Platinum-zirconium oxide porous catalytic electrode slurry and preparation method of catalytic electrode

Abstract

The invention provides platinum-zirconium oxide porous catalytic electrode slurry and a preparation method of a catalytic electrode, the platinum-zirconium oxide porous catalytic electrode slurry comprises the following components by weight: 50%-65% of platinum powder, 10%-20% of a pore-forming agent, 2%-5% of 8YSZ, 2%-5% of metal carbide powder and 15%-30% of an organic carrier, the particle size of the platinum powder is 1-3 [mu] m, the particle size of the pore-forming agent is 1-3 [mu] m, and the particle size of the metal carbide powder is 1-3 [mu] m. The decomposition temperature of the metal carbide is 600 to 1300 DEG C. According to the preparation method, carbides are added into the slurry, the carbides are decomposed to form oxides in the slurry sintering process, the oxides can be blocked among platinum particles, meanwhile, under the synergistic effect of the pore-forming agent, growth of the platinum particles is effectively inhibited, the catalytic specific surface area is reserved to a greater extent, and then the catalytic activity of the electrode is enhanced.

Description

TECHNICAL FIELD

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

[0002] The oxygen sensor is mainly used to monitor the oxygen content in the exhaust gas after engine combustion, and convert the oxygen content into a voltage signal to the ECU (Engine Control Unit), and the ECU analyzes the concentration of the mixture according to the signal, and modifies the injection time as appropriate, so that the engine obtains the best concentration of the mixture.

[0003] The platinum nanomaterial is widely used in various fields due to its excellent catalytic activity, but also because of the large specific surface area and large surface energy caused by small size, it tends to agglomerate and grow during drying and sintering. Due to the above reasons, at present, the platinum nanostructure in the preparation process of the sensor, the catalytic activity is obviously unable to achieve the expected situation. Especially as the platinum-based electrode material applied to the oxygen sensor, in order to realize the co-firing with the zirconia base porcelain film at high temperature (above 1400℃), and still need to maintain a high surface area after sintering as much as possible, therefore, it is necessary to reduce the agglomeration and growth of platinum grains in this process as much as possible; At the same time, for the electrolyte type gas sensor, such as zirconia-based oxygen sensor, the catalytic electrode also needs to obtain more "zirconia-platinum-gas" porous three-phase interface, so as to have high catalytic activity.

[0004] Therefore, it is necessary to design a platinum-zirconia porous catalytic electrode slurry and a preparation method of the catalytic electrode to solve the above problems. SUMMARY

[0005] The purpose of the present application is to provide a platinum-zirconia porous catalytic electrode slurry which can enhance the interface bonding strength between the electrode and the substrate and inhibit the sintering and growth of platinum particles at high temperature, so as to balance the catalytic activity and the reliability of the electrode.

[0006] In order to achieve the above purpose, the present application adopts the following technical scheme: a platinum-zirconia porous catalytic electrode slurry, comprising the following components in weight ratio: 50%-65% platinum powder, 10%-20% pore-forming agent, 2%-5% 8YSZ, 2%-5% metal carbide powder and 15%-30% organic carrier, wherein the particle size of the platinum powder is 1-3μm, and the decomposition temperature of the metal carbide is 600-1300℃.

[0007] As a further improved technical scheme of the present application, the metal carbide powder is one or both of zirconium carbide and aluminum carbide, and the particle size of the metal carbide is 200nm-1μm.

[0008] As a further improved technical solution of the present application, the molar ratio of aluminum carbide to zirconium carbide in the metal carbide powder is 1:(1-5).

[0009] As a further improved technical solution of the present application, the pore-forming agent has a particle size of 20 nm-10 μm, and the temperature at which the pore-forming agent forms pores in the catalytic electrode is 600-1200℃.

[0010] As a further improved technical solution of the present application, the pore-forming agent comprises nano-carbon powder having a particle size of 20-100 nm and micron-carbon powder having a particle size of 3-10 μm, the weight of the nano-carbon powder accounting for 40-60% of the total weight of the pore-forming agent, and the weight of the micron-carbon powder accounting for 40-60% of the total weight of the pore-forming agent.

