Production method of carbon-based alloy catalyst

Abstract

The invention relates to the field of preparation of catalysts, in particular to a production method of a carbon-based alloy catalyst. The production method comprises the following steps: (1) loading active metal on a carbon carrier to obtain a first precursor; (2) enabling first reducing gas to penetrate through the first precursor prepared in the step (1), and performing first fluidized calcination to obtain a second precursor; (3) sequentially carrying out acid pickling and drying on the second precursor obtained in the step (2) to obtain a third precursor; and (4) enabling a second reducing gas to penetrate through the third precursor prepared in the step (3), and carrying out second fluidized calcination. The catalyst is prepared through two-step fluidized calcination, macro preparation of the carbon-based alloy catalyst can be achieved, effective combination of laboratory basic research and actual industrial production is successfully achieved, the process of large-scale commercial application of fuel cells is expected to be promoted, and the prepared catalyst is high in alloying degree and good in industrial application prospect. The excellent electrochemical activity is shown.

Description

Technical Field

[0001] The present invention relates to the field of catalyst preparation, and particularly to a production method of a carbon-based alloy catalyst. Background Art

[0002] With the massive consumption of fossil fuels such as coal, oil, and natural gas globally, humans are facing an increasingly severe energy shortage problem. Actively developing new energy for sustainable development has become the consensus of countries around the world. As a green and efficient energy, hydrogen energy can be produced in a sustainable manner and is considered to be the most effective solution to the energy shortage problem. Among them, fuel cells are one of the key technologies of the hydrogen energy system. Fuel cells can directly convert the chemical energy stored in hydrogen into electrical energy with zero carbon emissions and are widely regarded as the most promising energy conversion devices for achieving sustainable energy development. However, limited by the slow oxygen reduction reaction (ORR) kinetics at the cathode, a large amount of expensive and scarce noble metal platinum is required to accelerate the ORR kinetics, which seriously hinders the large-scale commercial application of fuel cells.

[0003] Reducing the noble metal usage or developing non-noble metal catalysts are the two main development directions of current fuel cell cathode catalysts. Although developing non-noble metal catalysts can significantly reduce the manufacturing cost of fuel cells, and relevant research has successfully developed non-noble metal catalysts that can rival or even exceed the oxygen reduction performance of noble metal-based catalysts. However, under the actual operating conditions of fuel cells, facing a harsh acidic environment, the stability of non-noble metal catalysts has always been unsatisfactory, still far inferior to noble metal-based catalysts, and even fails to meet the requirements of the service life of automobiles. Therefore, the fuel cell vehicles developed by major mainstream automobile manufacturers in the world still use Pt-based catalysts as the preferred cathode catalysts.

[0004] So far, the Pt / C catalyst is still the most widely used cathode catalyst for fuel cells. However, in practical applications, the Pt / C catalyst faces problems of low activity and poor stability, which brings great pressure to the performance and service life of fuel cells. Compared with the Pt / C catalyst, Pt-based alloy catalysts can produce a strain effect and a ligand effect by introducing non-noble metals to form alloys with Pt, thereby significantly enhancing the ORR activity and durability of the catalyst. With this unique advantage, Pt-based alloy catalysts show broad application prospects in fuel cell ORR. However, at present, the preparation processes of most Pt-based alloy catalysts are complex, the preparation conditions are harsh, and the preparation cost is high, basically remaining at the laboratory stage; and Pt-based alloy catalysts prepared by high-temperature calcination using a tubular furnace. Summary of the Invention

[0005] The object of the present invention is to overcome the problem that the single-batch processing capacity of the preparation of alloy catalysts in the prior art has great limitations, the macroscale preparation of alloy catalysts cannot be achieved, and the degree of alloying is not high, and to provide a production method of a carbon-based alloy catalyst, which has the characteristics of a large preparation amount and a high degree of alloying of the catalyst. To achieve the above object, the present invention provides a production method of a carbon-based alloy catalyst, which production method includes the following steps: (1) loading an active metal on a carbon support to obtain a first precursor; (2) passing a first reducing gas through the first precursor prepared in step (1) for first fluidized calcination to obtain a second precursor; (3) sequentially subjecting the second precursor described in step (2) to pickling and drying to obtain a third precursor; (4) passing a second reducing gas through the third precursor prepared in step (3) for second fluidized calcination.

