used as the electrode solution to construct an electrolytic cell with a three-electrode system. -100 mA cm was applied to the working electrode. -2 At a constant current density of , the surface of the nickel foam substrate will quickly turn black. After applying a constant current density of 600s, the black Ni catalyst will tightly cover the surface of the nickel foam substrate to obtain a Ni pre-electrode.

[0065] Step 3: Clean the Ni pre-set electrode in step 2 with ethanol and distilled water alternately by ultrasonic cleaning for 5 minutes to remove the residue on the surface of the Ni pre-set electrode. Repeat this process three times, take out the electrode, and dry it in a vacuum oven at 80°C for 30 minutes to obtain a Ni / NF catalytic electrode.

[0066] Comparative Example 2

[0067] A method for preparing a Cu-CuO / NF catalytic electrode comprises the following steps:

[0068] Step 1, preparing a mixed aqueous solution of 0.02M copper sulfate and 0.06M ammonium sulfate to obtain a light blue electrolyte;

[0069] Step 2: Select a 1×2cm piece 2The nickel foam was used as the working electrode, saturated silver chloride was used as the reference electrode, platinum was used as the counter electrode, and the mixed solution of step 1 was used as the electrode solution to construct an electrolytic cell with a three-electrode system. -100 mA cm was applied to the working electrode. -2 At a constant current density of , the surface of the nickel foam substrate will quickly turn black. After applying a constant current density of 600s, the brown Cu-CuO catalyst will tightly cover the surface of the nickel foam substrate to obtain a Cu-CuO pre-electrode.

[0070] Step 3: Clean the Cu-CuO pre-set electrode in step 2 with ethanol and distilled water alternately by ultrasonic cleaning for 5 minutes to remove the residue on the surface of the Cu-CuO pre-set electrode. Repeat this three times, take out the electrode, and dry it in a vacuum oven at 80°C for 30 minutes to obtain a Cu-CuO catalytic electrode.

[0071] Comparative Example 3

[0072] A method for preparing a copper-nickel alloy catalytic electrode comprises the following steps:

[0073] Step 1, preparing a mixed solution containing 0.05M nickel sulfate hexahydrate, 0.01M copper sulfate and 0.06M sulfuric acid to obtain a light blue electrolyte;

[0074] Step 2: Select a 1×2cm piece 2 The nickel foam was used as the working electrode, saturated silver chloride was used as the reference electrode, platinum was used as the counter electrode, and the mixed solution of step 1 was used as the electrode solution to construct an electrolytic cell with a three-electrode system. -100 mA cm was applied to the working electrode. -2 At a constant current density of , the surface of the metal foam nickel substrate will quickly turn black. After applying a constant current density of 600s, the black copper-nickel alloy will tightly cover the surface of the metal foam nickel substrate to obtain a copper-nickel alloy pre-electrode.

[0075] Step 3: Clean the copper-nickel alloy pre-set electrode in step 2 with ethanol and distilled water alternately by ultrasonic cleaning for 5 minutes to remove the residue on the surface of the copper-nickel alloy pre-set electrode. Repeat this three times, take out the electrode, and put it into a vacuum oven and dry it at 80°C for 30 minutes to obtain a copper-nickel alloy catalytic electrode.

[0076] Characterization and performance testing:

[0077] XRD analysis was performed on Example 1, Comparative Example 1 and Comparative Example 2, respectively. Figure 2 As shown in Figures a to c, the catalytic materials on the electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2 all meet the requirements of Cu 0.81 Ni 0.19 , Ni and Cu-CuO phases.

[0078] SEM analysis was performed on Example 1, Comparative Example 1 and Comparative Example 2, respectively. Figure 3 As shown, through the comparison of a to c and d to e, it can be seen that the Cu 0.81 Ni 0.19 The material is evenly distributed on the surface of the nickel foam substrate in a dendritic shape, showing more pores, which is conducive to full contact with the substrate during the reaction process, thereby exposing more catalytic active sites and promoting the occurrence of catalytic reactions.

[0079] X-ray photoelectron spectroscopy was performed on the samples of Example 1, Comparative Example 1 and Comparative Example 2, respectively. Figure 4 As shown, Figure a is the XPS spectrum data of Cu 2p, and Figure b is the XPS spectrum data of Ni 2p. It can be seen that the catalytic electrode prepared in Example 1 has both Cu and Ni elements.

