Preparation method and application of plasma coupling catalyst based on electron beam irradiation
Plasma-coupled catalysts were prepared by impregnation and electron beam irradiation, and combined with a dielectric barrier discharge device, which solved the problems of low catalytic efficiency and high energy consumption in the existing technology, realizing efficient and low-energy ammonia synthesis, suitable for large-scale production.
Patent Information
- Application Number
- CN202511184876.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2025-11-21
AI Technical Summary
Existing plasma catalytic ammonia synthesis technology suffers from low catalytic efficiency, high energy consumption, and severe environmental pollution, making it difficult to achieve large-scale production.
Active ingredients were loaded onto the surface of a support using an impregnation method, and then a plasma-coupled catalyst was prepared by electron beam irradiation. Combined with a dielectric barrier discharge device, the synergistic effect of the catalyst and plasma was achieved to synthesize ammonia.
It improves the activity and dispersibility of the catalyst, reduces energy consumption, achieves a high ammonia synthesis rate, and has a simple, environmentally friendly process suitable for large-scale production.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of plasma catalysis technology, specifically to a method for preparing and applying a plasma-coupled catalyst based on electron beam irradiation. Background Technology
[0002] Plasma-catalyzed ammonia synthesis is an emerging technology that uses dielectric barrier discharge (DBD) to generate non-equilibrium plasma, which works synergistically with a catalyst to activate the reactants N2 and H2 to synthesize ammonia at low temperature and low pressure. Ammonia (NH3), as a major raw material for nitrogen fertilizer and a hydrogen energy carrier, plays a crucial role in global food security and the clean energy transition. Ammonia (NH3) is a vital basic chemical, supporting global food production as a core raw material for nitrogen fertilizer in agriculture, used in the manufacture of nitric acid, plastics, refrigerants, and cleaning agents in industry, and applied in environmental protection for flue gas denitrification and carbon capture. In recent years, ammonia has also become a key carrier for energy transition. Due to its high hydrogen content and easy liquefaction, it is considered a carbon-free fuel and hydrogen storage medium, and can be used in ammonia fuel engines, hydrogen production through cracking, and fuel cells. The rise of "green ammonia" technology has further made it an important pathway to achieve carbon neutrality. Although its toxicity and environmental risks require strict control, ammonia is indispensable for maintaining modern industry, agriculture, and future clean energy systems.
[0003] The traditional Haber-Bosch process, as the main industrial process for ammonia synthesis, has been used for over a century, but its inherent technical limitations are becoming increasingly apparent: high energy consumption, stringent operating conditions (400-500℃, 15-25 MPa), and significant carbon emissions severely restrict the sustainable development of this process. Against this backdrop, plasma-catalyzed ammonia synthesis technology exhibits significant innovative advantages. This technology represents a disruptive new paradigm for ammonia synthesis, achieving efficient activation of nitrogen molecules under mild conditions through active species (such as excited-state N2* and N radicals) generated by non-thermal equilibrium plasma, fundamentally breaking through the dependence of the traditional Haber process on high-temperature and high-pressure conditions. In existing technologies, the best effect achieved in plasma-catalyzed ammonia synthesis using the alumina-supported bimetallic catalyst Co-Al / Al2O3 is 3000 μmol / h, but this requires a catalyst weighing as much as 6g. In some plasma-catalyzed ammonia synthesis processes, MgCl2 is used as both a catalyst and an absorbent. While the energy efficiency of ammonia synthesis reaches 20.5 g / kWh, the total flow rate is as high as 4 L / min. Furthermore, using a Ni-MOF-74 catalyst achieves a maximum ammonia yield of 10.3%, but requires a high radio frequency plasma power of 300 W. Therefore, providing a highly efficient, controllable, and easily scalable catalytic material has become an urgent problem to be solved. Summary of the Invention
[0004] In view of the above-mentioned shortcomings in the prior art, the present invention provides a method for preparing plasma-coupled catalysts based on electron beam irradiation and its application, which effectively solves the problems of low catalytic efficiency, high energy consumption and serious environmental pollution of the prior art.
[0005] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is: to provide a method for preparing a plasma-coupled catalyst based on electron beam irradiation, comprising the following steps: S1. The active ingredient is adsorbed onto the surface of the carrier by impregnation, then allowed to stand, ultrasonicated and dried, and then calcined to obtain a catalyst loaded with the active ingredient. S2. The catalyst loaded with active components is irradiated under an electron beam to obtain a plasma-coupled catalyst based on electron beam irradiation.
