SiSiC foam ceramic electrically driven reactor for hydrogen production by ammonia decomposition and method for manufacturing the same

Abstract

The application discloses a SiSiC foam ceramic electric-driven reactor for hydrogen production by ammonia decomposition and a preparation method thereof. The electric-driven reactor comprises a quartz tube, a heating power supply, a SiSiC foam ceramic structure catalyst arranged in the quartz tube, a carbon felt arranged on the upper and lower sides of the SiSiC foam ceramic structure catalyst, and two hollow conductive metal tubes, one end of the conductive metal tubes is connected with the carbon felt, and the other end of the conductive metal tubes is connected with the heating power supply. The upper and lower ends of the quartz tube are respectively an air inlet and an air outlet. The SiSiC foam ceramic substrate used in the electric-driven reactor has high resistivity (up to 100 ohm*cm) and large surface area. Compared with a traditional wall heating reactor, the electric-driven reactor has the advantages of faster heating speed, higher heat transfer efficiency, higher hydrogen production efficiency by ammonia decomposition, less energy consumption and CO2 emission, and small size and integration, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of reactor design, specifically relating to a SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen and its preparation method. Background Technology

[0002] Ammonia, as a chemical hydrogen storage medium, has a high hydrogen content (approximately 17.6 wt%) and energy density (3000 Wh / kg), and is easy to store and transport. Traditional ammonia decomposition reactors mainly employ adiabatic reactors, which are filled with shaped catalyst particles. However, ammonia decomposition for hydrogen production is a strongly endothermic process, and using an adiabatic reactor would result in a large temperature gradient in the radial direction of the reactor, leading to reduced catalyst efficiency and increased energy consumption.

[0003] In this context, electrically driven reactors, as a new type of reactor, involve electricity acting directly or indirectly on a conductor with a certain resistance (i.e., a resistive element). The Joule heating effect of the resistive element heats the catalyst, which can not only save energy and reduce carbon emissions, but also enhance the heat transfer process within the reactor.

[0004] For electrically driven reactors, the key lies in the selection and preparation of the resistive catalyst within the reactor. Different resistive materials directly affect the temperature distribution and energy efficiency of the electrically driven reactor, as well as the stability and catalytic effect of the catalyst. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen and its preparation method. This electrically driven reactor achieves highly efficient catalytic ammonia decomposition to produce hydrogen under the action of an electric field, maintaining high energy utilization and ammonia-to-hydrogen conversion efficiency.

[0006] The technical solution adopted in this invention is as follows:

[0007] The first aspect of the present invention is to provide a SiSiC foam ceramic electrically driven reactor for hydrogen production by ammonia decomposition, comprising a quartz tube and a heating power supply, as well as a SiSiC foam ceramic structure catalyst, a carbon felt and two hollow conductive metal tubes disposed inside the quartz tube, wherein the carbon felt is disposed on the upper and lower sides of the SiSiC foam ceramic structure catalyst, and one end of the conductive metal tube is connected to the carbon felt and the other end is connected to the heating power supply.

[0008] The upper and lower ends of the quartz tube are the air inlet and air outlet, respectively.

[0009] The present invention is further configured such that the SiSiC foam ceramic structure catalyst is composed of a SiSiC foam ceramic matrix, an oxide support, and a metal-based active component supported on the oxide support.

[0010] The present invention is further configured such that the mass composition of the SiSiC foam ceramic structure catalyst is 0.6-3 wt% metal-based active component, 10.4-12 wt% support, and 85-88 wt% SiSiC foam ceramic matrix.

[0011] The present invention is further configured such that the porosity of the SiSiC foam ceramic matrix is ​​50-80%.

[0012] The present invention is further configured such that the metal-based active component is selected from one or more of Ru, Ni, Fe, Co, Rh, Pt and Pb.

[0013] The present invention is further configured such that the oxide support is one or more of alumina, silicon oxide and titanium oxide, preferably alumina.

[0014] The present invention is further configured such that the conductive metal tube is made of a material selected from stainless steel or copper; the resistivity of the conductive metal tube is (2.8-22.0)×10⁻⁶. -5 The resistivity of the carbon felt is (2.5-4.5)×10 Ω·cm. -5 Ω·cm.

