Method and reaction system for producing hydrogen through low-temperature ammonia decomposition

Abstract

The invention provides a method for producing hydrogen through ammonolysis, which comprises the following steps: in a reaction device, acting current on a conductive catalyst, and introducing ammonia gas for reaction to obtain hydrogen. The invention provides a current-assisted low-temperature ammonia decomposition hydrogen production strategy based on an electrochemical Joule thermocatalytic reactor, and also provides a corresponding supported integrated porous catalyst. According to the method for producing hydrogen through low-temperature ammonia decomposition, when current directly passes through the catalyst, the catalyst can be excited to induce ammonia dissociation and dehydrogenation, so that ammonia conversion is greatly promoted. Meanwhile, due to the intrinsic characteristic of high resistance of the catalyst, electric energy is partially converted into heat energy, so that the surface temperature of the catalyst is increased (higher than the external environment temperature), the catalytic reaction is further promoted, and the high-efficiency ammonia decomposition process at the low reaction furnace environment temperature is realized. The invention provides an alternative solution for the problem of low activity of the existing low-temperature catalytic system.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by decomposition of ammonia, and relates to a method and a reaction system for hydrogen production by decomposition of ammonia, and in particular to a method and a reaction system for hydrogen production by decomposition of ammonia at low temperature. Background Art

[0002] In the development and utilization of hydrogen energy, hydrogen storage has long been a major challenge. The efficient and safe storage of hydrogen is essential for its widespread application in many fields including transportation, power generation and industrial processes. One of the main difficulties is that the volumetric energy density of hydrogen is low under ambient conditions. Hydrogen has an extremely low boiling point, and high-pressure storage tanks or low-temperature environments are required to achieve sufficient storage density, which increases the complexity and cost of hydrogen storage systems. In addition, the storage of hydrogen in solid materials such as metal hydrides often encounters problems such as slow hydrogen absorption and desorption kinetics, limited cycle stability and high material costs. Compressed hydrogen storage also poses safety risks due to the high pressure involved. In addition, hydrogen molecules are extremely small and can penetrate many materials, which makes it difficult to ensure a leak-free storage system for a long time.

[0003] Ammonia has emerged as a promising liquid hydrogen carrier and has been hailed as "Hydrogen 2.0". It offers several unique advantages in the storage and transportation of hydrogen. First, ammonia has a relatively high hydrogen content of about 17.6% by weight. This means that a large amount of hydrogen can be stored and transported in the form of ammonia. Moreover, ammonia is liquid at ambient temperature and 8 atmospheres of pressure, which greatly simplifies the storage and handling process compared to gaseous hydrogen. At the same time, it is also less flammable and explosive than hydrogen, which significantly enhances safety during storage and transportation. Another key advantage is that ammonia has a ready-made production, storage and distribution infrastructure. The ammonia industry is already mature, and existing facilities have a high potential to be converted for ammonia-related applications. For example, ammonia can be easily transported using existing pipelines and tank trucks.

[0004] Despite the great potential of ammonia as a hydrogen carrier, the ammonia decomposition process for hydrogen production is not without challenges, one of the main issues is the high energy required for the decomposition reaction. The decomposition of ammonia into hydrogen and nitrogen is an endothermic process that usually requires high temperatures and a large amount of energy input. This not only increases operating costs, but also brings challenges in terms of energy efficiency and the integration of the process with other energy systems.

[0005] The development of efficient and stable catalysts that can promote reactions with high selectivity at lower temperatures is a key research area. At present, thermal decomposition is one of the most common ways to decompose ammonia. Under high temperature conditions (e.g., around 800°C to 1100°C), ammonia can be decomposed into hydrogen and nitrogen, with the reaction formula: 2NH3→N2+3H2. This method requires a lot of energy to maintain the required high temperature environment. In order to reduce the temperature of thermal decomposition and improve the reaction efficiency, a catalyst can be used. Commonly used catalysts include ruthenium-based, nickel-based, and iron-based catalysts. The presence of a catalyst can accelerate the decomposition reaction of ammonia at a relatively low temperature, however, there are still many problems. The performance of the catalyst is unstable and may gradually reduce its activity as the use time increases. Hydrogen separation and purification are difficult, and complex processes and equipment are required to separate high-purity hydrogen from the reaction products. In terms of safety risks, high temperature and high pressure reaction conditions and the presence of hydrogen increase safety hazards. High cost is also a challenge, including catalyst preparation costs, energy costs, and equipment maintenance costs.

