Composite catalytic electrode material, preparation method and application
By adsorbing MoO42- anions onto the (CoNiFe)OOH nanoporous structure, the catalytic site is anchored, which solves the problem of unstable cation oxygen evolution catalytic sites and improves the stability and activity of the catalytic electrode.
Patent Information
- Application Number
- CN202511908570.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-17
- Publication Date
- 2026-02-24
AI Technical Summary
In existing technologies, the cation oxygen evolution catalytic sites of Co, Ni, and Fe-based catalysts are unstable in alkaline electrolyte solutions, leading to a decline in catalytic performance.
By adsorbing MoO42- anions on the (CoNiFe)OOH nanoporous structure, the MoO3/CoNiFe composite precursor reacts with OH- at an oxidizing potential to generate MoO42-, anchoring the catalytic site and forming a composite catalytic electrode material.
It improves the stability and electrochemical active area of the catalytic electrode, reduces the cation solubility, and enhances the catalytic performance of the oxygen evolution reaction.
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Figure CN121556066A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrocatalytic hydrogen production technology, and more particularly to a method with a surface covered with MoO4. 2- Anion-modified (CoNiFe)OOH composite catalytic electrode material, preparation method and application. Background Technology
[0002] The energy crisis and environmental degradation caused by the overconsumption of fossil fuels are becoming increasingly severe, making the development of efficient and clean renewable energy sources a global research hotspot. Hydrogen, with its high energy density, pollution-free combustion, and diverse applications, is considered an ideal clean secondary energy source. The "green hydrogen" industry, which combines renewable energy with water electrolysis for hydrogen production, has advantages for sustainable development. However, the slow kinetics of the oxygen evolution reaction at the anode in water electrolysis severely restricts hydrogen production efficiency, and current mainstream noble metal oxide catalysts (such as IrO2 and RuO2) suffer from resource scarcity and high costs. This has prompted researchers to turn their attention to transition metal-based catalysts, which are abundant in reserves.
[0003] Among transition metal-based catalysts with electronic structures similar to noble metals, Co, Ni, and Fe-based oxides, hydroxides, and their hydroxy oxides have been shown to be oxygen evolution reaction (OER) catalysts with catalytic performance comparable to noble metal oxides. However, as the catalytically active sites for OER, Co, Ni, and Fe are typically over-oxidized during the anodic reaction, dissolving as high-valence cations in the alkaline electrolyte solution, thus leading to a decline in OER catalytic performance.
[0004] How to stabilize the aforementioned cation oxygen evolution catalytic sites and reduce their dissolution during the electrocatalytic oxygen evolution reaction is a current research hotspot for high-performance oxygen evolution reaction catalytic electrodes. Summary of the Invention
[0005] To address the shortcomings of existing technologies, this invention provides a composite catalytic electrode material, its preparation method, and its application, thereby solving the technical problems of unstable anchoring of active sites and high cation solubility in oxygen evolution catalysis.
[0006] This invention provides a composite catalytic electrode material comprising: a (CoNiFe)OOH nanoporous structure and MoO4 adsorbed on the (CoNiFe)OOH nanoporous structure. 2- The anion was obtained by electrochemical oxidation of the MoO3 / CoNiFe composite precursor, wherein MoO4 2- The anion anchors the catalytic site of the (CoNiFe)OOH cation.
[0007] Furthermore, the method for obtaining the (CoNiFe)OOH nanoporous structure is as follows:
[0008] It was obtained by electrochemical anodic oxidation reconstruction of CoNiFe alloy in the MoO3 / CoNiFe composite precursor.
[0009] Furthermore, the MoO4 2- The method for obtaining anions is as follows:
[0010] The MoO3 oxide in the MoO3 / CoNiFe composite precursor reacts with OH- in the alkaline electrolyte solution at an oxidizing potential. - The reaction is obtained.
[0011] Furthermore, in the composite catalytic electrode material, the molar ratio of iron, cobalt, nickel, and molybdenum is 1:1:1:1~1.5.
[0012] Furthermore, in the composite catalytic electrode material, the molar ratio of iron, cobalt, nickel, and molybdenum is 1:1:1:1.3.
