A metal-doped nickel-cobalt alloy catalyst, a preparation method and application thereof
By electrodepositing a metal-doped nickel-cobalt alloy catalyst on a conductive substrate, the problem of high cost of precious metal catalysts is solved, and efficient low-potential and highly selective product generation of glycerol electrooxidation is achieved. This catalyst is suitable for glycerol oxidation using non-precious metal-based catalysts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2023-09-13
- Publication Date
- 2026-04-28
AI Technical Summary
In the existing technology, precious metal catalysts are costly in the glycerol oxidation process, and their electrocatalytic performance needs to be improved, making it difficult to achieve efficient glycerol electrooxidation and control product selectivity.
A nickel-cobalt alloy catalyst with metal doping is used to grow nickel-cobalt alloy material on a conductive substrate by electrodeposition to form a wrinkled two-dimensional nanosheet structure for the electro-oxidation of glycerol. The doped metal in the catalyst is selected from copper, iron, manganese, chromium or aluminum.
It achieves a low oxidation potential and high formic acid selectivity in the electro-oxidation of glycerol, exhibits excellent catalytic performance, and has a simple and easy preparation method, making it suitable for large-scale production.
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Figure CN119615243B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrocatalytic materials technology, and particularly relates to a metal-doped nickel-cobalt alloy catalyst, its preparation method, and its application. Background Technology
[0002] As a sustainable and clean energy source, hydrogen (H2) is an essential part of future energy strategies. Water electrolysis is an effective method for producing clean and ultrapure hydrogen. However, the theoretical voltage for water decomposition is 1.23 V, resulting in slow reaction kinetics for the oxygen evolution reaction (OER) at the anode. Furthermore, the oxygen produced at the anode is prone to mixing with the H2 produced at the cathode, potentially leading to an explosion. Replacing the OER with organic oxidation is safer and more economical, not only reducing cell pressure but also generating high-value-added chemical products at the anode. Glycerol is a byproduct of biodiesel production; approximately 100 kg of glycerol can be produced from one ton of biodiesel. In recent years, with the rapid development of the biodiesel industry, glycerol production has increased annually, leading to a significant drop in glycerol prices. However, glycerol is an important biomass resource that can be converted into various high-value-added chemical products, such as glyceraldehyde, glyceric acid, hydroxymalonic acid, dihydroxyacetone, oxalic acid, lactic acid, glycolic acid, and formic acid, through processes such as oxidation, esterification, etherification, and acidification. Compared to traditional thermocatalysis and microbial fermentation processes, electrocatalysis offers many unique advantages in glycerol oxidation. First, the reaction takes place at room temperature and pressure, which is environmentally friendly. Second, the oxidation potential of glycerol is much lower than that of water. Finally, the selectivity of the products can be controlled by adjusting the catalyst and the electrocatalytic process. However, current research mainly focuses on noble metal catalysts. Considering cost and efficiency, it is more important to develop non-noble metal-based catalysts with excellent glycerol electrooxidation performance. Summary of the Invention
[0003] In view of this, the present invention provides a metal-doped nickel-cobalt alloy catalyst, its preparation method and application, the main purpose of which is to solve the technical problem that the catalytic performance of electrocatalysts needs to be improved.
[0004] On one hand, the present invention provides a metal-doped nickel-cobalt alloy catalyst, comprising a metal-doped nickel-cobalt alloy material, wherein the doping metal is selected from copper, iron, manganese, chromium or aluminum.
[0005] Optionally, the molar ratio of nickel, cobalt and doped metal in the metal-doped nickel-cobalt alloy material is 1:(0.1~2):(0.001~0.1).
[0006] Optionally, the molar ratio of cobalt to nickel is selected from any value or a range between 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0.
[0007] Optionally, the molar ratio of the doped metal to the nickel is selected from any value or a range between 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1.
[0008] Optionally, the metal-doped nickel-cobalt alloy catalyst further includes a conductive substrate; the metal-doped nickel-cobalt alloy material is loaded on the surface of the conductive substrate.
[0009] The mass ratio of the metal-doped nickel-cobalt alloy material to the conductive substrate of the present invention can be adjusted according to actual needs.
[0010] Optionally, the metal-doped nickel-cobalt alloy catalyst has a wrinkled two-dimensional nanosheet structure, and its crystal structure belongs to the face-centered cubic structure.
[0011] The metal-doped nickel-cobalt alloy catalyst provided by this invention has excellent electrocatalytic performance, exhibiting a low oxidation potential and high formic acid selectivity in the electro-oxidation of glycerol.
