Porous catalytic electrode and method of making and using same

Abstract

The present application relates to the technical field of electrode preparation, and particularly relates to a porous catalytic electrode and a preparation method and application thereof. The preparation method of the porous catalytic electrode comprises the following steps: S1: mixing a first powder and a second powder to obtain spraying powder; S2: depositing the spraying powder on a base electrode to obtain a catalytic electrode; S3: performing first calcination treatment on the catalytic electrode to obtain a porous catalytic electrode; wherein the first powder comprises metal powder and / or alloy powder, and the second powder comprises carbon-based material powder. Through optimization of the preparation method, the present application can avoid using concentrated alkali in the pore-forming process, and can also improve the bonding strength of the coating and the base electrode, and reduce the overpotential of hydrogen evolution and oxygen evolution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrode preparation, in particular to a porous catalytic electrode and a preparation method and application thereof. BACKGROUND

[0002] The traditional fossil fuel hydrogen production method still causes a large amount of carbon emissions. At present, green hydrogen production by using renewable energy power generation and alkaline water electrolysis is a most promising hydrogen production method.

[0003] At present, the alkaline water hydrogen production industry widely uses thermal spraying process to prepare Raney nickel electrodes or multi-element alloy electrodes. Although the catalytic active components of the electrodes are different, Al is used as a pore former. Specifically, by using mixed metal powder or multi-element alloy as a spraying powder, the metal powder is sprayed onto the substrate to form a catalytic coating by using thermal spraying process, and then the electrode is activated by using a concentrated alkali solution.

[0004] In the prior art, patents CN114606514A, CN114318361A and CN110408950B all use alkali activation treatment to prepare porous electrodes. This activation process will release a large amount of heat and hydrogen in a short time, which is prone to safety accidents. In addition, the concentrated alkali waste liquid is a hazardous waste, which needs to be treated to avoid pollution to the environment, and the environmental impact assessment requirement is high.

[0005] Therefore, it has become an urgent problem to develop a high-performance alkaline water hydrogen production electrode without alkali activation treatment. SUMMARY

[0006] The present application provides a porous catalytic electrode and a preparation method and application thereof, to solve the environmental problems caused by alkali activation treatment in the prior art, and to realize a simple and environmentally friendly preparation method of a porous catalytic electrode.

[0007] The present application provides a preparation method of a porous catalytic electrode, comprising:

[0008] S1: mixing a first powder and a second powder to obtain a spraying powder;

[0009] S2: depositing the spraying powder on a substrate electrode to obtain a catalytic electrode;

[0010] S3: performing first calcination treatment on the catalytic electrode to obtain a porous catalytic electrode;

[0011] The first powder comprises metal powder and / or alloy powder, and the second powder comprises carbon-based material powder.

[0012] According to the present application, a preparation method of a porous catalytic electrode is provided, which further comprises: performing second calcination treatment on the porous catalytic electrode in a reducing atmosphere.

[0013] According to the present application, a method for preparing a porous catalytic electrode is provided, wherein the first calcination treatment is performed at a temperature of 600-800℃.

[0014] According to the present application, a method for preparing a porous catalytic electrode is provided, wherein the calcination atmosphere of the first calcination treatment comprises 90-100wt% of argon and 0-10wt% of oxygen.

[0015] According to the present application, a method for preparing a porous catalytic electrode is provided, wherein the mass ratio of the first powder to the second powder is 80-99:1-20.

[0016] According to the present application, a method for preparing a porous catalytic electrode is provided, wherein the metal powder comprises one or more of nickel metal powder, cobalt metal powder, iron metal powder, molybdenum metal powder, chromium metal powder, platinum metal powder, ruthenium metal powder, rhodium metal powder and palladium metal powder; the alloy powder comprises one or more of nickel-based alloy powder, cobalt-based alloy powder and iron-based alloy powder; and the carbon-based material powder comprises one or more of carbon black, graphite, graphene, carbon fiber and porous carbon.

[0017] According to the present application, a method for preparing a porous catalytic electrode is provided, wherein the second calcination treatment comprises calcining the porous catalytic electrode in a hydrogen atmosphere at a temperature of 600-1000℃.

[0018] According to the present application, a method for preparing a porous catalytic electrode is provided, wherein the deposition is achieved by a thermal spraying technique, and the thermal spraying is a plasma spraying technique; more preferably, the plasma spraying is performed under the following conditions: the argon flow rate is 30-60L / min, the hydrogen flow rate is 1-10L / min, the spraying power is 20-35kW, the spraying distance is 100-200mm, and the spraying angle is 60-120°.

[0019] The present application further provides a porous catalytic electrode prepared by the above method.

[0020] The present application further provides the use of the porous catalytic electrode in hydrogen evolution or oxygen absorption.