[0006] Therefore, how to find a more suitable reaction mode to achieve hydrogen production by decomposing ammonia at a lower temperature has become one of the focuses of attention of many forward-looking technicians in the industry. Summary of the invention

[0007] In view of this, the present invention provides a method and reaction system for producing hydrogen by decomposing ammonia, in particular, a method for producing hydrogen by decomposing ammonia at low temperature. The present invention proposes a strategy for producing hydrogen by decomposing ammonia at low temperature assisted by current based on an electrochemical Joule thermal catalytic reactor, and designs a supported integrated porous catalyst, which breaks through the limitations of traditional thermal catalysis and provides an alternative solution to the problem of low activity of existing low-temperature catalytic systems.

[0008] The present invention provides a method for producing hydrogen by ammonolysis, comprising the following steps:

[0009] In the reaction device, electric current is applied to a conductive catalyst, and ammonia is introduced to react to obtain hydrogen.

[0010] Preferably, the conductive catalyst comprises a catalyst containing one or more of Ru, Pt, Fe and Ni;

[0011] The reaction device comprises a reaction device with a heating function;

[0012] The temperature of the reaction device is 20-1000°C.

[0013] Preferably, the current is 0.1 to 10A;

[0014] The DC voltage of the current source is 0.1-10V.

[0015] Preferably, the power of the current source is 0.1-100W.

[0016] Preferably, the conductive catalyst is specifically a conductive catalyst supported on a conductive substrate;

[0017] The conductive substrate includes one or more of a metal mesh, a metal foam, a carbon fiber fabric and a conductive ceramic.

[0018] Preferably, the flow rate of the ammonia gas is 1 to 100 sccm;

[0019] The reaction time is 1 to 60 seconds.

[0020] The present invention provides a reaction system for producing hydrogen by ammoniolysis, comprising a reaction device and a power source connected to the reaction device;

[0021] The reaction device comprises a base and a quartz reaction pool sealed on the base;

[0022] A conductive substrate loaded with a conductive catalyst is arranged in the quartz reaction cell;

[0023] The conductive substrate is connected to a power source via a conductive wire passing through the base;

[0024] An air inlet and an air outlet communicated with the quartz reaction pool.

[0025] Preferably, the base comprises a ceramic tube;

[0026] The quartz reaction cell comprises a quartz tube;

[0027] An air intake pipeline is provided in the quartz reaction pool;

[0028] The air inlet is connected to the quartz reaction pool through an air inlet pipeline.

[0029] Preferably, the air inlet is arranged on the base;

[0030] The air outlet is arranged on the base;

[0031] The conductive substrate is arranged at the outlet end of the air intake pipeline.

[0032] Preferably, the reaction system further comprises a heating device;

[0033] The reaction device is arranged in the heating device.

[0034] The present invention provides a method for producing hydrogen by ammonia decomposition, comprising the following steps: in a reaction device, an electric current is applied to a conductive catalyst, ammonia is introduced for catalytic decomposition reaction, and hydrogen is obtained. Compared with the prior art, the present invention believes that a prominent problem presented by the application of traditional electric heating or gas heating in the reactor is that the temperature distribution in the reactor is seriously uneven, which greatly restricts the reaction process of strong endothermic reaction. In the case of traditional electric heating, after the electric energy is converted into thermal energy, it needs to be heat-conducted to the gas through the reactor wall. The heat is dissipated in this process, which reduces the heating efficiency. In addition, the catalyst for the electrically assisted Joule heat catalytic reactor is subjected to instantaneous temperature changes under current fluctuations, and its catalytic material needs to have good structural stability (resistance to thermal shock and high electric density shock), and still maintain good catalytic activity to ensure its long-term stable operation; although the external current supply consumes a certain amount of electric energy, it is necessary to balance and optimize between energy utilization efficiency and catalytic effect.

[0035] The present invention creatively designs a method for producing hydrogen by decomposing ammonia, which is a current-assisted low-temperature ammonia decomposition hydrogen production strategy based on an electrochemical Joule heat catalytic reactor, and also provides a corresponding supported integrated porous catalyst. In the method for producing hydrogen by decomposing ammonia at low temperature provided by the present invention, when the current passes directly through the catalyst, the catalyst can be stimulated to induce ammonia dissociation and dehydrogenation, thereby greatly promoting ammonia conversion. At the same time, due to its own high resistance intrinsic characteristics, part of the electrical energy is converted into thermal energy, resulting in an increase in the catalyst surface temperature (higher than the external ambient temperature), further promoting the catalytic reaction, and realizing a highly efficient ammonia decomposition process at a low reactor ambient temperature. The present invention provides an alternative solution to overcome the problem of low activity of existing low-temperature catalytic systems.