[0012] Secondly, the present invention provides a method for preparing a metal-doped nickel-cobalt alloy catalyst, the method comprising the following steps:
[0013] The metal-doped nickel-cobalt alloy catalyst is obtained by electrodeposition of raw materials containing nickel salt, cobalt salt and doped metal salt on a conductive substrate.
[0014] The doped metal salt is selected from copper salt, iron salt, manganese salt, chromium salt or aluminum salt.
[0015] Optionally, the molar ratio of the nickel salt, the cobalt salt, and the doped metal salt is 1:(0.1~2):(0.001~0.1).
[0016] Optionally, the molar ratio of the cobalt salt to the nickel salt is selected from any value of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0 or a range between any two.
[0017] Optionally, the molar ratio of the doped metal salt to the nickel salt is selected from any value or a range between 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1.
[0018] Optionally, the electrodeposition process includes:
[0019] The electrolyte is a mixed solution of nickel salt, cobalt salt, doped metal salt and solvent;
[0020] A three-electrode mode is adopted, with a conductive substrate as the working electrode, and a counter electrode and a reference electrode, and deposition is carried out in a constant potential manner.
[0021] Optionally, the electrodeposition potential is -0.5 ~ -1.5 V, and the deposition time is 150 ~ 3600 s.
[0022] Optionally, the nickel salt is a divalent nickel salt.
[0023] Optionally, the divalent nickel salt is selected from nickel chloride and / or nickel sulfate.
[0024] The nickel salts of the present invention can also be selected from the prior art according to actual needs.
[0025] Optionally, the cobalt salt is a divalent cobalt salt.
[0026] Optionally, the divalent cobalt salt is selected from cobalt chloride and / or cobalt sulfate.
[0027] The cobalt salt of the present invention can also be selected from other types of existing technologies according to actual needs.
[0028] Optionally, the doped metal salt is the corresponding chloride and / or sulfate.
[0029] The doped metal salts of the present invention can also be selected from the prior art according to actual needs.
[0030] Optionally, the electrolyte may also include hydrochloric acid.
[0031] Optionally, the hydrochloric acid accounts for 0 to 0.01% of the total volume of the electrolyte.
[0032] Optionally, the conductive substrate is selected from carbon paper, carbon cloth, nickel foam, copper foam, iron foam, copper sheet, iron sheet or nickel sheet.
[0033] This invention provides a specific implementation method, including the following steps:
[0034] Step A: Add nickel salt, cobalt salt, and doped metal salt to water in a certain proportion, then add a certain amount of hydrochloric acid and mix well.
[0035] Step B: Using the above mixed solution as the electrolyte, a three-electrode mode is adopted, with a self-supporting substrate (i.e., a conductive substrate) as the working electrode, along with a counter electrode and a reference electrode, and deposition is carried out at a constant potential for a certain period of time.
[0036] Thirdly, the present invention provides the application of the above-mentioned metal-doped nickel-cobalt alloy catalyst as an electrocatalyst in the electro-oxidation of glycerol to formic acid.
[0037] Optionally, in the electro-oxidation process, the aforementioned metal-doped nickel-cobalt alloy catalyst is used as the working electrode, Hg / HgO is used as the reference electrode, a graphite rod is used as the counter electrode, and a mixed solution of 1 M potassium hydroxide and 0.1 M glycerol is used as the electrolyte.
[0038] Compared with the prior art, the present invention has the following beneficial effects:
[0039] 1) The metal-doped nickel-cobalt alloy catalyst provided by the present invention has excellent electrocatalytic performance, exhibiting a low oxidation potential and high formic acid selectivity in the electro-oxidation of glycerol.
[0040] 2) The preparation method of the metal-doped nickel-cobalt alloy catalyst provided by the present invention is simple and easy to implement, and easy to scale up production. Attached Figure Description
[0041] Figure 1 The X-ray diffraction (XRD) patterns of Example 1 of the present invention before and after iron doping are shown.
[0042] Figure 2 This is a scanning electron microscope (SEM) image of the manganese-doped nickel-cobalt alloy of Example 2 of the present invention;
[0043] Figure 3 The cyclic voltammetry (LSV) curves of the aluminum-doped nickel-cobalt alloy in 1M KOH and 0.1M glycerol electrolyte of Example 3 of the present invention are shown.
[0044] Figure 4 These are the products of copper-doped nickel-cobalt alloy under different voltages in Example 4 of the present invention. Detailed Implementation
[0045] The present application is further illustrated below with reference to specific embodiments. The following descriptions are merely a few embodiments of the present application and are not intended to limit the present application in any way. Although the present application discloses preferred embodiments as follows, they are not intended to limit the present application. Any modifications or variations made by those skilled in the art without departing from the scope of the technical solution of the present application using the disclosed technical content are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.
