Preparation method of battery catalyst and catalyst product

Abstract

This application discloses a method for preparing a battery catalyst and a catalyst product, belonging to the field of catalysts. The method comprises using a carrier substrate as a cathode and a graphite nozzle as an anode, and using the graphite nozzle to spray an electrolytic plating solution onto the carrier substrate for step-pulse electrodeposition to obtain a carrier with an Fe-Co-P catalyst attached; wherein the carrier substrate is a stainless steel plate, and the electrolytic plating solution comprises ferric chloride (FeCl3), cobalt chloride (CoCl2), and sodium phosphite (Na2HPO3·5H2O). This application solves the technical problem of weak binding strength of current battery catalysts.

Description

Technical Field

[0001] The present application relates to the field of catalyst technology, and in particular to a preparation method of a battery catalyst and a catalyst product. Background Art

[0002] In related technologies, PEMFC (Proton Exchange Membrane Fuel Cell) is a new type of power supply device that can convert chemical energy into electrical energy. It has the advantages of low operating temperature, fast startup, high specific power, simple structure, and easy operation. It is recognized as the preferred energy source for electric vehicles, fixed power stations, etc. Proton exchange membrane fuel cells mainly use green and environmentally friendly renewable clean energy such as hydrogen as the raw material to provide chemical energy.

[0003] In related technologies, the main method used to produce new energy hydrogen is water electrolysis, and the activation energy of water electrolysis is reduced by adding catalysts, thereby reducing the overpotential of water electrolysis and improving the conversion efficiency of hydrogen energy.

[0004] However, the existing catalysts for hydrogen production by water electrolysis are mostly based on precious metals such as Pt, Ru, Ir and their compounds. After a period of reaction, the precious metal catalysts are prone to agglomeration, which weakens the binding force of the catalyst and shortens the service life of the catalyst.

[0005] Application Contents

[0006] The main purpose of this application is to provide a preparation method of a battery catalyst and a catalyst product, aiming to solve the technical problem of weak binding force of battery catalysts.

[0007] To achieve the above objectives, the present application provides a method for preparing a battery catalyst, the method comprising:

[0008] A carrier substrate is used as a cathode and a graphite nozzle is used as an anode. The graphite nozzle is used to spray an electrolytic plating solution onto the carrier substrate for step pulse electrodeposition to obtain a carrier with an Fe-Co-P catalyst attached. The carrier substrate is a stainless steel plate, and the electrolytic plating solution includes ferric chloride FeCl3, cobalt chloride CoCl2, and sodium phosphite Na2HPO3·5H2O.

[0009] Optionally, before using the graphite nozzle to spray the electrolytic plating solution onto the carrier substrate for step pulse electrodeposition, the method further includes:

[0010] The carrier substrate is corroded by a sulfuric acid solution to improve the surface roughness of the carrier substrate; wherein the concentration of the sulfuric acid solution is 1 mol / L to 2 mol / L.

[0011] Optionally, before using the graphite nozzle to spray the electrolytic plating solution onto the carrier substrate for step pulse electrodeposition, the method further includes:

[0012] The carrier substrate is immersed in a hydrochloric acid solution and ultrasonically shaken to remove oil from the surface of the carrier substrate.

[0013] Optionally, the concentration of the hydrochloric acid solution is 0.5 mol / L to 1 mol / L. The ultrasonic oscillation is performed for 5 min to 20 min.

[0014] Optionally, the Fe atom doping content in the Fe-Co-P catalyst is 0.5 mol / L to 2 mol / L, and the Co atom doping content is 0.6 mol / L to 1.1 mol / L.

[0015] Optionally, in the electrolytic plating solution, the concentration of ferric chloride is 0.5 mol / L to 2 mol / L; the concentration of cobalt chloride is 0.6 mol / L to 1.1 mol / L; and the concentration of sodium phosphite is 0.5 mol / L to 2 mol / L.

