Plasma generating device based on catalysis of compact microporous material

Abstract

This invention relates to a plasma generator based on a dense microporous material catalysis, belonging to the field of low-temperature plasma technology. The plasma generator contains at least one discharge unit, which includes a first electrode, a microporous ceramic medium, and a second electrode. The first electrode is used to connect to a power source, and the second electrode is used for grounding. The microporous ceramic medium is used to adsorb gas molecules and active particles generated by the plasma discharge. This invention generates micro-discharge in a dense microporous medium, which has an extremely high specific surface area. When gas passes through, it is adsorbed onto the surface of the micropores in the medium. Similarly, active substances in the plasma are adsorbed onto the surface of the micropores in the medium. This improves the contact efficiency between short-lived, highly active particles and free radicals in the plasma and the reactants, promotes surface catalytic reactions, and improves the overall efficiency of the device.

Description

Technical Field

[0001] This invention belongs to the field of low-temperature plasma technology, and more specifically, relates to a plasma generating device based on dense microporous material catalysis. Background Technology

[0002] Plasma is a collection of particles composed of electrons, ions, neutral atoms, excited-state particles, metastable-state particles, and various active free radicals. It possesses extremely high chemical reactivity and shows promising application prospects in fields such as gas catalytic conversion and chemical synthesis. Current plasma generation devices, such as dielectric barrier discharge devices, experience arcing between the electrodes when high voltage is applied to both sides of the dielectric. This localizes the plasma discharge, failing to achieve the ideal uniform discharge effect of dielectric barrier plasma generators within the dielectric. Furthermore, the reactants have a short residence time in the plasma region, resulting in limited processing efficiency. In the sliding arc discharge device structure commonly used in plasma gas catalysis, the plasma moves periodically with the gas flow, with only a small portion of the gas reacting with the plasma; the majority of the gas flows out of the reactor without participating in the reaction.

[0003] Patent CN106102294A discloses a microporous dielectric barrier plasma reactor. The surface of its discharge electrode plate is covered with a nano-ceramic plate. Each layer of the nano-ceramic discharge device includes two discharge units, forming a plasma region between the two units. The plasma release region between the two discharge units is a gas channel with a width of 5-7 mm for the gas to be treated. The gas to be treated in the gas channel is discharged from the gas outlet after being treated by the discharge of the nano-ceramic electrode device. In this invention, the nano-ceramic plate is used as a medium to generate uniform plasma in the gas gap. The working gas has a short residence time in the plasma region, and the probability of collisions between active particles generated by discharge in the gas gap is high, accelerating the annihilation of active particles and resulting in a low average lifetime of active particles.

[0004] Patent CN106268302A discloses a packed bed plasma catalytic purifier. Each purification unit consists of two electrode plates, two insulating ceramic plates, an air inlet, two sealing plates, and two insulating ceramic plates arranged in parallel to form a purification channel. A sealing plate with an air inlet is connected to each end of the purification channel. An electrode plate is fixed to the outside of the purification channel formed by the insulating ceramic plates, and multiple catalytic balls are placed inside the purification channel. The catalytic balls are coated with TiO2 photocatalyst. In this invention, the catalyst is coated on the surface of the medium balls, which increases the contact area between air and the catalyst to some extent. However, the specific surface area of ​​the medium balls is small, and there are large gaps between the small balls. A large amount of gas flows through the gaps where there is no catalyst, resulting in low treatment efficiency.

[0005] Patent CN113041386A discloses a sterilization device based on porous dielectric discharge plasma. Conductive metal foam plate electrodes are arranged parallel to each other with a spacing between them. A porous medium is placed between the plate electrodes, and the plate electrodes and the porous medium are in close contact. Germicidal gas enters through the inlet, passes through the plate electrodes and the porous medium, and exits through the outlet, thus treating bacteria. In this invention, one of the important indicators for measuring the air sterilization effect is the airflow, which directly determines the sterilization efficiency of the indoor air environment. The device needs to have low air resistance. This invention uses porous ceramic with a porosity of 10-50 ppi and uses foam metal material as electrodes, allowing germicidal gas to pass through the plate electrodes and the porous medium. However, because the pore size is relatively large, typically above 0.3 mm, the improvement in the contact efficiency between the active ingredients generated by plasma surface discharge and the airflow is limited. Furthermore, the electrode has numerous pores. Even when the electrode is tightly bonded to the porous medium, surface discharge can still occur at the pores, causing not only additional energy loss but also oxidation and erosion, shortening the electrode's lifespan. Electrode erosion also leads to metal vapor entering the ambient air with the gas flow, creating additional hazards. Moreover, the actual discharge area is smaller than the electrode size. Plasma can only be generated at the location of the metal electrode, and the active components generated by the surrounding discharge diffuse into the electrode pores to treat the gas flowing through that area. In reality, plasma treatment is uneven.

