Nickel-based catalyst as well as preparation method and application thereof

Abstract

The invention discloses a nickel-based catalyst as well as a preparation method and application thereof. The preparation method of the nickel-based catalyst comprises the following steps: S1, carrying out electro-deposition on a deposition solution in a three-electrode system taking foamed nickel as a working electrode; a precursor material is obtained; the deposition liquid comprises nickel salt, cobalt salt, thiourea and a phosphorus source; the phosphorus source comprises hypophosphite and / or phosphite; and S2, carrying out annealing treatment on the precursor material. The nickel-based catalyst prepared by the preparation method disclosed by the invention is applied to a urea oxidation reaction and has relatively good catalytic activity and stability.

Description

Technical Field

[0001] This invention relates to a nickel-based catalyst, its preparation method, and its application. Background Technology

[0002] As the global energy structure shifts towards renewable energy sources such as wind and solar power, the key lies in converting intermittent energy into stable and storable chemical carriers. Hydrogen, as a clean secondary energy carrier, has attracted significant attention for its production technology via water electrolysis. However, the anodic oxygen evolution reaction (OER) occurring during water electrolysis has a high theoretical potential (1.23 V vs. RHE), leading to high energy consumption and low energy conversion efficiency in hydrogen production. To overcome these bottlenecks, researchers have recently proposed replacing OER with small-molecule oxidation reactions. Among these, the urea oxidation reaction (UOR) has a theoretical potential of only 0.37 V (vs. RHE), significantly lower than OER, theoretically potentially reducing hydrogen production energy consumption considerably. Furthermore, urea is widely present in industrial wastewater, domestic sewage, and agricultural runoff, making it a significant environmental pollutant. Coupled with the cathodic hydrogen evolution reaction, UOR can achieve low-energy hydrogen production while simultaneously purifying urea-containing wastewater, demonstrating both significant energy benefits and environmental value. UOR under alkaline conditions is a six-electron transfer reaction (CO(NH2)2 + 6OH-). − →N2 + CO2 + 5H2O + 6e − Due to its slow kinetics, it is of great significance to develop an efficient, stable and low-cost urea electro-oxidation catalyst.

[0003] Under alkaline conditions, transition metal nickel exhibits superior catalytic activity compared to noble metals in the urea oxidation reaction (UOR), leading to the widespread development of various nickel-based catalyst systems. Among these, nickel-based sulfides are considered a promising class of non-noble metal catalytic materials due to their excellent intrinsic activity and low cost. To further enhance catalytic performance, research has shown that introducing cobalt into the nickel matrix is ​​an effective strategy. Cobalt incorporation can modulate the electronic structure of nickel, reduce the formation potential of highly active, high-valence nickel species, thereby effectively lowering the onset overpotential of UOR and improving reaction kinetics.

[0004] However, there are still bottlenecks in improving the performance of UOR using a single nickel-cobalt sulfide system, and its catalytic activity and stability have not yet reached ideal levels. Summary of the Invention

[0005] The technical problem this invention aims to solve is to overcome the deficiency in existing technologies where nickel-based catalysts struggle to simultaneously achieve good catalytic activity and stability. This invention provides a nickel-based catalyst, its preparation method, and its applications. The nickel-based catalyst prepared according to this invention exhibits both superior catalytic activity and stability when applied to the urea oxidation reaction.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for preparing a nickel-based catalyst, comprising the following steps:

[0008] S1. Electrodeposit the deposition solution in a three-electrode system with nickel foam as the working electrode to obtain a precursor material; the deposition solution includes nickel salt, cobalt salt, thiourea and phosphorus source; the phosphorus source includes hypophosphite and / or phosphite;

[0009] S2. Anneal the precursor material.

[0010] In this invention, the three-electrode system is conventional in the art, generally including a working electrode, a reference electrode, and a counter electrode. The reference electrode is preferably silver chloride. The counter electrode is preferably a platinum sheet.

[0011] In this invention, the nickel foam can be selected according to conventional methods in the art. Specifically, the areal density of the nickel foam is preferably 100 g / m³. 2 The above, more preferably 200g / m 2 The above, for example, 286g / m 2 The preferred size of the nickel foam is (0.5-1.5) cm × (0.5-1.5) cm, for example, 1 × 1 cm.