[0021] The porous catalytic electrode and the method for preparing the same provided by the present application can avoid the use of concentrated alkali during the pore-forming process, improve the bonding strength between the coating and the substrate electrode, and reduce the overpotential of hydrogen evolution and oxygen evolution. DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be clearly and completely described below. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0023] A method for preparing a porous catalytic electrode according to the present application is described below, comprising:

[0024] S1: mixing a first powder and a second powder to obtain a spraying powder;

[0025] S2: depositing the spraying powder on a substrate electrode to obtain a catalytic electrode;

[0026] S3: performing a first calcination treatment on the catalytic electrode to obtain a porous catalytic electrode;

[0027] The first powder comprises metal powder and / or alloy powder, and the second powder comprises carbon-based material powder.

[0028] The present application finds that, by using carbon-based material as a pore-forming agent, the porous coating can be prepared by only removing carbon through calcination treatment by using the above preparation method, which not only avoids the environmental problems caused by the use of concentrated alkali in the traditional pore-forming process, but also significantly improves the bonding strength of the coating and the substrate electrode, and greatly reduces the hydrogen evolution and oxygen evolution overpotential.

[0029] According to a preferred embodiment of the present application, the method for preparing the porous catalytic electrode further comprises: performing a second calcination treatment on the porous catalytic electrode in a reducing atmosphere.

[0030] According to a preferred embodiment of the present application, the reducing atmosphere is a hydrogen atmosphere.

[0031] Further, the calcination time of the first calcination treatment and the second calcination treatment is the same or different, and is 1-6 hours.

[0032] The present application further finds that, when the first calcination treatment is combined with the second calcination treatment, the proportion of metal and metal oxide can be effectively controlled, and the hydrogen evolution and oxygen evolution overpotential can be further reduced.

[0033] According to a preferred embodiment of the present application, the temperature of the first calcination treatment is 600-800 degrees Celsius.

[0034] According to a preferred embodiment of the present application, the calcination atmosphere of the first calcination treatment comprises 90-100 wt% of argon and 0-10 wt% of oxygen.

[0035] According to a preferred embodiment of the present application, the mass ratio of the first powder to the second powder is 80-99:1-20.

[0036] According to a preferred embodiment of the present application, the metal powder comprises one or more of nickel metal powder, cobalt metal powder, iron metal powder, molybdenum metal powder, chromium metal powder, platinum metal powder, ruthenium metal powder, rhodium metal powder and palladium metal powder; the alloy powder comprises one or more of nickel-based alloy powder, cobalt-based alloy powder and iron-based alloy powder; and the carbon-based material powder comprises one or more of carbon black, graphite, graphene, carbon fiber and porous carbon.

[0037] According to a preferred embodiment of the present application, the second calcination treatment comprises calcining the porous catalytic electrode in a hydrogen atmosphere at 600-1000 degrees Celsius.

[0038] According to a preferred embodiment of the present application, the deposition is achieved by a thermal spraying technique, and the thermal spraying is a plasma spraying technique; more preferably, the conditions of the plasma spraying comprise an argon flow rate of 30-60 liters / minute, a hydrogen flow rate of 1-10 liters / minute, a spraying power of 20-35 kilowatts, a spraying distance of 100-200 millimeters, and a spraying angle of 60-120 degrees.

[0039] According to a preferred embodiment of the present application, the substrate electrode is pretreated before the deposition; the pretreatment comprises grit blasting the substrate electrode with 80-240 mesh white corundum sand at a grit blasting angle of 50-90 degrees, an air pressure of 0.3-0.6 megapascals and a grit blasting distance of 80-160 millimeters.

[0040] According to a preferred embodiment of the present application, the first powder and the second powder are mixed by stirring with a V-type mixer; preferably, the V-type mixer has a rotation speed of 6-15 revolutions / minute, and the mixing is performed for 4-24 hours to obtain the spraying powder.

[0041] According to a preferred embodiment of the present application, the method for preparing the porous catalytic electrode comprises:

[0042] S1: mixing the first powder and the second powder to obtain a spraying powder;

[0043] S2: grit blasting the substrate electrode to obtain a pretreated substrate electrode;

[0044] S3: depositing the spraying powder onto the pretreated substrate electrode to obtain a catalytic electrode;

[0045] S4: the catalytic electrode is subjected to a first calcination treatment in an atmosphere of 90-100 wt% argon and 0-10 wt% oxygen, and then subjected to a second calcination treatment in a hydrogen atmosphere, to obtain the porous catalytic electrode.

[0046] The first powder comprises metal powder and / or alloy powder, and the second powder comprises carbon-based material powder.

[0047] The application further provides a porous catalytic electrode prepared by the above preparation method.

[0048] The application also provides application of the porous catalytic electrode in hydrogen evolution or oxygen absorption; preferably, the application comprises electrolysis of water.

[0049] Unless otherwise specified, all the raw materials used in the examples are commercially available conventional raw materials, and the technical means used is conventional means familiar to those skilled in the art.

[0050] Example 1

[0051] The example provides a porous catalytic electrode, and a preparation method thereof comprises the following steps:

[0052] (1) 95 wt% of 300-500 mesh nickel-molybdenum alloy powder and 5 wt% of 300-500 mesh carbon black are weighed in sequence and then added into a V-type mixer, the rotation speed of the V-type mixer is 12 revolutions per minute, and mixing is performed for 6 hours to obtain spraying powder.