[0011] As a further improved technical solution of the present application, the organic carrier comprises ethyl cellulose in a weight ratio of 15-30% and a solvent in a weight ratio of 70-85%, the solvent being selected from one or more of terpineol, butyl carbitol acetate, diethylene glycol butyl ether, diethylene glycol ethyl ether, and diethylene glycol butyl ether acetate.

[0012] As a further improved technical solution of the present application, the 8YSZ has a particle size of 200 nm-1 μm.

[0013] The present application also aims to provide a preparation method of a platinum-zirconia porous catalytic electrode that enhances the interface bonding strength of the electrode and the substrate and inhibits the sintering and growth of platinum particles at high temperatures, thereby balancing the catalytic activity and the reliability of the electrode.

[0014] To achieve the above-mentioned purposes, the present application adopts the following technical solution: a preparation method of a platinum-zirconia porous catalytic electrode, comprising the following steps: Step 1: stirring a solvent and ethyl cellulose until they are uniformly mixed to obtain an organic carrier; Step 2: mixing platinum powder with 8YSZ and performing ball milling, and then drying to obtain platinum-8YSZ premixed powder; Step 3: placing the platinum-8YSZ premixed powder, a pore-forming agent, a metal carbide powder, and the organic carrier into a homogenizer to obtain a slurry semi-product; Step 4: transferring the slurry semi-product obtained in Step 3 into a three-roll grinding machine to perform grinding and vacuum defoaming, thereby obtaining a slurry product; Step 5: printing the slurry product on a zirconia green ceramic membrane and performing sintering.

[0015] As a further improved technical solution of the present application, in Step 2, the ball milling condition is 200-300 rpm, and the ball milling time is 1-3 h; in Step 4, the roller speed of the three-roll grinding machine is 50-100 r / min, the pressure is 2 MPa, and the rolling is performed 3-10 times.

[0016] As a further improved technical solution of the present application, the sintering temperature and time of step 4 are set as follows: from room temperature to T1 and keep for 30-60 min, to T2 and keep for 1-2 h, to T3 and keep for 1-2 h; wherein 200℃≤T1≤300℃, 500℃≤T2≤700℃, 900℃≤T3≤1300℃, the rate from room temperature to T1 is 0.5-1℃ / min, the rate from T1 to T2 is 0.5-1℃ / min, and the rate from T2 to T3 is 2-3℃ / min.

[0017] From the above technical solution, the platinum-zirconia porous catalytic electrode slurry and the preparation method of the catalytic electrode of the present application have the following advantages: The decomposition temperature of the metal carbide added in the slurry is 600-1300℃, which is lower than the densification temperature (about 1300℃) of 8YSZ, and the decomposition of the metal carbide presents a continuous gradient reaction characteristic. This temperature difference makes the oxides generated by the decomposition of the carbide to act on the substrate and platinum particles in advance before the densification of 8YSZ, creating conditions for improving the interface bonding and inhibiting the growth of platinum particles. At the same time, under the synergistic action of the pore-forming agent, the growth of platinum particles is effectively inhibited, so that the catalytic specific surface area can be retained to a greater extent, the porosity and uniformity of the electrode are significantly improved, and the catalytic activity of the electrode is enhanced.

[0018] In addition, the decomposition temperature of the carbide is about 600℃, which is slightly earlier than the sintering starting point of platinum and earlier than the densification temperature of the zirconia substrate. On the one hand, it is beneficial for the electrode slurry to combine and shrink with the zirconia ceramic film substrate through the generated aluminum oxide and zirconia, so that the interface bonding is more compact. On the other hand, it effectively reduces the sintering delamination problem, improves the qualification rate and reliability of the electrode, and is suitable for the manufacture of high-precision oxygen sensors. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The surface scanning electron microscope image of the sample obtained by printing and sintering of the slurry of Example 1 of the present application.

[0020] Figure 2 The surface scanning electron microscope image of the sample obtained by printing and sintering of the slurry of Example 2 of the present application.

[0021] Figure 3 The surface scanning electron microscope image of the sample obtained by printing and sintering of the slurry of Example 3 of the present application.

[0022] Figure 4 The surface scanning electron microscope image of the sample obtained by printing and sintering of the slurry of Example 4 of the present application.

[0023] Figure 5 A surface scanning electron microscope image of the sample obtained by printing and sintering the slurry of Comparative Example 1 of the present application.

