Fuel cell electrode preparation method based on non-noble metal high-entropy alloy

Abstract

The invention relates to the technical field of preparation of catalyst materials, and provides a preparation method of a fuel cell electrode based on a non-noble metal high-entropy alloy. The method for preparing the non-noble metal catalyst for the fuel cell by adopting a high-entropy alloy deposition method specifically comprises the following steps: soaking carbon paper in a high-entropy alloy precursor solution for deposition by utilizing an electroplating method to obtain a high-stability non-noble metal catalyst, and performing reduction treatment, centrifugal washing and drying to obtain an electrode. The prepared non-noble metal catalyst is high in stability, lower in price and suitable for commercial application.

Description

[0001] The present invention belongs to the technical field of fuel cell catalyst material preparation, and in particular relates to a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy. Background Art

[0002] With the rapid development of society, sustainable and environmentally friendly renewable energy is the key to the urgent development, and fuel cells, as a new electrochemical technology, have received widespread attention. In order to overcome the problems of catalytic reaction energy barriers and service life, precious metal materials such as platinum, palladium and iridium have become the preferred elements. However, in practical applications, the high price of precious metals hinders their large-scale application. Non-precious metals with low prices and abundant reserves have always been ideal materials for fuel cell catalyst applications, but their low stability and catalytic activity restrict their development. High entropy alloys have many promising properties such as high strength, high temperature resistance, excellent creep performance, good wear resistance, and their high catalytic activity and stability can make them applicable to fuel cells. At the same time, directly depositing them on the surface of carbon paper by electroplating to construct electrodes can effectively improve the stability of the catalyst and reduce the transmission impedance. Summary of the invention

[0003] In view of this, in order to overcome the deficiencies of the prior art, the present invention provides a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy.

[0004] The present invention provides a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, comprising:

[0005] 1. A method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, characterized in that the method comprises:

[0006] Step 1: Pretreatment of carbon paper

[0007] The carbon paper is immersed in a certain amount of high entropy alloy precursor solution, a certain amount of water, urea and ammonia water are added, and the temperature is raised to a certain temperature in a hydrothermal reactor and reacted for a certain time.

[0008] Step 2: Preparation of non-precious metal high entropy alloy electrodes

[0009] The impregnated carbon paper is dried and immersed in a precursor solution containing a high entropy alloy, with it as the cathode and the carbon rod as the anode. A gradient voltage is then applied across the electrodes, ① at 1-10 mA / cm 2 Run for 1 to 10 minutes at 5 to 15 mA / cm 2 Run for 1 to 15 minutes, ③ at 10 to 20 mA / cm 2Run for 1 to 15 minutes at 5 to 20 mA / cm 2 Run for 1 to 15 minutes and repeat this 1-4 program for 1 to 10 times.

[0010] Step 3: Preparation of electrode layer

[0011] The treated carbon paper is annealed in a reducing atmosphere at 300-800° C. for 1-8 hours. After naturally cooling to room temperature, the sample is treated in an acid solution at 20-90° C. for 1-10 hours, and after cleaning, is dried under vacuum at 50-80° C. for 5-50 hours.

[0012] Furthermore, the present invention provides a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, characterized in that, in step 1, the solubility of the high entropy alloy precursor solution is 5-50 mg / ml, and the ratio of urea to ammonia water is 2:5-8:1. The temperature is raised to 20-150°C, and the reaction time is 0.1-10 hours.

[0013] Furthermore, the present invention provides a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, characterized in that in step 2, the high entropy alloy precursor is any one or more of NiCl2·6H2O, Ni(NO3)2·6H2O, Al(NO3)3·9H2O, FeCl3·6H2O, CrCl3·6H2O, CoCl2·6H2O, MnCl2·4H2O, CuSO4·5H2O. The reaction time is 1-24 hours, and the heating temperature is 20-150°C.

[0014] Furthermore, the present invention provides a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, characterized in that the reducing atmosphere is hydrogen or a hydrogen-argon mixture, and the high-temperature annealing process is: heating from room temperature to 300-800°C at a heating rate of 2-5°C / min.

[0015] The present invention provides a method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, which has the following beneficial effects:

[0016] 1. The catalyst prepared by the present invention has good catalytic activity and stability, and the multi-element synergistic effect of high entropy alloy can effectively promote catalytic activity and improve the tolerance of each element in the fuel cell. Through hydrothermal pretreatment, it is convenient for the subsequent electroplating growth to be uniform.

[0017] 2. The catalyst layer prepared by the present invention is directly deposited on the carbon paper and can be directly used as the electrode layer, which not only improves the bonding force between the catalyst layer and the diffusion layer carbon paper, but also simplifies the preparation process of the electrode layer. It has a longer service life, good comprehensive performance and development prospects, and is suitable for application and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 TEM image of particles of high entropy alloy;

[0020] Figure 2 Polarization curve of the high entropy alloy prepared in Example 1 of the present invention as an anode catalyst DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] It should be noted that the following embodiments and features in the embodiments may be combined with each other in the absence of conflict; and, based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making any creative work are within the scope of protection of the present disclosure.

[0023] Example 1

[0024] Step 1: Pretreatment of carbon paper

[0025] Select 2cm 2 The carbon paper was immersed in 100 ml NiCl2·6H2O, FeCl3·6H2O, CrCl3·6H2O, CoCl2·6H2O, MnCl2·4H2O solution (all with a concentration of 10 mg / ml), and then 2 g urea and 1 g ammonia water were added, and the temperature was raised to 120 ° C in a hydrothermal reactor for 2 hours.