[0006] Through the above technical solution, the present invention has the following advantages: The present invention prepares the catalyst through two-step fluidized calcination, which can realize the macroscale preparation of the carbon-based alloy catalyst, successfully realizes the effective combination of laboratory basic research and actual industrial production, is expected to promote the process of large-scale commercial application of fuel cells, and the prepared catalyst has a high degree of alloying and exhibits excellent electrochemical activity. Description of the Drawings

[0007] Figure 1 is the superposition of the XRD patterns of the catalysts prepared in Example 1 and Comparative Example 1; Figure 2 In, (a) is the cyclic voltammetry (CV) curve of the catalysts prepared in Example 1 and Comparative Example 1; (b) is the linear sweep voltammetry (LSV) curve of the catalysts prepared in Example 1 and Comparative Example 1; Figure 3 In, (a) is the CV curve of the catalyst prepared in Comparative Example 1 during the Initial and 10k cycle ADT tests; (b) is the LSV curve of the catalyst prepared in Comparative Example 1 during the Initial and 10k cycle ADT tests; (c) is the CV curve of the catalyst prepared in Example 1 during the Initial and 10k cycle ADT tests; (d) is the LSV curve of the catalyst prepared in Example 1 during the Initial and 10k cycle ADT tests. Detailed Embodiments

[0008] The endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the values between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0009] The present invention provides a method for producing a carbon-based alloy catalyst, and the production method includes the following steps: (1) Loading an active metal on a carbon carrier to obtain a first precursor; (2) Passing a first reducing gas through the first precursor prepared in step (1) to perform a first fluidized calcination to obtain a second precursor; (3) The second precursor described in step (2) is sequentially subjected to pickling and drying to obtain a third precursor; (4) Passing a second reducing gas through the third precursor prepared in step (3) to perform a second fluidized calcination.

[0010] The present invention prepares the catalyst through two-step fluidized calcination, which can achieve the mass production of the carbon-based alloy catalyst, and the prepared catalyst has a high degree of alloying and exhibits excellent electrochemical activity.

[0011] According to a preferred embodiment of the present invention, the conditions for the first fluidized calcination include: the temperature is 300 - 800 °C, for example, it can be 350 °C, 400 °C, 500 °C, 550 °C, 600 °C, 650 °C, 700 °C, 750 °C, and preferably 400 - 700 °C. By adopting the foregoing preferred scheme, the degree of alloying and electrochemical activity of the prepared catalyst can be further improved.

[0012] In the present invention, the time of the first fluidized calcination is adjusted according to factors including the calcination temperature. According to a preferred embodiment of the present invention, the conditions for the first fluidized calcination include: the time is 2 - 6 h, and preferably 3 - 5 h.

[0013] According to a preferred embodiment of the present invention, the conditions for the first fluidized calcination include: the gas velocity is 0.5 - 3 L min -1 ; preferably 1 - 2 L min -1 . By adopting the foregoing preferred scheme, the degree of alloying and electrochemical activity of the prepared catalyst can be further improved.

[0014] According to a preferred embodiment of the present invention, the conditions for the second fluidized calcination include: the temperature is 200-600 °C, for example, it can be 250 °C, 300 °C, 400 °C, 450 °C, 500 °C, 550 °C, and preferably 300-500 °C. By adopting the foregoing preferred scheme, the alloying degree and electrochemical activity of the prepared catalyst can be further improved.

[0015] In the present invention, the time of the second fluidized calcination is adjusted according to factors including the calcination temperature. According to a preferred embodiment of the present invention, the time is 2-6 h, and preferably 3-5 h.

[0016] According to a preferred embodiment of the present invention, the conditions for the second fluidized calcination include: the gas velocity is 0.5-3 L / min -1 ; preferably 1-2 L / min -1 . By adopting the foregoing preferred scheme, the alloying degree and electrochemical activity of the prepared catalyst can be further improved.