[0012] In this invention, the nickel foam is preferably subjected to washing and drying steps before being used as a working electrode. The purpose of washing is to thoroughly remove the oxide layer and organic contaminants from the surface of the nickel foam. The washing is preferably performed by ultrasonic cleaning sequentially in hydrochloric acid aqueous solution, ethanol, and deionized water. The molar concentration of the hydrochloric acid aqueous solution is preferably 1-3 mol / L, for example, 2 mol / L. The ultrasonic cleaning time is preferably 5-15 min, for example, 10 min. The drying operation can be conventional in the art, such as vacuum drying. The drying temperature is preferably 50-80°C, for example, 60°C.

[0013] In this invention, the nickel salt can be of the conventional type in the art, and may include one or more of nickel sulfate, nickel sulfate hydrate, nickel chloride, nickel chloride hydrate, nickel nitrate and nickel nitrate hydrate, preferably nickel chloride and / or nickel chloride hydrate, such as nickel chloride hexahydrate (NiCl2·6H2O).

[0014] In this invention, the type of cobalt salt can be conventional in the art, and may include one or more of cobalt sulfate, cobalt sulfate hydrate, cobalt chloride, cobalt chloride hydrate, cobalt nitrate, and cobalt nitrate hydrate, preferably cobalt chloride and / or cobalt chloride hydrate, such as cobalt chloride hexahydrate (CoCl2·6H2O).

[0015] In this invention, the phosphorus source may be selected from one or more of hypophosphite, phosphite and their hydrates, preferably hypophosphite hydrates and / or phosphite, such as sodium hypophosphite monohydrate (NaH2PO2·H2O) or sodium phosphite.

[0016] In this invention, the molar ratio of the nickel salt, the cobalt salt, the thiourea and the phosphorus source can be 1:1:(6-8):(2-6), for example 1:1:7:5 or 1:1:6.6:4.7.

[0017] In this invention, the molar percentage of the nickel salt can be 1%-20%, preferably 3%-10%, for example 5.3%.

[0018] In this invention, the molar percentage of the cobalt salt can be 1%-20%, preferably 3%-10%, for example 5.3%.

[0019] In this invention, the molar percentage of thiourea can be 10%-60%, preferably 30%-40%, for example 34.7%.

[0020] In this invention, the molar percentage of the phosphorus source can be 10%-60%, preferably 20%-30%, for example 24.9%.

[0021] The above mole percentages represent the percentage of the number of moles of each component relative to the total number of moles of all components in the sediment.

[0022] In this invention, the preferred method for preparing the sedimentation solution includes the following steps: weighing nickel salt, cobalt salt, thiourea and phosphorus source respectively, adding deionized water to dissolve and make up to a certain volume.

[0023] In this invention, the sedimentation solution preferably further includes a buffer.

[0024] The buffer is preferably a weak acid or a weak acid salt, and more preferably selected from one or more of boric acid, borate, acetic acid, and acetate, such as boric acid. The weak acid refers to an acid with an ionization equilibrium constant Ka < 1. The weak acid salt refers to a salt compound formed by the combination of the anion of a weak acid and a metal cation (or ammonium ion).

[0025] The preferred molar ratio of the buffer to the nickel salt is 1:(4-7), for example, 1:5.6.

[0026] The molar concentration of the buffer in the sedimentation solution can be 0.5-0.8 mol / L, for example, 0.56 mol / L.

[0027] The preferred molar percentage of the buffer is 15%-50%, for example, 29.8%. The above molar percentage represents the percentage of the number of moles of the buffer relative to the total number of moles of all components in the sediment.

[0028] In this invention, the molar concentration of the nickel salt in the deposition solution can be 0.05-0.15 mol / L, for example 0.1 mol / L.

[0029] In this invention, the molar concentration of the cobalt salt in the deposition solution can be 0.05-0.15 mol / L, for example 0.1 mol / L.