[0026] Step 2: Preparation of non-precious metal high entropy alloy electrodes

[0027] The impregnated carbon paper was dried and immersed in a precursor solution containing a high entropy alloy. The carbon paper was used as the cathode and the carbon rod was used as the anode. A gradient voltage was applied across the electrodes at 20°C. ① At 2 mA / cm 2 Run for 2 minutes at 6 mA / cm 2 Run for 5 minutes at 15 mA / cm 2 Run for 2 minutes at 6 mA / cm 2 Run for 5 minutes and repeat this 1-4 program 5 times.

[0028] Step 3: Preparation of electrode layer

[0029] The treated carbon paper was annealed in a hydrogen reducing atmosphere at a rate of 2°C / min from room temperature to 400°C for 2 hours. After cooling naturally to room temperature, the sample was treated in an acid solution at 20°C for 2 hours, washed, and dried under vacuum at 60°C for 10 hours before being used as an electrode.

[0030] Example 2

[0031] Step 1: Pretreatment of carbon paper

[0032] Select 2cm 2 The carbon paper was immersed in 100 ml NiCl2·6H2O, FeCl3·6H2O, CuSO4·5H2O, CoCl2·6H2O, MnCl2·4H2O solution (all with a concentration of 10 mg / ml), and then 2 g urea and 1 g ammonia water were added, and the temperature was raised to 120 ° C in a hydrothermal reactor for 2 hours.

[0033] Step 2: Preparation of non-precious metal high entropy alloy electrodes

[0034] The impregnated carbon paper was dried and immersed in a precursor solution containing a high entropy alloy. The carbon paper was used as the cathode and the carbon rod was used as the anode. A gradient voltage was applied across the electrodes at 20°C. ① At 2 mA / cm 2 Run for 3 minutes at 6 mA / cm 2 Run for 6 minutes at 15mA / cm 2 Run for 3 minutes at 6 mA / cm 2 Run for 6 minutes and repeat this 1-4 program 6 times.

[0035] Step 3: Preparation of electrode layer

[0036] The treated carbon paper was annealed in a hydrogen reducing atmosphere at a rate of 2°C / min from room temperature to 400°C for 2 hours. After cooling naturally to room temperature, the sample was treated in an acid solution at 20°C for 2 hours, washed, and dried under vacuum at 60°C for 10 hours before being used as an electrode.

[0037] Example 3

[0038] Step 1: Pretreatment of carbon paper

[0039] Select 2cm 2 The carbon paper was immersed in 100 ml NiCl2·6H2O, FeCl3·6H2O, CuSO4·5H2O, CoCl2·6H2O, MnCl2·4H2O solution (all with a concentration of 10 mg / ml), and then 2 g urea and 1 g ammonia water were added, and the temperature was raised to 120 ° C in a hydrothermal reactor for 2 hours.

[0040] Step 2: Preparation of non-precious metal high entropy alloy electrodes

[0041] The impregnated carbon paper was dried and immersed in a precursor solution containing a high entropy alloy. The carbon paper was used as the cathode and the carbon rod was used as the anode. A gradient voltage was applied across the electrodes at 20°C. ① At 3 mA / cm 2 Run for 5 minutes at 10 mA / cm 2 Run for 10 minutes at 3 mA / cm 2 Run for 5 minutes at 10 mA / cm 2 Run for 10 minutes and repeat this 1-4 program 6 times.

[0042] Step 3: Preparation of electrode layer

[0043] The treated carbon paper was annealed in a hydrogen reducing atmosphere at a rate of 2°C / min from room temperature to 450°C for 3 hours. After cooling naturally to room temperature, the sample was treated in an acid solution at 20°C for 2 hours, washed, and dried under vacuum at 60°C for 10 hours before being used as an electrode.

[0044] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy, characterized in that: The method comprises: Step 1: Pretreatment of carbon paper The carbon paper is immersed in a certain amount of high entropy alloy precursor solution, a certain amount of water, urea and ammonia water are added, and the temperature is raised to a certain temperature in a hydrothermal reactor and reacted for a certain time. Step 2: Preparation of non-precious metal high entropy alloy electrodes The impregnated carbon paper is dried and immersed in a precursor solution containing a high entropy alloy, with it as the cathode and the carbon rod as the anode. A gradient voltage is then applied across the electrodes, ① at 1-10 mA / cm 2 Run for 1 to 10 minutes at 5 to 15 mA / cm 2 Run for 1 to 15 minutes, ③ at 10 to 20 mA / cm 2 Run for 1 to 15 minutes at 5 to 20 mA / cm 2 Run for 1 to 15 minutes and repeat this 1-4 program for 1 to 10 times. Step 3: Preparation of electrode layer The treated carbon paper is annealed in a reducing atmosphere at 300-800° C. for 1-8 hours. After naturally cooling to room temperature, the sample is treated in an acid solution at 20-90° C. for 1-10 hours, and after cleaning, is dried under vacuum at 50-80° C. for 5-50 hours.

2. A method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy according to claim 1, characterized in that: In step 1, the solubility of the high entropy alloy precursor solution is 5-50 mg / ml, and the ratio of urea to ammonia water is 2:5-8:

1. The temperature is raised to 20-150° C., and the reaction time is 0.1-10 hours.

3. A method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy according to claim 2, characterized in that: In step 2, the high entropy alloy precursor is any one or more of NiCl2·6H2O, Ni(NO3)2·6H2O, Al(NO3)3·9H2O, FeCl3·6H2O, CrCl3·6H2O, CoCl2·6H2O, MnCl2·4H2O, CuSO4·5H2O. The reaction time is 1-24 hours, and the heating temperature is 20-150°C.

4. A method for preparing a fuel cell electrode based on a non-precious metal high entropy alloy according to claim 3, characterized in that: The reducing atmosphere is hydrogen or a hydrogen-argon mixture, and the high temperature annealing process is: heating from room temperature to 300-800°C at a heating rate of 2-5°C / min.

Images