Two-step hydrogen fuel cell and preparation method thereof

Abstract

The invention provides a two-step hydrogen fuel cell which comprises a closed shell, an electrolyte membrane is arranged in the middle of the shell, and a hydrogen reaction area and an oxygen reaction area are arranged on the two sides of the electrolyte membrane respectively; the hydrogen reaction area comprises a hydrogen excitation chamber and a hydrogen reaction chamber, the oxygen reaction area comprises an oxygen excitation chamber and an oxygen reaction chamber, and ultraviolet exciters are arranged in the hydrogen excitation chamber and the oxygen excitation chamber. The invention also provides a preparation method of the hydrogen fuel cell. The preparation method comprises the steps of catalyst preparation, electrode plate preparation, catalyst coating, cell assembly and the like. According to the invention, hydrogen is excited by ultraviolet light, so that electrons of hydrogen atoms are transitioned or are at a transition critical point, thereby improving the reaction activity of hydrogen. In addition, a complex catalyst does not need to be used, so that the overall working stability is higher, the service life is correspondingly prolonged, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a two-step hydrogen fuel cell and a preparation method thereof. Background Art

[0002] A fuel cell is a power generation device that converts the chemical energy of a fuel and an oxidant directly into electrical energy through an electrochemical reaction. In theory, a fuel cell can operate at a thermal efficiency close to 100%, which is very economical. Due to the limitations of various technical factors and the energy consumption of the entire device system, the total conversion efficiency of various fuel cells currently in operation is mostly in the range of 45% to 60%. If heat exhaust utilization is considered, it can reach more than 80%. In addition, fuel cell devices contain no or very few moving parts, work reliably, require less maintenance, and are quieter than traditional generator sets. In addition, isothermal electrochemical methods directly convert chemical energy into electrical energy without going through a thermal engine process, and are not subject to the limitations of the Carnot cycle. Therefore, the energy conversion efficiency is high, and the reaction is clean and complete, with very few harmful substances produced. It is becoming an ideal way to utilize energy.

[0003] A fuel cell is a device that converts chemical energy directly into electrical energy. Its working principle is based on electrochemical reactions. The core process includes the following steps: 1. Supply of hydrogen and oxygen: Hydrogen enters the anode catalyst layer through the anode current collector, is oxidized under the action of the catalyst, and decomposes into positively charged hydrogen ions and negatively charged electrons; oxygen enters the cathode catalyst layer through the cathode current collector. 2. Electrochemical reaction: At the anode, hydrogen molecules decompose into hydrogen ions and electrons. The hydrogen ions pass through the proton exchange membrane to reach the cathode, and the electrons form an electric current through the external circuit to supply load electrical energy; at the cathode, hydrogen ions react with oxygen and electrons to generate water and release heat. At the same time, the incompletely reacted hydrogen is discharged from the anode and can be recycled for further use. The generated water is discharged at the same time as the incompletely reacted oxygen. After separation, the oxygen can also be reused, so only clean water is finally discharged.

[0004] The current hydrogen fuel cells are limited by the difficulty of storing hydrogen energy, safety and other issues, and have not yet been widely used. They are in the process of continuous improvement and development. At present, the research and development of hydrogen fuel cells is mainly focused on catalysts, and new high-efficiency catalysts are used to improve the reaction activity, while reducing the use of precious metals such as platinum, thereby reducing costs. For example, the Chinese invention patent with application number 2020106528204 discloses a silicon-doped iron nitrogen / carbon composite catalyst, its preparation method and application, using mesoporous silica balls as templates, different types of iron precursors and pyrrole as raw materials, gas phase polymerization in pyrrole vapor to obtain Fe / mSiO2@PPY composite materials, and then high-temperature calcination and hydrofluoric acid treatment to obtain Si-doped iron nitrogen / carbon (Si-FeNx / C). The present invention uses Si-doped iron nitrogen / carbon as a fuel cell cathode material to construct an oxygen reduction catalyst with excellent performance. The Si-doped iron nitrogen / carbon catalyst prepared by the present invention exhibits better catalytic activity than commercial Pt / C under alkaline conditions, and at the same time exhibits the advantages of high stability and tolerance to methanol.