[0030] In this invention, the molar concentration of thiourea in the sedimentation solution can be 0.5-1.0 mol / L, for example 0.66 mol / L.

[0031] In this invention, the molar concentration of the phosphorus source in the sedimentation solution can be 0.5-1.0 mol / L, for example 0.47 mol / L.

[0032] In this invention, the electrodeposition equipment can be conventional in the art, such as an electrolytic cell.

[0033] In this invention, the electrodeposition can be a conventional electrodeposition method in the art, preferably a constant current deposition. The preferred current intensity for electrodeposition is -10 mA·cm. −2 up to -100 mA·cm −2 For example, -20mA·cm −2 .

[0034] In this invention, the electrodeposition time can be the conventional electrodeposition time in the art, preferably 60s-300s, for example 120s.

[0035] In this invention, after electrodeposition and before annealing, a drying operation is preferably performed.

[0036] The drying method can be a conventional drying method in the art, preferably selected from one or more of low temperature drying, radiation drying and vacuum drying, such as vacuum drying.

[0037] The drying temperature can be a conventional drying temperature in the art, preferably 40-80℃, for example 60℃.

[0038] In this invention, the annealing equipment can be conventional in the art, such as a tube furnace.

[0039] In this invention, the annealing temperature can be 300°C-450°C, for example, 350°C.

[0040] In this invention, the annealing time can be 0.5-2 hours, for example, 1 hour.

[0041] In this invention, the heating rate from room temperature to the annealing temperature can be 3-8°C·min.-1 For example, 5°C·min -1 .

[0042] In this invention, the annealing treatment is preferably performed under an inert atmosphere. The inert atmosphere is preferably selected from one or more of helium, nitrogen, and argon, for example, nitrogen.

[0043] The present invention also provides a nickel-based catalyst, which is prepared by the preparation method described above.

[0044] The present invention also provides a nickel-based catalyst, the nickel-based catalyst comprising a nickel foam support and an active component supported on the nickel foam support; the active component comprises a Ni3S2 crystal phase, a Co9S8 crystal phase and a phosphorus-containing substance.

[0045] In this invention, the active ingredient is preferably in particulate form. The size of the active ingredient is preferably 100-200 nm.

[0046] In this invention, the molar ratio of Ni to Co in the active ingredient is preferably (0.8-1.2):(0.8-1.2), for example 1:1.

[0047] The present invention also provides the application of the nickel-based catalyst as described above in the urea oxidation reaction.

[0048] In this invention, the nickel-based catalyst can be directly used as a working electrode in the urea oxidation reaction without the need for a binder.

[0049] The positive and progressive effects of this invention are as follows:

[0050] (1) The present invention electrodeposits a deposition liquid including nickel salt, cobalt salt, thiourea and phosphorus source on a nickel foam support, and the resulting nickel-based catalyst has better catalytic kinetics and stability.

[0051] (2) By introducing phosphorus into nickel-cobalt bimetallic sulfide, the present invention effectively regulates the electronic structure of the catalyst and optimizes the surface nanomorphology, significantly enhances the conductivity of the catalyst, improves the reaction kinetics of the catalyst, and has a lower onset potential, higher current density and better stability when applied to UOR.

[0052] In some preferred embodiments of the present invention, the obtained nickel-based catalyst exhibits excellent electrocatalytic activity in urea electrolyte, along with rapid reaction kinetics, characterized by a low Tafel slope and small charge transfer resistance. Furthermore, it can operate stably for over 500 hours at high current densities without a significant increase in potential, demonstrating outstanding long-term stability.

[0053] (3) The nickel-based catalyst prepared by the present invention can be directly used as a working electrode in the urea oxidation reaction without the need for a binder, which effectively avoids the problems of active component shedding and large interfacial contact resistance of traditional powder catalysts.

[0054] (4) The preparation method provided by the present invention is simple, low-cost, requires no complex equipment, and is easy to scale up. Attached Figure Description

[0055] Figure 1 The XRD patterns are those of the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1.

[0056] Figure 2 The images show SEM images of the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1.