[0015] The invention is further configured such that a thermocouple is built into the conductive metal tube for measuring the temperature of the upper and lower surfaces of the SiSiC foam ceramic structure catalyst, and a capillary quartz tube is fitted over the thermocouple for insulation.

[0016] A second aspect of the present invention provides a method for preparing a SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen, comprising the following steps:

[0017] (1) A powder catalyst is prepared by impregnation or homogeneous precipitation, wherein the powder catalyst is a catalyst prepared by supporting one or more of Ru, Ni, Fe, Co, Rh, Pt and Pb on a support, wherein the support is alumina, silicon oxide or titanium oxide;

[0018] (2) Prepare catalyst slurry with the following components by mass fraction: 1-3 wt% polyethanol; 25-50 wt% glycerol; 10-13 wt% powdered catalyst; balance deionized water;

[0019] The powdered catalyst was dissolved in a mixed solution of the remaining components and ball-milled at 50-150 rpm for 18-24 hours to obtain a catalyst slurry.

[0020] (3) Immerse the SiSiC foam ceramic matrix in the above catalyst slurry, rotate it in a high-speed centrifuge at 1000-2000 rpm for 2-4 min, and then dry it in a muffle furnace at 300-500℃ for 10-30 min. Repeat this process several times.

[0021] (4) Place the dried SiSiC foam ceramic structure catalyst in a reduction furnace at 500-700℃ and reduce it with 50-100mL / min of hydrogen for 2-5h.

[0022] (5) The reduced SiSiC foam ceramic structure catalyst is placed in a quartz tube, and then carbon felt, conductive metal tube and thermocouple are installed. The conductive metal tube and heating power supply are connected to complete the preparation of the SiSiC foam ceramic electric drive reactor for ammonia decomposition to produce hydrogen.

[0023] The present invention is further configured such that the current supplied to the heating power supply is 1.2-5.0A.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) The SiSiC foam ceramic matrix used in the SiSiC foam ceramic electrically driven reactor of the present invention has a high resistivity (up to 100 Ω·cm). Its high resistivity enables it to directly convert electrical energy into heat energy through resistance heating, achieving rapid and uniform heating inside the electrically driven reactor and reducing power loss. In addition, SiSiC foam ceramic is a porous material with excellent mechanical strength and good chemical stability. Its open-cell structure provides a large specific surface area, which is beneficial to the uniform loading of catalyst and efficient heat transfer, resulting in a highly uniform support-loaded metal catalyst coating.

[0026] (2) Compared with traditional wall-heated reactors, the SiSiC foam ceramic electric-driven reactor prepared by this invention has a faster heating rate inside the catalyst, higher heat transfer efficiency, and higher efficiency in catalytic ammonia decomposition to produce hydrogen.

[0027] (3) Compared with traditional wall-heated reactors, the SiSiC foam ceramic electric-driven reactor of the present invention can effectively reduce energy consumption and CO2 emissions during use, and can realize the miniaturization and integration of ammonia decomposition hydrogen production reactor, which has broad application prospects. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a SiSiC foam ceramic electrically driven reactor used for hydrogen production from ammonia decomposition.

[0029] Figure 2 This is a schematic diagram of a traditional wall-heated reactor.

[0030] Figure 3 This is a comparison chart of the heating response time between the SiSiC foam ceramic electrically driven reactor of the present invention and the traditional wall-heated reactor.

[0031] Figure 4 This is a comparison diagram of the ammonia decomposition catalytic performance of the SiSiC foam ceramic electrically driven reactor of the present invention and the traditional wall-heated reactor.

[0032] In the picture:

[0033] 1-Quartz tube; 2-Heating power supply; 3-SiSiC foam ceramic structure catalyst; 4-Carbon felt; 5-Conductive metal tube; 6-Thermocouple; 7-Powdered catalyst. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings and specific embodiments. It should be understood that the following embodiments are only some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art without creative effort should be covered within the protection scope of the present invention.