[0006] Existing plasma generators, in processes such as gas catalytic conversion, pollutant treatment, and air disinfection, suffer from short residence times of reactants in the plasma region and insufficient contact with active groups within the plasma. Consequently, most reactants cannot directly participate in the chemical reaction, resulting in low reactant utilization, low product concentration, poor reactant conversion efficiency, and high energy consumption. Therefore, ensuring that all reactants remain within the plasma discharge region and improving the contact efficiency between short-lived, highly reactive particles and free radicals in the plasma and the reactants, so that all reactants can participate in the reaction, remains a significant challenge in the field of plasma technology. Summary of the Invention

[0007] To address the shortcomings and improvement needs of existing technologies, this invention provides a plasma generator based on dense microporous material catalysis. Its purpose is to generate micro-discharges in a dense microporous medium. This medium has an extremely high specific surface area, allowing gas to be adsorbed onto the surface of the micropores as it passes through. Similarly, active substances in the plasma are adsorbed onto the surface of the micropores, improving the contact efficiency between short-lived, highly active particles and free radicals in the plasma and the reactants, promoting surface catalytic reactions, and enhancing the overall efficiency of the device.

[0008] According to the present invention, a plasma generating device based on microporous material catalysis is provided. The plasma generating device includes at least one discharge unit, the discharge unit including a first electrode, a microporous ceramic medium, and a second electrode. The first electrode is used to connect to a power source, and the second electrode is used to ground. The microporous ceramic medium is used to adsorb gas molecules and active particles generated by plasma discharge in the electric field formed between the first electrode and the second electrode.

[0009] Preferably, the first electrode, the microporous ceramic medium, and the second electrode are flat plate structures or coaxial cylindrical structures, wherein the microporous ceramic medium is located between the first electrode and the second electrode.

[0010] Preferably, any surface of the microporous ceramic medium is covered with a solid insulating dielectric plate, or a layer of solid insulating dielectric plate is inserted into the microporous ceramic medium.

[0011] Preferably, the plasma generating device contains multiple discharge units, and the first electrode and the second electrode are arranged alternately from top to bottom or from inside to outside.

[0012] Preferably, the first electrode and the second electrode are embedded in a microporous ceramic medium.

[0013] Preferably, the first electrode and the second electrode form a square array or a ring array.

[0014] Preferably, the pore size of the microporous ceramic medium is 0.1μm-50μm.

[0015] Preferably, the microporous ceramic medium is alumina or silicon carbide.

[0016] Preferably, the catalyst is supported on the microporous ceramic medium.

[0017] Preferably, the catalyst is a metal oxide, a photocatalyst, or a noble metal material.

[0018] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0019] (1) The reactants have a long residence time in the plasma, resulting in high contact efficiency with active particles and free radicals in the plasma and high processing efficiency. This invention employs dense microporous materials with pore sizes on the micrometer or nanometer scale, significantly increasing the specific surface area of ​​the medium. This is beneficial for the adsorption of gas molecules by the micropores and also for the adsorption of active particles generated by plasma discharge. A higher specific surface area allows for the loading of more catalysts, which is beneficial for surface catalysis, improving chemical reaction efficiency and enabling chemical synthesis applications such as plasma-catalyzed gas conversion.

[0020] (2) Avoid electrode surface discharge, reduce additional energy loss, prevent electrode ablation, and extend service life. Discharge occurring in electrode pores causes additional energy consumption and severe oxidation and ablation of the electrode edges. Furthermore, because the discharge occurs on the electrode surface, the plasma does not directly contact the reactant molecules adsorbed in the micropores of the medium or the supported catalyst, resulting in very low reactant processing efficiency due to discharge in the electrode pores. Using a complete metal plate or cylinder as the electrode effectively avoids discharge in the electrode pores.