[0024] Figure 6 A scanning electron microscope image of the interface between the electrode layer and the substrate after co-sintering of the zirconia and platinum electrode of Example 1 of the present application. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described in detail below with reference to the drawings and specific examples.

[0026] Example 1

[0027] Preparation of the organic vehicle: diethylene glycol butyl ether was heated to 60°C, and ethyl cellulose was slowly added under stirring, and stirring was continued for 2 hours until complete dissolution, and it was cooled to room temperature for standby use. The weight ratio of ethyl cellulose to diethylene glycol butyl ether was 1:3.

[0028] Preparation of platinum-8YSZ premixed powder: 65 g of platinum powder (spherical, particle size 1-3 μm) was mixed with 3 g of 8YSZ (particle size 500 nm), and 200 g of zirconia balls (diameter 5 mm) were added, and ball milling was carried out in a ball mill at 250 rpm for 2 hours. After ball milling, the mixture was vacuum dried at 80°C for 3 hours, and it was passed through a 300 mesh screen.

[0029] Preparation of the slurry: the platinum-8YSZ premixed powder, 10 g of pore-forming agent (nanometer carbon powder 9 g + micron carbon powder 6 g), and 5 g of zirconium carbide powder (particle size 500 nm) were added to a homogenizer. 17 g of the organic vehicle was slowly added, and homogenization was carried out at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill, the roller speed was 80 r / min, the pressure was 2 MPa, and it was circulated and milled 5 times. It was defoamed at a vacuum degree of 0.09 MPa for 30 minutes to obtain the final slurry.

[0030] Preparation of the electrode: the slurry was screen printed on the zirconia green ceramic film with a thickness of 100 μm. The sintering curve was: room temperature→250°C (heating rate 0.8°C / min, holding for 45 minutes); 250°C→600°C (heating rate 0.8°C / min, holding for 1.5 hours); 600°C→1100°C (heating rate 2.5°C / min, holding for 1.5 hours).

[0031] Example 2

[0032] Preparation of the organic vehicle: same as Example 1.

[0033] Preparation of platinum-8YSZ premix powder: 60 g platinum powder (spherical, particle size 1-3 μm) was mixed with 5 g 8YSZ (particle size 800 nm) and 200 g zirconia balls (diameter 5 mm) were added to the mixture. The mixture was ball milled in a ball mill at 200 rpm for 3 hours. After ball milling, the mixture was vacuum dried at 80°C for 3 hours and sieved through a 300 mesh sieve.

[0034] Preparation of slurry: The platinum-8YSZ premix powder, 15 g pore former (12 g nano carbon powder + 3 g micro carbon powder), 3 g zirconium carbide powder (particle size 500 nm) were added to a homogenizer. 17 g organic vehicle was slowly added and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with roller speed 80 r / min and pressure 2 MPa for 5 cycles. The final slurry was degassed at 0.09 MPa vacuum for 30 minutes.

[0035] Electrode preparation: Same as Example 1.

[0036] Example 3

[0037] Preparation of organic vehicle: Same as Example 1.

[0038] Preparation of platinum-8YSZ premix powder: 60 g platinum powder (spherical, particle size 1-3 μm) was mixed with 4 g 8YSZ (particle size 400 nm) and 200 g zirconia balls (diameter 5 mm) were added to the mixture. The mixture was ball milled in a ball mill at 250 rpm for 2 hours. After ball milling, the mixture was vacuum dried at 80°C for 3 hours and sieved through a 300 mesh sieve.

[0039] Preparation of slurry: The platinum-8YSZ premix powder, 12 g pore former (6 g nano carbon powder + 6 g micro carbon powder), 3.2 g zirconium carbide powder and 0.8 g aluminum carbide powder (particle size 500 nm) were added to a homogenizer. 20 g organic vehicle was slowly added and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with roller speed 80 r / min and pressure 2 MPa for 5 cycles. The final slurry was degassed at 0.09 MPa vacuum for 30 minutes.

[0040] Electrode preparation: The slurry was screen printed on a zirconia green tape with thickness 100 μm. Sintering profile: room temperature→220°C (heating rate 1°C / min, hold for 60 minutes); 250°C→700°C (heating rate 1°C / min, hold for 1 hour); 700°C→1200°C (heating rate 3°C / min, hold for 1 hour).