[0005] However, the current research and development of fuel cells has also reached a bottleneck, that is, the catalytic activity of the catalyst has not been improved significantly, which makes it difficult to further improve the reaction efficiency. Improvements need to be made in another direction to further improve the reaction degree. In addition, the current fuel cells use catalysts with various complex doping structures, which also leads to a low service life of the electrode plates, resulting in high cost of use. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a two-step hydrogen fuel cell and a method for preparing the same, which solves the problems in the prior art of being difficult to further improve the degree of reaction and being relatively costly.

[0007] In a first aspect, the present invention provides a two-step hydrogen fuel cell, comprising a closed shell, an electrolyte membrane is arranged in the middle of the shell, and a hydrogen reaction zone and an oxygen reaction zone are arranged on both sides of the electrolyte membrane respectively;

[0008] The hydrogen reaction zone comprises a hydrogen excitation chamber and a hydrogen reaction chamber which are connected in sequence, wherein the hydrogen reaction chamber is adjacent to the electrolyte membrane, and an anode plate close to the electrolyte membrane is arranged inside the hydrogen reaction chamber, and a hydrogen inlet pipe and a hydrogen outlet pipe are arranged at opposite ends of the hydrogen excitation chamber and the hydrogen reaction chamber respectively;

[0009] The oxygen reaction zone comprises an oxygen excitation chamber and an oxygen reaction chamber which are connected in sequence, wherein the oxygen reaction chamber is adjacent to the electrolyte membrane, and a cathode plate close to the electrolyte membrane is arranged inside the oxygen reaction chamber, and an oxygen inlet pipe and a water outlet pipe are arranged at opposite ends of the oxygen excitation chamber and the oxygen reaction chamber respectively;

[0010] The anode plate and the cathode plate are arranged side by side and symmetrically relative to the electrolyte membrane;

[0011] Ultraviolet light exciters are arranged inside the hydrogen excitation chamber and the oxygen excitation chamber, and ultraviolet light emitted by the ultraviolet light exciters is evenly scattered in the inner space of the hydrogen excitation chamber and / or the oxygen excitation chamber.

[0012] Furthermore, the anode plate and the cathode plate are three-dimensional porous structures, and the surfaces of the anode plate and the cathode plate are coated with catalysts.

[0013] Furthermore, the hydrogen excitation chamber and the oxygen excitation chamber are tubular structures, and the ultraviolet light exciter includes a plurality of ultraviolet lamp tubes, which are arranged on the inner wall of the hydrogen excitation chamber and / or the oxygen excitation chamber around the central axis of the hydrogen excitation chamber and / or the oxygen excitation chamber, and a tubular lampshade is also sleeved on the outside of the ultraviolet lamp tube.

[0014] Preferably, the light emission wavelength range of the ultraviolet light exciter is 220-360nm, and the power is 90-150W.

[0015] In a second aspect, the present invention also proposes a two-step method for preparing a hydrogen fuel cell, comprising the following steps:

[0016] S1. Preparation of catalyst: taking an iron source, dissolving it in a carbon source and a nitrogen source to obtain a mixed solution, wherein the mass ratio of the iron source to the carbon source and the nitrogen source is 4:11-15:20-27; inputting the mixed solution into a vertical tubular furnace, while introducing a protective gas, the raw material solution is gasified and thermally decomposed in the high temperature zone of the tubular furnace to form nanoclusters, and after the thermal decomposition is completed, the nanoclusters form nitrogen-doped carbon-coated iron nanocore-shell particle products; placing the nitrogen-doped carbon-coated iron nanocore-shell particles in an aqueous regia solution for acid washing, then filtering, washing with water to remove residual aqueous regia solution, and then drying to obtain an iron-nitrogen-carbon catalyst;

[0017] The iron source is ferrocene or ferric acetylacetonate; the carbon source is acetonitrile or formaldehyde; the nitrogen source is pyrrole or melamine;

[0018] The nano-metal particles of platinum and tungsten are prepared by chemical reduction method, with the particle size of 5-8nm, of which the mass proportion of platinum is 28-40%;