[0021] (3) Plasma characteristics can be more flexibly controlled. Since the electrodes do not require gas flow, metal electrodes can be used, or a solid insulating medium can be used to cover the surface of the metal electrode. By employing different discharge modes, the plasma gas temperature, electric field strength, electron density, and electron temperature can be controlled. Using metal electrodes to generate micro-discharges in micropores can achieve higher electron density and higher gas temperature; while using electrodes covered with a solid insulating medium results in higher electric field strength and lower gas temperature.

[0022] (4) Enhances discharge and increases the density of active particles and free radicals in plasma. Dense microporous dielectric materials can enhance the local electric field, strengthen local ionization, and generate more electrons, ions, excited-state particles, and free radicals. Moreover, because of their small pore size and large number, they facilitate the contact between short-lived particles and gaseous reactants, promote surface catalytic reactions, improve plasma catalytic reactions, and increase the working efficiency of the device.

[0023] (5) The device of this invention generates micro-discharge in micropores with a dense microporous medium. The surface of the micropores can adsorb reactants and active substances in the plasma, thereby ensuring that all reactants are in the plasma discharge region, allowing the plasma and reactants to fully contact each other, more effectively initiating plasma physicochemical reactions, saving costs, increasing product concentration, reducing energy consumption, and improving the overall efficiency of the device. It is not only applicable to plasma nitrogen fixation reactions using air as reactants, but can also realize gas catalytic synthesis reactions such as plasma ammonia synthesis, CO2 conversion, and methane cracking to hydrogen production by changing the raw material gas. It is also applicable to chemical synthesis reactions using liquid substances as reactants.

[0024] (6) Preferably, the first electrode and the second electrode can be flat metal electrodes, or a solid insulating dielectric plate (non-microporous structure) can be covered on the surface of the metal electrode. Using a flat metal electrode is similar to surface discharge, where plasma is generated along the microporous surface and fills the pores. Using an electrode covered with an insulating dielectric plate is similar to dielectric barrier discharge, which can generate uniform plasma in the gaps. The dense microporous dielectric material replaces the air gaps, increasing the local electric field strength and enhancing the discharge effect, thus improving the efficiency of the surface chemical reaction. Furthermore, increasing the gas residence time improves the contact efficiency between the reactants and the plasma, allowing the reactants to react fully.

[0025] (7) In this invention, different dielectric materials can be selected as needed. Different dielectric constants of materials will affect the electric field strength of plasma discharge, thereby controlling the density of various active particles and free radicals generated by plasma. Different pore sizes will directly affect the specific surface area of ​​the medium, and affect the contact rate and residence time of reactant gas and plasma.

[0026] (8) Preferably, the dense microporous medium of the present invention can support different types of catalysts, including but not limited to metal oxides, photocatalysts, and noble metal materials. Dense microporous materials have a high specific surface area, making them very suitable as catalyst supports. They can ensure full contact between the catalyst and the active components and reactants in the plasma, greatly improving the catalytic activity of the catalyst and achieving a synergistic effect between the catalyst and the plasma.

[0027] (9) Preferably, the device of the present invention can be configured with multiple discharge units, not limited to a single layer. Using a multi-layer discharge structure can generate uniform plasma over a larger area, improving processing efficiency and significantly saving time and space resources. It also avoids the problem of excessively large distances between single-layer discharge electrodes, making discharge difficult, or excessive spacing leading to uneven discharge. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a flat-plate plasma generator based on dense microporous material catalysis, provided by the present invention.

[0029] Figure 2 This is a schematic diagram of a two-layer discharge unit of a flat-plate device provided by the present invention.

[0030] Figure 3 The present invention provides a schematic diagram of the discharge structure of a planar device consisting of "electrode-microporous medium-medium (non-microporous structure)-microporous medium-electrode" (from top to bottom, 4 and 5 below are also examples).

[0031] Figure 4A schematic diagram of the discharge structure of a planar device provided by the present invention, which is "electrode-dielectric (non-microporous structure)-microporous dielectric-electrode".