[0017] According to a preferred embodiment of the present invention, the temperature of the first fluidized calcination is 50-300 °C higher than the temperature of the second fluidized calcination, for example, it can be 80 °C, 100 °C, 150 °C, 180 °C, 200 °C, 250 °C, and preferably 50-100 °C. By adopting the foregoing preferred scheme, the alloying degree and electrochemical activity of the prepared catalyst can be further improved.

[0018] In the present invention, the active metal can be a conventional metal in the art. According to a preferred embodiment of the present invention, the active metal is selected from noble metals and / or non-noble metals, and preferably noble metals and Group VIII non-noble metals.

[0019] According to a preferred embodiment of the present invention, in the active metal, the molar ratio of the noble metal to the Group VIII non-noble metal is 3:1-2 in terms of elements.

[0020] In the present invention, the noble metal can be a conventional selection in the art. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the noble metal is selected from at least one of Pt, Rh, Ru, and Pd, and preferably Pt.

[0021] In the present invention, the Group VIII non-noble metal can be a conventional selection in the art. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the Group VIII non-noble metal is selected from at least one of Fe, Co, and Ni, and preferably Co.

[0022] According to a preferred embodiment of the present invention, the volume content of the reducing gas in the first reducing gas is 3-15%, for example, it can be 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, preferably 5-10%. By adopting the foregoing preferred scheme, the alloying degree and electrochemical activity of the prepared catalyst can be further improved.

[0023] According to a preferred embodiment of the present invention, the volume content of the reducing gas in the second reducing gas is 2-10%, for example, it can be 3%, 4%, 5%, 6%, 7%, 10%, 9%, preferably 3-8%. By adopting the foregoing preferred scheme, the alloying degree and electrochemical activity of the prepared catalyst can be further improved.

[0024] The first reducing gas and the second reducing gas are doped with an inert gas, such as argon.

[0025] According to a preferred embodiment of the present invention, the volume content of the reducing gas in the first reducing gas is 2-3% greater than that in the second reducing gas. By adopting the foregoing preferred scheme, the alloying degree and electrochemical activity of the prepared catalyst can be further improved.

[0026] According to the present invention, step (1) includes: first mixing the solvent and the carbon support, then adding the active metal precursor for second mixing; then adjusting the pH value of the solution to 8-12; finally adding a reducing agent, contacting and reacting, and performing solid-liquid separation, drying, and shaping.

[0027] In the present invention, the solvent can be a conventional choice in the art as long as the object of the present invention can be achieved. The following is a demonstration, but it does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the solvent is at least one of water, ethanol, and ethylene glycol.

[0028] In the present invention, the active metal precursor can be a conventional choice in the art as long as the object of the present invention can be achieved. The following is a demonstration, but it does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the active metal precursor is a soluble salt corresponding to the active metal. Preferably, the soluble salt is a halide salt, a nitrate salt, and an organometallic compound. For example, when the active metal is Pt, the Pt precursor can be selected from at least one of chloroplatinic acid hexahydrate, platinum nitrate, and platinum acetylacetonate; when the active metal is Co, the Co precursor can be selected from at least one of cobalt chloride hexahydrate, cobalt nitrate hexahydrate, and cobalt acetylacetonate.

[0029] In the present invention, the reducing agent can be a conventional choice in the art as long as it can achieve the purpose of the present invention. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the reducing agent is at least one of sodium borohydride, dimethylaminoborane, and hydrazine hydrate.

[0030] In the present invention, the reducing agent is added in such a way that a reducing agent solution is first prepared and then added dropwise.

[0031] In the present invention, the method of solid-liquid separation can be a conventional choice in the art, for example, it can be suction filtration.

[0032] In the present invention, the drying conditions have a relatively wide optional range. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the drying conditions include: the drying temperature is 40 - 120 °C.

[0033] In the present invention, the forming method includes conventional methods such as grinding, and it is preferably formed into a powder.

[0034] In the present invention, the conditions for the contact reaction have a relatively wide optional range. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the conditions for the contact reaction include: the reaction temperature is 40 - 100 °C; and / or the reaction time is 2 - 8 h.

[0035] In the process of the contact reaction in step (1) of the present invention, the amounts of each material are not particularly limited. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the mass ratio of the carbon support, the active metal precursor, and the reducing agent is 200 - 600∶40 - 400∶200 - 800; for the amount of the solvent, as long as it can ensure that each material is fully dissolved.