[0006] Furthermore, in step S1, the active component is one of the following: a supported metal oxide catalyst active component, a supported transition metal catalyst active component, and a supported noble metal catalyst active component.
[0007] Furthermore, the active component of the supported metal oxide catalyst is one of MnO, CuO, Cr2O3, NiO, and MoO3.
[0008] Furthermore, the active component of the supported transition metal catalyst is one of Fe, Co, Ni, and Cu.
[0009] Furthermore, the active component of the supported noble metal catalyst is one of Ru, Pt, Pd, Rh and Ir.
[0010] Furthermore, in step S1, the support is one of AL2O3, SiO2, TiO2 and CeO2.
[0011] Furthermore, in step S1, the amount of active ingredient added is 2-3% of the carrier mass.
[0012] Furthermore, in step S1, the amount of active ingredient added is 2% of the carrier mass.
[0013] Furthermore, in step S1, the mixture is left to stand at room temperature for 3-10 hours.
[0014] Furthermore, in step S1, the mixture is left to stand at room temperature for 6 hours.
[0015] Furthermore, in step S1, ultrasound is performed for 5-30 minutes.
[0016] Furthermore, in step S1, ultrasound is performed for 10 minutes.
[0017] Furthermore, in step S1, the product is dried in an oven at 60-100°C.
[0018] Furthermore, in step S1, the product is dried in an oven at 80°C.
[0019] Further, in step S1, the temperature is increased to 400-600 °C for 1-5 h in a muffle furnace under air atmosphere at a rate of 5-10 °C / min.
[0020] Furthermore, in step S1, the temperature is increased to 500 °C for 2 h in a muffle furnace under air atmosphere at a rate of 5 °C / min.
[0021] Furthermore, in step S2, during irradiation, the electron beam current energy is 0.1-10 MeV, the average beam power is 19-21 KW, the average beam current intensity is 1-3 mA, the scan width is 600-800 mm, and the irradiation dose is 5-100 KGy.
[0022] Furthermore, in step S2, during irradiation, the electron beam current energy is 10 MeV, the average beam power is 20 KW, the average beam current intensity is 2 mA, the scan width is 700 mm, and the irradiation dose is 20 KGy.
[0023] The plasma-coupled catalyst based on electron beam irradiation was prepared by the above-described method for preparing plasma-coupled catalysts based on electron beam irradiation.
[0024] The above-mentioned plasma-coupled catalyst based on electron beam irradiation is used in ammonia synthesis.
[0025] A method for synthesizing ammonia using a plasma-coupled catalyst based on electron beam irradiation includes the following steps: filling the plasma-coupled catalyst based on electron beam irradiation into a quartz glass tube and introducing nitrogen and hydrogen gas; then reducing and heating the quartz glass tube; after cooling, the quartz glass tube, inner electrode, and outer electrode form a coaxial dielectric barrier discharge device; the quartz glass tube, low-temperature plasma power supply, high-voltage electrode, and low-voltage electrode form a plasma dielectric barrier discharge catalytic device; the high-voltage electrode of the low-temperature plasma power supply is connected to the inner electrode, and the low-voltage electrode is connected to the outer electrode; the low-temperature plasma power supply supplies power to the outer electrode; and ammonia is synthesized through the synergistic effect of plasma and the plasma-coupled catalyst based on electron beam irradiation.
[0026] Furthermore, nitrogen and hydrogen are introduced through the air inlet at the top of the quartz glass tube.
[0027] Furthermore, the flow rate ratio of nitrogen to hydrogen is 1-4:4-1.
[0028] Furthermore, the total flow rate is 10-100 mL / min.
[0029] Furthermore, the temperature is increased to 400-600℃ in a tube furnace at a rate of 5-10℃ / min and held for 2-4 hours.
[0030] Furthermore, the temperature was increased to 500°C at a rate of 5°C / min and held for 2 hours using a tube furnace.
[0031] Furthermore, during heating, both nitrogen and hydrogen are maintained at a flow rate of 40 mL / min.
[0032] Furthermore, it is allowed to cool to room temperature.