[0036] The hydrogen production method provided by the present invention can heat the catalyst bed to the required reaction temperature in a short time, thereby accelerating the catalytic reaction; and by adjusting the input current value, the catalyst surface temperature can be increased to meet the strict requirements of different catalytic reactions on temperature conditions; and the catalyst has high stability, the reactor structure is simple, and the operation is safe and reliable, which is in line with future development trends. Compared with traditional particle catalysts, the reaction process avoids axial or radial temperature differences of the catalyst. Because when the catalyst is filled in the reactor, the catalyst itself has poor thermal conductivity, which leads to an increase in the radial temperature difference of the bed (from the reactor wall to the center, the temperature shows a gradual decrease trend), so in order to make the catalyst in the center reach the reaction temperature, more heat needs to be supplied, resulting in heat loss and many side reactions in the near-wall section (high-temperature end). BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a reactor for producing hydrogen by decomposing ammonia provided by the present invention;

[0038] Figure 2A schematic diagram of the structure of the electrically assisted Joule heat catalytic reaction cell component provided by the present invention;

[0039] Figure 3 This is an infrared imaging image of the catalyst region at room temperature in Example 1 of the present invention;

[0040] Figure 4 This is an infrared imaging image of the catalyst region under application of current in Example 1 of the present invention;

[0041] Figure 5 This is an electron scanning image of the catalyst used in Example 1 of the present invention. DETAILED DESCRIPTION

[0042] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention rather than limiting the patent claims of the present invention.

[0043] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0044] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses analytically pure raw materials or raw materials of conventional purity used in the field of hydrogen production by ammonolysis.

[0045] Joule heating effect: When current passes through a material with a certain resistance, heat is generated (Q = I 2 Rt, where Q is heat, I is current, R is resistance, and t is time). In Joule thermocatalysis, the Joule heat generated by the applied current is used to adjust the catalyst surface temperature. For example, by adjusting the applied current, the catalyst material's own resistance generates Joule heat, causing the temperature around the catalyst to rise rapidly. This patent will achieve chemical reactions and reduce comprehensive energy consumption under a traditional low-temperature catalytic bed by Joule heat compensation. The thermoelectric effect includes the Seebeck effect and the Peltier effect. The Seebeck effect refers to the electromotive force generated when there is a temperature difference at two joints in a loop composed of two different conductive materials; the Peltier effect is the opposite. When current passes through a loop composed of two different conductive materials, endothermic or exothermic phenomena will occur at the joints. In Joule thermocatalysis, this thermoelectric effect is combined with a catalytic reaction. For example, the electromotive force generated by the Seebeck effect is used to drive the transfer of electrons on the catalyst surface, thereby promoting the progress of chemical reactions. Alternatively, the Peltier effect can be used to adjust the temperature of the catalyst surface. The generated Joule heat increases the catalyst temperature, reduces the activation energy, and enables more reactant molecules to cross the reaction energy barrier, thereby accelerating the reaction.

[0046] The present invention provides a method for producing hydrogen by ammonolysis, comprising the following steps:

[0047] In the reaction device, electric current is applied to a conductive catalyst, and ammonia is introduced to react to obtain hydrogen.

[0048] In the present invention, the conductive catalyst preferably includes a catalyst containing one or more of Ru, Pt, Fe and Ni, and more preferably a catalyst containing one of Ru, Pt, Fe and Ni.

[0049] In the present invention, the reaction device preferably includes a reaction device with a heating function.

[0050] In the present invention, the temperature of the reaction device is preferably 20 to 1000°C, more preferably 100 to 700°C, more preferably 200 to 600°C, and more preferably 300 to 500°C.

[0051] In the present invention, the magnitude of the current is preferably 0.1 to 10A, more preferably 2 to 8A, and even more preferably 4 to 6A.

[0052] In the present invention, the DC voltage of the current source is preferably 0.1 to 10V, more preferably 2 to 8V, and even more preferably 4 to 6V.

[0053] In the present invention, the power of the current source is preferably 0.1 to 100 W, more preferably 20 to 80 W, and even more preferably 40 to 60 W.

[0054] In the present invention, the surface temperature of the conductive catalyst is preferably 400 to 1000°C, more preferably 500 to 900°C, and even more preferably 600 to 800°C.

[0055] In the present invention, the conductive catalyst is preferably a conductive catalyst supported on a conductive substrate.

