A Cu 1200 Ni 500 Catalytic electrode materials, preparation methods and applications

Abstract

This invention relates to the field of electrocatalysis technology and provides Cu 1200 Ni 500 The preparation method of the catalytic electrode material includes the following steps: Cu(NO3)2•3H2O is added to deionized water and ultrasonically treated to obtain a mixed solution; constant voltage electroplating is performed in a dual-electrode system using carbon paper as the working electrode and a platinum electrode as the counter electrode for 1200 s to obtain Cu. 1200 Electrode; NiSO4•6H2O and sodium citrate trihydrate were added to deionized water and ultrasonically treated to obtain a mixed solution. In a two-electrode system, Cu... 1200 The Cu electrode is used as the working electrode, and the platinum electrode is used as the counter electrode. Constant current electroplating is performed for 500 seconds to obtain the Cu. 1200 Ni 500 Catalytic electrode material. This invention also provides a Cu... 1200 Ni 500 Catalytic electrode material. This invention also provides a Cu... 1200 Ni 500 Application of catalytic electrode materials in the reduction of nitrate to ammonia. The preparation process of this invention is simple, and it exhibits good stability, high ammonia yield, and excellent Faraday efficiency during the electrochemical reduction of nitrate to ammonia.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis technology, and particularly relates to a Cu 1200 Ni 500 Catalytic electrode materials, preparation methods and applications. Background Technology

[0002] Traditional ammonia synthesis uses the Haber-Bosch process, which utilizes H2 and N2 under high temperature and pressure, resulting in high energy consumption and high cost. Recent studies have shown that NH3 can be synthesized from N2 and H2O via electrochemical methods, but N2 has poor solubility in water and the nitrogen-nitrogen bond energy (941 kJ•mol) remains a challenge. -1 The nitrogen content of nitrogen fertilizers is high, and the ammonia production faradaic efficiency is low, nearly three orders of magnitude lower than that of industrially synthesized NH3. Furthermore, due to the excessive use of nitrogen fertilizers and fuel combustion, NO3 production is also high. - NO3 has become one of the most common water pollutants. Its abundant accumulation in water bodies leads to water quality deterioration and threatens human health. - Electrocatalytic reduction to NH3 reaction (NITRR) is an excellent method for converting waste into valuable products and solving environmental and energy problems.

[0003] Despite the attractiveness of NITRR, its selectivity and efficiency are severely limited by its complex eight-electron reaction process and competing H2 production reaction: NO3 - + 6H2O + 8e - →NH3 + 9OH - 2H₂O + 2e - →H2 + 2OH - ; Furthermore, the complex side reactions involving nitrogen, nitrite, hydrazine, and hydroxylamine that result in NITRR interfere with the main NITRR process to some extent, and the catalyst synthesis is complex, with catalyst stability remaining a challenge. Therefore, the rational design and development of electrocatalysts to break the binding relationships between intermediates in the reaction pathway and inhibit HER are key measures to improve NITRR activity. Summary of the Invention

[0004] The purpose of this invention is to provide a Cu 1200 Ni 500 The method for preparing catalytic electrode materials aims to solve the problems existing in the background technology mentioned above.

[0005] The present invention is implemented as follows: a Cu 1200 Ni 500 The preparation method of the catalytic electrode material includes the following steps: Cu(NO3)2•3H2O was added to deionized water and ultrasonically treated to obtain a mixed solution. Constant voltage electroplating was then performed in a two-electrode system using carbon paper as the working electrode and a platinum electrode as the counter electrode for 1200 s to obtain Cu. 1200 electrode; NiSO4•6H2O and sodium citrate trihydrate were added to deionized water and ultrasonically treated to obtain a mixed solution. In a two-electrode system, Cu... 1200 The Cu electrode is used as the working electrode, and the platinum electrode is used as the counter electrode. Constant current electroplating is performed for 500 seconds to obtain the Cu. 1200 Ni 500 Catalytic electrode materials.