[0016] Optionally, in the electrolytic plating solution, the concentration of ferric chloride is 0.5 mol / L, the concentration of cobalt chloride is 0.6 mol / L, and the concentration of sodium phosphite is 0.5 mol / L.

[0017] Optional process parameters for step pulse electrodeposition include:

[0018] The preparation environment temperature is room temperature, the electroplating time is 20S~40S, the high voltage turn-on time of the step power supply voltage within the preset cycle is 0.4s~0.8s, the high voltage of the step power supply voltage is set to 1.4V, and the low voltage turn-on time of the step power supply voltage within the preset cycle is 0.6S~1S, the low voltage of the step power supply voltage is set to 0.5V, and the temperature of the electrolytic plating solution is 30℃~80℃.

[0019] In a second aspect, the present application provides a catalyst product, comprising a carrier substrate and a Fe-Co-P catalyst attached to the carrier substrate, wherein the catalyst product is prepared by the method for preparing a battery catalyst described in any of the above methods.

[0020] The Fe-Co-P catalyst is in the form of nano-spheres on a carrier substrate.

[0021] The present invention proposes a method for preparing a battery catalyst. A stainless steel plate is used as a cathode carrier substrate, a graphite nozzle is used as an anode, and an electrolyte plating solution composed of ferric chloride, cobalt chloride, and sodium phosphite is prepared. The electrolyte plating solution is sprayed onto the carrier substrate through the graphite nozzle for step-pulse electrodeposition to obtain a carrier with an Fe-Co-P catalyst attached, thereby completing the preparation of the battery catalyst. Thus, the present invention prepares the Fe-Co-P catalyst by using a step-pulse electrodeposition method, thereby enhancing the catalyst's binding force and extending the catalyst's life.

[0022] In addition, the battery catalyst in the present application is in the form of nanospheres on the electroplating carrier, thereby expanding the electrochemical active area of the reaction, effectively expanding the electrochemical area of the battery catalyst, increasing the active sites, and thus meeting the needs of efficient catalysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an image of the nanosphere structure under a scanning electron microscope;

[0024] Figure 2 Schematic diagram of overpotential of Example 1;

[0025] Figure 3 Schematic diagram of overpotential of Example 2;

[0026] Figure 4 Schematic diagram of overpotential of Example 3;

[0027] Figure 5 Schematic diagram of overpotential of Example 4;

[0028] Figure 6 Schematic diagram of overpotential of Example 5;

[0029] Figure 7 Schematic diagram of overpotential of Example 6.

[0030] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0032] At present, the production of new energy hydrogen is mainly through the electrolysis of water, and the efficiency of hydrogen production is improved by adding catalysts. However, after the catalyst reacts for a period of time, the catalyst is prone to agglomeration, resulting in a decrease in the electrochemical area of the catalyst and a reduction in active sites, leading to low catalytic efficiency.

[0033] The present application provides a solution, using a stainless steel plate as the carrier substrate of the cathode, a graphite nozzle as the anode, and an electrolyte plating solution prepared from ferric chloride, cobalt chloride, and sodium phosphite. The electrolytic plating solution is sprayed onto the electroplating carrier substrate using a graphite nozzle for step pulse electrodeposition to obtain a carrier with Fe-Co-P catalyst attached, thereby completing the preparation of the battery catalyst. Thus, the present application attaches the electrolytic plating solution to the electroplating carrier through a step pulse electrodeposition method, and obtains a battery catalyst with a nanosphere structure through layer-by-layer stacking. This not only makes the catalyst's binding force stronger and prolongs the catalyst's life, but also expands the catalyst's active area, thereby increasing the active sites and improving the catalytic efficiency.

[0034] The present invention is described in detail below by way of examples, but the present invention is not limited thereto.