[0033] Furthermore, the reduced plasma-coupled catalyst based on electron beam irradiation is fixed at both ends with quartz wool.
[0034] Furthermore, the inner electrode is disposed inside the quartz glass tube, and the outer electrode is disposed outside the quartz glass tube.
[0035] Furthermore, the external electrode is 2.5 cm.
[0036] Furthermore, the outer electrode is tightly attached to the outside of the glass tube and fixed with copper wire so that the outer electrode just covers the area of the catalyst and quartz wool.
[0037] Furthermore, the power of the cryogenic plasma power supply is 25 W.
[0038] Furthermore, the high-voltage electrode is one of a stainless steel rod, a tungsten rod, and a molybdenum rod.
[0039] Furthermore, the low-voltage electrode is one of stainless steel sheet, copper foil, or aluminum foil.
[0040] Furthermore, the high-voltage electrode is placed inside the quartz glass tube, while the low-voltage electrode is placed outside the quartz glass tube.
[0041] Furthermore, the low-voltage electrode is wound around the outer electrode.
[0042] Furthermore, ammonia gas is discharged from the outlet at the bottom of the quartz glass tube.
[0043] In summary, the present invention has the following beneficial effects: 1. This invention prepares a catalyst by impregnation, in which the active components can be uniformly loaded on the catalyst surface and within the pores, thereby improving the dispersibility of the active components. Subsequently, electron beam irradiation is used to improve the performance of the catalyst in ammonia synthesis. Through the interaction between high-energy electrons and the catalyst, surface defects are induced and the microstructure is controlled. The overall operation is convenient, the process is simple, the irradiation dose is controllable, and it can be used for large-scale production.
[0044] 2. High-energy electron beam irradiation technology provides an efficient, controllable, and easily scalable method for modifying catalytic materials. This invention utilizes high-energy electrons to achieve precise control over the bulk phase and surface structure of catalysts at room temperature and pressure, enabling the large-scale preparation of catalytic materials with abundant active sites. Compared to traditional chemical treatment or high-temperature calcination methods, electron beam irradiation is simple, environmentally friendly, requires no complex post-processing steps, and can be directly integrated with existing catalyst production lines. The application of industrial-grade electron accelerators enables this technology to process ton-scale catalysts with good batch-to-batch repeatability and stable product performance. This "green manufacturing" technology not only overcomes the limitations of traditional methods in terms of the precision and uniformity of material modification, but also provides a new technical route for the industrial production of catalytic materials due to its simple operation, high production efficiency, and low energy consumption, demonstrating unique advantages in large-scale applications in energy conversion, environmental governance, and other fields.
[0045] 3. This invention achieves a synergistic effect between the irradiated catalyst and the plasma generated by the dielectric barrier discharge device. The type of active component on the catalyst can be varied, and the gas flow rate ratio can be controlled from 1:4 to 4:1 to adjust the total gas flow rate and thus achieve the optimal ammonia synthesis rate. The plasma-coupled catalyst based on electron beam irradiation prepared by this invention can achieve an ammonia synthesis rate of up to 1148 μmol / g / h. Furthermore, the raw materials used in this invention are abundant, inexpensive, and environmentally friendly, aligning with the trend of green chemistry. Attached Figure Description
[0046] Figure 1 This is a comparison of XRD patterns before and after the 2% MnO / Al2O3 reaction in Example 1; Figure 2 The graph shows the comparison of ammonia synthesis rates using different catalysts in Example 1 and Comparative Example 1. Figure 3 The graph shows the comparison of ammonia synthesis rates using different catalysts in Example 2 and Comparative Example 2. Detailed Implementation
[0047] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.
[0048] Example 1 The preparation method of plasma-coupled catalyst based on electron beam irradiation includes the following steps: S1. Using the impregnation method, MnO is dissolved in deionized water, and then Al2O3 is added. The mixture is stirred at room temperature until the active ingredient is adsorbed on the surface of the support. The amount of MnO added is 2% of the mass of Al2O3. After standing at room temperature for 6 h, it is sonicated for 10 min and dried in an oven at 80℃. Then, it is calcined in a muffle furnace at a rate of 5℃ / min to 500℃ for 2 h in an air atmosphere to obtain a catalyst loaded with active ingredients. S2. 0.8 g of the catalyst loaded with active ingredients was irradiated under an electron beam. During irradiation, the electron beam current energy was 10 MeV, the average beam power was 20 KW, the average beam current intensity was 2 mA, the scan width was 700 mm, and the irradiation dose was 20 KGy, thus obtaining a plasma-coupled catalyst (2% MnO / Al2O3) based on electron beam irradiation.