[0019] S2. Preparation of electrode plates: weigh raw materials according to the ratio of 25-62% silicon carbide, 24-37% ferric oxide, 2-14% aluminum oxide, 2-16% silicon dioxide, 0.6-8% mineralizer, and 5-20% pore-forming agent, mix and stir evenly, add 3-10% of the raw material weight of adhesive, put into a powder making machine to prepare powder, pour the powder into a mold, press it into a plate, and then sinter it in air or oxygen atmosphere to obtain an electrode plate with a porous ceramic structure;

[0020] The mineralizer is one or a mixture of two or more of calcium oxide, barium oxide and boron oxide;

[0021] The pore-forming agent is one of starch, polystyrene or polymethyl methacrylate;

[0022] The binder is carboxymethyl cellulose or phenolic resin;

[0023] S3, catalyst coating: grinding the iron nitrogen carbon catalyst into powder, adding it to the organosilicon polymer adhesive, and fully mixing it to form a cathode catalyst mixture; adding nano metal particles of platinum and tungsten to the organosilicon polymer adhesive, and fully mixing it to form an anode catalyst mixture;

[0024] Then, the electrode plates are immersed in the cathode catalyst mixture and the anode catalyst mixture respectively, the electrode plates are continuously rotated and immersed for 20-30 minutes, taken out and dried at 220-260° C. for 45-60 minutes, and the cathode plates and the anode plates are obtained respectively;

[0025] S4. Battery assembly: Install gas diffusion layers on the surfaces of the prepared positive and negative plates with catalyst coatings, and install electrolyte membranes on the parallel cathode and anode plates, keeping the installation spacing on both sides of the electrolyte membranes uniform and well sealed to prevent gas leakage and short circuit. Then, set a hydrogen excitation chamber and the oxygen excitation chamber on the outside of the cathode and anode plates, so that the hydrogen excitation chamber is connected to the anode plate, the oxygen excitation chamber is connected to the cathode plate, and the hydrogen excitation chamber and the oxygen excitation chamber are connected to the hydrogen source and the oxygen source respectively to form a complete hydrogen fuel cell.

[0026] Preferably, in step S1, the reaction temperature of the tube furnace is 500-1300°C, and the heating rate is 5-15°C / min.

[0027] Preferably, in step S1, during pickling, heating and stirring are also performed, the heating temperature is 30-90° C., and the stirring time is 2-10 h.

[0028] Preferably, in step S1, during drying, the iron-nitrogen-carbon catalyst is placed in a vacuum environment and heated at a temperature of 200-400° C. for a holding time of 10-120 min.

[0029] Preferably, in step S2, the heating rate of the sintering process is 1-3°C / min, the target temperature of the sintering is 1200-1600°C, and the holding time after reaching the target temperature is 0.5-3h.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] Before hydrogen and oxygen enter the anode plate and cathode plate areas of the fuel cell, they first pass through the oxygen excitation chamber and the oxygen reaction chamber, and at the same time, the ultraviolet light exciter device is turned on to excite the hydrogen, so that the electrons of the hydrogen atoms can transition or be at the critical point of transition, thereby increasing the reactivity of the hydrogen. Therefore, when hydrogen enters the positive plate and oxygen enters the negative plate, it is in the best activation state, which improves its participation and reaction efficiency in the electrochemical reaction. In this way, the reaction degree and reaction efficiency of the redox reaction can be further improved without changing the catalyst, thereby increasing the energy output power of the battery. In addition, the present invention does not need to use a complex catalyst, so that its overall working stability is stronger, and correspondingly also improves the service life and reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0033] Figure 2 The figure is a schematic diagram of the installation of the ultraviolet lamp in the hydrogen excitation chamber according to the embodiment of the present invention.

[0034] In the above drawings: 1. Shell; 2. Electrolyte membrane; 3. Hydrogen excitation chamber; 4. Hydrogen reaction chamber; 5. Oxygen excitation chamber; 6. Oxygen reaction chamber; 7. Anode plate; 8. Cathode plate; 9. Ultraviolet light exciter; 31. Hydrogen inlet pipe; 32. Ultraviolet lamp tube; 33. Lampshade; 41. Hydrogen outlet pipe; 51. Oxygen inlet pipe; 61. Water outlet pipe. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0036] like Figure 1 As shown, an embodiment of the present invention proposes a two-step hydrogen fuel cell, comprising a closed shell 1, an electrolyte membrane 2 is arranged in the middle of the shell 1, and a hydrogen reaction zone and an oxygen reaction zone are respectively arranged on both sides of the electrolyte membrane 2.