[0080] The linear voltammetric curves of the hydrogen evolution reaction (HER) were tested under 1M KOH alkaline conditions using the catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2, as shown in FIG. Figure 5 As shown in Figure a, it can be seen that the Cu prepared in Example 1 0.81 Ni 0.19 Catalytic electrode at -100 mA cm -2 The overpotential is 162 mV at a current density of , and the catalytic performance is significantly better than that of the catalytic electrodes prepared in Comparative Examples 1 and 2; As can be seen from Figure b, the Cu prepared in Example 1 0.81 Ni 0.19 The Faraday efficiency of hydrogen production of the catalytic electrode at different times is higher than 90%, which proves that the catalytic electrode prepared in Example 1 has excellent hydrogen production performance.

[0081] Figure 6 The Cu prepared in Example 1 0.81 Ni 0.19 The catalytic electrode was subjected to a three-electrode reaction at -50 mA cm in 1 M KOH alkaline conditions. -2 The HER timing voltage curve of electrolysis for 30 h under a constant current density of , the results show that the Cu prepared in Example 1 0.81 Ni 0.19 The catalytic electrode has good stability and can be used in actual industrial production of hydrogen.

[0082] Figure 7 The HER linear voltammetric curves of the nickel-copper alloy catalytic electrodes prepared by deposition in the electrolyte of nickel salt and copper salt in different proportions in Examples 1 to 5 and Comparative Example 3 and tested under 1M KOH alkaline conditions are shown in Table 1. Figure 7It can be seen that the hydrogen evolution performance of the material deposited when the ratio of nickel salt to copper salt is 1.5:1 is the best. In Comparative Example 3, excessive nickel salt is added, and the hydrogen evolution performance is significantly reduced.

[0083] The catalytic electrodes prepared in Example 1, Comparative Example 1 and Comparative Example 2 were respectively tested for cyclohexanone oxidation (COR) performance, yield and Faraday efficiency in 1 M KOH and 0.4 M cyclohexanone solutions. Figure 8 As shown in Figure a, the Cu prepared in Example 1 0.81 Ni 0.19 The / NF catalytic electrode has excellent cyclohexanone oxidation catalytic performance, which is significantly better than the catalyst performance of Ni / NF and Cu-CuO / NF electrode materials. As can be seen from Figures b and c, the Cu prepared in Example 1 0.81 Ni 0.19 The / NF catalytic electrode has excellent yield and Faradaic efficiency for electrocatalytic cyclohexanone oxidation to produce adipic acid, and the efficiency of producing adipic acid can reach 92% at a voltage of 1.45V.

[0084] Test Example 1 prepared Cu 0.81 Ni 0.19 The cyclohexanone conversion rate and the yield of synthetic adipic acid of the NF catalytic electrode in 1M KOH and 0.4M cyclohexanone solution at different reaction times and the corresponding H NMR spectrum data, such as Fig. 9 As shown in Figures a and b in FIG, with the increase of electrolysis time, the yield of adipic acid increases continuously, reaching a maximum adipic acid yield of 80% in 10 h, indicating that the Cu prepared in Example 1 0.81 Ni 0.19 / NF catalytic electrode has excellent industrial value in the synthesis of adipic acid.

[0085] Test Example Preparation of Cu 0.81 Ni 0.19 The stability diagram of the yield and Faradaic efficiency of the NF catalytic electrode in 1M KOH and 0.4M cyclohexanone solution for cyclohexanone oxidation (COR) to synthesize adipic acid was tested for 5 times without changing the catalyst. Fig.10 As shown, it can be seen that the Cu prepared in this embodiment 0.81 Ni 0.19 The MgO / NF catalytic electrode exhibits excellent adipic acid yield and Faradaic efficiency stability.