[0056] In the present invention, the conductive substrate preferably includes one or more of metal mesh, metal foam, carbon fiber fabric and conductive ceramic, more preferably metal mesh, metal foam, carbon fiber fabric or conductive ceramic.

[0057] In the present invention, the flow rate of the ammonia gas is preferably 1 to 100 sccm, more preferably 20 to 80 sccm, and even more preferably 40 to 60 sccm.

[0058] In the present invention, the reaction time is preferably 1 to 60 s, more preferably 10 to 50 s, and more preferably 20 to 40 s.

[0059] The present invention provides a reaction system for producing hydrogen by ammoniolysis, comprising a reaction device and a power source connected to the reaction device;

[0060] The reaction device comprises a base and a quartz reaction pool sealed on the base;

[0061] A conductive substrate loaded with a conductive catalyst is arranged in the quartz reaction cell;

[0062] The conductive substrate is connected to a power source via a conductive wire passing through the base;

[0063] An air inlet and an air outlet communicated with the quartz reaction pool.

[0064] In the present invention, the base preferably comprises a ceramic tube.

[0065] In the present invention, the quartz reaction cell preferably comprises a quartz tube.

[0066] In the present invention, the quartz reaction cell is preferably provided with an air intake pipeline.

[0067] In the present invention, the air inlet is preferably connected to the quartz reaction cell through an air inlet pipeline.

[0068] In the present invention, the air inlet is preferably arranged on the base.

[0069] In the present invention, the air outlet is preferably arranged on the base.

[0070] In the present invention, the conductive substrate is preferably arranged at the outlet end of the air intake pipeline.

[0071] In the present invention, the reaction system preferably further comprises a heating device.

[0072] In the present invention, the reaction device is preferably arranged in a heating device.

[0073] See also Figure 1 , Figure 1 The present invention provides a schematic diagram of a reactor for producing hydrogen by decomposing ammonia, wherein 1 is a voltage-stabilized DC power supply, 2 is a muffle furnace, 3 is a reactor, 4 is an air inlet, and 5 is an air outlet.

[0074] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of the components of the electrically assisted Joule heat catalytic reaction cell provided by the present invention. 1 is a ceramic tube, 2 is a fixing screw, 3 is a stainless steel mesh, 4 is a quartz tube, 5 is a conductive metal wire, 6 is an air inlet, and 7 is an air outlet.

[0075] The above content of the present invention provides a method and reaction system for producing hydrogen by decomposing ammonia at low temperature. The present invention provides a current-assisted low-temperature ammonia decomposition hydrogen production strategy based on an electrochemical Joule heat catalytic reactor, and also provides a corresponding supported integrated porous catalyst. In the method for producing hydrogen by decomposing ammonia at low temperature provided by the present invention, when the current passes directly through the catalyst, the catalyst can be stimulated to induce ammonia dissociation and dehydrogenation, thereby greatly promoting ammonia conversion. At the same time, due to its own high resistance intrinsic characteristics, part of the electrical energy is converted into thermal energy, resulting in an increase in the catalyst surface temperature (higher than the external ambient temperature), further promoting the catalytic reaction, and realizing a high-efficiency ammonia decomposition process at a low reactor ambient temperature. The present invention provides an alternative solution to overcome the problem of low activity of existing low-temperature catalytic systems.

[0076] The hydrogen production method provided by the present invention can heat the catalyst bed to the required reaction temperature in a short time, thereby accelerating the catalytic reaction; and by adjusting the input current value, the catalyst surface temperature can be increased to meet the strict requirements of different catalytic reactions on temperature conditions; and the catalyst has high stability, the reactor structure is simple, and the operation is safe and reliable, which is in line with future development trends. Compared with traditional particle catalysts, the reaction process avoids axial or radial temperature differences of the catalyst. Because when the catalyst is filled in the reactor, the catalyst itself has poor thermal conductivity, which leads to an increase in the radial temperature difference of the bed (from the reactor wall to the center, the temperature shows a gradual decrease trend), so in order to make the catalyst in the center reach the reaction temperature, more heat needs to be supplied, resulting in heat loss and many side reactions in the near-wall section (high-temperature end).

[0077] In order to further illustrate the present invention, a method for producing hydrogen by decomposition of ammonia and a reaction system provided by the present invention are described in detail below in combination with embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical scheme of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention, and the protection scope of the present invention is not limited to the following embodiments.

[0078] Example 1

[0079] Ammonia decomposition hydrogen production reactor and reaction cell components such as Figure 1 and Figure 2 shown.