[0006] Preferably, in the step of adding Cu(NO3)2•3H2O to deionized water and ultrasonically treating it to obtain a mixed solution, the concentration of Cu(NO3)2•3H2O in the solution is 0.05-0.15 mol•L. -1 .

[0007] Preferably, in the step of adding NiSO4•6H2O and sodium citrate trihydrate to deionized water and ultrasonically treating to obtain a mixed solution, the concentration of NiSO4•6H2O in the solution is 0.05-0.15 mol•L. -1 .

[0008] Preferably, in the constant voltage electroplating step using carbon paper as the working electrode and platinum electrode as the counter electrode in the dual-electrode system, the voltage is -2.5V.

[0009] Preferably, in the two-electrode system, Cu 1200 In the constant current electroplating step where the electrode is the working electrode and the platinum electrode is the counter electrode, the current is -50mA.

[0010] Another objective of this invention is to provide a Cu 1200 Ni 500 Cu prepared by the method of preparing catalytic electrode material 1200 Ni 500 Catalytic electrode materials.

[0011] Another objective of this invention is to provide a Cu 1200 Ni 500 Application of catalytic electrode materials in the reduction of nitrate to ammonia.

[0012] Preferably, the ammonia production by nitrate reduction is carried out in an electrolytic cell by electrolysis. The electrolytic cell is a single-cell three-electrode system, in which Cu is the primary electrode. 1200 Ni 500The catalytic electrode material is used as the working electrode, platinum is used as the counter electrode, and Ag / AgCl is used as the reference electrode. The electrolytic cell uses Na2SO4 solution and NaNO3 solution as electrolytes.

[0013] Preferably, the concentration of the Na₂SO₄ solution is 0.1 mol•L. -1 The concentration of the NaNO3 solution is 1000 ppm.

[0014] Preferably, the voltage applied during energization is in the range of -0.5 to 0 V relative to the reversible hydrogen electrode.

[0015] An embodiment of the present invention provides a Cu 1200 Ni 500 The catalytic electrode material has a simple preparation process, low cost, and fast electrode preparation. It also exhibits good stability, high ammonia yield, and excellent Faraday efficiency in the electrochemical reduction of nitrate to ammonia. The entire reaction process requires simple equipment and has broad market application prospects. Attached Figure Description

[0016] Figure 1 Cu provided for embodiments of the present invention 1200 Ni 500 XRD characterization images of catalytic electrode materials and CuNi series catalytic electrode materials; Figure 2 Cu provided for embodiments of the present invention 1200 Ni 500 LSV curves of catalytic electrode materials and CuNi series catalytic electrode materials; Figure 3 Cu provided for embodiments of the present invention 1200 Ni 500 Ammonia production Faraday diagram of catalytic electrode materials and CuNi series catalytic electrode materials; Figure 4 Cu provided for embodiments of the present invention 1200 Ni 500 Faraday plot and ammonia yield plot of catalytic electrode materials; Figure 5 Cu provided for embodiments of the present invention 1200 Ni 500 Cyclic electrolysis stability diagram of catalytic electrode material. Implementation

[0017] 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.

[0018] A Cu 1200 Ni 500 The preparation method of the catalytic electrode material includes the following steps: 0.995–2.865 g of Cu(NO3)2•3H2O was added to 50–150 mL of deionized water and sonicated to obtain a mixed solution. In a two-electrode system, using carbon paper as the working electrode and a platinum electrode as the counter electrode, constant voltage electroplating was performed at a voltage of -2.5 V for 1200 s to obtain Cu. 1200 electrode; Add 1.05-4.20 g NiSO4•6H2O and 3-4 g sodium citrate trihydrate to 50-150 mL of deionized water and sonicate to obtain a mixed solution. In a two-electrode system, Cu... 1200 The Cu electrode is used as the working electrode, and the platinum electrode is used as the counter electrode. Constant current electroplating is performed with a current of -50 mA and a plating time of 500 s to obtain the Cu. 1200 Ni 500 Catalytic electrode materials.