[0032] Figure 5 A schematic diagram of the discharge structure of a planar device provided by the present invention, consisting of "electrode-dielectric (non-microporous structure)-microporous dielectric-dielectric (non-microporous structure)-electrode".

[0033] Figure 6 This is a schematic diagram of a coaxial cylindrical plasma generator based on dense alumina microporous ceramic media barrier catalysis provided by the present invention.

[0034] Figure 7 This is a schematic diagram of a two-layer discharge unit of a coaxial cylindrical device provided by the present invention.

[0035] Figure 8 The present invention provides a schematic diagram of the discharge structure of a coaxial cylindrical device consisting of "electrode-microporous medium-medium (non-microporous structure)-microporous medium-electrode" (in order from the outside to the inside, 9 and 10 below are also examples).

[0036] Figure 9 The present invention provides a schematic diagram of the discharge structure of a coaxial cylindrical device consisting of an electrode, a dielectric (non-microporous structure), a microporous dielectric, a dielectric (non-microporous structure), and an electrode.

[0037] Figure 10 The present invention provides a schematic diagram of the discharge structure of a coaxial cylindrical device consisting of an electrode, a dielectric (non-microporous structure), a microporous dielectric, a dielectric (non-microporous structure), and an electrode.

[0038] Figure 11 Image (a) is a schematic diagram of a multi-electrode square array discharge device provided by the present invention. Figure 11 (b) in the figure is a cross-sectional view of the electrode arrangement.

[0039] Figure 12 Image (a) is a schematic diagram of a multi-electrode ring array discharge device provided by the present invention. Figure 12 (b) in the figure is a cross-sectional view of the electrode arrangement.

[0040] The markings in the diagram are as follows: 1-First electrode, 2-Second electrode, 3-Alumina microporous ceramic dielectric, 4-Air inlet, 5-Air outlet, 6-Insulating shell, 7-High voltage wire, 8-High voltage power supply, 9-Dielectric (non-microporous structure) Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0042] This invention provides a plasma generator based on dense microporous material catalysis, which can generate uniform plasma in the medium by producing micro-discharges within the micropores of the dense microporous medium. The microporous surface can adsorb reactants and active substances in the plasma, ensuring sufficient contact between reactants and plasma, making full use of the short-lived, highly active components in the plasma, reducing energy consumption, and improving the overall efficiency of the device.

[0043] The present invention provides a plasma generating device based on dense microporous material catalysis. The device includes: an insulating housing, the housing having an air inlet, an air outlet, a first electrode, a second electrode, a dense microporous medium, and a high-voltage power supply.

[0044] The first and second electrodes are respectively attached to both sides of the microporous dielectric material and connected to the high-voltage electrode and ground electrode of the high-voltage power supply, respectively. After voltage is applied to the electrodes, a discharge channel can be generated and filled in the tiny pores of the dense microporous medium, rather than just creating a single discharge channel. A gas pump or fan is used to allow gas to enter the air passage formed by the insulating shell of the device from the air inlet. The airflow direction is parallel to the plane where the flat electrode is located. After passing through the dense microporous medium, the gas flows out from the air outlet. As it flows through the dense microporous medium, it is adsorbed on the surface of the micropores of the medium, thus making full contact with the plasma.

[0045] In some embodiments, the first electrode and the second electrode can be flat metal electrodes, or a solid insulating dielectric plate (non-microporous structure) can be covered on the surface of the metal electrode.

[0046] Beneficial effects: Employing a metal plate electrode, similar to surface discharge, plasma is generated along the microporous surface and fills the pores. Using an electrode covered with an insulating dielectric plate, similar to dielectric barrier discharge, uniform plasma can be generated within the gaps. The dense microporous dielectric material replaces the air gaps, increasing the local electric field strength and enhancing the discharge effect, thus improving the efficiency of surface chemical reactions. Furthermore, increasing the gas residence time improves the contact efficiency between reactants and plasma, allowing for more complete reactions.

[0047] In some embodiments, the first electrode, the second electrode, and the dense microporous material can be parallel flat plate structures, forming a three-layer structure of electrode-microporous medium-electrode. Alternatively, they can be coaxial cylindrical structures, with dense microporous material between the inner and outer coaxial electrodes. Plasma is generated in the microporous material through discharge, allowing reactant gases to pass through.