[0053] (2) Then, a nickel mesh with a wire diameter of 0.25 mm and a mesh of 46 is subjected to sandblasting roughening treatment with 80 mesh white corundum sand, the sandblasting angle is 60 degrees, the air pressure is 0.5 MPa, and the sandblasting distance is 100 mm.

[0054] (3) The spraying powder is deposited onto the pretreated nickel mesh by using atmospheric plasma spraying technology to obtain a catalytic electrode; wherein the argon flow rate is 58 L / min, the hydrogen flow rate is 2 L / min, the spraying power is 32 kW, the spraying distance is 160 mm, and the spraying angle is 80 degrees.

[0055] (4) The catalytic electrode is subjected to a first calcination treatment at 700 degrees Celsius for 1 hour in an atmosphere of 95 wt% Ar and 5 wt% O2, and then subjected to a second calcination treatment in a hydrogen atmosphere at 800 degrees Celsius for 1 hour, to obtain a porous catalytic electrode.

[0056] Example 2

[0057] The example provides a porous catalytic electrode, and the difference between the preparation method thereof and that of Example 1 is that the nickel-molybdenum alloy powder is replaced by an equal amount of nickel powder.

[0058] Example 3

[0059] This example provides a porous catalytic electrode, the difference between the preparation method and example 1 is only that the temperature of the first calcination treatment is 600 degrees Celsius.

[0060] Example 4

[0061] This example provides a porous catalytic electrode, the difference between the preparation method and example 1 is only that the spraying powder includes 90wt% nickel molybdenum alloy powder, 5wt% aluminum powder and 5wt% carbon black.

[0062] Example 5

[0063] This example provides a porous catalytic electrode, the difference between the preparation method and example 1 is only that the temperature of the second calcination treatment is 1000 degrees Celsius.

[0064] Example 6

[0065] This example provides a porous catalytic electrode, the difference between the preparation method and example 1 is only that the second calcination treatment is not performed.

[0066] Comparative Example 1

[0067] This comparative example provides a porous catalytic electrode, the difference between the preparation method and example 4 is only that the catalytic electrode is immersed in a 10wt% NaOH solution at a temperature of 80 degrees Celsius for 6 hours, without performing the first calcination treatment and the second calcination treatment.

[0068] Test Example

[0069] The effects (including the bonding strength of the substrate electrode and the coating, the electrode performance, etc.) of the porous catalytic electrodes prepared in the examples and the comparative examples are further tested, and the test results are shown in Table 1:

[0070] Table 1

[0071]

[0072]

[0073] Among them, the electrode weight loss test method includes the following steps: 1. Weigh the weight of the electrode to be tested before testing; 2. Soak the electrode to be tested in a beaker containing water, place the beaker in an ultrasonic machine, and continuously ultrasonic for 3 hours, then clean and dry and weigh the electrode after testing; 3. Calculate the weight difference before and after testing, and further calculate to obtain the percentage of electrode weight loss.

[0074] Potential test method: a three-electrode electrochemical test system is used, the reference electrode is saturated calomel electrode, and the potential is measured at 3kA / m 2The potential of the working electrode is tested under the dense state, and the working electrode is tested as a cathode and an anode respectively to test the hydrogen evolution overpotential and the oxygen evolution overpotential of the electrode.

[0075] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a porous catalytic electrode, characterized by, The method comprises: S1: mixing a first powder with a second powder to obtain a spraying powder; S2: depositing the spraying powder on a substrate electrode to obtain a catalytic electrode; S3: performing a first calcination treatment on the catalytic electrode to obtain a porous catalytic electrode; S4: performing a second calcination treatment on the porous catalytic electrode under a reducing atmosphere; The first powder is a nickel-molybdenum alloy powder, and the second powder is carbon black; the mass ratio of the first powder to the second powder is 80-99:1-20; The temperature of the first calcination treatment is 600-800 degrees Celsius; The second calcination treatment comprises: calcining the porous catalytic electrode under a hydrogen atmosphere at 600-1000 degrees Celsius.

2. The method for preparing a porous catalytic electrode according to claim 1, characterized by, The calcination atmosphere of the first calcination treatment comprises 90-100 wt% argon and 0-10 wt% oxygen.

3. The method for preparing a porous catalytic electrode according to claim 1 or 2, characterized in that, The deposition is achieved by a thermal spraying technique, and the thermal spraying is a plasma spraying technique.

4. The method of claim 3, wherein the porous catalytic electrode is prepared by The conditions of the plasma spraying comprise: an argon flow rate of 30-60 liters / minute, a hydrogen flow rate of 1-10 liters / minute, a spraying power of 20-35 kilowatts, a spraying distance of 100-200 millimeters, and a spraying angle of 60-120 degrees.

5. A porous catalytic electrode characterized in that, The porous catalytic electrode is prepared by the preparation method of any one of claims 1-4.

6. Use of the porous catalytic electrode of claim 5 in hydrogen evolution or oxygen evolution.

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