[0037] The hydrogen reaction zone includes a hydrogen excitation chamber 3 and a hydrogen reaction chamber 4 which are connected in sequence, wherein the hydrogen reaction chamber 4 is adjacent to the electrolyte membrane 2, and an anode plate 7 close to the electrolyte membrane 2 is arranged inside the hydrogen reaction chamber 4, and a hydrogen inlet pipe 31 and a hydrogen outlet pipe 41 are respectively arranged at the opposite ends of the hydrogen excitation chamber 3 and the hydrogen reaction chamber 4.

[0038] The oxygen reaction zone includes an oxygen excitation chamber 5 and an oxygen reaction chamber 6 which are connected in sequence, wherein the oxygen reaction chamber 6 is adjacent to the electrolyte membrane 2, and a cathode plate 8 close to the electrolyte membrane 2 is arranged inside the oxygen reaction chamber 6, and an oxygen inlet pipe 51 and a water outlet pipe 61 are respectively arranged at the opposite ends of the oxygen excitation chamber 5 and the oxygen reaction chamber 6.

[0039] The anode plate 7 and the cathode plate 8 are arranged side by side and symmetrically relative to the electrolyte membrane 2. In addition, in this embodiment, a gas diffusion layer is also provided on one side of the anode plate 7 and the cathode plate 8, and an external circuit is connected at the same time. The structure thereof refers to the existing conventional fuel cell and is not described in detail here.

[0040] In this embodiment, an ultraviolet light exciter 9 is provided inside the hydrogen excitation chamber 3 and the oxygen excitation chamber 5, and the ultraviolet light emitted by the ultraviolet light exciter 9 is evenly scattered in the internal space of the hydrogen excitation chamber 3 and / or the oxygen excitation chamber 5. The ultraviolet light exciter 9 device excites the hydrogen passing through, so that the electrons of the hydrogen atoms can transition or be at the critical point of transition, thereby improving the reaction activity of the hydrogen. Therefore, when the hydrogen enters the positive plate and the oxygen enters the negative plate, it is in the best activation state, thereby improving its participation and reaction efficiency in the electrochemical reaction.

[0041] Furthermore, the anode plate 7 and the cathode plate 8 are three-dimensional porous structures, and the surfaces of the anode plate 7 and the cathode plate 8 are coated with catalysts. This structure can greatly increase the surface area of ​​the anode plate 7 and the cathode plate 8, so that the contact area between the catalyst and hydrogen and oxygen is larger, thereby improving the catalytic efficiency.

[0042] like Figure 2 As shown, in the embodiment of the present invention, preferably, the hydrogen excitation chamber 3 and the oxygen excitation chamber 5 are tubular structures, and the ultraviolet light exciter 9 includes twelve ultraviolet lamp tubes 32, and the ultraviolet lamp tubes 32 are arranged on the inner wall of the hydrogen excitation chamber 3 and / or the oxygen excitation chamber 5 around the central axis of the hydrogen excitation chamber 3 and / or the oxygen excitation chamber 5, and a tubular lampshade 33 is also sleeved on the outer side of the ultraviolet lamp tube 32. In this embodiment, the emission wavelength range of the ultraviolet light exciter 9 is 220-360nm, and the power is 90-150W. The parameters of the ultraviolet light exciter 9 are adjusted according to the size of the hydrogen excitation chamber 3 and the oxygen excitation chamber 5. By accurately controlling the power and irradiation time of the ultraviolet lamp, it is ensured that the hydrogen is in the best activation state when entering the positive electrode, while avoiding excessive excitation to cause energy waste and potential safety problems.

[0043] The preparation method of the two-step hydrogen fuel cell in this embodiment includes the following steps:

[0044] S1. Preparation of catalyst: Take an iron source, dissolve it in a carbon source and a nitrogen source to obtain a mixed solution, wherein the mass ratio of the iron source to the carbon source and the nitrogen source is 4:11:20; input the mixed solution into a vertical tubular furnace, and introduce a protective gas at the same time. The raw material solution is gasified and thermally decomposed in the high temperature zone of the tubular furnace to form nanoclusters. The reaction temperature of the tubular furnace is 500°C, and the heating rate is 5°C / min.