[0048] In some embodiments, the first and second electrodes can be arrays of multiple electrodes, with high-voltage and ground electrodes arranged alternately and embedded in a dense microporous material. The presence of multiple electrodes is beneficial for discharge uniformity and can also increase the density of active particles in the plasma, thereby enhancing the processing effect. The array arrangement can be, but is not limited to, square arrays, ring arrays, and other structures.

[0049] In some embodiments, the electrodes and other conductive materials of the device may be, but are not limited to, one of the following metallic materials: aluminum, copper, tungsten, stainless steel, etc.

[0050] In some embodiments, the device may use a DC power supply, an AC power supply, a pulse power supply, or other types of power supply.

[0051] In some embodiments, the reactants introduced into the device may be, but are not limited to, one or more mixed gases such as air, nitrogen, oxygen, carbon dioxide, and methane, or they may be liquids.

[0052] In some embodiments, the microporous medium of the device can be any material with a dense microporous structure, including but not limited to materials such as alumina and silicon carbide, with a pore size on the order of micrometers or nanometers, approximately 0.1-50 μm.

[0053] Beneficial effects: The device can select different dielectric materials as needed. Different dielectric constants of the materials will affect the electric field strength of plasma discharge, thereby controlling the density of various active particles and free radicals generated by the plasma. Different pore sizes will directly affect the specific surface area of ​​the medium, affecting the contact rate and residence time between the reactant gas and the plasma.

[0054] In some embodiments, the dense microporous medium can support different types of catalysts, including but not limited to metal oxides, photocatalysts, and noble metal materials.

[0055] Beneficial effects: Dense microporous materials have a high specific surface area, making them very suitable as catalyst supports. They can ensure full contact between the catalyst and the active components and reactants in the plasma, greatly improving the catalytic activity of the catalyst and achieving synergistic effects between the catalyst and the plasma.

[0056] In some embodiments, the device may be configured with multiple discharge units, rather than being limited to a single layer.

[0057] Beneficial effects: The multi-layer discharge structure can generate uniform plasma over a larger area, improving processing efficiency and significantly saving time and space resources. It also avoids the problem of insufficient discharge due to excessive distance between single-layer discharge electrodes, or uneven discharge caused by excessive spacing.

[0058] In some embodiments, the device can be used for gas conversion, pollution control, or chemical synthesis.

[0059] Beneficial effects: The device generates micro-discharges within micropores of a dense microporous medium. The micropore surface can adsorb reactants and active substances in the plasma, ensuring that all reactants are within the plasma discharge region. This allows for sufficient contact between the plasma and reactants, more effectively initiating plasma physicochemical reactions, saving costs, increasing product concentration, reducing energy consumption, and improving the overall efficiency of the device. It is not only applicable to plasma nitrogen fixation reactions using air as a reactant, but can also achieve various plasma-catalyzed gas conversion applications by changing the feed gas. For example, ammonia can be synthesized using nitrogen and hydrogen as feedstocks under plasma catalysis; or CO2 can be converted using carbon dioxide as a feedstock gas under plasma catalysis, reducing greenhouse gases; or hydrogen can be prepared using methane as a feedstock gas under plasma catalysis. It is also suitable for chemical synthesis reactions using liquid substances as reactants.

[0060] Example 1

[0061] like Figure 1 As shown, the first electrode 1 is a high-voltage electrode, powered by a high-voltage power supply 8. The high-voltage power supply 8 uses AC power, with a discharge frequency of 1-50kHz and a discharge voltage of 10-30kV. The second electrode 2 is a ground electrode. Between the first electrode 1 and the second electrode 2 is an alumina ceramic medium 3 with a pore size of approximately 10 micrometers. The entire discharge structure is a planar discharge structure. A voltage is applied to the first electrode 1, giving it a high potential. Plasma is uniformly generated in the dense micropores of the alumina micron-sized ceramic medium 3, and the active particles in the plasma are adsorbed onto the surface of the micropores. The surface of the alumina ceramic medium 3 is loaded with a TiO2 photocatalyst catalyst. Simultaneously, air is introduced into the device through the air inlet 4, and can only pass through the dense micropores of the alumina ceramic medium 3. The gaseous components in the air are also adsorbed onto the surface of the micropores, reacting with the TiO2 catalyst and the active particles in the plasma, converting nitrogen and oxygen in the air into nitrogen oxides. The products are discharged through the air outlet 5 and enter the subsequent collection and detection device.