[0036] In the present invention, the acid used for pickling can be a conventional choice in the art. According to a preferred embodiment of the present invention, the acid used for pickling is selected from at least one of HClO4, H2SO4, and HNO3.

[0037] In the present invention, the pickling has a relatively wide optional range as long as it can achieve the purpose of the present invention. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the pickling conditions include pickling at 40 - 80 °C for 3 - 10 h.

[0038] In the present invention, the carbon support can be a conventional choice in the art. The following is a demonstration but does not limit the scope of the present invention. According to a preferred embodiment of the present invention, the carbon support is at least one of XC-72, XC-72R, and EC300J.

[0039] The present invention will be described in detail below with reference to embodiments.

[0040] Embodiment 1 Step 1: First, add 7.5 L of water into the reaction kettle, then add 90 g of carbon support EC300J, and stir magnetically for 60 min; then add a precursor mixture of 0.125 mol of platinum nitrate and 0.083 mol of cobalt nitrate hexahydrate, and stir magnetically for 60 min; then adjust the pH value of the solution to 10 using NaOH solution. Finally, weigh 100 g of dimethylaminoborane and dissolve it in 2.5 L of water. After the reducing agent is completely dissolved, slowly drop it into the reaction kettle, heat it in a water bath to 55 °C, and react for 6 h. After the reaction is completed, collect the product by suction filtration, and place the obtained product in a blast drying oven at 80 °C for drying. After drying, grind it for 40 min to a powder to obtain the catalyst precursor.

[0041] Step 2: Place all the precursors in the reaction tube of the fluidized bed carbonization furnace (vertically placed). First, pass hydrogen-argon mixed gas (the volume ratio of hydrogen to argon is 8%) through the sample from bottom to top for 40 min, then keep passing the gas and heat up to 550 °C and maintain for 4 h, and then naturally cool to room temperature to obtain the Pt3Co alloy catalyst precursor.

[0042] Step 3: Place all the Pt3Co alloy catalyst precursors in the reaction kettle, add 5 L of 0.1 M HClO4 solution, and carry out pickling at 60 °C for 6 h. After pickling is completed, collect the product by suction filtration, and place the obtained product in a blast drying oven at 80 °C for drying. After drying, grind it for 40 min to a powder to obtain the pickled catalyst precursor.

[0043] Step 4: Place all the pickled precursors in the reaction tube of the fluidized bed carbonization furnace. First, pass hydrogen-argon mixed gas (the volume ratio of hydrogen to argon is 6%) through the sample for 40 min, then heat up to 500 °C and maintain for 4 h, and then naturally cool to room temperature to obtain the Pt3Co / C alloy catalyst, denoted as Pt3Co / C@fluidized bed. After weighing, the final yield of the catalyst is 103.35 g.

[0044] The XRD pattern of the prepared catalyst is as Figure 1As shown, it can be seen that both the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst correspond to the four crystal planes of (111), (200), (220), and (311) of face-centered cubic Pt. In addition, it can also be observed that compared with the characteristic peak positions of the powder diffraction standard card of Pt, the 2θ values of the characteristic peaks of the Pt3Co / C@fluidized bed catalyst and the Pt3Co / C@tubular furnace catalyst have shifted to the right, moving to a higher angle, and basically coincide with the characteristic peak positions of the powder diffraction standard card of Pt3Co, indicating that the introduced Co atoms have alloyed with Pt atoms, resulting in lattice contraction and forming a Pt3Co alloy catalyst. It is confirmed that both the prepared Pt3Co / C@fluidized bed catalyst and the Pt3Co / C@tubular furnace catalyst are Pt3Co alloy catalysts. It should be noted that from Figure 1 It can also be seen that the characteristic peaks of the XRD pattern of the Pt3Co / C@fluidized bed catalyst are sharper and have higher intensity compared to the Pt3Co / C@tubular furnace catalyst, indicating that the heat transfer effect of fluidized bed calcination is better and more conducive to the alloying of the catalyst.

