Foamed nickel electro-catalytic material loaded with iron-doped cobalt hydroxide as well as preparation method and application of foamed nickel electro-catalytic material

Abstract

The invention discloses an iron-doped cobalt hydroxide loaded foamed nickel electro-catalytic material as well as preparation and application thereof. Cobalt nitrate hexahydrate and iron nitrate nonahydrate are respectively used as a cobalt source and an iron source, urea is used as a precipitator, and iron-doped cobalt hydroxide is loaded on the surface of foamed nickel through a hydrothermal method. The method has the advantages of simple operation, easily available raw materials, low preparation cost, short reaction period and high repeatability. The material can be used as an electrocatalyst to be applied to a conversion reaction from glycerol oxidation to formic acid under industrial-grade current, in a 1 mol / L KOH + 0.2 mol / L glycerol solution, the potential is 1.37 V vs.RHE when the current density reaches 100 mA / cm < 2 >, the potential is 1.46 V vs.RHE when the current density reaches 700 mA / cm < 2 >, the current density can reach 1000 mA / cm < 2 > under the potential of 2.05 V in a flowing electrolytic tank, and the material can stably run for 120 h under the current density and has excellent catalytic performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalysts and relates to a method for preparing a nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide. It also relates to its application in the preparation of hydrogen evolution catalyst materials and hydrogen evolution electrodes. The invention also has potential application value in other fields such as energy development and environmental protection. Background Art

[0002] With the growing demand and consumption of traditional fossil fuels leading to severe energy crises and environmental problems, increasing attention is being focused on the development, efficient utilization, and value-added conversion of various energy sources. Hydrogen, with its high energy density and environmentally friendly, pollution-free nature, has become a promising alternative to fossil fuels. Unlike fossil fuels such as coal, oil, and natural gas, hydrogen does not exist naturally and requires the use of other energy sources to produce it. Current hydrogen production still relies heavily on fossil fuels, a production process that still generates significant pollution and fails to truly address the aforementioned energy challenges. In contrast, hydrogen production by water electrolysis offers a high-energy-density, pollution-free energy source, but is limited by its slow reaction kinetics and high overpotential, hindering large-scale industrial application. Traditional water electrolysis for hydrogen production consists of two half-reactions: a hydrogen evolution reaction at the cathode and a hydrogen evolution reaction at the anode. Ideally, the theoretical thermodynamic voltage for hydrogen production by water electrolysis is 1.23 V. However, because both half-reactions experience overpotentials during the electrolysis process, a higher voltage is required to maintain the desired hydrogen production rate and achieve industrial production.

[0003] To address these issues, a hybrid water splitting strategy has been proposed, which can fundamentally reduce the energy consumption of electrocatalytic hydrogen production by utilizing an alternative electrooxidation reaction with lower energy requirements than the hydrogen evolution reaction (HER). Glycerol, as an important platform molecule, can be converted into a variety of high-value-added chemicals, such as dihydroxyacetone, formic acid, glyceric acid, glyceraldehyde, and lactic acid. Formic acid, one of the products, is an important industrial intermediate and is considered a promising chemical hydrogen storage material. Compared to the HER in traditional water electrolysis, the HER induction reaction of glycerol to formic acid has a lower potential (0.69 V vs. RHE). Coupling the HER electrooxidation reaction, which has lower energy requirements than the HER, with the HER can fundamentally reduce the energy consumption of hydrogen production. Furthermore, the HER can achieve value-added conversion through glycerol oxidation, further improving the economic efficiency of the electrolysis system. Designing low-cost, highly active, and stable electrocatalysts can further improve energy conversion efficiency. Although current research on glycerol oxidation catalysts has primarily focused on precious metal-based catalysts, these catalysts face challenges such as resource scarcity, high cost, and susceptibility to poisoning due to irreversible adsorption of intermediates generated during the reaction. Therefore, from a cost-effectiveness perspective, the development and use of low-cost and highly efficient non-precious metal catalysts is more attractive. Although these non-precious metal catalysts have great development potential due to their low cost and abundant reserves, they still suffer from low selectivity and low catalytic activity. Therefore, the design and development of non-precious metal-based catalysts with high catalytic activity and stable performance is a key issue that needs to be addressed. Summary of the Invention