[0086] Test Example 1 prepared Cu 0.81 Ni 0.19 The performance diagram of the full decomposition system of KA oil oxidation and hydrogen evolution was tested in a flowable electrolyzer using a mixed solution of 1M KOH and 0.4M cyclohexanone / cyclohexanol (KA oil) using a NF catalytic electrode, as shown in Figure 2. Fig.11As shown in Figure a, it can be seen that the Cu prepared in Example 1 0.81 Ni 0.19 The Cu / NF catalytic electrode has excellent KA oil oxidation coupled with hydrogen evolution full decomposition performance. From Figure b and Figure c, it can be seen that the Cu prepared in Example 1 0.81 Ni 0.19 / NF catalytic electrode at 25, 50, 75, 100, 125 mA cm -2 The Faradaic efficiency for producing hydrogen and adipic acid is over 90%.

[0087] Test Example 1 prepared Cu 0.81 Ni 0.19 The catalytic electrode of the NF was used in a mixed solution of 1 M KOH and 0.4 M cyclohexanone / cyclohexanol (KA oil) to test the full decomposition system of KA oil oxidation and hydrogen evolution reaction in a flow electrolyzer at 100 mA cm -2 The stability test curve under the current density is as follows: Fig.12 As shown, the Cu prepared in Example 1 0.81 Ni 0.19 The NF / SiC catalytic electrode has excellent long-term working stability.

[0088] The copper-nickel alloy catalytic electrode prepared by the present invention has a dendritic morphology, is evenly distributed, has abundant active sites and specific surface area, and in the process of being applied to the electrosynthesis of adipic acid coupled with the production of hydrogen, the catalytic electrode prepared by the present invention has a high adipic acid yield, excellent hydrogen evolution catalytic activity and good stability, and can be actually applied to equipment for producing adipic acid and hydrogen.

[0089] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A copper-nickel alloy catalytic electrode, characterized in that: The invention comprises a nickel foam substrate and a copper-nickel alloy vertically loaded on the surface of the nickel foam substrate, wherein the molecular formula of the copper-nickel alloy is Cu 0.81 Ni 0.19 , the copper-nickel alloy is a nanostructure with a dendritic morphology.

2. The copper-nickel alloy catalytic electrode according to claim 1, characterized in that: The length of the copper-nickel alloy catalytic electrode is 1 to 2 cm, and the width of the copper-nickel alloy catalytic electrode is 1 to 2 cm.

3. A method for preparing a copper-nickel alloy catalytic electrode according to any one of claims 1 or 2, characterized in that: The following steps are involved: a) adding copper sulfate, nickel sulfate and ammonium sulfate into water and stirring to obtain an electrolyte; b) using a nickel foam substrate as a working electrode, a saturated silver-silver chloride electrode as a reference electrode, and a platinum sheet or graphite rod electrode as a counter electrode, placing the working electrode, the reference electrode and the counter electrode in the electrolyte respectively, applying a constant current density to the working electrode, and obtaining a copper-nickel alloy preset electrode; c) using ethanol and distilled water to alternately clean the copper-nickel alloy pre-set electrode, and vacuum drying to obtain the copper-nickel alloy catalytic electrode.

4. The method for preparing a copper-nickel alloy catalytic electrode according to claim 3, characterized in that: In step a), the concentration of copper sulfate in the electrolyte is 12.5-37.5 mM; The concentration of nickel sulfate in the electrolyte is 12.5-37.5 mM; The concentration of the ammonium sulfate is 50-60 mM.

5. The method for preparing a copper-nickel alloy catalytic electrode according to claim 4, characterized in that: The molar ratio of nickel sulfate to copper sulfate in the electrolyte is 1:1.5-2.

6. The method for preparing a copper-nickel alloy catalytic electrode according to claim 3, characterized in that: In step b), the constant current density applied to the working electrode is -150 to -50 mA cm -2 ; The constant current density is applied for a time of 2 to 15 minutes.

7. The method for preparing a copper-nickel alloy catalytic electrode according to claim 6, characterized in that: In step b), the constant current density applied to the working electrode is -100 mA cm -2 ; The constant current density is applied for 10 min.

8. The method for preparing a copper-nickel alloy catalytic electrode according to claim 3, characterized in that: In step c), the number of alternating cleanings is 3 to 5 times; The vacuum drying temperature is 80-100°C.

9. Use of the copper-nickel alloy catalytic electrode according to claim 1 or 2 or the copper-nickel alloy catalytic electrode obtained according to the preparation method according to any one of claims 3 to 8 in the production of hydrogen by electrocatalytic cyclohexanone synthesis of adipic acid coupled with hydrogen evolution reaction.

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