[0013] The present invention also provides a method for preparing a composite catalytic electrode material, comprising the following steps:
[0014] Step 1: Mix iron-containing metal nitrate, cobalt-containing metal nitrate, nickel-containing metal nitrate and ammonium molybdate in a molar ratio of 1:1:1:1~1.5, then dissolve glycine fuel in deionized water solvent and stir until homogeneous to form a mixed solution;
[0015] Step 2: Place the nickel foam into a ceramic boat containing the mixed solution prepared in Step 1, and place it in a high-temperature furnace for self-propagating combustion to prepare a MoO3 / CoNiFe composite precursor with a porous structure grown on the surface of the nickel foam.
[0016] Step 3: Electrochemically oxidize the MoO3 / CoNiFe composite precursor prepared in Step 2 using a constant potential oxidation method to obtain MoO4. 2- A composite catalytic electrode material with anion-modified (CoNiFe)OOH nanoporous layers.
[0017] Furthermore, in step 1, the molar ratio of glycine fuel to total metal cations is 1.5:1, and the amount of deionized water used is 4 mL.
[0018] Furthermore, in step 2, the specific process of self-propagating combustion is as follows: the temperature is increased to 300°C at a rate of 5°C / min, without holding time, and then naturally cooled to room temperature.
[0019] Furthermore, in step 3, the specific process of the constant potential oxidation method is as follows: using the nickel foam loaded with precursor material in step 2 as the working electrode; using Ag / AgCl as the reference electrode; using a platinum sheet as the counter electrode; using 1 M KOH as the electrolyte solution, and performing electrochemical oxidation at the potential corresponding to the oxygen evolution reaction for an oxidation time of not less than 3 hours.
[0020] This invention also provides an application of a composite catalytic electrode material in alkaline water electrolysis for hydrogen production.
[0021] The beneficial effects of this invention are:
[0022] This invention relates to the in-situ reaction of MoO3 to generate MoO4 under alkaline electrolyte conditions. 2- Anions are adsorbed onto (CoNiFe)OOH, MoO4 2- Anions can anchor the catalytic sites of Co, Ni, and Fe in (CoNiFe)OOH through electrostatic attraction, thereby reducing the solubility of metal cations in the electrolyte solution and ensuring the stability of oxygen evolution catalysis of the electrode.
[0023] This invention utilizes solution combustion synthesis technology to prepare a precursor composite material in which MoO3 oxide is grown in situ in CoNiFe alloy, which is beneficial for the uniform adsorption of anions in the oxidation reconstruction product.
[0024] This invention utilizes electrochemical oxidation technology to transform CoNiFe alloy in situ into the corresponding metal hydroxyl oxide. This oxidative reconstruction not only generates (CoNiFe)OOH species with high catalytic activity, but also effectively increases the electrochemical active area of the electrode. Attached Figure Description
[0025] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings:
[0026] Figure 1 This is a structural model diagram of a specific embodiment of the present invention;
[0027] Figure 2 This is a SEM image of the CoNiFe alloy with a hierarchical porous structure in specific embodiment 1 of the present invention;
[0028] Figure 3 These are the potentiostatic chronoamperometry curves of the electrodes in specific embodiments 1 and 2 of the present invention during the electrochemical oxidation process;
[0029] Figure 4 The image shows the SEM image of the CoNiFeMo@NF electrode after electrochemical oxidation reconstruction in specific embodiment 2 of this invention.
[0030] Figure 5 The image shows the EDS spectrum of the CoNiFeMo@NF electrode material after electrochemical oxidation reconstruction in specific embodiment 2 of the present invention.
[0031] Figure 6 The chronoamperometry curves for oxygen evolution catalytic stability testing of the CoNiFeMo@NF electrode material after electrochemical oxidation reconstruction in Specific Embodiment 2 of the present invention are shown. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0033] The present invention will be further illustrated below with reference to specific embodiments. Those skilled in the art should understand that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Modifications to the present invention in various equivalent forms all fall within the scope defined by the appended claims.