[0057] Figure 3 Part a shows a TEM image of the nickel-based catalyst prepared in Example 1 at a scale bar of 200 nm. Figure 3 The TEM image of the nickel-based catalyst prepared in Example 1 is shown in part b at a scale bar of 5 nm.

[0058] Figure 4 Part a consists of the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1, at a concentration of 1.0 mol·L⁻¹. -1 Cyclic voltammetry (CV) curves in KOH electrolyte; Figure 4 Part b refers to the nickel-based catalysts prepared in Example 1 and Comparative Example 1 at 1.0 mol·L⁻¹ -1 KOH + 0.5 mol·L -1 Linear sweep voltammetry (LSV) curves in urea electrolyte; Figure 4 Part c is a diagram of the Tafel slope obtained by linear fitting of the Tafel region based on the LSV curve. Figure 4 Part d is the electrochemical impedance spectroscopy (EIS) spectrum of the nickel-based catalysts prepared in Example 1 and Comparative Example 1 at 1.40 V (vs. RHE).

[0059] Figure 5 The nickel-based catalyst prepared in Example 1 was subjected to a reaction at 100 mA·cm⁻¹. -2 Figure showing the results of the time-voltage stability test under constant current density conditions. Detailed Implementation

[0060] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0061] Example 1:

[0062] S1, (1) Washing and drying of nickel foam: Take a piece of nickel foam with a size of 1cm×1cm and a surface density of 286g / m³. 2 Nickel foam, sequentially placed in 2 mol·L -1 The surface was ultrasonically cleaned for 10 minutes each in hydrochloric acid aqueous solution, anhydrous ethanol and deionized water to thoroughly remove the oxide layer and organic contaminants, and then vacuum dried at 60°C for later use.

[0063] (2) Preparation of sedimentation solution: Weigh 0.356 g nickel chloride hexahydrate (NiCl2·6H2O), 0.357 g cobalt chloride hexahydrate (CoCl2·6H2O), 0.75 g thiourea, 0.45 g sodium hypophosphite monohydrate (NaH2PO2·H2O) and 0.525 g boric acid (H3BO3), add deionized water to dissolve and make up to 15 mL to prepare sedimentation solution, and transfer to electrolytic cell.

[0064] (3) Preparation of precursor materials: A three-electrode system was constructed using washed and dried nickel foam as the working electrode, a platinum sheet as the counter electrode, and a silver chloride electrode in a saturated potassium chloride system as the reference electrode. The system was operated at a constant current density of -20 mA·cm⁻¹. −2 Electrodeposition was performed for 120 seconds to obtain the precursor material.

[0065] S2. After vacuum drying the precursor material at 60℃, place it in a tube furnace and heat it under a nitrogen atmosphere from room temperature (25℃) at a rate of 5℃·min. −1 The temperature was raised to 350℃, held for 1 hour, and then naturally cooled to room temperature to obtain a nickel-based catalyst, denoted as P-NiCoS / NF. This nickel-based catalyst comprises a nickel foam support and active components supported on the nickel foam support; the active components include Ni3S2 crystalline phase, Co9S8 crystalline phase, and phosphorus-containing substances; the molar ratio of Ni to Co is 1:1.

[0066] Comparative Example 1:

[0067] The difference between Comparative Example 1 and Example 1 is only in S1(2), where the sedimentation solution is prepared by the following method: 0.356 g of nickel chloride hexahydrate (NiCl2·6H2O), 0.357 g of cobalt chloride hexahydrate (CoCl2·6H2O), 1.5 g of thiourea and 0.525 g of boric acid (H3BO3) are weighed, dissolved in deionized water and diluted to 15 mL to prepare the sedimentation solution.

[0068] The remaining steps and parameters are the same as in Example 1.

[0069] The nickel-based catalyst prepared in this comparative example is denoted as NiCoS / NF.

[0070] Verification Example 1

[0071] 1. XRD Analysis

[0072] The nickel-based catalysts prepared in Example 1 and Comparative Example 1 were analyzed using a Bruker D8 Advance X-ray diffractometer. Figure 1 The images show the XRD patterns of the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1. Figure 1 It can be seen that both the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1 showed strong diffraction peaks belonging to nickel foam, as well as a set of diffraction peaks corresponding to Ni3S2 (PDF#01-076-1870), proving the successful synthesis of the nickel-based catalyst.