[0062] Example 2

[0063] like Figure 2As shown, the electrode structure in Example 1 is partially replaced with a structure of "first electrode 1 - alumina ceramic medium 3 - second electrode 2 - alumina ceramic medium 3 - first electrode 1". First electrode 1 is a high-voltage electrode, powered by a high-voltage AC power supply, with a discharge frequency of 1-50kHz and a discharge voltage of 10-30kV. Second electrode 2 is a ground electrode. The alumina ceramic medium 3, with a pore size of approximately 10 micrometers, lies between first electrode 1 and second electrode 2. The entire discharge structure is a planar discharge structure. When a voltage is applied to first electrode 1, plasma can be uniformly generated within the dense micropores of the upper and lower layers of alumina micron-sized ceramic medium 3. Active particles in the plasma are adsorbed onto the surface of the micropores, catalytically converting nitrogen and oxygen in the air into nitrogen oxides.

[0064] Example 3

[0065] like Figure 3 As shown, the electrode structure in Example 1 is partially replaced with a structure of "first electrode 1 - alumina ceramic medium 3 - medium (non-microporous structure) 9 - alumina ceramic medium 3 - second electrode 2". The first electrode 1 is a high-voltage electrode, powered by a high-voltage AC power supply, with a discharge frequency of 1-50kHz and a discharge voltage of 10-30kV. The second electrode 2 is a ground electrode. The alumina ceramic medium 3 has a pore size of approximately 50 micrometers. The entire discharge structure is a planar discharge structure. When a voltage is applied to the first electrode 1, plasma is uniformly generated in the micropores of the alumina micron-sized ceramic medium 3, and the active particles in the plasma are adsorbed onto the surface of the micropores. A catalyst can be loaded onto the surface of the alumina ceramic medium 3. Simultaneously, as air passes through the dense micropores of the alumina ceramic medium 3, the gases in the air are also adsorbed onto the surface of the micropores. The catalyst and the active particles in the plasma undergo a surface reaction, converting nitrogen and oxygen in the air into nitrogen oxides.

[0066] Example 4

[0067] like Figure 4 As shown, the electrode structure in Example 1 is partially replaced with a structure of "first electrode 1 - dielectric (non-microporous structure) 9 - alumina ceramic dielectric 3 - second electrode 2". The first electrode 1 is a high-voltage electrode, powered by a high-voltage pulse power supply, with a discharge frequency of 1-10kHz, a pulse width of 200ns-5μs, and a pulse voltage amplitude of 15-30kV. The second electrode 2 is a ground electrode. The alumina ceramic dielectric 3 has a pore size of approximately 50 micrometers. The entire discharge structure is a planar discharge structure. When a voltage is applied to the first electrode 1, plasma is uniformly generated in the micropores of the alumina micron-sized ceramic dielectric 3. When air flows through the dense micropores of the alumina ceramic dielectric 3, it reacts with the active particles in the plasma on the surface, achieving gas conversion.

[0068] Example 5

[0069] like Figure 5 As shown, the electrode structure in Example 1 is partially replaced with a structure of "first electrode 1 - dielectric (non-microporous structure) 9 - alumina ceramic dielectric 3 - dielectric (non-microporous structure) 9 - second electrode 2". The first electrode 1 is a high-voltage electrode, powered by a high-voltage nanosecond pulse power supply, and the second electrode 2 is a ground electrode. The alumina ceramic dielectric 3 has a pore size of approximately 50 micrometers. The entire discharge structure is a planar discharge structure. When a voltage is applied to the first electrode 1, plasma is uniformly generated in the micropores of the alumina micron-sized ceramic dielectric 3. When air flows through the dense micropores of the alumina ceramic dielectric 3, it reacts with the active particles in the plasma on the surface, transforming into nitrogen oxides.