[0035] like Figure 1 As shown, the SiSiC foam ceramic electrically driven reactor for hydrogen production from ammonia decomposition includes a quartz tube 1 and a heating power supply 2, as well as a SiSiC foam ceramic structure catalyst 3, a carbon felt 4 and two hollow conductive metal tubes 5 disposed inside the quartz tube 1. The carbon felt 4 is disposed on the upper and lower sides of the SiSiC foam ceramic structure catalyst 3. One end of the conductive metal tube 5 is connected to the carbon felt 4 and the other end is connected to the heating power supply 2.

[0036] The upper and lower ends of the quartz tube 1 are the air inlet and the air outlet, respectively.

[0037] The present invention is further configured such that both the conductive metal tube 5 and the carbon felt 4 are extremely low resistivity materials, and the material of the conductive metal tube 5 is selected from stainless steel metal tubes, copper metal tubes, etc.; preferably, the resistivity of the conductive metal tube 5 is (2.8-22.0)×10⁻¹⁰. -5 The resistivity of the carbon felt 4 is (2.5-4.5)×10 Ω·cm. -5 Ω·cm.

[0038] The present invention is further configured such that the conductive metal tube 5 has a built-in thermocouple 6 for measuring the temperature of the upper and lower surfaces of the SiSiC foam ceramic structure catalyst 3;

[0039] The thermocouple 6 is covered with a capillary quartz tube (not shown in the figure) for insulation.

[0040] The specific preparation process of the SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen is shown in Examples 1-4 below:

[0041] Example 1

[0042] S1: Preparation of SiSiC foam ceramic structured nickel-based catalyst

[0043] (1) Preparation of nickel-based alumina powder catalyst by impregnation method: 5.1 g of 0.4 M Ni(NO3)2·6H2O was dissolved in 40 mL of deionized water and then mixed with 3.20 g of γ-Al2O3 powder; the above mixed solution was evaporated at 100 °C; calcined at 600 °C for 5 h in air atmosphere; the obtained powder was placed in a reduction furnace at 500 °C and reduced by 100 mL / min H2 for 4 h to obtain Ni / Al2O3 powder catalyst.

[0044] (2) Preparation of impregnation slurry: Polyvinyl alcohol was dissolved in deionized water at 85°C, then glycerol was added and stirred to dissolve, and finally the nickel-based alumina powder catalyst obtained in step (1) was added and ball-milled at 80 rpm for 22 h to prepare the impregnation slurry; the mass percentage of each component in the impregnation slurry was: polyvinyl alcohol 2.49 wt%, deionized water 37.34 wt%, glycerol 39.42 wt%, and nickel-based alumina powder catalyst 20.75 wt%.

[0045] (3) Place 1.23g of SiSiC foam ceramic matrix with a porosity of 75% in a muffle furnace at 800℃ and calcine for 10h for later use;

[0046] (4) The calcined SiSiC foam ceramic matrix is ​​placed in the impregnation slurry obtained in step (2) for 2 minutes, and then rotated in a high-speed centrifuge at 1000 rpm for 2 minutes to remove excess slurry.

[0047] (5) Place in a muffle furnace at 400℃ and dry for 20 minutes;

[0048] (6) Repeat the above impregnation step (4) and drying step (5) multiple times;

[0049] (7) Finally, the obtained SiSiC foam ceramic structured nickel-based catalyst was placed in a reduction furnace and reduced by 100 mL / min of hydrogen at 500 °C for 4 h.

[0050] S2: Assembly of the electrically driven reactor

[0051] First, the SiSiC foam ceramic structured nickel-based catalyst is placed inside a quartz tube 1 with a diameter of 17.6 mm. Carbon felt 4 is filled on both the top and bottom sides of the SiSiC foam ceramic structured nickel-based catalyst. One end of the conductive metal tube 5 is connected to the carbon felt 4, and the other end is connected to the heating power supply 2 through an electrode clamp. Thermocouple 6 is placed inside the conductive metal tube 5 and passes through the carbon felt 4 to connect to the surface of the SiSiC foam ceramic structured nickel-based catalyst. This completes the preparation of the SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen.