[0046] Unless otherwise specified, the raw materials used in the embodiments of this application are all purchased commercially and used directly without any special treatment.
[0047] Unless otherwise specified, the analytical methods in the embodiments all adopt conventional instrument or equipment settings and conventional analytical methods.
[0048] The analysis method in this embodiment of the invention is as follows:
[0049] Linear scanning voltammetry curves were tested using a CHI 760E electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.) (voltage 0-0.6 V (vs. Hg / HgO), scan rate 10 mV / s, electrolyte was a mixed solution of 1 M KOH and 0.1 M glycerol).
[0050] The product was detected by high performance liquid chromatography (HPLC) with 5 mM H2SO4 as the mobile phase.
[0051] Example 1 (Iron-doped nickel-cobalt alloy catalyst)
[0052] Prepare 20 mL of a solution of 0.2 M nickel sulfate, 0.2 M cobalt sulfate, 0.0005 M ferric sulfate, and 20 μL of 2 M hydrochloric acid, and stir well to form an electrolyte. Use an Ag / AgCl electrode as the reference electrode, a graphite rod as the counter electrode, and carbon paper as the working electrode to assemble a three-electrode system. Deposition is performed using a constant potential method with a deposition voltage of -1 V (vs. Ag / AgCl) and a deposition time of 1200 s. After deposition, rinse with deionized water and dry at room temperature to obtain the iron-doped nickel-cobalt alloy catalyst.
[0053] Figure 1 The XRD pattern shows that the diffraction peaks remain unchanged before and after iron doping, still being the diffraction peaks of nickel and cobalt. Furthermore, the catalyst has a face-centered cubic crystal structure.
[0054] Example 2 (Manganese-doped nickel-cobalt alloy catalyst)
[0055] Prepare 20 mL of 0.2 M nickel sulfate, 0.4 M cobalt sulfate, 0.01 M manganese sulfate, and 100 μL of 1 M hydrochloric acid solution, stir well, and use as the electrolyte. Use an Ag / AgCl electrode as the reference electrode, a graphite rod as the counter electrode, and a copper sheet as the working electrode to assemble a three-electrode system. Deposition is carried out using a constant potential method with a deposition voltage of -1.5 V (vs. Ag / AgCl) and a deposition time of 300 s. After the deposition is completed, rinse with deionized water and dry at room temperature to obtain the manganese-doped nickel-cobalt alloy catalyst.
[0056] Figure 2The image shows a SEM image of a manganese-doped nickel-cobalt alloy, which clearly shows a nanosheet-like structure.
[0057] Example 3 (Aluminum-doped nickel-cobalt alloy catalyst)
[0058] Prepare 20 mL of 0.2 M nickel chloride, 0.05 M cobalt chloride, 0.002 M aluminum chloride, and 50 μL of 1 M hydrochloric acid solution, stir well, and use as the electrolyte. Use an Ag / AgCl electrode as the reference electrode, a graphite rod as the counter electrode, and nickel foam as the working electrode to assemble a three-electrode system. Deposition is carried out using a constant potential method, with a deposition voltage of -1.2 V (vs. Ag / AgCl) and a deposition time of 600 s. After the deposition is completed, rinse with deionized water and dry at room temperature to obtain the aluminum-doped nickel-cobalt alloy catalyst.
[0059] Example 4 (Copper-doped nickel-cobalt alloy catalyst)
[0060] Prepare 20 mL of 0.2 M nickel chloride, 0.1 M cobalt chloride, 0.001 M copper chloride, and 10 μL of 5 M hydrochloric acid solution, stir well, and use as the electrolyte. Use an Ag / AgCl electrode as the reference electrode, a graphite rod as the counter electrode, and nickel foam as the working electrode to assemble a three-electrode system. Deposition is carried out using a constant potential method with a deposition voltage of -0.8 V (vs. Ag / AgCl) and a deposition time of 1800 s. After the deposition is completed, rinse with deionized water and dry at room temperature to obtain the copper-doped nickel-cobalt alloy catalyst.
[0061] Example 5 (Electro-oxidation application)
[0062] The aluminum-doped nickel-cobalt alloy prepared in Example 3 was used as the working electrode, Hg / HgO as the reference electrode, a graphite rod as the counter electrode, and a mixed solution of 1 M potassium hydroxide and 0.1 M glycerol as the electrolyte. The linear sweep voltammetry curve was tested using a CHI 760E electrochemical workstation (voltage range: 0~0.6 V (vs. Hg / HgO), scan rate: 10 mV / s).