[0004] The present invention addresses the above-mentioned problems. Cobalt nitrate hexahydrate and ferric nitrate nonahydrate are used as cobalt and iron sources, respectively, and urea is used as a precipitant to load iron-doped cobalt hydroxide on the surface of nickel foam by a hydrothermal method. The method is simple to operate, the raw materials are readily available, the preparation cost is low, the reaction cycle is short, and the repeatability is high. The material can be used as an electrocatalyst in the glycerol oxidation to formic acid conversion reaction under industrial-grade current. In a 1 mol / L KOH + 0.2 mol / L glycerol solution, the electrocatalytic efficiency reaches 100 mA / cm 2 The potential was 1.37 V vs. RHE at a current density of 700 mA / cm 2 The potential at the current density is 1.46 V vs. RHE. In the flow electrolysis cell, the current density can reach 1000 mA cm at a potential of 2.05 V. -2 , and can operate stably at this current density for up to 120 h, showing excellent catalytic performance.

[0005] In order to achieve the above object, the technical solutions specifically adopted by the present invention are as follows:

[0006] In a first aspect, the present invention provides a method for preparing a nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide, wherein cobalt nitrate hexahydrate and ferric nitrate nonahydrate are used as cobalt sources and iron sources, respectively, and urea is used as a precipitant, and iron-doped cobalt hydroxide is loaded on the surface of the nickel foam by a hydrothermal method.

[0007] The specific steps include:

[0008] (1) Dissolve 0.07 to 0.16 parts by weight of cobalt nitrate hexahydrate and 0.02 to 0.1 parts by weight of ferric nitrate nonahydrate in deionized water and stir thoroughly to form a suspension; then add 0.12 to 0.24 parts by weight of urea and stir magnetically for 20 to 30 minutes until the suspension becomes clear. Then transfer the suspension to a stainless steel hydrothermal autoclave containing an inert liner (such as a polytetrafluoroethylene liner), cut the pretreated nickel foam into a suitable size and place it in the autoclave, and place it in an oven at 120°C for 12 hours;

[0009] (2) After cooling to room temperature, the nickel foam obtained in step (1) is rinsed alternately with deionized water and ethanol to remove surface impurities, and then dried in a vacuum oven at 60°C overnight to obtain a nickel foam loaded with iron-doped cobalt hydroxide. The iron-doped cobalt hydroxide complex is coated on the surface of the nickel foam and forms clusters in the form of nano-needle structures with a structural scale of 50 to 100 nm;

[0010] In a second aspect, the present invention provides a nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide, which is prepared by the above method.

[0011] From the appearance photos, it can be preliminarily seen that iron-doped cobalt hydroxide is evenly covered on the surface of nickel foam; scanning electron microscopy images show that the iron-doped cobalt hydroxide complex forms a nanoneedle structure with a structural width of 50~100 nm; the lattice lines in the high-magnification transmission electron microscopy image confirm the crystal planes of cobalt hydroxide and cobalt oxyhydroxide present in the iron-doped cobalt hydroxide.

[0012] X-ray diffraction patterns and X-ray photoelectron spectroscopy patterns show that Co mainly grows on the nickel substrate. 2+ and Fe 3+ , partly Co 3+ and Fe 2+ ; Oxygen is mainly in the form of OH - and H2O. From the in-situ Raman spectrum, it can be seen that there is obvious Co 3+ The presence of the peak indicates that the catalyst has a strong effect on the glycerol oxidation reaction. 3+ is the main active site; with the increase of potential, Co 3+ The peak intensity of gradually decreases, indicating that the cobalt oxyhydroxide generated at high potential can be reduced to cobalt hydroxide, forming a reversible cyclic redox process.