[0019] The specific implementation of the present invention will be described in detail below with reference to specific embodiments. Example

[0020] A Cu 1200 Ni 500 The preparation method of the catalytic electrode material includes the following steps: 1.91 g of Cu(NO3)2•3H2O was added to 80 mL of deionized water and sonicated for 3 min to obtain a homogeneous copper nitrate solution. Electroplating was performed in a two-electrode system using 2 cm × 2 cm carbon paper as the working electrode and a platinum electrode as the counter electrode at -2.5 V for 1200 s to obtain Cu. 1200 electrode; Then, 2.1 g NiSO4•6H2O and 3.5292 g sodium citrate trihydrate were added to 80 mL of deionized water and sonicated for 5 min to obtain a mixed solution. The solution was then processed in a two-electrode system using Cu... 1200 The electrode is the working electrode, and the platinum electrode is the counter electrode. Constant current electroplating is performed with a plating current of -50 mA and a plating time of 500 s to obtain Cu. 1200 Ni 500 Catalytic electrode materials; The obtained material was subjected to X-ray diffraction analysis, and the results are as follows: Figure 1 As shown. Example

[0021] The catalyst electrode material prepared in Example 1 was applied to the electrocatalytic reduction of nitrate to ammonia, and the specific steps are as follows: A single-cell three-electrode electrolytic cell is used, with the three electrodes being the counter electrode (platinum electrode), the working electrode (Cu electrode), and the electrolytic cell. 1200 Ni 500 Catalytic electrode material), reference electrode (Ag / AgCl electrode), electrolyte solution of 0.1 mol•L -1 Na2SO4 solution and 1000ppm NaNO3 solution were prepared using a Chenhua 660 workstation. The main testing method was linear sweep voltammetry (LSV), with the applied voltage ranging from -0.6 to 0 V relative to the reversible hydrogen electrode. The results are as follows: Figure 2 As shown. Example

[0022] The catalyst electrode material prepared in Example 1 was applied to the electrocatalytic reduction of nitrate to ammonia, and the specific steps are as follows: A single-cell three-electrode electrolytic cell is used, with the three electrodes being the counter electrode (platinum electrode), the working electrode (Cu electrode), and the electrolytic cell. 1200 Ni 500 Catalytic electrode material), reference electrode (Ag / AgCl electrode), electrolyte solution of 0.1 mol•L -1 Na2SO4 solution and 1000ppm NaNO3 solution were prepared using a Chenhua 660 workstation. Its electrochemical performance was tested by controlling the voltage range within the range of -0.5 to -1.0 V (relative to the reversible hydrogen electrode). A sample was taken with a charge of 80 coulombs, and the Faraday efficiency was determined by ultraviolet spectrophotometry. The Faraday efficiency was then calculated, and the results are as follows: Figure 3 As shown. Example

[0023] Under the conditions of Example 3, the prepared Cu 1200 Ni 500 The catalytic electrode material was used as the working electrode, and all other conditions were the same as in Example 3. The specific test methods were also the same as in Example 3, including the Faraday efficiency test and the ammonia yield test. The best Faraday efficiency was 84.1%, and the ammonia yield was 180.5 μmol·h⁻¹. -1 •cm -2 The specific results are as follows Figure 4 As shown; In summary, the catalytic electrode material prepared in the embodiments of the present invention exhibits high ammonia yield and excellent Faraday efficiency during the electrochemical reduction of nitrate to ammonia. Example