[0045] After the thermal decomposition is completed, the nanoclusters form nitrogen-doped carbon-coated iron nanocore-shell particles; the nitrogen-doped carbon-coated iron nanocore-shell particles are placed in aqua regia for acid washing, while being heated and stirred at a heating temperature of 30°C and a stirring time of 2h.

[0046] Then filter, wash with water to remove residual aqua regia solution, and then dry. Heat the iron nitrogen carbon catalyst in a vacuum environment at 200° C. for 10 minutes to obtain an iron nitrogen carbon catalyst.

[0047] In this embodiment, the iron source is ferrocene; the carbon source is acetonitrile, and the nitrogen source is pyrrole.

[0048] Nano-metal particles of platinum and tungsten were prepared by chemical reduction method, with a particle size of 5nm, of which the mass of platinum accounted for 28%.

[0049] S2. Preparation of electrode plates: weigh raw materials according to the proportion of 25% silicon carbide, 37% ferric oxide, 14% aluminum oxide, 2% silicon dioxide, 8% mineralizer and 16% pore-forming agent, mix and stir evenly, add 3% adhesive by weight of the raw materials, put them into a powder making machine to prepare powder, pour the powder into a mold, press it into a plate, and then sinter it in air or oxygen atmosphere at a heating rate of 1°C / min. The target sintering temperature is 1200°C, and the insulation time after reaching the target temperature is 0.5h to obtain an electrode plate with a porous ceramic structure.

[0050] In this embodiment, the mineralizer is calcium oxide, the pore-forming agent is starch, and the binder is carboxymethyl cellulose.

[0051] S3. Catalyst coating: Grind the iron-nitrogen-carbon catalyst into powder, add it into the organosilicon polymer adhesive, and mix it thoroughly to form a cathode catalyst mixture; add nano-metal particles of platinum and tungsten into the organosilicon polymer adhesive, and mix it thoroughly to form an anode catalyst mixture.

[0052] Then, the electrode plates were immersed in the cathode catalyst mixture and the anode catalyst mixture respectively, and the electrode plates were continuously rotated and immersed for 20 minutes. They were taken out and dried at 220° C. for 45 minutes to obtain cathode plates 8 and anode plates 7 respectively.

[0053] S4. Battery assembly: Install a gas diffusion layer on the surface of the prepared positive plate and negative plate with a catalyst coating, and install an electrolyte membrane 2 on the parallel cathode plate 8 and anode plate 7, keep the installation spacing on both sides of the electrolyte membrane 2 uniform and well sealed to prevent gas leakage and short circuit, then set a hydrogen excitation chamber 3 and the oxygen excitation chamber 5 on the outside of the cathode plate 8 and the anode plate 7, so that the hydrogen excitation chamber 3 is connected to the anode plate 7, and the oxygen excitation chamber 5 is connected to the cathode plate 8, and the hydrogen excitation chamber 3 and the oxygen excitation chamber 5 are respectively connected to the hydrogen source and the oxygen source to form a complete hydrogen fuel cell.

[0054] Embodiment 2:

[0055] The rest of the present embodiment is the same as that in the embodiment 1, except that the preparation method of the two-step hydrogen fuel cell in the present embodiment includes the following steps:

[0056] S1. Preparation of catalyst: Take an iron source, dissolve it in a carbon source and a nitrogen source to obtain a mixed solution, wherein the mass ratio of the iron source to the carbon source and the nitrogen source is 4:15:27; input the mixed solution into a vertical tubular furnace, and introduce a protective gas at the same time. The raw material solution is gasified and thermally decomposed in the high temperature zone of the tubular furnace to form nanoclusters. The reaction temperature of the tubular furnace is 1300°C, and the heating rate is 15°C / min.

[0057] After the thermal decomposition is completed, the nanoclusters form nitrogen-doped carbon-coated iron nanocore-shell particles; the nitrogen-doped carbon-coated iron nanocore-shell particles are placed in aqua regia for acid washing, while being heated and stirred at a heating temperature of 90°C and a stirring time of 10 hours.

[0058] Then filter, wash with water to remove residual aqua regia solution, and then dry. Heat the iron nitrogen carbon catalyst in a vacuum environment at a heating temperature of 400° C. for 120 minutes to obtain an iron nitrogen carbon catalyst.