[0013] Electrochemical performance test:

[0014] (1) In an H-type electrolytic cell, 1 mol / L KOH + 0.2 mol / L glycerol solution was used as the electrolyte, nickel foam loaded with iron-doped cobalt hydroxide was used as the working electrode, mercury / mercuric oxide electrode was used as the reference electrode, and platinum mesh was used as the counter electrode. The test temperature was 10 ~ 30 °C, and the current was 100 mA cm -2 The potential was 1.37 V vs. RHE at a current density of 700 mAcm -2 The potential at the current density was 1.46 V vs. RHE, and when the applied voltage was 1.45 ~ 1.65 V, the Faradaic efficiency of formic acid production was 86 ~ 90%.

[0015] (2) In a flow electrolytic cell, 1.0 mol / L KOH + 0.5 mol / L glycerol solution was used as the electrolyte, nickel foam loaded with iron-doped cobalt hydroxide was used as the anode, and a commercial platinum-carbon gas diffusion electrode was used as the cathode. The test temperature was 10 ~ 30 °C. When the applied current density was 1000 mA cm -2 When the potential is 2.05 V, it can operate stably at this current density for up to 120 h.

[0016] Therefore, the third aspect of the present invention provides the use of the above-mentioned iron-doped cobalt hydroxide loaded nickel foam electrocatalytic material in the electrocatalytic oxidation of glycerol to produce formic acid, specifically in the preparation of electrolytic hydrogen decomposition electrodes, such as in the preparation of H-type electrolytic cell working electrode materials or in the preparation of flow electrolytic cell anode materials.

[0017] In a fourth aspect, the present invention provides an electrolytic hydrogen evolution electrode comprising a carrier and a catalyst material supported thereon, wherein the catalyst material is an iron-doped cobalt hydroxide-supported foam nickel electrocatalytic material prepared by any of the methods described above.

[0018] In a fifth aspect, the present invention provides a method for producing formic acid by electrocatalytic oxidation of glycerol, using the aforementioned electrolytic hydrogen-decomposing electrode as a working electrode or anode. Preferably, the electrolyte is a 0.1 M KOH + 0.5 M glycerol solution.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) A simple hydrothermal method was used to prepare nickel foam loaded with iron-doped cobalt hydroxide. The preparation method is simple and low-cost, and it has excellent selectivity for the electrocatalytic oxidation of glycerol to formic acid and industrial-grade current density. The synthesis process does not require complex instruments and is easy to operate, which is conducive to large-scale industrial application.

[0021] (2) The nickel foam loaded with iron doped with cobalt hydroxide was used as a catalyst for the electrocatalytic oxidation of glycerol. The results showed that it had excellent selectivity and activity for the electrocatalytic oxidation of glycerol to formic acid. When the electrocatalytic activity reached 100 mA / cm in an H-type electrolytic cell, the electrocatalytic activity of nickel foam was 0.05, which was 0.08. 2 The potential was 1.37 V vs. RHE at a current density of 700 mA / cm 2 The potential was 1.46 V vs. RHE at the current density. When the applied voltage was 1.45 ~ 1.65 V, the Faradaic efficiency of formic acid production was 86 ~ 90%; when the current density was 1000 mA / cm in the flow electrolysis cell, the Faradaic efficiency of formic acid production was 1.46 V vs. RHE. When the applied voltage was 1.45 ~ 1.65 V, the Faradaic efficiency of formic acid production was 86 ~ 90%. 2 When the potential is 2.05 V, it can run stably at this current density for 120 h.