[0080] Take a piece of graphite felt with high conductivity, and remove surface oil and other impurities through acid washing, alkali washing and drying processes respectively. Connect the graphite felt to the power supply through a silver wire to form a current loop, assemble the reaction device, and use an infrared imager to perform imaging analysis under room temperature conditions ( Figure 3 ). See Figure 3 , Figure 3 This is an infrared imaging image of the catalyst region in Example 1 of the present invention at room temperature.

[0081] The results show that the graphite felt is consistent with the ambient temperature. A certain current is applied to the graphite felt, and after it stabilizes, infrared imaging analysis is performed. Figure 4 As shown, the local maximum temperature reaches 451℃ ( Figure 4 ), confirming the generation of Joule heating effect and the feasibility of the present invention. Figure 4 , Figure 4 This is an infrared imaging image of the catalyst region under applied current in Example 1 of the present invention.

[0082] See also Figure 5 , Figure 5 This is an electron scanning image of the catalyst used in Example 1 of the present invention.

[0083] Subsequently, RuO2@CeO2 nanopowder ( Figure 5 ) were evenly sprayed on the graphite felt surface, and the catalyst loadings were 3, 7, 15, and 50 mg cm -2 , placed in a 60°C oven for drying for standby use. Connect the graphite felt to the power supply through a silver wire to form a current loop, assemble the reaction device, and place it in a muffle furnace to maintain the external thermal field environment. 1) Heat the muffle furnace to 600°C and introduce reducing gas H2 for 30 minutes, wherein RuO2 is converted to Ru in situ; 2) Switch to argon purge gas, set a 0.1M sulfuric acid aqueous solution ammonia removal bottle and a color-changing silica gel water removal bottle at the gas outlet respectively, adjust the muffle furnace temperature, applied current, voltage and other key variables, and change the surface temperature of the catalyst; 3) Switch to ammonia reaction gas, set the ammonia flow rate to 5sccm, and conduct an ammonia decomposition test. After maintaining for 5 minutes, analyze the gas composition and content discharged from the reaction, calculate the ratio of the actually generated hydrogen to the theoretically generated hydrogen, and calculate the ammonia decomposition rate. The test results are listed in Tables 1 to 4. Table 1 shows the parameter statistics and ammonia decomposition rate (3mgcm in Example 1 of the present invention) -2 ).

[0084] Table 1

[0085]

[0086] See Table 2, which shows the parameter statistics and ammonia decomposition rate (7 mg cm -2 ).

[0087] Table 2

[0088]

[0089] See Table 3, which shows the parameter statistics and ammonia decomposition rate (15 mg cm -2 ).

[0090] Table 3

[0091]

[0092] See Table 4, which shows the parameter statistics and ammonia decomposition rate (50 mg cm -2 ).

[0093] Table 4

[0094]

[0095] The results show that the ammonia decomposition efficiency increases with the increase of muffle furnace temperature, applied current, voltage, and catalyst loading. When the ammonia flow rate is 5 sccm, the muffle furnace temperature is 500 °C, the current is 2.507 A, the voltage is 3.329 V, the power is 8.491 W, and the RuO2@CeO2 catalyst addition amount is 50 mg cm -2 When the temperature of the muffle furnace is raised to 600℃, after the current is applied to the catalyst, the catalyst melts and agglomerates due to the high temperature, which reduces the active sites of the catalytic reaction and thus reduces the ammonia decomposition efficiency.

[0096] Comparative Example 1

[0097] The catalytic reactor and catalyst prepared in Example 1 were used, and only external heating of the heating furnace was used (no current Joule heating effect was applied), and the furnace temperature was adjusted to 200-600°C. The other experimental settings were the same as in Example 1, and the online analysis was started after the temperature was kept constant for 5 minutes. The NH3 raw gas flow rate was 5 sccm, and the tail gas content was detected. The values ​​are summarized in Tables 5-9, which are the parameter statistics and conversion effects (ammonia decomposition rate) in Comparative Example 1 provided by the present invention.