[0073] 2. SEM Analysis

[0074] The surface morphology of the nickel-based catalysts prepared in Example 1 and Comparative Example 1 was observed using a Zeiss Crossbeam 540 focused ion beam scanning electron microscope. Figure 2 Part a is a SEM image of the nickel-based catalyst prepared in Example 1. Figure 2 Part b shows the SEM images of the nickel-based catalyst prepared in Comparative Example 1. The resolution of all images is 1536×1024 pixels, and the magnification is 1000 times.

[0075] Depend on Figure 2 It can be seen that the nickel-based catalyst prepared in Example 1 has a rough surface with a large number of irregular nanoparticle clusters; while the nickel-based catalyst prepared in Comparative Example 1 has a relatively dense and smooth surface; indicating that phosphorus doping significantly changes the surface microstructure of the nickel-based catalyst.

[0076] 3. TEM analysis

[0077] Figure 3 The surface morphology of the nickel-based catalyst prepared in Example 1 is shown at different magnifications obtained using a Tecnai G2 F20 S-TWIN transmission electron microscope (TEM) from FEI. Figure 3 The scale bar for part a is 200 nm. Figure 3 The scale bar for part b is 5 nm.

[0078] Depend on Figure 3 As can be seen from part a, the chemical agent prepared in Example 1 exhibits a distinct nanoparticle stacking morphology, with particle sizes distributed between 100-200 nm. Figure 3 As can be seen from part b, in the higher resolution image, two sets of lattice fringes with different orientations can be clearly observed. Their interplanar spacings were measured to be 0.287 nm and 0.351 nm, respectively, corresponding to the (110) crystal plane of Ni3S2 and the (220) crystal plane of Co9S8, confirming the formation of the nickel-based catalyst.

[0079] The above test methods all verified the successful preparation of the nickel-based catalyst in Example 1.

[0080] Example 2: Electrochemical Performance Testing

[0081] Electrochemical performance tests were conducted in a standard three-electrode system. The nickel-based catalyst prepared in Example 1 or Comparative Example 1 was used as the working electrode, and a platinum electrode as the counter electrode. The Hg / HgO ratio was 1.0 mol·L⁻¹. −1 KOH was used as the reference electrode. The electrolyte was 1.0 mol·L⁻¹. -1 Potassium hydroxide solution and 0.5 mol·L -1 The mixed electrolyte prepared from urea aqueous solution.

[0082] Before conducting the formal test, the working electrode was placed in a 1.0 mol·L⁻¹ solution. -1 In potassium hydroxide electrolyte, within the potential range of 0–0.9 V (vs. Hg / HgO), the flow rate is 10 mV·s. -1 Cyclic voltammetry scans were performed at a certain scan rate until the cyclic voltammetry curves stabilized, thus completing the electrode activation process.

[0083] Linear scan voltammetry was performed within the same potential window at a scan rate of 5 mV·s. -1 During testing, 95% iR compensation was applied. All test potentials were converted to the reversible hydrogen electrode (RHE) scale using the following formula:

[0084] E(RHE) = E(Hg / HgO)+0.0592×pH + 0.098 V.

[0085] The Tafel slope is obtained by linearly fitting the Tafel region in the linear sweep voltammetric curve.

[0086] Electrochemical impedance spectroscopy (EIS) measurements were performed at a constant potential of 1.40 V (vs. RHE) over a frequency range of 10 Hz. 5 -0.1 Hz.

[0087] The stability of the electrode was evaluated by a time-potential test, in which the electrode potential was continuously tested for a preset time under constant current density conditions, and the changes in electrode potential over time were recorded.

[0088] The test results are as follows:

[0089] Figure 4 Part a represents the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1, at a concentration of 1.0 mol·L⁻¹. -1Cyclic voltammetry (CV) curves in KOH electrolyte. As shown in the figure, the Ni content in the nickel-based catalyst prepared in Example 1... 2+ / Ni 3+ The oxidation peak onset potential of the redox pair showed a significant negative shift compared to the nickel-based catalyst prepared in Comparative Example 1, indicating that phosphorus doping can reduce the energy barrier in the valence state transition process of nickel species and promote the high-valence active species Ni. 3+ The generation of urea helps to lower the onset potential of the urea oxidation reaction.