[0022] (3) During the preparation process, all reagents were commercial products and did not require further processing;

[0023] (4) The synthesis method is simple and the obtained materials are easy to use, which is conducive to promotion and application in industrial production. It also has potential application value in other fields of energy development and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a digital photo of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1;

[0025] Figure 2 This is a scanning electron micrograph of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1, wherein a, 5 μm, b, 1 μm;

[0026] Figure 3 1 is a transmission electron micrograph of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1, wherein a, 100 nm, b, 10 nm;

[0027] Figure 4 is the X-ray diffraction pattern of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1;

[0028] Figure 5 is the X-ray photoelectron spectrum of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1, where a, Co 2p, b, O 1s, c, Fe 2p;

[0029] Figure 6 This is an in-situ Raman spectrum of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1;

[0030] Figure 7The linear sweep voltammetry curve of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 as the working electrode in a 0.1 M KOH + 0.2 M glycerol solution as the electrolyte;

[0031] Figure 8 3. This is a Faradaic efficiency diagram of the product formic acid at different voltages when the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 is used in an H-type electrolytic cell with 0.1 M KOH + 0.2 M glycerol solution as the electrolyte;

[0032] Figure 9 Graphs of cell voltage corresponding to different current densities when the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 is used in a flow electrolytic cell with 0.1 M KOH and 0.1 M KOH + 0.5 M glycerol solution as the electrolyte, respectively;

[0033] Figure 10 The nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 was electrolyzed in a flow cell with 0.1 M KOH + 0.5 M glycerol solution as the electrolyte at a current density of 500 mA / cm 2 and 1000 mA / cm 2 Constant current curve when . DETAILED DESCRIPTION

[0034] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] " Scope " disclosed herein is in the form of lower limit and upper limit. Can be respectively one or more lower limits, and one or more upper limits. A given range is limited by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundary of a particular range. All ranges that can be limited in this way are inclusive and combinable, i.e. any lower limit can be combined with any upper limit to form a range. For example, for a particular parameter, a range of 100 ~ 140 and 500 ~ 900 is listed, and it is understood that a range of 100 ~ 140 and 500 ~ 900 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range 3,4 and 5 are listed, then the following ranges can all be expected: 1 ~ 2, 1 ~ 4, 1 ~ 5, 2 ~ 3, 2 ~ 4 and 2 ~ 5.

[0036] In this disclosure, unless otherwise specified, the numerical range "a to b" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between "0" and "5" are listed herein, and "0 to 5" is merely an abbreviation for these numerical combinations.

[0037] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.

[0038] Example 1

[0039] 1. Preparation of nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide

[0040] 0.139 g of cobalt nitrate hexahydrate and 0.0485 g of ferric nitrate nonahydrate were dissolved in 30 mL of deionized water and stirred thoroughly to form a suspension. 0.2402 g of urea was then added and magnetically stirred for 30 minutes until the suspension clarified. The suspension was then transferred to a Teflon-lined stainless steel hydrothermal autoclave, where the pretreated nickel foam was cut to a suitable size and placed in the autoclave. The foam was then placed in an oven at 120°C for 12 hours. After cooling to room temperature, the resulting nickel foam was rinsed alternately with deionized water and ethanol to remove surface impurities and then dried in a vacuum oven at 60°C overnight to obtain the nickel foam loaded with iron-doped cobalt hydroxide.

[0041] 2. Performance Characterization Test

[0042] Figure 1 This is a digital photo of the product prepared in Example 1. It can be seen that the prepared nickel foam loaded with iron-doped cobalt hydroxide is uniformly covered on the surface of the nickel foam.

[0043] Figure 2 This is a scanning electron microscope image of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1. It can be seen that a dense layer of nano-needle structures is covered on the surface of the nickel foam substrate.

[0044] Figure 3 This is the transmission electron microscopy image of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1. It can be seen that the scale of the nanoneedle structure is 50 ~ 100 nm. The lattice lines in the high-magnification transmission electron microscopy image confirm the (011) crystal plane of cobalt hydroxide and the (102) crystal plane of cobalt oxyhydroxide present in the iron-doped cobalt hydroxide.