[0041] Example 4

[0042] Preparation of organic vehicle: Same as Example 1.

[0043] Preparation of platinum-8YSZ premix powder: 58 g platinum powder (spherical, particle size 1-3 μm) was mixed with 4 g 8YSZ (particle size 600 nm), 200 g zirconia balls (diameter 5 mm) were added and ball milled in a ball mill for 2 hours at 250 rpm. After ball milling, the mixture was vacuum dried at 80°C for 3 hours and sieved through a 300 mesh screen.

[0044] Preparation of slurry: The platinum-8YSZ premix powder, 16 g pore former (8 g nano carbon powder + 8 g micro carbon powder), 2 g zirconium carbide powder and 2 g aluminum carbide powder (particle size 500 nm) were added to a homogenizer. 18 g of organic vehicle was slowly added and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with a roller speed of 80 r / min and a pressure of 2 MPa for 5 cycles. The final slurry was degassed at a vacuum of 0.09 MPa for 30 minutes.

[0045] Electrode preparation: Same as Example 3.

[0046] Example 5

[0047] Preparation of organic vehicle: Same as Example 1.

[0048] Preparation of platinum-8YSZ premix powder: 57 g platinum powder (spherical, particle size 1-3 μm) was mixed with 4 g 8YSZ (particle size 400 nm), 200 g zirconia balls (diameter 5 mm) were added and ball milled in a ball mill for 2 hours at 250 rpm. After ball milling, the mixture was vacuum dried at 80°C for 3 hours and sieved through a 300 mesh screen.

[0049] Preparation of slurry: The platinum-8YSZ premix powder, 12 g pore former (6 g nano carbon powder + 6 g micro carbon powder), 4 g aluminum carbide powder (particle size 500 nm) were added to a homogenizer. 23 g of organic vehicle was slowly added and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with a roller speed of 80 r / min and a pressure of 2 MPa for 5 cycles. The final slurry was degassed at a vacuum of 0.09 MPa for 30 minutes.

[0050] Electrode preparation: Same as Example 1.

[0051] Comparative Example 1

[0052] Preparation of organic vehicle: Same as Example 1.

[0053] Preparation of platinum-8YSZ premix powder: 65 g platinum powder (spherical, particle size 1-3 μm) was mixed with 5 g 8YSZ (particle size 400 nm), 200 g zirconia balls (diameter 5 mm) were added and ball milled in a ball mill for 2 hours at 250 rpm. After ball milling, the mixture was vacuum dried at 80°C for 3 hours and sieved through a 300 mesh screen.

[0054] Preparation of slurry: Pt-8YSZ premixed powder was added into a homogenizer, 30 g of organic vehicle was added slowly, and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with roller speed of 80 r / min and pressure of 2 MPa for 5 cycles. The final slurry was degassed under vacuum of 0.09 MPa for 30 minutes.

[0055] Electrode preparation: same as Example 1.

[0056] Comparative Example 2

[0057] Preparation of organic vehicle: same as Example 1.

[0058] Preparation of Pt-8YSZ premixed powder: 65 g of platinum powder (spherical, particle size 1-3 μm) was mixed with 3 g of 8YSZ (particle size 400 nm), 200 g of zirconia balls (diameter 5 mm) was added, and ball-milled in a ball mill at 250 rpm for 2 hours. After ball-milling, the mixture was vacuum dried at 80 °C for 3 hours, and passed through a 300 mesh sieve.

[0059] Preparation of slurry: Pt-8YSZ premixed powder, 3.2 g of zirconium carbide powder, and 0.8 g of aluminum carbide powder were added into a homogenizer, 28 g of organic vehicle was added slowly, and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with roller speed of 80 r / min and pressure of 2 MPa for 5 cycles. The final slurry was degassed under vacuum of 0.09 MPa for 30 minutes.

[0060] Electrode preparation: same as Example 3.

[0061] Comparative Example 3

[0062] Preparation of organic vehicle: same as Example 1.