[0045] Example 2 Step 1: First, add 5 L of water to the reaction kettle, then add 45 g of carbon support XC-72, and stir magnetically for 30 min; then add a precursor mixture of 0.0625 mol of platinum nitrate and 0.0208 mol of cobalt nitrate hexahydrate, and stir magnetically for 30 min; then adjust the pH value of the solution to 9 using NaOH solution, and finally weigh 50 g of dimethylaminoborane and dissolve it in 1.25 L of water. After the reducing agent is completely dissolved, slowly drop it into the reaction kettle, heat it in a water bath to 50°C, and react for 3 h. After the reaction is completed, filter and collect the product, and place the obtained product in a blast drying oven at 60°C for drying. After drying, grind it for 40 min to a powder to obtain the catalyst precursor.

[0046] Step 2: Place all the precursors in the reaction tube of the fluidized bed carbonization furnace (vertically placed). First, pass hydrogen-argon mixed gas (hydrogen-argon volume ratio is 7%) through the sample (from bottom to top) for 40 min, then keep passing the gas and heat up to 500°C and keep it for 4 h, and then naturally cool to room temperature to obtain the Pt3Co alloy catalyst precursor.

[0047] Step 3: Place all the Pt3Co alloy catalyst precursors in the reaction kettle, add 3 L of 0.1 M HClO4 solution, and carry out acid washing at 60°C for 3 h. After the acid washing is completed, filter and collect the product, and place the obtained product in a blast drying oven at 60°C for drying. After drying, grind it for 40 min to a powder to obtain the acid-washed catalyst precursor.

[0048] Step 4: Place all the pickling precursors in the reaction tube of the fluidized bed carbonization furnace. First, purge the sample with a hydrogen-argon mixture (hydrogen-argon volume ratio is 4%) for 40 min, then heat it to 400 °C and hold for 4 h, and then naturally cool to room temperature to obtain the Pt3Co / C alloy catalyst.

[0049] Example 3 Step 1: First, add 15 L of water to the reaction kettle, then add 150 g of carbon support EC300J, and stir magnetically for 90 min; then add a mixture of 0.208 mol of palladium nitrate and 0.139 mol of nickel nitrate hexahydrate precursor, and stir magnetically for 90 min; then adjust the pH value of the solution to 11 using NaOH solution. Finally, weigh 200 g of dimethylaminoborane and dissolve it in 5 L of water. After the reducing agent is completely dissolved, slowly drop it into the reaction kettle, heat to 60 °C, and react for 9 h. After the reaction is completed, filter and collect the product, and place the obtained product in a blast drying oven at 100 °C for drying. After drying, grind for 40 min to a powder to obtain the catalyst precursor.

[0050] Step 2: Place all the precursors in the reaction tube of the fluidized bed carbonization furnace (vertically placed). First, purge the sample with a hydrogen-argon mixture (hydrogen-argon volume ratio is 9%) from bottom to top for 40 min, then keep purging and heat to 600 °C and hold for 4 h, and then naturally cool to room temperature to obtain the alloy catalyst precursor.

[0051] Step 3: Place all the alloy catalyst precursors in the reaction kettle, add 8 L of 0.1 M HClO4 solution, and pickle at 60 °C for 9 h. After pickling is completed, filter and collect the product, and place the obtained product in a blast drying oven at 100 °C for drying. After drying, grind for 40 min to a powder to obtain the pickling precursor of the catalyst.

[0052] Step 4: Place all the pickling precursors in the reaction tube of the fluidized bed carbonization furnace. First, purge the sample with a hydrogen-argon mixture (hydrogen-argon volume ratio is 7%) for 40 min, then heat it to 550 °C and hold for 4 h, and then naturally cool to room temperature to obtain the alloy catalyst.

[0053] Example 4 Same as Example 1, except that in Step 4, heat to 400 °C and hold for 4 h. Obtain the Pt3Co / C alloy catalyst.

[0054] Example 5 Same as Example 1, except that in Step 4, the hydrogen-argon volume ratio is 4%.

[0055] Comparative Example 1 Same as Example 1, except that the material feeding amount was reduced by 250 times, carried out in a flask, and the reaction tube of the fluidized bed carbonization furnace was replaced with a tubular furnace (horizontally placed), and the reducing gas was introduced from left to right to obtain a Pt3Co / C alloy catalyst, denoted as Pt3Co / C@tubular furnace.