[0045] Figure 4This is the X-ray diffraction pattern of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1. The scanning speed is 3° / min and the scanning range is 10°~80°. The obvious sharp diffraction peaks at 44.61°, 51.98°, and 76.59° are attributed to the metallic nickel (111), (200), and (220) planes of the nickel foam substrate (PDF #01-070-0989).

[0046] Figure 5 This is the X-ray photoelectron spectrum of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1. The Co2p spectrum proves that the cobalt grown on the nickel foam is mainly Co 2+ , partly Co 3+ ; O 1s spectrum shows that oxygen is mainly in the form of OH - and H2O, and the Fe 2p spectrum shows that the iron grown on nickel foam is mainly Fe 3+ , and some Fe 2+ .

[0047] Figure 6 This is the in-situ Raman spectrum of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1. It can be seen that there is obvious Co 3+ The presence of the peak indicates that the catalyst has a strong effect on the glycerol oxidation reaction. 3+ is the main active site; with the increase of potential, Co 3+ The peak intensity of gradually decreases, indicating that the cobalt oxyhydroxide generated at high potential can be reduced to cobalt hydroxide, forming a reversible cyclic redox process.

[0048] 3. Electrochemical performance test

[0049] The electrochemical test was carried out at room temperature using a standard three-electrode system connected to a CHI 660E electrochemical workstation. Nickel foam loaded with iron-doped cobalt hydroxide, platinum mesh, and mercury / mercuric oxide electrodes served as the working electrode, counter electrode, and reference electrode, respectively. The glycerol oxidation reaction test environment was a 1 M KOH electrolyte with an additional 0.2 M glycerol added, and the electrolytic cell was an H-type cell. The electrochemical performance of the prepared catalyst material was evaluated by linear sweep voltammetry curves at 1 mV·s -1 The formic acid produced by the glycerol oxidation reaction was analyzed by high performance liquid chromatography (Shimazu LC-40D).

[0050] Figure 6 This is the in-situ Raman spectrum of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1. It can be seen that there is obvious Co 3+ The presence of the peak indicates that the catalyst has a strong effect on the glycerol oxidation reaction. 3+is the main active site; with the increase of potential, Co 3+ The peak intensity of gradually decreases, indicating that the cobalt oxyhydroxide generated at high potential can be reduced to cobalt hydroxide, forming a reversible cyclic redox process.

[0051] Figure 7 The linear sweep voltammetry curve of the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 was used as the working electrode in 0.1 M KOH + 0.2 M glycerol solution as the electrolyte. The test conditions were a standard three-electrode system, with the nickel foam loaded with iron-doped cobalt hydroxide, platinum mesh, and mercury / mercuric oxide electrode as the working electrode, counter electrode, and reference electrode, respectively. Among them, curve 1 is the nickel foam loaded with iron-doped cobalt hydroxide, and curve 2 is the comparison sample nickel foam loaded with cobalt hydroxide. It can be seen that the nickel foam loaded with iron-doped cobalt hydroxide has better electrochemical performance. When the current density is 100 mA cm -2 When the potential reaches 700 mA·cm -2 At a current density of 1.5 wt %, the potential of nickel foam loaded with cobalt hydroxide was only 1.46 V vs. RHE, demonstrating the excellent catalytic activity of nickel foam loaded with iron-doped cobalt hydroxide.

[0052] Figure 8 This is a diagram of the Faraday efficiency of the product formic acid at different voltages when the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 is used in an H-type electrolytic cell with 0.1 M KOH + 0.2 M glycerol solution as the electrolyte. The nickel foam loaded with iron-doped cobalt hydroxide is used as the working electrode, the mercury / mercuric oxide electrode is used as the reference electrode, and the platinum mesh is used as the counter electrode. The test temperature is room temperature, and different constant voltages are applied by a CHI660 electrochemical workstation. When the applied voltage is 1.45 ~ 1.65 V, the Faraday efficiency of formic acid production is 86 ~ 90%. At a potential of 1.65 V, the Faraday efficiency of formic acid reaches 90.1%.