[0035] A first embodiment of the present application is proposed. In this embodiment, the method includes:

[0036] A carrier substrate is used as a cathode and a graphite nozzle is used as an anode. The graphite nozzle is used to spray an electrolytic plating solution onto the carrier substrate for step pulse electrodeposition to obtain a carrier with an Fe-Co-P catalyst attached. The carrier substrate is a stainless steel plate, and the electrolytic plating solution includes ferric chloride FeCl3, cobalt chloride CoCl2, and sodium phosphite Na2HPO3·5H2O.

[0037] It can be understood that the anode graphite nozzle sprays the electrolytic plating solution onto the cathode carrier substrate, and the cations sprayed from the graphite nozzle are reduced to crystal nuclei through the step pulse electrodeposition method. The cations reduced to crystal nuclei adhere to the carrier substrate, thereby obtaining a Fe-Co-P catalyst to enhance the binding force of the catalyst.

[0038] In this embodiment, a stainless steel plate is used as a carrier substrate for the cathode, a graphite nozzle is used as an anode, an anhydrous ferric chloride solution, a cobalt chloride solution, and a sodium phosphite solution are mixed to prepare an electrolytic plating solution, and the electrolytic plating solution is sprayed onto the stainless steel plate through the graphite nozzle for step pulse electrodeposition. The step pulse electrodeposition method is used to embed nanoparticles in the metal plating layer, and the nanoparticles are co-deposited with metal ions to obtain a carrier with an Fe-Co-P catalyst attached, thereby enhancing the binding force of the catalyst and extending the life of the catalyst.

[0039] The second embodiment of the present application is proposed based on the above embodiment.

[0040] Before the steps of the first embodiment, the method further includes the following steps:

[0041] Step 1: Immerse the carrier substrate in a hydrochloric acid solution and perform ultrasonic vibration to remove oil from the surface of the carrier substrate.

[0042] Step 2: etching the carrier substrate with a sulfuric acid solution to increase the surface roughness of the carrier substrate; wherein the concentration of the sulfuric acid solution is 1 mol / L to 2 mol / L.

[0043] Specifically, in step 1, the carrier substrate is immersed in a hydrochloric acid solution with a concentration of 0.5 mol / L to 1 mol / L and ultrasonically shaken for 5 minutes to 20 minutes to remove the oil on the surface of the carrier substrate, thereby preventing the oil on the surface of the carrier substrate from contaminating the electrolytic plating solution during the subsequent preparation of the catalyst. In step 2, the carrier substrate with the surface oil removed is immersed in a sulfuric acid solution with a concentration of 1 mol / L to 2 mol / L, so that the stainless steel plate serving as the carrier substrate reacts chemically with the sulfuric acid. The surface of the stainless steel plate is corroded by the sulfuric acid, thereby increasing the surface roughness of the carrier substrate. In the subsequent preparation of the catalyst, the Fe-Co-P catalyst is more easily attached to the carrier substrate, improving the agglomeration of the catalyst, and thus facilitating the formation of a nanosphere structure.

[0044] In this embodiment, before preparing the battery catalyst, the electroplating carrier substrate is pretreated, that is, the stainless steel carrier substrate is immersed in a hydrochloric acid solution with a concentration of 0.5 mol / L to 1 mol / L and ultrasonically shaken for 5 minutes to 20 minutes to remove the oil on the surface of the carrier substrate. The stainless steel carrier substrate after deoiling is then immersed in a sulfuric acid solution with a concentration of 1 mol / L to 2 mol / L to increase the roughness of the carrier substrate surface to facilitate metal adhesion, thereby improving the efficiency of preparing the catalyst by the electrodeposition method.

[0045] In the electrolytic plating solution, the concentration of ferric chloride is 0.5mol / L to 2mol / L; the concentration of cobalt chloride is 0.6mol / L to 1.1mol / L, and the concentration of sodium phosphite is 0.5mol / L to 2mol / L. The process parameters of the step pulse electrodeposition include: the preparation environment temperature is room temperature, the electroplating time is 20S to 40S, the high voltage of the step power supply voltage is turned on for 0.4s to 0.8s within the preset period, the high voltage of the step power supply voltage is set to 1.4V, and the low voltage of the step power supply voltage is turned on for 0.6S to 1S within the preset period, the low voltage of the step power supply voltage is set to 0.5V, and the temperature of the electrolytic plating solution is 30°C to 80°C. The preset period can be one period, which is not limited in this embodiment.