[0098] Table 5 Parameter statistics and ammonia decomposition rate in comparative example 1 (without catalyst)

[0099] Furnace temperature ℃ 200 300 400 500 600 Ammonia decomposition rate % 0.80 1.30 1.80 3.10 4.30

[0100] Table 6 Parameter statistics and ammonia decomposition rate (3 mg cm) in comparative example 1 -2 )

[0101] Furnace temperature ℃ 200 300 400 500 600 Ammonia decomposition rate % 1.90 2.50 3.20 7.20 9.40

[0102] Table 7 Parameter statistics and ammonia decomposition rate (7 mg cm) in Comparative Example 1 -2 )

[0103] Furnace temperature ℃ 200 300 400 500 600 Ammonia decomposition rate % 2.50 5.50 11.00 12.20 13.10

[0104] Table 8 Parameter statistics and conversion effect in comparative example 1 (15 mg cm -2 )

[0105] Furnace temperature ℃ 200 300 400 500 600 Ammonia decomposition rate % 8.70 13.10 22.50 29.30 11.00

[0106] Table 9 Parameter statistics and ammonia decomposition rate (50 mg cm) in Comparative Example 1 -2 )

[0107] Furnace temperature ℃ 200 300 400 500 600 Ammonia decomposition rate % 29.70 31.50 37.80 61.10 38.20

[0108] The results show that the ammonia decomposition efficiency increases with the increase of muffle furnace temperature and catalyst loading. When the reaction temperature is 600℃ and the addition amount of RuO2@CeO2 nanopowder is 50mg cm -2 When , the ammonia decomposition rate was 38.2%. Compared with Example 1, the ammonia decomposition effect was greatly reduced due to the lack of external current Joule heat.

[0109] Comparative Example 2

[0110] The catalytic reactor prepared in Example 1 was used to perform the ammonia decomposition test only by relying on the Joule heating effect of the conductive carrier (graphite felt, without catalyst). The other experimental settings were the same as in Example 1. The online analysis was started after the temperature was kept constant for 5 minutes. NH3 raw gas was introduced at a flow rate of 5 sccm, and the tail gas content was detected. The values ​​are summarized in Table 10, which is the parameter statistics and conversion effect (ammonia decomposition rate) provided by Comparative Example 2 of the present invention.

[0111] Table 10 Parameter statistics and ammonia decomposition rate in comparative example 2

[0112]

[0113]

[0114] The results show that the ammonia decomposition efficiency increases with the increase of the muffle furnace temperature, applied current and voltage. When the flow rate of ammonia is 5 sccm, the muffle furnace temperature is 600°C, the current is 3.002A, the voltage is 2.797V, and the power is 8.365W, the ammonia decomposition efficiency is 8.00%. Compared with Example 1, the ammonia decomposition effect is greatly reduced due to the lack of the catalyst.

[0115] The above is a detailed introduction to a method and reaction system for producing hydrogen by decomposing ammonia at low temperature provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and its core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for producing hydrogen by ammonolysis, characterized in that: The following steps are involved: In the reaction device, electric current is applied to a conductive catalyst, and ammonia is introduced to react to obtain hydrogen.

2. The method according to claim 1, characterized in that The conductive catalyst includes a catalyst containing one or more of Ru, Pt, Fe and Ni; The reaction device comprises a reaction device with a heating function; The temperature of the reaction device is 20-1000°C.

3. The method according to claim 1, characterized in that The magnitude of the current is 0.1 to 10A; The DC voltage of the current source is 0.1-10V.

4. The method according to claim 1, characterized in that: The power of the current source is 0.1-100W.

5. The method according to claim 1, characterized in that The conductive catalyst is specifically a conductive catalyst supported on a conductive substrate; The conductive substrate includes one or more of a metal mesh, a metal foam, a carbon fiber fabric and a conductive ceramic.

6. The method according to claim 1, characterized in that The flow rate of the ammonia gas is 1 to 100 sccm; The reaction time is 1 to 60 seconds.

7. A reaction system for producing hydrogen by ammonolysis, characterized in that: It includes a reaction device and a power source connected to the reaction device; The reaction device comprises a base and a quartz reaction pool sealed on the base; A conductive substrate loaded with a conductive catalyst is arranged in the quartz reaction cell; The conductive substrate is connected to a power source via a conductive wire passing through the base; An air inlet and an air outlet communicated with the quartz reaction pool.

8. The reaction system according to claim 7, characterized in that: The base includes a ceramic tube; The quartz reaction cell comprises a quartz tube; An air intake pipeline is provided in the quartz reaction pool; The air inlet is connected to the quartz reaction pool through an air inlet pipeline.

9. The reaction system according to claim 8, characterized in that: The air inlet is arranged on the base; The air outlet is arranged on the base; The conductive substrate is arranged at the outlet end of the air intake pipeline.

10. The reaction system according to claim 7, characterized in that: The reaction system also includes a heating device; The reaction device is arranged in the heating device.

Images