[0052] Turn on the heating power supply 2 and pass current through it. The current passes through the conductive metal tube 5, carbon felt 4 and SiSiC foam ceramic structured nickel-based catalyst. The high resistivity of the SiSiC foam ceramic matrix generates a large Joule heating effect to provide energy for the ammonia decomposition reaction process.

[0053] Example 2

[0054] S1: Preparation of SiSiC foam ceramic structured nickel-based catalyst

[0055] (1) Preparation of nickel-based alumina powder catalyst by homogeneous precipitation method: Ni(NO3)2·6H2O and Al(NO3)3·9H2O were dissolved in deionized water to prepare nickel nitrate and aluminum nitrate solutions with concentrations of 0.086 mol / L and 0.102 mol / L, respectively; (NH2)2CO was dissolved in deionized water to form a 6 mol / L solution; the above solutions were mixed in a flask and reacted at 85℃ for 10 h; the precipitate was filtered and washed three times with deionized water; it was dried in an oven at 110℃ for 12 h; the dried precipitate was calcined in a muffle furnace at 600℃ for 5 h. The powder prepared above was placed in a reduction furnace at 500℃ and reduced by 100 mL / min H2 for 4 h to obtain Ni / Al2O3 powder catalyst.

[0056] (2) Preparation of impregnation slurry: Polyvinyl alcohol was dissolved in deionized water at 85°C, then glycerol was added and stirred to dissolve, and finally the Ni / Al2O3 powder catalyst obtained in step (1) was added and ball-milled at 100 rpm for 20 h to prepare the impregnation slurry; the mass percentage of each component in the impregnation slurry was: polyvinyl alcohol 1.27 wt%, deionized water 47.77 wt%, glycerol 35.03 wt%, and nickel-based alumina powder catalyst 15.92 wt%;

[0057] (3) Place 1.34g of SiSiC foam ceramic matrix with a porosity of 50% in a muffle furnace at 800℃ and calcine for 10h for later use;

[0058] (4) The calcined SiSiC foam ceramic matrix is ​​placed in the impregnation slurry obtained in step (2) for 2 minutes, and then rotated in a high-speed centrifuge at 2000 rpm for 2 minutes to remove excess slurry.

[0059] (5) Then place it in a muffle furnace at 400℃ and dry for 15 minutes;

[0060] (6) Repeat the above impregnation step (4) and drying step (5) multiple times;

[0061] (7) Finally, the obtained SiSiC foam ceramic structured nickel-based catalyst was placed in a reduction furnace and reduced by 100 mL / min of hydrogen at 600 °C for 3 h.

[0062] S2: Assembly of the electrically driven reactor

[0063] First, the SiSiC foam ceramic structured nickel-based catalyst is placed in a quartz tube 1 with a diameter of 17.6 mm, and carbon felt 4 is filled on the upper and lower sides of the SiSiC foam ceramic structured nickel-based catalyst. One end of the conductive metal tube 5 is connected to the carbon felt 4, and the other end is connected to the heating power supply 2 through the electrode clamp. Thermocouple 6 is placed in the conductive metal tube 5 and passes through the carbon felt 4 to connect to the surface of the SiSiC foam ceramic structured nickel-based catalyst.

[0064] Turn on the heating power supply 2 and pass current through it. The current passes through the conductive metal tube 5, carbon felt 4 and SiSiC foam ceramic structured nickel-based catalyst. The high resistivity of the SiSiC foam ceramic matrix generates a large Joule heating effect to provide energy for the ammonia decomposition reaction process.

[0065] Example 3

[0066] S1: Preparation of SiSiC foam ceramic structured ruthenium-based catalyst

[0067] (1) Preparation of ruthenium-based alumina powder catalyst by impregnation method: 1.20 g of γ-Al2O3 powder was dried at 120 °C overnight, RuCl3 solution (7.5 wt% Ru) was added dropwise to γ-Al2O3 powder, and finally dried at 80 °C for 2 h;