[0046] That is, in this embodiment, the solute concentration contained in the electrolytic plating solution is within the above range, and the step pulse electrodeposition process parameters are continuously adjusted, so that the prepared battery catalyst has a larger electrochemical area, more active sites, and stronger binding ability than the existing catalyst.

[0047] In one specific embodiment, the concentration of ferric chloride is 0.5 mol / L, the concentration of cobalt chloride is 0.6 mol / L, and the concentration of sodium phosphite is 0.5 mol / L.

[0048] The process parameter values of the electrolytic plating solution proposed in this embodiment are the optimal concentration values of the solution contained in the electrolytic plating solution. That is, when the concentration value of the solution contained in the electrolytic plating solution is the concentration value of this embodiment, compared with other concentration values of the solution contained in the electrolytic plating solution of this application, the electrochemical area is the largest, the active sites are the most, and the binding ability is the strongest.

[0049] This application also provides a catalyst product comprising a carrier substrate and an Fe-Co-P catalyst attached to the carrier substrate. The catalyst product is prepared using any of the above-described battery catalyst preparation methods. Because this catalyst product utilizes all of the technical solutions of all of the above-described embodiments, it possesses at least all of the beneficial effects provided by the technical solutions of the above-described embodiments, and therefore will not be further detailed here.

[0050] In one embodiment, the Fe-Co-P catalyst is in the form of nanospheres on a carrier substrate. A graphite nozzle is used to spray an electrolytic plating solution onto the electroplating carrier for step pulse electrodeposition. After the metal cations are sprayed from the anode nozzle to the cathode, a Fe-Co-P coating is formed on the carrier substrate through a reduction reaction. The Fe-Co-P coating has a nanosphere structure under an electron microscope, as shown in FIG. Figure 1 Before the graphite nozzle sprays the electrolytic plating solution onto the electroplating carrier, the surface of the electroplating carrier needs to be corroded by sulfuric acid to increase the surface roughness of the electroplating carrier. Then, after the metal cations undergo a reduction reaction at the cathode, the Fe-Co-P coating is more easily deposited on the surface of the electroplating carrier, thereby continuously depositing and accumulating to form a nanosphere-structured catalyst.

[0051] In this embodiment, the electrolytic plating solution is sprayed through a graphite nozzle onto a stainless steel plate for step pulse electrodeposition. Nanoparticles are embedded in the metal plating layer using the step pulse electrodeposition method, so that the nanoparticles and metal ions are co-deposited to obtain a nano-spherical Fe-Co-P catalyst, thereby expanding the electrochemical active area of the reaction, effectively expanding the electrochemical area of the battery catalyst, increasing the active sites, and thus meeting the needs of efficient catalysis.

[0052] For easier understanding, the following example illustrates:

[0053] The following experiments were all conducted to prepare Fe-Co-P catalysts. In a laboratory at an ambient temperature of 25°C, a 2cm×2cm stainless steel plate was used as a support for the catalyst preparation. The support was first pretreated with hydrochloric acid. A 40ml solution containing anhydrous ferric chloride, cobalt chloride, and sodium phosphite was prepared as follows:

[0054] Example 1:

[0055] This example uses a plating solution with anhydrous ferric chloride concentration of 0.5 mol / L, cobalt chloride concentration of 0.6 mol / L, and sodium phosphite concentration of 0.5 mol / L; the total plating time is 20 s, the high voltage start time of the step power supply within the preset cycle is 0.4 s, the low voltage start time of the step power supply within the preset cycle is 0.6 s, the high voltage of the step power supply is 1.4 V, the low voltage of the step power supply is 0.5 V, the plating solution temperature is 30 ° C, and the overpotential is measured at a current density of 10 to be 45 mV (see Figure 2 ).