[0070] Example 6

[0071] like Figure 6 As shown, the entire discharge structure is a coaxial cylindrical discharge structure. The first electrode 1 is a high-voltage electrode, powered by a high-voltage power supply 8. The power supply uses a high-voltage nanosecond pulse power supply with a discharge frequency of 1-10kHz, a pulse width of 200ns-5μs, and a pulse voltage amplitude of 15-30kV. The nanosecond pulse power supply has an extremely fast rise edge, which can achieve overvoltage breakdown. The plasma reduction electric field is higher, which is conducive to the generation of higher density active particles and promotes chemical reactions. The second electrode 2 is a ground electrode. The alumina micron-sized ceramic medium 3 is located between the first electrode 1 and the second electrode 2. A voltage is applied to the first electrode 1 to give it a high potential. The plasma is uniformly generated in the dense micropores of the alumina ceramic medium 3. Under the drive of the nanosecond pulse power supply, the generated plasma is more uniform. At the same time, air is introduced into the device through the air inlet 4 and passes through the dense micropores of the alumina ceramic medium 3. The gas components in the air react with the plasma during the flow to produce nitrogen oxides, which are discharged through the air outlet 5 and enter the collection and detection device.

[0072] Example 7

[0073] like Figure 7 As shown, the discharge structure in Example 6 is replaced with a coaxial structure of "first electrode 1 - alumina ceramic medium 3 - second electrode 2 - alumina ceramic medium 3 - first electrode 1". First electrode 1 is a high-voltage electrode, powered by a high-voltage power supply 8. The high-voltage power supply uses a high-voltage nanosecond pulse power supply, which is beneficial for generating higher density active particles and promoting chemical reactions. Second electrode 2 is a ground electrode. The alumina ceramic medium 3 has a pore size of 0.1 micrometers. Plasma is uniformly generated in the dense micropores of the alumina ceramic medium 3, and the generated plasma is more uniform under the drive of the nanosecond pulse power supply. Simultaneously, when air passes through the dense micropores of the alumina ceramic medium 3, it reacts with the plasma to produce nitrogen oxides.

[0074] Example 8

[0075] like Figure 8 As shown, the discharge structure in Example 6 is replaced with a coaxial structure of "first electrode 1 - dielectric (non-microporous structure) 9 - alumina ceramic dielectric 3 - second electrode 2". The first electrode 1 is a high-voltage electrode, powered by a high-voltage power supply 8. The high-voltage power supply uses a high-voltage nanosecond pulse power supply, which is beneficial for generating higher density active particles and promoting chemical reactions. The second electrode 2 is a ground electrode. The alumina ceramic dielectric 3 has a pore size of 0.1 micrometers. Plasma is uniformly generated in the dense micropores of the alumina ceramic dielectric 3, and the generated plasma is even more uniform under the drive of the nanosecond pulse power supply. When air passes through the dense micropores of the alumina ceramic dielectric 3, it reacts with the plasma to produce nitrogen oxides.

[0076] Example 9

[0077] like Figure 9 As shown, the discharge structure in Example 6 is replaced with a coaxial structure of "first electrode 1 - alumina ceramic medium 3 - medium (non-microporous structure) 9 - second electrode 2". The first electrode 1 is a high-voltage electrode, powered by a high-voltage power supply 8. The high-voltage power supply uses a high-voltage nanosecond pulse power supply, which is beneficial for generating higher density active particles and promoting chemical reactions. The second electrode 2 is a ground electrode. The alumina ceramic medium 3 has a pore size of 50 micrometers. Plasma is uniformly generated in the dense micropores of the alumina ceramic medium 3, and the generated plasma is even more uniform under the drive of the nanosecond pulse power supply. When air passes through the dense micropores of the alumina ceramic medium 3, it reacts with the plasma to produce nitrogen oxides.

[0078] Example 10

[0079] like Figure 10 As shown, Figure 6 In the illustrated embodiment, the discharge structure is replaced with a coaxial structure of "first electrode 1 - dielectric (non-microporous structure) 9 - alumina ceramic dielectric 3 - dielectric (non-microporous structure) 9 - second electrode 2". First electrode 1 is a high-voltage electrode, powered by a high-voltage power supply 8, which uses a high-voltage AC power supply. Second electrode 2 is a ground electrode. The alumina ceramic dielectric 3 has a pore size of 50 micrometers. Plasma is uniformly generated within the dense micropores of the alumina ceramic dielectric 3. When air passes through the dense micropores of the alumina ceramic dielectric 3, it reacts with the plasma to produce nitrogen oxides.