[0068] (2) Preparation of impregnation slurry: Polyvinyl alcohol was dissolved in deionized water at 85°C according to the mass ratio, glycerol was added and stirred to dissolve, and finally the ruthenium-based alumina powder catalyst obtained in step (1) was added and ball-milled at 80 rpm for 22 h to prepare the impregnation slurry; the mass ratio of each component in the impregnation slurry was: polyvinyl alcohol 2.49 wt%, deionized water 37.34 wt%, glycerol 39.42 wt%, ruthenium-based alumina powder catalyst 20.75 wt%;

[0069] (3) Place 1.32g of SiSiC foam ceramic matrix with a porosity of 75% in a muffle furnace at 800℃ and calcine for 10h for later use;

[0070] (4) The calcined SiSiC foam ceramic matrix is ​​placed in the impregnation slurry obtained in step (2) for 2 minutes, and then rotated in a high-speed centrifuge at 1000 rpm for 2 minutes to remove excess slurry.

[0071] (5) Then place it in a muffle furnace at 400℃ and dry for 20 minutes;

[0072] (6) Repeat the above impregnation step (4) and drying step (5) multiple times;

[0073] (7) Finally, the obtained SiSiC foam ceramic structured ruthenium-based catalyst was placed in a reduction furnace and reduced by hydrogen at 50 mL / min for 3 h at 500 °C.

[0074] S2: Assembly of the electrically driven reactor

[0075] First, the SiSiC foam ceramic structured ruthenium-based catalyst is placed inside a quartz tube 1 with a diameter of 17.6 mm. Carbon felt 4 is filled on both the top and bottom sides of the SiSiC foam ceramic structured ruthenium-based catalyst. One end of a conductive metal tube 5 is connected to the carbon felt 4, and the other end is connected to a heating power supply 2 through an electrode clamp. A thermocouple 6 is placed inside the conductive metal tube 5 and passes through the carbon felt 4 to connect to the surface of the SiSiC foam ceramic structured ruthenium-based catalyst.

[0076] Turn on the heating power supply 2 and pass current through it. The current passes through the conductive metal tube 5, carbon felt 4 and SiSiC foam ceramic structured ruthenium-based catalyst. The high resistivity of the SiSiC foam ceramic matrix generates a large Joule heating effect to provide energy for the ammonia decomposition reaction process.

[0077] Example 4

[0078] S1: Preparation of SiSiC foam ceramic structured nickel-iron based catalyst

[0079] (1) Preparation of nickel-iron-based bimetallic alumina powder catalyst by impregnation method: 0.298 g each of Ni(NO3)2·6H2O and Fe(NO3)3·9H2O were dissolved in 100 mL of deionized water and stirred continuously. At 90 °C, 1.8 g of γ-Al2O3 powder was added to the above solution under magnetic stirring. After the solution was completely evaporated, the powder was collected and dried in an oven at 100 °C for 12 h. Finally, it was annealed in a muffle furnace at 700 °C for 4 h.

[0080] (2) Preparation of impregnation slurry: Polyvinyl alcohol was dissolved in % deionized water at 85°C, then glycerol was added and stirred to dissolve, and finally the nickel-iron-based bimetallic alumina powder catalyst obtained in step (1) was added and ball-milled at 100 rpm for 20 h to prepare the impregnation slurry; the mass percentage of each component in the impregnation slurry was: polyvinyl alcohol 1.27 wt%, deionized water 47.77 wt%, glycerol 35.03 wt%, and nickel-iron-based bimetallic alumina powder catalyst 15.92 wt%;

[0081] (3) Place 1.26g of SiSiC foam ceramic matrix with a porosity of 50% in a muffle furnace at 800℃ and calcine for 10h for later use;

[0082] (4) Place the calcined SiSiC foam ceramic matrix into the slurry obtained in step (2) for 2 minutes, and then rotate it in a high-speed centrifuge at 2000 rpm for 2 minutes to remove excess slurry.

[0083] (5) Then place it in a muffle furnace at 400℃ and dry for 15 minutes;

[0084] (6) Repeat the above impregnation step (4) and drying step (5) multiple times;

[0085] (7) Finally, the obtained SiSiC foam ceramic structured nickel-iron-based catalyst was placed in a reduction furnace and reduced by hydrogen at 70 mL / min at 600 °C for 3 h.