[0034] like Figure 1 As shown, a specific embodiment of the present invention provides a composite catalytic electrode material, comprising: a (CoNiFe)OOH nanoporous structure and MoO4 adsorbed on the (CoNiFe)OOH nanoporous structure. 2- The anion was obtained by electrochemical oxidation of the MoO3 / CoNiFe composite precursor, wherein MoO4 2- The anion anchors the catalytic site of the (CoNiFe)OOH cation.
[0035] (CoNiFe)OOH is obtained by electrochemical oxidation reconstruction of the CoNiFe alloy precursor in an alkaline electrolyte solution, serving as the actual active site for oxygen evolution catalysis. (MoO4) 2- Anions are formed when MoO3 oxide from the precursor reacts with OH- in an alkaline electrolyte solution at the oxidation potential. - The reaction produces and adsorbs onto the (CoNiFe)OOH surface, anchoring the catalytic site.
[0036] MoO4 was constructed in situ. 2- Anion-modified (CoNiFe)OOH composite catalytic electrode material is used to anchor the active sites of oxygen evolution catalysis and reduce cation solubility. MoO4 2-The composite nanoporous layer formed by anion and (CoNiFe)OOH can be used as a stable oxygen evolution reaction catalytic electrode.
[0037] A specific embodiment of the present invention also provides a method for preparing a composite catalytic electrode material, comprising the following steps:
[0038] Step 1: Mix iron-containing metal nitrate, cobalt-containing metal nitrate, nickel-containing metal nitrate and ammonium molybdate in a molar ratio of 1:1:1:1~1.5, then dissolve glycine fuel in deionized water solvent and stir until homogeneous to form a mixed solution;
[0039] Step 2: Place the nickel foam into a ceramic boat containing the mixed solution prepared in Step 1, and place it in a high-temperature furnace for self-propagating combustion to prepare a MoO3 / CoNiFe composite precursor with a porous structure grown on the surface of the nickel foam. The specific process of self-propagating combustion is as follows: heat up to 300 °C at a rate of 5 °C / min, without holding time, and then cool naturally to room temperature.
[0040] Step 3: Electrochemically oxidize the MoO3 / CoNiFe composite precursor prepared in Step 2 using a constant potential oxidation method to obtain MoO4. 2- The composite catalytic electrode material of anion-modified (CoNiFe)OOH nanoporous layer, wherein the specific process of the constant potential oxidation method is as follows: using nickel foam loaded with precursor material in step 2 as the working electrode; using Ag / AgCl as the reference electrode; using a platinum sheet as the counter electrode; using 1 M KOH as the electrolyte solution, electrochemical oxidation is carried out at the potential corresponding to the oxygen evolution reaction, and the oxidation time is not less than 3 hours.
[0041] The effects of the present invention are illustrated below through three examples, wherein Example 1 serves as a control group;
[0042] Example 1:
[0043] MoO4 was not introduced 2- The preparation method of the anion-based (CoNiFe)OOH catalytic electrode (CoNiFe@NF) includes the following steps:
[0044] Step 1: Cut the nickel foam into pieces with a working area of 1*1 cm. 2 The sample was then placed in 3 M dilute hydrochloric acid and ultrasonically cleaned for 5 minutes, then placed in anhydrous ethanol and ultrasonically cleaned for 5 minutes, and finally immersed in deionized water and ultrasonically cleaned for 5 minutes. The cleaning process can remove oil and oxides from the surface of the nickel foam.
[0045] Step 2: Weigh out 1 mmol of Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Fe(NO3)3·9H2O and 5.84 mmol of glycine respectively, dissolve them all in 3 mL of deionized water solvent, and stir thoroughly at room temperature to form a homogeneous solution;
[0046] The pretreated nickel foam was immersed in 1 mL of the above solution and placed in a muffle furnace. The temperature was increased to 300 °C at a rate of 5 °C / min, and then allowed to cool naturally to room temperature to obtain the CoNiFe alloy grown on the nickel foam. Its microstructure is as follows: Figure 2 As shown;
[0047] Step 3: Using the nickel foam with CoNiFe alloy grown above as the working electrode, Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and 1M KOH as the electrolyte solution, the oxygen evolution reaction current density is 20 mA cm⁻¹. -2 Electrochemical oxidation was carried out at the corresponding potential for 3 hours.