[0053] Figure 9 The cell voltage diagram corresponding to different current densities when the nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 is used as the electrolyte in a flow electrolytic cell with 0.1 M KOH and 0.1 M KOH + 0.5 M glycerol solution, respectively. The nickel foam loaded with iron-doped cobalt hydroxide is used as the anode and the commercial platinum-carbon gas diffusion electrode is used as the cathode. The test temperature is room temperature; Curve 1 is the oxygen evolution reaction when 0.1 M KOH solution is used as the electrolyte, and Curve 2 is the glycerol oxidation reaction when 0.1 M KOH + 0.5 M glycerol solution is used as the electrolyte. It can be seen that in the glycerol oxidation reaction, when the applied current density is 1000 mA cm -2 The potential is 2.05 V, demonstrating its excellent catalytic performance at high current density.

[0054] Figure 10 The nickel foam loaded with iron-doped cobalt hydroxide prepared in Example 1 was electrolyzed in a flow electrolytic cell with a current density of 500 mA·cm using 0.1 M KOH + 0.5 M glycerol solution as the electrolyte. -2 and 1000 mA·cm -2 The constant current curve is shown in Figure 1. The nickel foam loaded with iron-doped cobalt hydroxide is used as the anode and the commercial platinum-carbon gas diffusion electrode is used as the cathode. The test temperature is room temperature. Curve 1 is the current density of 1000 mA cm -2 Curve 2 is the constant current curve when the current density is 500 mAcm -2 From the constant current curve, it can be seen that the nickel foam loaded with iron doped cobalt hydroxide prepared by the present invention is used as the anode and there is no obvious decay in the continuous electrolysis for 120 hours at a constant high current density, which proves that the nickel foam loaded with iron doped cobalt hydroxide prepared by the present invention has excellent stability as an electrode.

[0055] Compared with existing material preparation methods for electrocatalytic oxidation of glycerol to produce formic acid, the present invention has the following advantages: the material synthesis operation is simple and can be prepared on a large scale; it uses non-precious metals with abundant reserves and low cost; it has excellent electrocatalytic glycerol oxidation activity and can achieve stable and efficient conversion of glycerol to formic acid under industrial-grade current conditions.

[0056] Example 2

[0057] 0.07 g of cobalt nitrate hexahydrate and 0.024 g of ferric nitrate nine hydrate were dissolved in 15 mL of deionized water and stirred thoroughly to form a suspension. 0.12 g of urea was then added and magnetically stirred for 30 minutes until the suspension was clarified. The suspension was then transferred to a polytetrafluoroethylene-lined stainless steel hydrothermal kettle, and the pretreated nickel foam was cut to a suitable size and placed therein. The foam was then placed in an oven at 120 ° C for 12 hours. After cooling to room temperature, the obtained nickel foam was alternately rinsed with deionized water and ethanol to remove surface impurities, and then placed in a 60 ° C vacuum oven and dried overnight to obtain a nickel foam loaded with iron-doped cobalt hydroxide. The features and properties were similar to those in Example 1.

[0058] Example 3

[0059] 0.12 g of cobalt nitrate hexahydrate and 0.04 g of ferric nitrate nonahydrate were dissolved in 26 mL of deionized water and stirred thoroughly to form a suspension. 0.21 g of urea was then added and magnetically stirred for 20 minutes until the suspension was clarified. The suspension was then transferred to a polytetrafluoroethylene-lined stainless steel hydrothermal reactor, and the pretreated nickel foam was cut to a suitable size and placed therein. The foam was then placed in an oven at 120 ° C for 12 hours. After cooling to room temperature, the obtained nickel foam was alternately rinsed with deionized water and ethanol to remove surface impurities, and then dried in a 60 ° C vacuum oven overnight to obtain a nickel foam loaded with iron-doped cobalt hydroxide. The characteristics and properties were similar to those of Example 1.