[0080] Example 11

[0081] Replace the discharge structure in Example 1 with, as shown below Figure 11The structure shown embeds multiple electrode rods within a microporous ceramic medium 3, with the first electrode 1 and the second electrode 2 arranged alternately. The first electrode is a high-voltage electrode, driven by a high-voltage power supply 8. The high-voltage power supply is a high-voltage pulse power supply with a discharge frequency of 1-10 kHz, a pulse width of 200 ns-5 μs, and a pulse voltage amplitude of 15-30 kV, which facilitates the generation of higher-density active particles and promotes chemical reactions. The second electrode is a ground electrode, and the microporous ceramic medium 3 is an alumina ceramic medium with a pore size of 20 micrometers. Plasma is uniformly generated within the dense micropores of the microporous ceramic medium 3. When air passes through the dense micropores of the alumina ceramic medium 3, it reacts with the plasma to produce nitrogen oxides. Alternatively, other working gases can be used to achieve various gas catalytic conversion applications.

[0082] Example 12

[0083] Replace the discharge structure in Example 6 with the following: Figure 12 The structure shown is as follows. Multiple first electrodes 1 are embedded in the microporous ceramic medium 3 within the coaxial electrode structure of "second electrode 2 - alumina ceramic medium 3 - second electrode". The first electrodes are high-voltage electrodes, driven by a high-voltage power supply 8. The high-voltage power supply is a high-voltage AC power supply with a discharge frequency of 1-50kHz and a discharge voltage of 10-30kV. The second electrode is a ground electrode, and the microporous ceramic medium 3 is an alumina ceramic medium with a pore size of 10 micrometers. Plasma is uniformly generated in the dense micropores of the microporous ceramic medium 3 between the first electrodes 1 and the second electrodes 2. When air passes through the dense micropores of the alumina ceramic medium 3, it undergoes transformation under the catalytic action of the plasma.

[0084] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A plasma generator based on microporous material catalysis, characterized in that, The plasma generating device includes at least one discharge unit, which includes a first electrode, a microporous ceramic medium, and a second electrode. The first electrode is used to connect to a power source, and the second electrode is used to ground. The microporous ceramic medium is used to adsorb gas molecules and active particles generated by plasma discharge in the electric field formed between the first electrode and the second electrode. The surface of the microporous ceramic medium is covered with a solid insulating dielectric plate with a non-microporous structure, or a solid insulating dielectric plate with a non-microporous structure is inserted into the microporous ceramic medium. The catalyst is supported on the microporous ceramic medium.

2. The plasma generator based on microporous material catalysis as described in claim 1, characterized in that, The first electrode, the microporous ceramic medium, and the second electrode are either flat plate structures or coaxial cylindrical structures, wherein the microporous ceramic medium is located between the first electrode and the second electrode.

3. The plasma generator based on microporous material catalysis as described in claim 1 or 2, characterized in that, The plasma generator contains multiple discharge units, and the first electrode and the second electrode are arranged alternately from top to bottom or from inside to outside.

4. The plasma generator based on microporous material catalysis as described in claim 1, characterized in that, The first electrode and the second electrode are embedded in a microporous ceramic medium.

5. The plasma generator based on microporous material catalysis as described in claim 4, characterized in that, The first electrode and the second electrode form a square array or a ring array.

6. The plasma generator based on microporous material catalysis as described in claim 1, characterized in that, The pore size of the microporous ceramic medium is 0.1 μm-50 μm.

7. The plasma generator based on microporous material catalysis as described in claim 1 or 6, characterized in that, The microporous ceramic medium is alumina or silicon carbide.

8. The plasma generator based on microporous material catalysis as described in claim 1, characterized in that, The catalyst is a metal oxide or a noble metal material.

9. The plasma generator based on microporous material catalysis as described in claim 1, characterized in that, The catalyst is a photocatalyst.

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