[0056] Example 2:

[0057] In this example, the plating solution concentrations are 0.8 mol / L of anhydrous ferric chloride, 0.7 mol / L of cobalt chloride, and 0.9 mol / L of sodium phosphite; the total plating time is 23 s; the high voltage start time of the step power supply within the preset cycle is 0.4 s, the low voltage start time of the step power supply within the preset cycle is 0.6 s, the high voltage of the step power supply is 1.4 V, the low voltage of the step power supply is 0.5 V, the plating solution temperature is 40 ° C, and the overpotential is measured at a current density of 10 to be 125 mV (see Figure 3 ).

[0058] Example 3:

[0059] This example uses a plating solution with anhydrous ferric chloride concentration of 1.1 mol / L, cobalt chloride concentration of 0.8 mol / L, and sodium phosphite concentration of 1.3 mol / L. The total plating time is 26 s, the high voltage start time of the step power supply within the preset cycle is 0.5 s, the low voltage start time of the step power supply within the preset cycle is 0.7 s, the high voltage of the step power supply is 1.4 V, the low voltage of the step power supply is 0.5 V, the plating solution temperature is 50 ° C, and the overpotential is measured at a current density of 10 to be 135 mV (see Figure 4 ).

[0060] Example 4:

[0061] This example uses a plating solution with anhydrous ferric chloride concentration of 1.4 mol / L, cobalt chloride concentration of 0.9 mol / L, and sodium phosphite concentration of 1.7 mol / L. The total plating time is 29 s, the high voltage start time of the step power supply within the preset cycle is 0.6 s, the low voltage start time of the step power supply within the preset cycle is 0.8 s, the high voltage of the step power supply is 1.4 V, the low voltage of the step power supply is 0.5 V, the plating solution temperature is 60 ° C, and the overpotential is measured at a current density of 10 to be 148 mV (see Figure 5 ).

[0062] Example 5:

[0063] This example uses a plating solution with anhydrous ferric chloride concentration of 2 mol / L, cobalt chloride concentration of 1.1 mol / L, and sodium phosphite concentration of 2 mol / L. The total plating time is 40 s, the high voltage start time of the step power supply within the preset cycle is 0.8 s, the low voltage start time of the step power supply within the preset cycle is 1 s, the high voltage of the step power supply is 1.4 V, the low voltage of the step power supply is 0.5 V, and the plating solution temperature is 80°C. The overpotential is measured to be 132 mV at a current density of 10 (see Figure 6 ).

[0064] Example 6:

[0065] This example uses a plating solution with anhydrous ferric chloride concentration of 1.8 mol / L, cobalt chloride concentration of 0.95 mol / L, and sodium phosphite concentration of 1.8 mol / L. The total plating time is 35 s, the high voltage start time of the step power supply within the preset cycle is 0.7 s, the low voltage start time of the step power supply within the preset cycle is 0.9 s, the high voltage of the step power supply is 1.25 V, the low voltage of the step power supply is 0.45 V, and the plating solution temperature is 75°C. The overpotential is measured to be 146 mV at a current density of 10 (see Figure 7 ).

[0066] According to the above experimental data, the following table is drawn:

[0067]

[0068]

[0069] Among them, overpotential refers to the value of the electrode potential deviating from the equilibrium potential, that is, when current passes through the electrode, an irreversible electrode reaction must occur. The electrode potential at this time will obviously be different from the reversible electrode potential. The phenomenon of the electrode potential exhibited by the electrode when current passes through it deviating from the reversible electrode potential is called "electrode polarization." The magnitude of the deviation (absolute value) is called "overpotential." Overpotential is an important parameter for measuring the catalytic activity of a catalyst. The smaller the overpotential value, the lower the actual voltage required for the current density, the relatively lower the energy consumption, and the higher the catalyst activity.