[0048] like Figure 3 As shown, after 3 hours of electrochemical oxidation, the current density of the oxygen evolution reaction decreased by 6.5%, indicating that the catalytic sites of (CoNiFe)OOH dissolved due to excessive oxidation during the oxygen evolution catalysis process, resulting in a decrease in catalytic activity and insufficient catalytic stability.
[0049] Example 2:
[0050] A method of introducing MoO4 2- The preparation method of anion-modified (CoNiFe)OOH catalytic electrode material (CoNiFeMo@NF) includes the following steps:
[0051] Step 1: Cut the nickel foam into pieces with a working area of 1*1 cm. 2 The sample was then placed in 3 M dilute hydrochloric acid and ultrasonically cleaned for 5 minutes, then placed in anhydrous ethanol and ultrasonically cleaned for 5 minutes, and finally immersed in deionized water and ultrasonically cleaned for 5 minutes. The above cleaning process can remove oil and oxides from the surface of the nickel foam.
[0052] Step 2: Weigh 1 mmol of Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, (NH4)2MoO4 and 7.5 mmol of glycine respectively, dissolve them all in 4 mL of deionized water solvent, and stir thoroughly at room temperature to form a homogeneous solution;
[0053] The pretreated nickel foam was immersed in 1 mL of the above solution and placed in a muffle furnace. The temperature was increased to 300 °C at a rate of 5 °C / min without holding time. Then it was naturally cooled to room temperature to obtain the MoO3 / CoNiFe composite precursor grown on the nickel foam.
[0054] Step 3: Using the nickel foam with the MoO3 / CoNiFe composite precursor prepared above as the working electrode, Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and 1M KOH as the electrolyte solution, electrochemical oxidation is performed at the potential corresponding to the oxygen evolution reaction current density for 3 hours to obtain a surface with MoO4. 2- Anion-modified (CoNiFe)OOH nanoporous layer.
[0055] The electrode material obtained after electrochemical oxidation also exhibits a hierarchical porous structure in its microstructure, such as... Figure 4 As shown.
[0056] like Figure 3 As shown, after 3 hours of electrochemical oxidation, the current density of CoNiFeMo@NF increased by 18.5%. Figure 5 The EDS spectrum shown demonstrates that MoO4 was formed on the electrode surface after electrochemical oxidation. 2- Anion-modified (CoNiFe)OOH nanoporous layer. Stability testing was performed on the electrode material after electrochemical oxidation, such as... Figure 6 As shown, after a 100-hour oxygen evolution reaction catalytic test, its current density still remained at 94.2%. Comparatively with Example 1, the above tests all demonstrate that MoO4... 2- Anchoring of the surface oxygen evolution catalytic active sites of (CoNiFe)OOH with anions can significantly improve its catalytic stability, making it a highly active and stable catalytic electrode material for the oxygen evolution reaction.
[0057] Example 3:
[0058] A method of introducing MoO4 2- Anion-modified (CoNiFe)OOH catalytic electrode material (CoNiFeMo) 1.3 The preparation method of @NF includes the following steps:
[0059] Step 1: First, cut the nickel foam into pieces with a working area of 1*1 cm. 2 The sample was then placed in 3 M dilute hydrochloric acid and ultrasonically cleaned for 5 minutes, then placed in anhydrous ethanol and ultrasonically cleaned for 5 minutes, and finally immersed in deionized water and ultrasonically cleaned for 5 minutes. The above cleaning process can remove oil and oxides from the surface of the nickel foam.
[0060] Step 2: Weigh out 1 mmol of Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Fe(NO3)3·9H2O, 1.3 mmol of (NH4)2MoO4 and 8.01 mmol of glycine respectively, dissolve them all in 4 mL of deionized water solvent, and stir thoroughly at room temperature to form a homogeneous solution.
[0061] The pretreated nickel foam was immersed in 1 mL of the above solution and placed in a muffle furnace. The temperature was increased to 300 °C at a rate of 5 °C / min without holding time. Then it was naturally cooled to room temperature to obtain the MoO3 / CoNiFe composite precursor grown on the nickel foam.