[0059] In this embodiment, the iron source is ferric acetylacetonate; the carbon source is formaldehyde; and the nitrogen source is melamine.

[0060] Nano-metal particles of platinum and tungsten were prepared by chemical reduction method, with a particle size of 8nm, of which the mass of platinum accounted for 40%.

[0061] S2. Preparation of electrode plates: weigh raw materials according to the proportion of 62% silicon carbide, 24% ferric oxide, 2% aluminum oxide, 5% silicon dioxide, 2% mineralizer and 5% pore-forming agent, mix and stir evenly, add 10% adhesive by weight of the raw materials, put them into a powder making machine to prepare powder, pour the powder into a mold, press it into a plate, and then sinter it in air or oxygen atmosphere at a heating rate of 3°C / min. The target sintering temperature is 1600°C, and the insulation time after reaching the target temperature is 3h to obtain an electrode plate with a porous ceramic structure.

[0062] In this embodiment, the mineralizer is a mixture of calcium oxide and barium oxide in equal proportions, the pore-forming agent is polystyrene, and the binder is phenolic resin.

[0063] S3. Catalyst coating: Grind the iron-nitrogen-carbon catalyst into powder, add it into the organosilicon polymer adhesive, and mix it thoroughly to form a cathode catalyst mixture; add nano-metal particles of platinum and tungsten into the organosilicon polymer adhesive, and mix it thoroughly to form an anode catalyst mixture.

[0064] Then, the electrode plates were immersed in the cathode catalyst mixture and the anode catalyst mixture respectively, and the electrode plates were continuously rotated and immersed for 30 minutes. They were taken out and dried at 260° C. for 60 minutes to obtain cathode plates 8 and anode plates 7 respectively.

[0065] S4. Battery assembly: Install a gas diffusion layer on the surface of the prepared positive plate and negative plate with a catalyst coating, and install an electrolyte membrane 2 on the parallel cathode plate 8 and anode plate 7, keep the installation spacing on both sides of the electrolyte membrane 2 uniform and well sealed to prevent gas leakage and short circuit, then set a hydrogen excitation chamber 3 and the oxygen excitation chamber 5 on the outside of the cathode plate 8 and the anode plate 7, so that the hydrogen excitation chamber 3 is connected to the anode plate 7, and the oxygen excitation chamber 5 is connected to the cathode plate 8, and the hydrogen excitation chamber 3 and the oxygen excitation chamber 5 are respectively connected to the hydrogen source and the oxygen source to form a complete hydrogen fuel cell.

[0066] Embodiment 3:

[0067] The rest of the present embodiment is the same as that in the embodiment 1, except that the preparation method of the two-step hydrogen fuel cell in the present embodiment includes the following steps:

[0068] S1. Preparation of catalyst: Take an iron source, dissolve it in a carbon source and a nitrogen source to obtain a mixed solution, wherein the mass ratio of the iron source to the carbon source and the nitrogen source is 4:13:24; input the mixed solution into a vertical tubular furnace, and introduce a protective gas at the same time. The raw material solution is gasified and thermally decomposed in the high temperature zone of the tubular furnace to form nanoclusters. The reaction temperature of the tubular furnace is 900°C, and the heating rate is 10°C / min.

[0069] After the thermal decomposition is completed, the nanoclusters form nitrogen-doped carbon-coated iron nanocore-shell particles; the nitrogen-doped carbon-coated iron nanocore-shell particles are placed in aqua regia for acid washing while being heated and stirred at a heating temperature of 60°C and a stirring time of 6 hours.

[0070] Then filter, wash with water to remove residual aqua regia solution, and then dry. Heat the iron nitrogen carbon catalyst in a vacuum environment at a heating temperature of 300° C. for 65 minutes to obtain an iron nitrogen carbon catalyst.

[0071] In this embodiment, the iron source is ferrocene; the carbon source is acetonitrile, and the nitrogen source is melamine.

[0072] Nano-metal particles of platinum and tungsten were prepared by chemical reduction method, with a particle size of 12.5nm, of which the mass of platinum accounted for 54%.