[0070] Therefore, it can be seen from the above table that the overpotential measured using the experimental parameters of Example 1 is the lowest, that is, the process parameters and electrolytic plating solution parameters of Example 1 are used to prepare the Fe-Co-P catalyst as the optimal parameters. At this time, under the same current density, the same step power supply voltage high voltage, and the same step power supply voltage low voltage, the catalyst is prepared using the process parameters and electrolytic plating solution parameters of Example 1, and its overpotential is the smallest. Therefore, compared with other embodiments, the catalyst prepared using the process parameters and electrolytic plating solution concentration parameters of Example 1 is more active.

[0071] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for preparing a battery catalyst, characterized in that: The specific steps are as follows: A carrier substrate is used as a cathode and a graphite nozzle is used as an anode. The graphite nozzle is used to spray an electrolytic plating solution onto the carrier substrate to perform step pulse electrodeposition, so that nanoparticles and metal ions are co-deposited to obtain a carrier with an Fe-Co-P catalyst attached. The carrier substrate is a stainless steel plate, the electrolytic plating solution includes ferric chloride (FeCl3), cobalt chloride (CoCl2), and sodium phosphite (Na2HPO3·5H2O); and the Fe-Co-P catalyst is a nano-spherical structure. In the electrolytic plating solution, the concentration of ferric chloride is 0.5 mol / L to 2 mol / L; the concentration of cobalt chloride is 0.6 mol / L to 1.1 mol / L; and the concentration of sodium phosphite is 0.5 mol / L to 2 mol / L. The process parameters of step pulse electrodeposition include: the preparation environment temperature is room temperature, the electroplating time is 20S~40S, the high voltage turn-on time of the step power supply voltage within the preset cycle is 0.4s~0.8s, the high voltage of the step power supply voltage is set to 1.4V, and the low voltage turn-on time of the step power supply voltage within the preset cycle is 0.6S~1S, and the low voltage of the step power supply voltage is set to 0.5V.

2. The method for preparing a battery catalyst according to claim 1, wherein: Before using the graphite nozzle to spray the electrolytic plating solution onto the carrier substrate for step pulse electrodeposition, the method further includes: The carrier substrate is corroded by a sulfuric acid solution to improve the surface roughness of the carrier substrate; wherein the concentration of the sulfuric acid solution is 1 mol / L to 2 mol / L.

3. The method for preparing a battery catalyst according to claim 1, wherein: Before using the graphite nozzle to spray the electrolytic plating solution onto the carrier substrate for step pulse electrodeposition, the method further includes: The carrier substrate is immersed in a hydrochloric acid solution and ultrasonically shaken to remove oil from the surface of the carrier substrate.

4. The method for preparing a battery catalyst according to claim 3, wherein: The concentration of the hydrochloric acid solution is 0.5 mol / L to 1 mol / L, and the ultrasonic oscillation is performed for 5 min to 20 min.

5. The method for preparing a battery catalyst according to claim 1, wherein: The Fe-Co-P catalyst has an Fe atom doping content of 0.5 mol / L to 2 mol / L, and a Co atom doping content of 0.6 mol / L to 1.1 mol / L.

6. The method for preparing a battery catalyst according to claim 1, wherein: In the electrolytic plating solution, the concentration of ferric chloride is 0.5 mol / L, the concentration of cobalt chloride is 0.6 mol / L, and the concentration of sodium phosphite is 0.5 mol / L.

7. The method for preparing a battery catalyst according to claim 1, wherein: The temperature of the electrolytic plating solution is 30°C to 80°C.

8. A catalyst product, characterized in that The catalyst product comprises a carrier substrate and a Fe-Co-P catalyst attached to the carrier substrate, wherein the catalyst product is prepared by the preparation method of the battery catalyst according to any one of claims 1 to 7.

9. The catalyst product according to claim 8, characterized in that The Fe-Co-P catalyst is in the shape of nano-spheres on a carrier substrate.

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