[0063] Preparation of Pt-8YSZ premixed powder: 65 g of platinum powder (spherical, particle size 1-3 μm) was mixed with 3 g of 8YSZ (particle size 400 nm), 200 g of zirconia balls (diameter 5 mm) was added, and ball-milled in a ball mill at 250 rpm for 2 hours. After ball-milling, the mixture was vacuum dried at 80 °C for 3 hours, and passed through a 300 mesh sieve.

[0064] Preparation of slurry: Pt-8YSZ premixed powder, 12 g of pore-forming agent (6 g of nano-carbon powder + 6 g of micro-carbon powder) were added into a homogenizer, 20 g of organic vehicle was added slowly, and homogenized at 1500 rpm for 60 minutes. The slurry semi-product was passed through a three-roll mill with roller speed of 80 r / min and pressure of 2 MPa for 5 cycles. The final slurry was degassed under vacuum of 0.09 MPa for 30 minutes.

[0065] Electrode preparation: same as Example 3.

[0066] The component content of each of Examples 1-5 and Comparative Examples 1-3 is shown in Table 1.

[0067] Table 1: Component and weight percentage settings of examples and comparative examples

[0068] Performance tests were performed on the sintered samples of Examples 1-5 and Comparative Examples 1-3: Porosity and pore uniformity: The porosity of the hole samples was tested and calculated according to the method of “ISO 2738:2017 Sintered metallic materials (excluding cemented carbides) - Sintered metallic materials - Determination of density, oil content and open porosity”, and the results are shown in Table 2; the pore uniformity of the samples was determined by scanning electron microscope photograph observation method, and the results are shown in Table 2 and Figures 1-5 .

[0069] Catalytic activity determination: The slurry was screen printed on a zirconia green ceramic membrane, dried, laminated, and isostatic pressed to prepare a 4-wire linear switch oxygen sensor, and the catalytic activity was evaluated by the response time to oxygen, and the results are shown in Table 2.

[0070] Interface bonding reliability evaluation: The interface bonding reliability was evaluated by the signal attenuation after cycling under normal working conditions of the chip (specifically, the catalytic activity after 1000 cycles was determined), and the results are shown in Table 2. If the interface bonding is not reliable, microcracks will appear in the interface under the action of thermal shock stress after a period of time, resulting in a decrease in current density or even failure.

[0071] Table 2: Test results of sintered slurry samples of examples and comparative examples

[0072] From the differences in slurry composition and content, combined with the effects of metal carbide, carbon powder and other components during sintering, the electrode test results of the examples and comparative examples differ, please refer to Figures 1-6 and Table 2, specifically: Effect of metal carbide on electrode performance: Metal carbide was added in Examples 1-5 and Comparative Example 2, and the oxides generated by the decomposition of the carbide during sintering improved the interface bonding and inhibited the growth of platinum particles, so the bonding effect of the electrode layer and the substrate was significantly better than that of Comparative Examples 1 and 3. Please refer to Figure 6As shown, the white strip part is the electrode layer, and the rest is the substrate. The strip is continuous without interruption, and the contact line with the zirconia substrate is continuous without black gap, which indicates that the two are well combined. During co-firing, the platinum layer diffuses with the substrate surface atoms to form a firm bonding interface, which can withstand subsequent processing. In addition, the growth of platinum particles is effectively inhibited, and the specific surface area of the catalyst is retained to a greater extent. Therefore, the catalytic activity of the example is higher than that of the comparative example, so that the metal carbide not only improves the bonding force, but also has a certain influence on the improvement of the catalytic activity. Although comparative example 2 contains metal carbide, its overall synergistic effect is not as good as that of the example, so the catalytic activity is also lower.

[0073] Effect of carbon powder on electrode performance: carbon powder is added in examples 1-5, which acts as a pore-forming agent and will be oxidized and volatilized during sintering to form pores. At the same time, under the synergistic effect of the decomposition of metal carbide, the growth of platinum particles is further inhibited, ensuring good uniformity of the pores, providing sufficient active sites and good mass transfer channels for catalytic reaction (see Figures 1-4 Effect of carbon powder on electrode performance: carbon powder is added in examples 1-5, which acts as a pore-forming agent and will be oxidized and volatilized during sintering to form pores. At the same time, under the synergistic effect of the decomposition of metal carbide, the growth of platinum particles is further inhibited, ensuring good uniformity of the pores, providing sufficient active sites and good mass transfer channels for catalytic reaction (see

[0074] The above examples are only used to illustrate the technical solutions described in the present application and do not limit the technical solutions described in the present application. The understanding of the specification should be based on the skilled person in the art. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the skilled person in the art can still modify or equivalently replace the present application, and all technical solutions and improvements which do not deviate from the spirit and scope of the present application should be covered within the scope of the claims of the present application.