[0024] Cu was prepared under the conditions of Example 1. 1200The electrode process is the same as in Example 1. Then, 2.1 g of NiSO4•6H2O and 3.5292 g of sodium citrate trihydrate are added to 80 ml of deionized water and sonicated for 5 min to obtain a mixed solution. In the dual-electrode system, Cu... 1200 The electrode is the working electrode, and the platinum electrode is the counter electrode. Constant current electroplating is performed with an electroplating current of -50mA and electroplating times of 100s, 250s, and 750s to obtain CuNi series catalytic electrode materials. X-ray diffraction analysis was performed on the obtained CuNi series catalytic electrode materials, and the results are as follows: Figure 1 As shown; The prepared catalytic electrode material was applied to the electrocatalytic reduction of nitrate to ammonia. The specific steps are as follows: a single-cell three-electrode electrolytic cell was used, with a counter electrode (platinum electrode), a working electrode (catalytic electrode material), and a reference electrode (Ag / AgCl electrode). The electrolyte solution was 0.1 mol•L. -1 Na2SO4 solution and 1000ppm NaNO3 solution were prepared using a Chenhua 660 workstation. The main testing method was linear sweep voltammetry (LSV), with the applied voltage ranging from -0.6 to 0 V relative to the reversible hydrogen electrode. The results are as follows: Figure 2 As shown. Example

[0025] Under the conditions of Example 5, the electrolysis system was the same as in Example 5. Its electrochemical performance was tested by controlling the voltage range to -0.5 to -1.0 V (relative to the reversible hydrogen electrode). A sample was taken with a charge of 80 coulombs, and the Faraday efficiency was determined by ultraviolet spectrophotometry. The Faraday efficiency was calculated, and the results are as follows: Figure 3 As shown. Example

[0026] The catalytic electrode material prepared in Example 1 was applied to a cyclic experiment of electrocatalytic reduction of nitrate to ammonia. Specifically, a single-cell three-electrode system was used, comprising a counter electrode (platinum electrode), a working electrode (catalytic electrode material), a reference electrode (Ag / AgCl electrode), and an electrolyte solution of 0.1 mol•L⁻¹. -1 Na2SO4 solution and 1000ppm NaNO3 solution were prepared using a Chenhua 660 workstation. The stability of the electrode material was tested by controlling a constant voltage of -0.8V (relative to the reversible hydrogen electrode). Sampling was performed with a charge of 80 coulombs. The electrolyte was replaced after each sampling, but the electrode remained the same. This cycle was repeated 6 times. The Faradaic efficiency and ammonia yield were determined by ultraviolet spectrophotometry. The Faradaic efficiency and ammonia yield were calculated, and the results are as follows: Figure 5As shown, after six cycles, the Faraday efficiency and yield did not fluctuate significantly, indicating that the catalytic electrode material prepared in this embodiment of the invention has good stability for the reduction of nitrate to ammonia. Example

[0027] Under the conditions of Example 1, Cu(NO3)2•3H2O was replaced with 0.955g and added to 80ml of deionized water. The solution was ultrasonically mixed for 3min to obtain a homogeneous copper nitrate solution. Electroplating was performed in a two-electrode system using 2cm×2cm carbon paper as the working electrode and a platinum electrode as the counter electrode at -2.5V for 1200s, yielding Cu... 1200 Electrode; then 1.05g NiSO4•6H2O and 3.5292g sodium citrate trihydrate were added to 80ml deionized water and sonicated for 5min to obtain a mixed solution. In the dual-electrode system, Cu 1200 The electrode is the working electrode, and the platinum electrode is the counter electrode. Constant current electroplating is performed with a plating current of -50 mA and a plating time of 500 s to obtain Cu. 1200 Ni 500 Catalytic electrode materials. Example

[0028] Under the conditions of Example 1, 2.65 g of Cu(NO3)2•3H2O was added to 80 ml of deionized water and sonicated for 3 min to obtain a homogeneous copper nitrate solution. Electroplating was performed in a two-electrode system using 2 cm × 2 cm carbon paper as the working electrode and a platinum electrode as the counter electrode at -2.5 V for 1200 s to obtain Cu. 1200 Electrode; then 4.2 g NiSO4•6H2O and 3.5292 g sodium citrate trihydrate were added to 80 ml deionized water and sonicated for 5 min to obtain a mixed solution. In the dual-electrode system, Cu 1200 The electrode is the working electrode, and the platinum electrode is the counter electrode. Constant current electroplating is performed with a plating current of -50 mA and a plating time of 500 s to obtain Cu. 1200 Ni 500 Catalytic electrode materials.