[0049] Example 2 The preparation method of plasma-coupled catalyst based on electron beam irradiation includes the following steps: S1. Using the impregnation method, Ni is dissolved in deionized water, and then Al2O3 is added. The mixture is stirred at room temperature until the active ingredient is adsorbed on the surface of the support. The amount of Ni added is 2% of the mass of Al2O3. After standing at room temperature for 6 h, it is sonicated for 10 min and dried in an oven at 80℃. Then, it is calcined in a muffle furnace at a rate of 5℃ / min to 500℃ for 2 h in an air atmosphere to obtain a catalyst loaded with active ingredients. S2. 0.8 g of catalyst loaded with active ingredient is placed under an electron beam for irradiation. During irradiation, the electron beam current energy is 10 MeV, the average beam power is 20 KW, the average beam current intensity is 2 mA, the scan width is 700 mm, and the irradiation dose is 20 KGy, thus obtaining a plasma-coupled catalyst based on electron beam irradiation.
[0050] Example 3 The preparation method of plasma-coupled catalyst based on electron beam irradiation includes the following steps: S1. Using the impregnation method, Pt is dissolved in deionized water, and then SiO2 is added. The mixture is stirred at room temperature until the active ingredient is adsorbed on the surface of the support. The amount of Pt added is 2% of the mass of SiO2. After standing at room temperature for 3 h, it is sonicated for 5 min and dried in an oven at 60 °C. Then, it is calcined in a muffle furnace at a rate of 8 °C / min to 400 °C for 1 h in an air atmosphere to obtain a catalyst loaded with active ingredients. S2. 0.8 g of catalyst loaded with active ingredient is placed under an electron beam for irradiation. During irradiation, the electron beam current energy is 0.1 MeV, the average beam power is 19 KW, the average beam current intensity is 1 mA, the scan width is 600 mm, and the irradiation dose is 5 KGy, thus obtaining a plasma-coupled catalyst based on electron beam irradiation.
[0051] Example 4 The preparation method of plasma-coupled catalyst based on electron beam irradiation includes the following steps: S1. Using the impregnation method, CuO is dissolved in deionized water, and then TiO2 is added. The mixture is stirred at room temperature until the active ingredient is adsorbed on the surface of the support. The amount of CuO added is 3% of the mass of TiO2. After standing at room temperature for 10 h, it is sonicated for 30 min and dried in an oven at 100℃. Then, it is calcined in a muffle furnace at a rate of 10℃ / min to 600℃ for 5 h in an air atmosphere to obtain a catalyst loaded with active ingredients. S2. 0.8 g of catalyst loaded with active ingredient is placed under an electron beam for irradiation. During irradiation, the electron beam current energy is 5 MeV, the average beam power is 21 KW, the average beam current intensity is 3 mA, the scan width is 700 mm, and the irradiation dose is 100 KGy, thus obtaining a plasma-coupled catalyst based on electron beam irradiation.
[0052] Comparative Example 1 A plasma-coupled catalyst, which differs from Example 1 in that Comparative Example 1 is not irradiated.
[0053] Comparative Example 2 A plasma-coupled catalyst, which differs from Example 1 in that Comparative Example 2 is not irradiated.
[0054] Experimental Example 1 The XRD patterns of Al2O3 and the electron beam irradiated plasma-coupled catalyst (2% MnO / Al2O3) prepared in Example 1 before and after the catalytic reaction are as follows: Figure 1 As shown.
[0055] Depend on Figure 1 It can be seen that in the X-ray diffraction characteristic peaks of 2%MnO / Al2O3-Before, obvious MnO2 characteristic peaks appeared at 27.8°, 56.8° and 72.5°. However, after 2 hours of reduction in a nitrogen and hydrogen mixed atmosphere at 500°C, MnO2 was reduced to MnO, which can be observed in the X-ray diffraction characteristic peaks of 2%MnO / Al2O3-After, with obvious MnO characteristic peaks appearing at 40.6° and 58.7°.