[0063] like Figure 3 As shown, at 10 mA / cm 2 The voltage at the current density was 1.23 V (vs. RHE), and the doped catalyst showed excellent electro-oxidation performance of glycerol.
[0064] Example 6 (Electro-oxidation application)
[0065] The copper-doped nickel-cobalt alloy prepared in Example 4 was used as the working electrode, Hg / HgO as the reference electrode, and a graphite rod as the counter electrode. A mixed solution of 1 M potassium hydroxide and 0.1 M glycerol was used as the electrolyte. Time-current curves were measured using a CHI 760E electrochemical workstation at voltages of 1.35, 1.4, 1.45, 1.5, 1.55, and 1.6 V (vs. RHE). The product was quantitatively analyzed by high-performance liquid chromatography (HPLC) with 5 mM H₂SO₄ as the mobile phase.
[0066] Figure 4 The figure shows the products and their selectivity obtained under different voltages. As can be seen from the figure, the main product of the electro-oxidation of glycerol is formic acid, with a selectivity of up to 80%.
[0067] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A metal-doped nickel-cobalt alloy catalyst, characterized in that, The metal-doped nickel-cobalt alloy catalyst comprises a metal-doped nickel-cobalt alloy material, wherein the doping metal is selected from copper or aluminum; The molar ratio of nickel, cobalt and doped metal in the metal-doped nickel-cobalt alloy material is 1:(0.1 ~ 2):(0.001 ~ 0.009).
2. The metal-doped nickel-cobalt alloy catalyst according to claim 1, characterized in that, The metal-doped nickel-cobalt alloy catalyst further includes a conductive substrate; the metal-doped nickel-cobalt alloy material is loaded on the surface of the conductive substrate.
3. The metal-doped nickel-cobalt alloy catalyst according to claim 1, characterized in that, The metal-doped nickel-cobalt alloy catalyst has a wrinkled two-dimensional nanosheet structure, and its crystal structure belongs to the face-centered cubic structure.
4. A method for preparing a metal-doped nickel-cobalt alloy catalyst according to any one of claims 1 to 3, characterized in that, The method includes the following steps: The metal-doped nickel-cobalt alloy catalyst is obtained by electrodeposition of raw materials containing nickel salt, cobalt salt and doped metal salt on a conductive substrate. The doped metal salt is selected from copper salt or aluminum salt.
5. The method for preparing a metal-doped nickel-cobalt alloy catalyst according to claim 4, characterized in that, The electrodeposition process includes: The electrolyte is a mixed solution of nickel salt, cobalt salt, doped metal salt and solvent; A three-electrode mode is adopted, with a conductive substrate as the working electrode, and a counter electrode and a reference electrode, and deposition is carried out in a constant potential manner.
6. The method for preparing a metal-doped nickel-cobalt alloy catalyst according to claim 4, characterized in that, The electrodeposition potential is -0.5 ~ -1.5 V, and the deposition time is 150 ~ 3600 s.
7. The method for preparing a metal-doped nickel-cobalt alloy catalyst according to claim 4, characterized in that, The nickel salt is a divalent nickel salt, selected from nickel chloride and / or nickel sulfate; the cobalt salt is a divalent cobalt salt, selected from cobalt chloride and / or cobalt sulfate; the doped metal salt is the corresponding chloride and / or sulfate.
8. The method for preparing a metal-doped nickel-cobalt alloy catalyst according to claim 5, characterized in that, The electrolyte also includes hydrochloric acid; the hydrochloric acid accounts for 0 to 0.01% of the total volume of the electrolyte.
9. The method for preparing a metal-doped nickel-cobalt alloy catalyst according to claim 4, characterized in that, The conductive substrate is selected from carbon paper, carbon cloth, nickel foam, copper foam, iron foam, copper sheet, iron sheet or nickel sheet.
10. The application of the metal-doped nickel-cobalt alloy catalyst according to any one of claims 1 to 3 as an electrocatalyst in the electro-oxidation of glycerol to formic acid.
11. The application according to claim 10, characterized in that, In the electro-oxidation process, a metal-doped nickel-cobalt alloy catalyst as described in any one of claims 1 to 3 is used as the working electrode, Hg / HgO is used as the reference electrode, a graphite rod is used as the counter electrode, and a mixed solution of 1 M potassium hydroxide and 0.1 M glycerol is used as the electrolyte.