[0029] In this embodiment of the invention, the Faradaic efficiency and ammonia yield of ammonia were both determined by ultraviolet spectrophotometry, and the relevant formulas are as follows: The Faraday efficiency formula for ammonia is: FE = (8 * F * C * V) / (14 * Q) The ammonia yield formula is: Y (μmol•h) -1 •cm -2 = (C*V / 14*S*t) Where 8 represents the number of transferred electrons, F is the Faraday constant, C is the ammonia concentration (mg / L), V is the electrolyte volume (L), Q is the charge (C), and S is the electrode area (cm²). 2 ), where t is the reaction time (h).

[0030] 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. A Cu 1200 Ni 500 The method for preparing catalytic electrode materials is characterized by, Includes the following steps: Cu(NO3)2•3H2O was added to deionized water and ultrasonically treated to obtain a mixed solution. Constant voltage electroplating was then performed in a two-electrode system using carbon paper as the working electrode and a platinum electrode as the counter electrode for 1200 s to obtain Cu. 1200 electrode; NiSO4•6H2O and sodium citrate trihydrate were added to deionized water and ultrasonically treated to obtain a mixed solution. In a two-electrode system, Cu... 1200 The Cu electrode is used as the working electrode, and the platinum electrode is used as the counter electrode. Constant current electroplating is performed for 500 seconds to obtain the Cu. 1200 Ni 500 Catalytic electrode materials; In the constant voltage electroplating step using carbon paper as the working electrode and platinum electrode as the counter electrode in the dual-electrode system, the voltage is -2.5V; Cu 1200 In the constant current electroplating step where the electrode is the working electrode and the platinum electrode is the counter electrode, the current is -50mA.

2. The Cu according to claim 1 1200 Ni 500 The method for preparing catalytic electrode materials is characterized by, In the step of adding Cu(NO3)2•3H2O to deionized water and ultrasonically treating it to obtain a mixed solution, the concentration of Cu(NO3)2•3H2O in the solution is 0.05-0.15 mol•L. -1 .

3. The Cu according to claim 1 1200 Ni 500 The method for preparing catalytic electrode materials is characterized by, In the step of adding NiSO4•6H2O and sodium citrate trihydrate to deionized water and ultrasonically treating to obtain a mixed solution, the concentration of NiSO4•6H2O in the solution is 0.05-0.15 mol•L. -1 .

4. A Cu as described in any one of claims 1-3 1200 Ni 500 Cu prepared by the method of preparing catalytic electrode material 1200 Ni 500 Catalytic electrode materials.

5. A Cu as described in claim 4 1200 Ni 500 Application of catalytic electrode materials in the reduction of nitrate to ammonia.

6. The Cu according to claim 5 1200 Ni 500 The application of catalytic electrode materials in the reduction of nitrate to ammonia is characterized by, The ammonia production by nitrate reduction is carried out in an electrolytic cell by electrolysis. The electrolytic cell is a single-cell three-electrode system, in which Cu is the primary electrode. 1200 Ni 500 The catalytic electrode material is used as the working electrode, platinum is used as the counter electrode, and Ag / AgCl is used as the reference electrode. The electrolytic cell uses Na2SO4 solution and NaNO3 solution as electrolytes.

7. The Cu according to claim 6 1200 Ni 500 The application of catalytic electrode materials in the reduction of nitrate to ammonia is characterized by, The concentration of the Na₂SO₄ solution is 0.1 mol•L. -1 The concentration of the NaNO3 solution is 1000 ppm.

8. The Cu according to claim 6 1200 Ni 500 The application of catalytic electrode materials in the reduction of nitrate to ammonia is characterized by, The voltage applied during energization is in the range of -0.5 to 0 V relative to the reversible hydrogen electrode.

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