[0060] In summary, the material obtained by the present invention is used for the electrocatalytic oxidation of glycerol to produce formic acid. The preparation of nickel foam loaded with iron-doped cobalt hydroxide for the electrocatalytic oxidation of glycerol to produce formic acid is carried out at room temperature and pressure, with 0.1 M KOH + 0.2 M glycerol solution as the electrolyte. A standard three-electrode system is used in the flow reaction cell, with the nickel foam loaded with iron-doped cobalt hydroxide as the working electrode, the mercury / mercury oxide electrode as the reference electrode, and the platinum mesh as the counter electrode, and the test temperature is room temperature; in the flow electrolysis cell, the nickel foam loaded with iron-doped cobalt hydroxide is used as the anode and the commercial platinum-carbon gas diffusion electrode is used as the cathode, and the test temperature is room temperature.

[0061] The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without departing from the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A method for preparing a nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide, characterized in that: The steps include: (1) Dissolve 0.07 to 0.16 parts by weight of cobalt nitrate hexahydrate and 0.02 to 0.1 parts by weight of ferric nitrate nonahydrate in deionized water and stir thoroughly to form a suspension; then add 0.12 to 0.24 parts by weight of urea and stir magnetically for 20 to 30 minutes until the suspension becomes clear. Then transfer the suspension to a stainless steel hydrothermal autoclave containing an inert liner, cut the pretreated support carrier into a suitable size and place it in the autoclave, and place it in an oven at 120°C for a certain period of time; (2) After cooling to room temperature, the nickel foam obtained in step (1) is rinsed alternately with deionized water and ethanol to remove surface impurities, and then placed in a vacuum oven at 60°C for overnight drying to obtain nickel foam loaded with iron-doped cobalt hydroxide.

2. The preparation method according to claim 1, wherein: in, In step (1), the final concentration of cobalt nitrate hexahydrate is 0.0046 g / mL, the final concentration of ferric nitrate nonahydrate is 0.0016 g / mL, and the final concentration of urea is 0.008 g / mL.

3. The preparation method according to claim 1, wherein: in, The inert lining is selected from polytetrafluoroethylene lining; the supporting carrier is selected from foam nickel; and the drying time of the oven is 12 hours.

4. A nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide, characterized in that: The method according to any one of claims 1 to 3 is used for preparation.

5. The electrocatalytic composite material according to claim 4, characterized in that In the material, iron-doped cobalt hydroxide is evenly covered on the surface of nickel foam; the iron-doped cobalt hydroxide complex forms a nano-needle structure with a width of 50-100 nm; Co is mainly grown on the nickel foam substrate. 2+ and Fe 3+ , partly Co 3+ and Fe 2+ .

6. Use of the nickel foam electrocatalytic material loaded with iron-doped cobalt hydroxide according to claim 4 or 5 in the electrocatalytic oxidation of glycerol to produce formic acid.

7. The use according to claim 6, characterized in that The application is application in preparing an electrode for electrolytic hydrogen evolution in the reaction of electrocatalytic oxidation of glycerol to prepare formic acid.

8. The use according to claim 7, characterized in that The electrolytic hydrogen-decomposing electrode is a working electrode of an H-type electrolytic cell or an anode of a flow electrolytic cell.

9. An electrolytic hydrogen evolution electrode, characterized in that The invention comprises a carrier and a catalyst material supported on the carrier, wherein the catalyst material is a nickel foam electrocatalytic material supported on iron-doped cobalt hydroxide and prepared by the method according to any one of claims 1 to 3.

10. A method for preparing formic acid by electrocatalytic oxidation of glycerol, characterized in that: The electrolytic hydrogen evolution electrode according to claim 9 is used as a working electrode or anode.

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