[0056] The XRD patterns of the prepared catalysts are as Figure 1 shown.

[0057] Comparative Example 2 Same as Example 1, except that the reaction tube of the fluidized bed carbonization furnace was replaced with a tubular furnace (horizontally placed), and the reducing gas was introduced from left to right.

[0058] Example 6 Preparation of catalyst ink: Weigh 3 mg of the catalyst with an electronic balance and place it in a plastic sample tube. Then, add 30 μL of Nafion solution and 570 μL of anhydrous ethanol solution in sequence, and ultrasonically disperse for 1 h to prepare a uniformly mixed catalyst ink.

[0059] Preparation of working electrode: Use a pipette to transfer 5 μL of the prepared catalyst ink and evenly drop it on a polished and clean glassy carbon electrode. After the ethanol has completely evaporated, repeat the dropping 3 times to prepare a working electrode to be tested.

[0060] Cyclic voltammetry (CV) curve test: In a 0.1 M HClO4 electrolyte saturated with N2, in the potential range of 0 - 1.1 V, scan rate of 0.1 V s -1 Perform cyclic voltammetry tests to obtain the CV curves of the catalysts prepared in Example 1 and Comparative Example 1; as Figure 2 shown in (a).

[0061] Linear sweep voltammetry (LSV) curve: In a 0.1 M HClO4 electrolyte saturated with O2, in the potential range of 0 - 1.1 V, rotation speed of 1600 rpm, scan rate of 0.01 V s -1 Perform linear sweep voltammetry tests to obtain the LSV curves of the catalysts prepared in Example 1 and Comparative Example 1; as Figure 2 shown in (b).

[0062] Catalyst stability test: Using accelerated durability test (ADT), in a 0.1 M HClO4 electrolyte saturated with N2, in the potential range of 0.6 - 0.95 V, scan rate of 0.05 V s -1 Perform 10k cyclic scans, and test the CV curves and LSV curves of the catalysts prepared in Example 1 and Comparative Example 1 at Initial and every 10k cycles respectively, as Figure 3As shown, (a) and (b) are the CV curves and LSV curves of the Pt3Co / C@tubular furnace catalyst; (c) and (d) are the CV curves and LSV curves of the Pt3Co / C@fluidized bed catalyst; From Figure 2 the CV curve of (a), the electrochemically active surface areas (ECSAs) of the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst can be calculated by the hydrogen underpotential deposition method to be 40.37 m 2 g -1 and 45.28 m 2 g -1 respectively. Having a relatively large ECSA indicates that both the Pt3Co / C alloy catalyst prepared on a small scale and the Pt3Co / C alloy catalyst prepared in bulk can expose more Pt active sites, thus facilitating the improvement of the ORR performance of the catalyst. From Figure 2 the LSV curve of (b), the half-wave potentials (E 1 / 2 1 / 2 1 / 2 1 / 2 Figure 2 of the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst can be obtained as 0.881 V and 0.885 V respectively. Having a relatively high E -2 1 / 2 -2 1 / 2

[0063] Figure 3 shows the CV curves and LSV curves of the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst during the Initial and 10k-cycle accelerated durability (ADT) tests. From Figure 3 the CV curves of (a) and Figure 3 (c), the ECSAs of the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst can be calculated by the hydrogen underpotential deposition method to decrease to 35.06 m 2 g -1 and 38.78 m 2 g -1 respectively after 10k ADT tests. The ECSAs are lost by 13.16% and 14.37% respectively, showing a relatively small loss of ECSA. In addition, fromFigure 3 (b) and Figure 3 From the LSV curves of (d), the E of the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst can be obtained 1 / 2 After 10k ADT tests, they decreased to 0.867 V and 0.870 V respectively. The E 1 / 2 Shifted negatively by 14 mV and 15 mV respectively, showing a smaller E 1 / 2 Decrease. In addition, from Figure 3 (b) and Figure 3 From the LSV curves of (d), using the Koutecky-Levich equation, the mass activities (MA) of the Pt3Co / C@tubular furnace catalyst and the Pt3Co / C@fluidized bed catalyst at 0.9 V decayed by 25.83% and 29.43% respectively, both meeting the US DOE 2025 target (<40%), showing less MA decay. The above ADT test results fully confirm that both the Pt3Co / C alloy catalyst prepared on a small scale and the Pt3Co / C alloy catalyst prepared on a large scale have excellent electrochemical stability.