[0090] Figure 4 Part b consists of the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1, at a concentration of 1.0 mol·L⁻¹. -1 KOH + 0.5 mol·L -1 Linear sweep voltammetry (LSV) curves in urea electrolyte. It can be seen that the nickel-based catalyst prepared in Example 1 achieves 10 mA·cm⁻¹ at 1.27 V (vs. RHE). -2 The current density of the catalyst prepared in Example 1 was significantly higher than that of the nickel-based catalyst prepared in Comparative Example 1 throughout the entire test potential range, indicating that the nickel-based catalyst prepared in Example 1 exhibits higher electrochemical activity in the electrocatalytic oxidation of urea.

[0091] Figure 4 Part c shows the Tafel slope results obtained based on linear fitting of the LSV curve in the Tafel region. The Tafel slope of the nickel-based catalyst prepared in Example 1 is 72.5 mV·dec. -1 This is lower than the 79.4 mV·dec of the nickel-based catalyst prepared in Comparative Example 1. -1 This indicates that the nickel-based catalyst prepared in Example 1 has a faster reaction kinetics.

[0092] Figure 4 Part d shows the electrochemical impedance spectroscopy (EIS) spectra of the nickel-based catalyst prepared in Example 1 and the nickel-based catalyst prepared in Comparative Example 1, measured at 1.40 V (vs. RHE), with a test frequency range of 10. 5 -0.1 Hz. (By...) Figure 4 As can be seen from part d, the diameter of the impedance arc semicircle corresponding to the nickel-based catalyst prepared in Example 1 is significantly smaller than that of the nickel-based catalyst prepared in Comparative Example 1, indicating that it has a lower charge transfer resistance. This suggests that phosphorus doping helps to reduce the charge transport resistance at the electrode / electrolyte interface and improve the electronic conduction efficiency of the reaction system.

[0093] Figure 5 The nickel-based catalyst prepared in Example 1 was subjected to a reaction at 100 mA·cm⁻¹. -2The results of the chronopotential stability test under constant current density conditions are shown in the figure. As can be seen from the figure, the electrode potential remained stable throughout the 500-hour continuous test, without any obvious potential drift or performance degradation. This indicates that the nickel-based catalyst prepared in Example 1 has good electrochemical and structural stability under the strongly alkaline urea electrocatalytic oxidation reaction conditions.

[0094] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for preparing a nickel-based catalyst, characterized in that, It includes the following steps: S1. Electrodeposit the deposition solution in a three-electrode system with nickel foam as the working electrode to obtain a precursor material; the deposition solution includes nickel salt, cobalt salt, thiourea and phosphorus source; the phosphorus source includes hypophosphite and / or phosphite; S2. Anneal the precursor material.

2. The method for preparing the nickel-based catalyst according to claim 1, characterized in that, The preparation method of the nickel-based catalyst satisfies one or more of the following conditions: (1) The areal density of the nickel foam is 100 g / m³. 2 The above is preferably 200g / m 2 The above, for example, 286g / m 2 ; (2) The size of the nickel foam is (0.5-1.5) cm × (0.5-1.5) cm, for example, 1 × 1 cm; (3) The nickel foam is further subjected to washing and drying steps before being used as a working electrode; The washing process is preferably performed by ultrasonic cleaning in sequence with hydrochloric acid aqueous solution, ethanol, and deionized water; the molar concentration of the hydrochloric acid aqueous solution is preferably 1-3 mol / L, for example 2 mol / L; and the ultrasonic cleaning time is preferably 5-15 min, for example 10 min. The drying process is preferably vacuum drying; the drying temperature is preferably 50-80℃, for example, 60℃. (4) The reference electrode in the three-electrode system is silver chloride; (5) The counter electrode in the three-electrode system is a platinum sheet.