[0086] S2: Assembly of the electrically driven reactor

[0087] First, the SiSiC foam ceramic structured nickel-iron-based catalyst is placed in a quartz tube 1 with a diameter of 17.6 mm, and carbon felt 4 is filled on the upper and lower sides of the SiSiC foam ceramic structured nickel-iron-based catalyst. One end of the conductive metal tube 5 is connected to the carbon felt 4, and the other end is connected to the heating power supply 2 through the electrode clamp. Thermocouple 6 is placed in the conductive metal tube 5 and passes through the carbon felt 4 to connect to the surface of the SiSiC foam ceramic structured nickel-iron-based catalyst.

[0088] Turn on the heating power supply 2 and pass current through it. The current passes through the conductive metal tube 5, carbon felt 4, and SiSiC foam ceramic structured nickel-iron-based catalyst. The high resistivity of the SiSiC foam ceramic matrix generates a large Joule heating effect to provide energy for the ammonia decomposition reaction process.

[0089] Comparative Example 1

[0090] like Figure 2As shown, the conventional wall-heated catalytic reactor includes a quartz tube 1, and a powdered catalyst 7, a carbon felt 4, and a thermocouple 6 disposed inside the quartz tube 1. The carbon felt 4 is disposed on the upper and lower sides of the powdered catalyst 7, and the thermocouple 6 passes through the carbon felt 4 and is connected to the surface of the powdered catalyst 6 to measure the temperature of the upper and lower surfaces of the powdered catalyst 7.

[0091] The upper and lower ends of the quartz tube 1 are the air inlet and the air outlet, respectively.

[0092] The preparation process of the above-mentioned conventional wall-heated catalytic reactor is as follows:

[0093] S1: Preparation of powdered catalyst

[0094] (1) Preparation of nickel-based alumina powder catalyst by impregnation method: 5.1 g of Ni(NO3)2·6H2O was dissolved in 40 mL of deionized water and mixed with 3.2 g of γ-Al2O3 powder; the above mixed solution was evaporated at 100 °C; calcined at 600 °C for 5 h in air atmosphere; the powder prepared above was placed in a reduction furnace at 500 °C and reduced by 100 mL / min H2 for 4 h to obtain Ni / Al2O3 powder catalyst.

[0095] S2: Assembly of a conventional wall-heated catalytic reactor

[0096] First, the Ni / Al2O3 powder catalyst is placed in the quartz tube 1, and carbon felt 4 is filled on the upper and lower sides of the Ni / Al2O3 powder catalyst. Thermocouple 6 passes through the carbon felt 4 and is connected to the surface of the Ni / Al2O3 powder catalyst. The catalyst is heated by a heating furnace.

[0097] Application Examples

[0098] The SiSiC foam ceramic electrically driven reactors prepared in Examples 1 and 2 above were compared with the conventional wall-heated catalytic reactor of Comparative Example 1 for catalytic ammonia decomposition to produce hydrogen. The details are as follows:

[0099] Pure ammonia gas was introduced into the electrically driven reactor prepared in Example 1, a power source was connected, and a current of 1.2-4.4A was applied to provide in-situ heating to the catalyst.

[0100] Pure ammonia gas was introduced into the electrically driven reactor prepared in Example 2, a power source was connected, and a current of 1.5-5.0A was applied to heat the catalyst in situ.

[0101] Pure ammonia gas was introduced into the conventional wall-heated catalytic reactor of Comparative Example 1, and the heating furnace was turned on to heat the catalyst.

[0102] Figure 3 The temperature response diagrams are for the SiSiC foam ceramic electrically driven reactor of Example 1 and the conventional wall-heated catalytic reactor of Comparative Example 1. Figure 4 The graph shows a comparison of the ammonia decomposition catalytic performance of the SiSiC foam ceramic electrically driven reactors of Examples 1 and 2 with that of the conventional wall-heated catalytic reactor of Comparative Example 1.

[0103] Depend on Figure 3 and Figure 4 As can be seen, the electrically driven reactor of the present invention can quickly reach the set reaction temperature, and the ammonia decomposition to hydrogen production reaction occurs rapidly in the catalytic zone to produce hydrogen; the ammonia conversion rate is also significantly better than that of the traditional wall-heated catalytic reactor.