[0064] Using the same method as described above to test the catalysts prepared in Examples 4-5 and Comparative Example 2, it was found that compared with Example 1, the half-wave potentials (E 1 / 2 ) of the catalysts prepared in Examples 4-5 and Comparative Example 2 were 0.842 V, 0.856 V, and 0.723 V respectively, and the limiting current densities were 5.34 mA cm -2 , 5.65 mA cm -2 , 4.22 mA cm -2 respectively. The ECSAs decreased by 21.62%, 18.73%, and 32.13% respectively. The E 1 / 2 Shifted negatively by 19 mV, 17 mV, and 25 mV respectively, and the mass activities (MA) at 0.9 V decayed by 34.43%, 31.34%, and 48.58% respectively.

[0065] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for producing a carbon-based alloy catalyst, characterized in that: The production method comprises the following steps: (1) loading an active metal on a carbon support to obtain a first precursor; (2) passing a first reducing gas through the first precursor prepared in step (1) to perform a first fluidized calcination to obtain a second precursor; (3) The second precursor described in step (2) is successively acid-washed and dried to obtain a third precursor; (4) Allowing a second reducing gas to flow through the third precursor prepared in step (3) to perform a second fluidized calcination.

2. The production method according to claim 1, wherein The conditions of the first fluidized calcination include: a temperature of 300-800° C., preferably 400-700° C.; and / or The time is 2-6 h, preferably 3-5 h; and / or Gas flow rate: 0.5-3 L min -1 .

3. The production method according to claim 1, wherein The conditions of the second fluidized calcination include: a temperature of 200-600° C., preferably 300-500° C.; and / or The time is 2-6 h, preferably 3-5 h; and / or Gas flow rate: 0.5-3 L min -1 .

4. The production method according to claim 1, wherein The temperature of the first fluidized calcination is 50-300°C higher than the temperature of the second fluidized calcination, preferably 50-100°C.

5. The production method according to claim 1, wherein The active metal is selected from noble metals and / or non-noble metals, preferably noble metals and Group VIII non-noble metals. More preferably, the molar ratio of the noble metal to the Group VIII non-noble metal in the active metal is 3:1-2, calculated as the element. More preferably, The noble metal is selected from at least one of Pt, Rh, Ru and Pd, preferably Pt; and / or The Group VIII non-noble metal is at least one selected from Fe, Co and Ni, preferably Co.

6. The production method according to claim 1, wherein By volume, The volume content of reducing gas in the first reducing gas is 3-15%, preferably 5-10%; and / or The volume content of reducing gas in the second reducing gas is 2-10%, preferably 3-8%; Preferably, the volume content of reducing gas in the first reducing gas is 2-3% greater than the volume content of reducing gas in the second reducing gas.

7. The production method according to claim 1, wherein: The step (1) comprises: firstly mixing the solvent and the carbon carrier, then adding the active metal precursor and mixing them; then adjusting the pH value of the solution to 8-12; finally adding the reducing agent, contact reaction, solid-liquid separation, drying, and molding.

8. The production method according to claim 7, wherein: The solvent is at least one of water, ethanol and ethylene glycol; and / or The active metal precursor is a soluble salt corresponding to the active metal, preferably the soluble salt is a halide salt, a nitrate and an organic metal compound; and / or The reducing agent is at least one of sodium borohydride, dimethylamino borane and hydrazine hydrate.

9. The production method according to claim 7, wherein: The conditions of the contact reaction include: The reaction temperature is 40-100°C; and / or The reaction time is 2-8 h; and / or The mass ratio of the carbon carrier, the active metal precursor and the reducing agent is 200-600:40-400:200-800.

10. The production method according to any one of claims 1 to 8, wherein: The acid used for pickling is selected from at least one of HClO4, H2SO4, and HNO3; and / or The pickling conditions include pickling at 40-80°C for 3-10 h; and / or The carbon carrier is at least one of XC-72, XC-72R, and EC300J.

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