Claims

1. A platinum-zirconia porous catalytic electrode slurry characterized by: The components include the following weight ratios: 50%-65% platinum powder, 10%-20% pore-forming agent, 2%-5% 8YSZ, 2%-5% metal carbide powder, and 15%-30% organic carrier, wherein the particle size of the platinum powder is 1-3 μm, and the decomposition temperature of the metal carbide is 600-1300 ℃.

2. The platinum-zirconia porous catalytic electrode slurry of claim 1, wherein: The metal carbide powder is one or both of zirconium carbide and aluminum carbide, and the particle size of the metal carbide is 200 nm-1 μm.

3. The platinum-zirconia porous catalytic electrode slurry of claim 1, wherein: The molar ratio of aluminum carbide to zirconium carbide in the metal carbide powder is 1:(1-5).

4. The platinum-zirconia porous catalytic electrode slurry of claim 1, wherein: The particle size of the pore-forming agent is 20 nm-10 μm, and the temperature at which the pore-forming agent forms pores in the catalytic electrode is 600-1200 ℃.

5. The platinum-zirconia porous catalytic electrode slurry of claim 1, wherein: The pore-forming agent includes nano-carbon powder with a particle size of 20-100 nm and micron-carbon powder with a particle size of 3-10 μm, and the weight of the nano-carbon powder accounts for 40-60% of the total weight of the pore-forming agent, and the weight of the micron-carbon powder accounts for 40-60% of the total weight of the pore-forming agent.

6. The platinum-zirconia porous catalytic electrode slurry of claim 1, wherein: The organic carrier includes ethyl cellulose with a weight ratio of 15-30% and a solvent with a weight ratio of 70-85%, and the solvent is selected from one or more of the following: terpineol, butyl carbitol acetate, diethylene glycol butyl ether, diethylene glycol ethyl ether, and diethylene glycol butyl ether acetate.

7. The platinum-zirconia porous catalytic electrode slurry of claim 1, wherein: The particle size of the 8YSZ is 200 nm-1 μm.

8. A method of making a platinum-zirconia porous catalytic electrode, characterized by: The method includes the following steps: Step 1: stirring the solvent and ethyl cellulose until they are uniformly mixed to obtain an organic carrier; Step 2: mixing the platinum powder and 8YSZ and performing ball milling, and then drying to obtain platinum-8YSZ premixed powder; Step 3: placing the platinum-8YSZ premixed powder, pore-forming agent, metal carbide powder, and organic carrier into a homogenizer to obtain a slurry semi-product; Step 4: transferring the slurry semi-product obtained in step 3 into a three-roll grinding machine to grind and reduce pressure to remove bubbles, thereby obtaining a slurry product; Step 5: printing the slurry product on a zirconia green ceramic membrane and performing sintering.

9. The method of claim 8, wherein the platinum-zirconia porous catalytic electrode is prepared by: In step 2, the ball milling condition is 200-300 rpm, and the ball milling time is 1-3 h; in step 4, the roller speed of the three-roll grinding machine is 50-100 r / min, the pressure is 2 MPa, and the rolling is performed 3-10 times.

10. The method for preparing a platinum-zirconia porous catalytic electrode according to claim 8, characterized by: In step 4, the sintering temperature and time are set as follows: increasing the temperature from room temperature to T1 and maintaining for 30-60 min, increasing the temperature to T2 and maintaining for 1-2 h, and increasing the temperature to T3 and maintaining for 1-2 h; wherein 200 ℃≤T1≤300 ℃, 500 ℃≤T2≤700 ℃, and 900 ℃≤T3≤1300 ℃, the rate of increasing the temperature from room temperature to T1 is 0.5-1 ℃ / min, the rate of increasing the temperature from T1 to T2 is 0.5-1 ℃ / min, and the rate of increasing the temperature from T2 to T3 is 2-3 ℃ / min.

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