3. The method for preparing the nickel-based catalyst as described in claim 1, characterized in that, The preparation method of the nickel-based catalyst satisfies one or more of the following conditions: (1) The nickel salt comprises one or more of nickel sulfate, nickel sulfate hydrate, nickel chloride, nickel chloride hydrate, nickel nitrate and nickel nitrate hydrate, preferably nickel chloride and / or nickel chloride hydrate, such as nickel chloride hexahydrate; (2) The cobalt salt comprises one or more of cobalt sulfate, cobalt sulfate hydrate, cobalt chloride, cobalt chloride hydrate, cobalt nitrate and cobalt nitrate hydrate, preferably cobalt chloride and / or cobalt chloride hydrate, such as cobalt chloride hexahydrate; (3) The phosphorus source is selected from one or more of hypophosphite, phosphite and their hydrates, preferably hypophosphite hydrates and / or phosphite, such as sodium hypophosphite monohydrate or sodium phosphite.

4. The method for preparing the nickel-based catalyst according to claim 1, characterized in that, The preparation method of the nickel-based catalyst satisfies one or more of the following conditions: (1) The molar ratio of the nickel salt, the cobalt salt, the thiourea and the phosphorus source is 1:1:(6-8):(2-6), for example 1:1:7:5 or 1:1:6.6:4.7; (2) The molar percentage of the nickel salt is 1%-20%, preferably 3%-10%, for example 5.3%; (3) The molar percentage of the cobalt salt is 1%-20%, preferably 3%-10%, for example 5.3%; (4) The molar percentage of the thiourea is 10%-60%, preferably 30%-40%, for example 34.7%; (5) The molar percentage of the phosphorus source is 10%-60%, preferably 20%-30%, for example 24.9%; The mole percentage represents the percentage of the number of moles of each component relative to the total number of moles of all components in the sediment.

5. The method for preparing the nickel-based catalyst according to claim 1, characterized in that, The sedimentation solution also includes a buffer; The buffer is preferably a weak acid or a weak acid salt, and is more preferably selected from one or more of boric acid, borate, acetic acid and acetate, such as boric acid; The preferred molar ratio of the buffer to the nickel salt is 1:(4-7), for example, 1:5.6; The molar concentration of the buffer in the sedimentation solution is 0.5-0.8 mol / L, for example, 0.56 mol / L; The preferred molar percentage of the buffer is 15%-50%, for example, 29.8%; the above molar percentage represents the percentage of the number of moles of the buffer relative to the total number of moles of all components in the sediment.

6. The method for preparing the nickel-based catalyst according to claim 1, characterized in that, The preparation method of the nickel-based catalyst satisfies one or more of the following conditions: (1) The current intensity of the electrodeposition is -10 mA·cm −2 up to -100 mA·cm −2 For example, -20mA·cm −2 ; (2) The electrodeposition time is 60s-300s, for example 120s; (3) The annealing temperature is 300°C-450°C, for example 350°C; (4) The annealing time is 0.5-2 h, for example 1 h; (5) The heating rate from room temperature to the annealing temperature is 3-8°C·min. -1 For example, 5°C·min -1 ; (6) The annealing process is carried out under an inert atmosphere; The inert atmosphere is preferably selected from one or more of helium, nitrogen, and argon, such as nitrogen.

7. A nickel-based catalyst, characterized in that, It is prepared by the method for preparing nickel-based catalysts as described in any one of claims 1-6.

8. A nickel-based catalyst, characterized in that, The nickel-based catalyst comprises a nickel foam support and an active component supported on the nickel foam support; the active component comprises Ni3S2 crystal phase, Co9S8 crystal phase and phosphorus-containing substances.

9. The nickel-based catalyst according to claim 8, characterized in that, The nickel-based catalyst satisfies one or more of the following conditions: (1) The active ingredient is in granular form; (2) The size of the active ingredient is 100-200 nm; (3) The molar ratio of Ni to Co in the active ingredient is preferably (0.8-1.2):(0.8-1.2), for example 1:

1.

10. The use of a nickel-based catalyst as described in claim 8 or 9 in the urea oxidation reaction.

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