[0062] Step 3: Using the nickel foam with MoO3 / CoNiFe composite grown above as the working electrode, Ag / AgCl as the reference electrode, a platinum sheet as the counter electrode, and 1M KOH as the electrolyte solution, electrochemical oxidation is performed at the potential corresponding to the oxygen evolution reaction current density for 3 hours to obtain a surface with MoO4. 2- Anion-modified (CoNiFe)OOH nanoporous layer.
[0063] Unlike Example 2, Example 3 increased the proportion of Mo introduced. After 3 hours of electrochemical oxidation, CoNiFeMo... 1.3 The current density of @NF also increased by 15.2%. Compared to Example 1, CoNiFeMo 1.3 The catalytic stability of both @NF and CoNiFMo@NF was significantly improved after electrochemical oxidation, further demonstrating the effectiveness of MoO4. 2- The anchoring effect of anions on the oxygen evolution catalytic sites of cations in (CoNiFe)OOH significantly improves the stability of the electrode in oxygen evolution catalysis in alkaline electrolyte.
[0064] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A composite catalytic electrode material, characterized in that, include: (CoNiFe)OOH nanoporous structure and MoO4 adsorbed on (CoNiFe)OOH nanoporous structure 2- The anion was obtained by electrochemical oxidation of the MoO3 / CoNiFe composite precursor, wherein MoO4 2- The anion anchors the catalytic site of the (CoNiFe)OOH cation.
2. The composite catalytic electrode material as described in claim 1, characterized in that, The method for obtaining the (CoNiFe)OOH nanoporous structure is as follows: It was obtained by electrochemical anodic oxidation reconstruction of CoNiFe alloy in the MoO3 / CoNiFe composite precursor.
3. The composite catalytic electrode material as described in claim 1, characterized in that, The MoO4 2- The method for obtaining anions is as follows: The MoO3 oxide in the MoO3 / CoNiFe composite precursor reacts with OH- in the alkaline electrolyte solution at an oxidizing potential. - The reaction is obtained.
4. The composite catalytic electrode material as described in claim 1, characterized in that, In the composite catalytic electrode material, the molar ratio of iron, cobalt, nickel and molybdenum is 1:1:1:1~1.
5.
5. The composite catalytic electrode material as described in claim 4, characterized in that, In the composite catalytic electrode material, the molar ratio of iron, cobalt, nickel and molybdenum is 1:1:1:1.
3.
6. A method for preparing a composite catalytic electrode material as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Mix iron-containing metal nitrate, cobalt-containing metal nitrate, nickel-containing metal nitrate and ammonium molybdate in a molar ratio of 1:1:1:1~1.5, then dissolve glycine fuel in deionized water solvent and stir until homogeneous to form a mixed solution; Step 2: Place the nickel foam into a ceramic boat containing the mixed solution prepared in Step 1, and place it in a high-temperature furnace for self-propagating combustion to prepare a MoO3 / CoNiFe composite precursor with a porous structure grown on the surface of the nickel foam. Step 3: Electrochemically oxidize the MoO3 / CoNiFe composite precursor prepared in Step 2 using a constant potential oxidation method to obtain MoO4. 2- A composite catalytic electrode material with anion-modified (CoNiFe)OOH nanoporous layers.
7. The method for preparing the composite catalytic electrode material according to claim 6, characterized in that, In step 1, the molar ratio of glycine fuel to total metal cations is 1.5:1, and the amount of deionized water used is 4 mL.
8. The method for preparing the composite catalytic electrode material as described in claim 6, characterized in that, In step 2, the specific process of self-propagating combustion is as follows: the temperature is increased to 300 ℃ at a rate of 5 ℃ / min, without holding time, and then naturally cooled to room temperature.
9. The method for preparing the composite catalytic electrode material as described in claim 6, characterized in that, In step 3, the specific process of the constant potential oxidation method is as follows: using nickel foam loaded with precursor material in step 2 as the working electrode; using Ag / AgCl as the reference electrode; using a platinum sheet as the counter electrode; using 1 M KOH as the electrolyte solution, and performing electrochemical oxidation at the potential corresponding to the oxygen evolution reaction for an oxidation time of not less than 3 hours.
10. The application of a composite catalytic electrode material as described in any one of claims 1-5 in alkaline water electrolysis for hydrogen production.