[0073] S2. Preparation of electrode plates: weigh raw materials according to the proportion of 25.4% silicon carbide, 24% ferric oxide, 14% aluminum oxide, 16% silicon dioxide, 0.6% mineralizer and 20% pore-forming agent, mix and stir evenly, add 6.5% adhesive by weight of the raw materials, put them into a powder making machine to prepare powder, pour the powder into a mold, press it into a plate, and then sinter it in air or oxygen atmosphere at a heating rate of 2°C / min. The target sintering temperature is 1400°C, and the insulation time after reaching the target temperature is 2.5h to obtain an electrode plate with a porous ceramic structure.

[0074] In this embodiment, the mineralizer is a mixture of calcium oxide, barium oxide and boron oxide in equal proportions. The pore-forming agent is polymethyl methacrylate. The binder is carboxymethyl cellulose.

[0075] S3. Catalyst coating: Grind the iron-nitrogen-carbon catalyst into powder, add it into the organosilicon polymer adhesive, and mix it thoroughly to form a cathode catalyst mixture; add nano-metal particles of platinum and tungsten into the organosilicon polymer adhesive, and mix it thoroughly to form an anode catalyst mixture.

[0076] Then, the electrode plates were immersed in the cathode catalyst mixture and the anode catalyst mixture respectively, and the electrode plates were continuously rotated and immersed for 25 minutes. They were taken out and dried at 240° C. for 52 minutes to obtain cathode plate 8 and anode plate 7 respectively.

[0077] S4. Battery assembly: Install a gas diffusion layer on the surface of the prepared positive plate and negative plate with a catalyst coating, and install an electrolyte membrane 2 on the parallel cathode plate 8 and anode plate 7, keep the installation spacing on both sides of the electrolyte membrane 2 uniform and well sealed to prevent gas leakage and short circuit, then set a hydrogen excitation chamber 3 and the oxygen excitation chamber 5 on the outside of the cathode plate 8 and the anode plate 7, so that the hydrogen excitation chamber 3 is connected to the anode plate 7, and the oxygen excitation chamber 5 is connected to the cathode plate 8, and the hydrogen excitation chamber 3 and the oxygen excitation chamber 5 are respectively connected to the hydrogen source and the oxygen source to form a complete hydrogen fuel cell.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A two-step hydrogen fuel cell, characterized in that: It comprises a closed shell, wherein an electrolyte membrane is arranged in the middle of the shell, and a hydrogen reaction zone and an oxygen reaction zone are arranged on both sides of the electrolyte membrane respectively; The hydrogen reaction zone comprises a hydrogen excitation chamber and a hydrogen reaction chamber which are connected in sequence, wherein the hydrogen reaction chamber is adjacent to the electrolyte membrane, and an anode plate close to the electrolyte membrane is arranged inside the hydrogen reaction chamber, and a hydrogen inlet pipe and a hydrogen outlet pipe are arranged at opposite ends of the hydrogen excitation chamber and the hydrogen reaction chamber respectively; The oxygen reaction zone comprises an oxygen excitation chamber and an oxygen reaction chamber which are connected in sequence, wherein the oxygen reaction chamber is adjacent to the electrolyte membrane, and a cathode plate close to the electrolyte membrane is arranged inside the oxygen reaction chamber, and an oxygen inlet pipe and a water outlet pipe are arranged at opposite ends of the oxygen excitation chamber and the oxygen reaction chamber respectively; The anode plate and the cathode plate are arranged side by side and symmetrically relative to the electrolyte membrane; Ultraviolet light exciters are arranged inside the hydrogen excitation chamber and the oxygen excitation chamber, and ultraviolet light emitted by the ultraviolet light exciters is evenly scattered in the inner space of the hydrogen excitation chamber and / or the oxygen excitation chamber.

2. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 1, characterized in that: The anode plate and the cathode plate are three-dimensional porous structures, and the surfaces of the anode plate and the cathode plate are coated with catalysts.

3. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 1, characterized in that: The hydrogen excitation chamber and the oxygen excitation chamber are tubular structures, and the ultraviolet light exciter includes a plurality of ultraviolet lamp tubes, which are arranged on the inner wall of the hydrogen excitation chamber and / or the oxygen excitation chamber around the central axis of the hydrogen excitation chamber and / or the oxygen excitation chamber, and a tubular lampshade is also sleeved on the outside of the ultraviolet lamp tube.

4. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 1, characterized in that: The luminous wavelength range of the ultraviolet light exciter is 220-360nm, and the power is 90-150W.

5. A method for preparing a two-step hydrogen fuel cell as claimed in claim 1, characterized in that: The steps include: S1. Preparation of catalyst: taking an iron source, dissolving it in a carbon source and a nitrogen source to obtain a mixed solution, wherein the mass ratio of the iron source to the carbon source and the nitrogen source is 4:11-15:20-27; inputting the mixed solution into a vertical tubular furnace, while introducing a protective gas, the raw material solution is gasified and thermally decomposed in the high temperature zone of the tubular furnace to form nanoclusters, and after the thermal decomposition is completed, the nanoclusters form nitrogen-doped carbon-coated iron nanocore-shell particle products; placing the nitrogen-doped carbon-coated iron nanocore-shell particles in an aqueous regia solution for acid washing, then filtering, washing with water to remove residual aqueous regia solution, and then drying to obtain an iron-nitrogen-carbon catalyst; The iron source is ferrocene or ferric acetylacetonate; the carbon source is acetonitrile or formaldehyde; the nitrogen source is pyrrole or melamine; The nano-metal particles of platinum and tungsten are prepared by chemical reduction method, with the particle size of 5-8nm, of which the mass proportion of platinum is 28-40%; S2. Preparation of electrode plates: weigh raw materials according to the ratio of 25-62% silicon carbide, 24-37% ferric oxide, 2-14% aluminum oxide, 2-16% silicon dioxide, 0.6-8% mineralizer, and 5-20% pore-forming agent, mix and stir evenly, add 3-10% of the raw material weight of adhesive, put into a powder making machine to prepare powder, pour the powder into a mold, press it into a plate, and then sinter it in air or oxygen atmosphere to obtain an electrode plate with a porous ceramic structure; The mineralizer is one or a mixture of two or more of calcium oxide, barium oxide and boron oxide; The pore-forming agent is one of starch, polystyrene or polymethyl methacrylate; The binder is carboxymethyl cellulose or phenolic resin; S3, catalyst coating: grinding the iron nitrogen carbon catalyst into powder, adding it to the organosilicon polymer adhesive, and fully mixing it to form a cathode catalyst mixture; adding nano metal particles of platinum and tungsten to the organosilicon polymer adhesive, and fully mixing it to form an anode catalyst mixture; Then, the electrode plates are immersed in the cathode catalyst mixture and the anode catalyst mixture respectively, the electrode plates are continuously rotated and immersed for 20-30 minutes, taken out and dried at 220-260° C. for 45-60 minutes, and the cathode plates and the anode plates are obtained respectively; S4. Battery assembly: Install gas diffusion layers on the surfaces of the prepared positive and negative plates with catalyst coatings, and install electrolyte membranes on the parallel cathode and anode plates, keeping the installation spacing on both sides of the electrolyte membranes uniform and well sealed to prevent gas leakage and short circuit. Then, set a hydrogen excitation chamber and the oxygen excitation chamber on the outside of the cathode and anode plates, so that the hydrogen excitation chamber is connected to the anode plate, the oxygen excitation chamber is connected to the cathode plate, and the hydrogen excitation chamber and the oxygen excitation chamber are connected to the hydrogen source and the oxygen source respectively to form a complete hydrogen fuel cell.

6. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 5, characterized in that: In the step S1, the reaction temperature of the tubular furnace is 500-1300° C., and the heating rate is 5-15° C. / min.

7. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 5, characterized in that: In the step S1, during pickling, heating and stirring are also performed, the heating temperature is 30-90° C., and the stirring time is 2-10 hours.

8. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 5, characterized in that: In the step S1, during drying, the iron-nitrogen-carbon catalyst is placed in a vacuum environment and heated at a temperature of 200-400° C. for a holding time of 10-120 min.

9. A two-step hydrogen fuel cell and a method for preparing the same as claimed in claim 5, characterized in that: In the step S2, the heating rate of the sintering process is 1-3°C / min, the target temperature of the sintering is 1200-1600°C, and the holding time after reaching the target temperature is 0.5-3h.

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