[0104] The above embodiments have described the technical solutions of this application in detail, but they are not intended to limit the scope of protection of this invention. All equivalent substitutions made within the principles and spirit of this application are within the scope of protection of this invention.

Claims

1. A SiSiC foam ceramic electrically driven reactor for hydrogen production from ammonia decomposition, characterized in that, It includes a quartz tube and a heating power supply, as well as a SiSiC foam ceramic structure catalyst, a carbon felt, and two hollow conductive metal tubes disposed inside the quartz tube. The carbon felt is disposed on the upper and lower sides of the SiSiC foam ceramic structure catalyst, and one end of the conductive metal tube is connected to the carbon felt, while the other end is connected to the external heating power supply. The upper and lower ends of the quartz tube are the air inlet and air outlet, respectively.

2. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 1, characterized in that, The SiSiC foam ceramic structure catalyst consists of a SiSiC foam ceramic matrix, an oxide support, and a metal-based active component supported on the oxide support.

3. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to hydrogen production according to claim 2, characterized in that, The SiSiC foam ceramic structure catalyst has the following composition: 0.6-3 wt% metal-based active component, 10.4-12 wt% support, and 85-88 wt% SiSiC foam ceramic matrix.

4. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 3, characterized in that, The porosity of the SiSiC foam ceramic matrix is ​​50-80%.

5. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 3, characterized in that, The metal-based active component is selected from one or more of Ru, Ni, Fe, Co, Rh, Pt, and Pb.

6. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 3, characterized in that, The oxide support is one or more of aluminum oxide, silicon oxide, and titanium oxide.

7. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 3, characterized in that, The oxide carrier is aluminum oxide.

8. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 1, characterized in that, The conductive metal tube is made of either stainless steel or copper; the resistivity of the conductive metal tube is (2.8-22.0) × 10⁻⁶. -5 The resistivity of the carbon felt is (2.5-4.5) × 10 Ω·cm. -5 Ω·cm.

9. The SiSiC foam ceramic electrically driven reactor for ammonia decomposition to produce hydrogen according to claim 1, characterized in that, The conductive metal tube contains a built-in thermocouple for measuring the temperature of the upper and lower surfaces of the SiSiC foam catalyst. The thermocouple is covered with a capillary quartz tube for insulation.

10. The method for preparing a SiSiC foam ceramic electrically driven reactor for ammonia decomposition to hydrogen production according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) A powder catalyst is prepared by impregnation or homogeneous precipitation, wherein the powder catalyst is a catalyst prepared by supporting one or more of Ru, Ni, Fe, Co, Rh, Pt and Pb on a support, wherein the support is alumina, silicon oxide or titanium oxide; (2) Prepare catalyst slurry with the following components by mass fraction: 1-3 wt% polyethanol; 25-50 wt% glycerol; 10-13 wt% powdered catalyst; balance deionized water; The powdered catalyst was dissolved in a mixed solution of the remaining components and ball-milled at 50-150 rpm for 18-24 h to obtain a catalyst slurry. (3) Immerse the SiSiC foam ceramic matrix in the above catalyst slurry, rotate it in a high-speed centrifuge at 1000-2000 rpm for 2-4 min, and then dry it in a muffle furnace at 300-500 ℃ for 10-30 min. Repeat this process several times. (4) Place the dried SiSiC foam ceramic structure catalyst in a reduction furnace at 500-700 °C and reduce it with hydrogen gas at 50-100 mL / min for 2-5 h. (5) The reduced SiSiC foam ceramic structure catalyst is placed in a quartz tube, and then carbon felt, conductive metal tube and thermocouple are installed. The conductive metal tube and heating power supply are connected to complete the preparation of the SiSiC foam ceramic electric drive reactor for ammonia decomposition to produce hydrogen.

11. The method for preparing the SiSiC foam ceramic electrically driven reactor for ammonia decomposition to hydrogen production according to claim 10, characterized in that, The current supplied to the heating power source is 1.2-5.0 A.

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