[0056] Experimental Example 2 The plasma-coupled catalyst based on electron beam irradiation prepared in Example 1 was used for ammonia synthesis. The process included the following steps: (1) The plasma-coupled catalyst based on electron beam irradiation was filled into a quartz glass tube. The quartz glass tube filled with the catalyst was heated by a tube furnace. The tube furnace was heated to 500 ℃ at a rate of 5 ℃ / min and held for 2 h. During this period, nitrogen and hydrogen were circulated at a flow rate of 40 mL / min. The two ends of the reduced plasma-coupled catalyst based on electron beam irradiation were fixed with quartz wool. The inner electrode passed through the middle and was fixed in the glass tube by a sealing plug. The 2.5 cm outer electrode was attached to the outside of the glass tube and fixed by copper wire, which could just wrap the area of the catalyst and quartz wool to form a coaxial dielectric barrier discharge. The gas cylinder provided nitrogen and hydrogen to the upper gas inlet of the quartz tube. The lower gas outlet was connected to the infrared chromatograph by a rubber tube to detect the synthesis rate of ammonia. (2) Adjust the mass flow meter to make the flow rates of nitrogen and hydrogen reach 40 mL / min respectively, and maintain the ventilation for 10 min to remove the air from the gas cell inside the quartz glass tube and the infrared spectrometer. The high-voltage electrode of the low-temperature plasma power supply is connected to the inner electrode, and the low-voltage electrode is wound around the outer electrode. The power supply is energized to the high-voltage electrode at a power of 25 W until it stabilizes. Plasma is generated in the quartz glass tube and coupled with the catalyst to activate nitrogen and hydrogen to synthesize ammonia, which is then purged into the infrared spectrometer. (3) Record the last five sets of data after the ammonia synthesis is stable. At the same time, adjust the flow rates of nitrogen and hydrogen, increasing the total flow rate in increments of 20 mL / min while maintaining their flow rate ratio at 1:1. The total flow rate is increased from 80 mL / min to 200 mL / min. Record the last five sets of data after each change in flow rate is stable.
[0057] The rate of ammonia synthesis using the plasma-coupled catalyst prepared in Comparative Example 1 was tested using the same method. The results of the examples and Comparative Example 1 are as follows: Figure 2 As shown.
[0058] Depend on Figure 2 It can be seen that the ammonia synthesis rate achieved by the plasma-coupled catalyst prepared in Comparative Example 1 at different flow rates is approximately 600-700 μmol / g / h, while the ammonia synthesis rate achieved by the electron beam irradiated plasma-coupled catalyst prepared in Example 1 at different flow rates is approximately 950-1100 μmol / g / h. At a total flow rate of 200 mL / min, the efficiency of ammonia synthesis by the electron beam irradiated plasma-coupled catalyst is approximately 60.6% higher than that of the plasma-coupled catalyst.
[0059] Experimental Example 3 Using the method described in Example 2, the ammonia synthesis rates of the plasma-coupled catalyst based on electron beam irradiation prepared in Example 2 and the plasma-coupled catalyst prepared in Comparative Example 2 were tested. The results are as follows: Figure 3 As shown.
[0060] Depend on Figure 3 It can be seen that the ammonia synthesis rate achieved by the plasma-coupled catalyst prepared in Comparative Example 2 at different flow rates is approximately 600-700 μmol / g / h, while the ammonia synthesis rate achieved by the electron beam-irradiated plasma-coupled catalyst prepared in Example 2 at different flow rates is approximately 700-900 μmol / g / h. At a total flow rate of 200 mL / min, the efficiency of ammonia synthesis by the electron beam-irradiated plasma-coupled catalyst is approximately 17.9% higher than that of the plasma-coupled catalyst.
[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a plasma-coupled catalyst based on electron beam irradiation, characterized in that, Includes the following steps: S1. The active ingredient is adsorbed onto the surface of the carrier by impregnation, then allowed to stand, ultrasonicated and dried, and then calcined to obtain a catalyst loaded with the active ingredient. S2. The catalyst loaded with active components is irradiated under an electron beam to obtain a plasma-coupled catalyst based on electron beam irradiation.
2. The method for preparing a plasma-coupled catalyst based on electron beam irradiation as described in claim 1, characterized in that, In step S1, the active ingredient is one of the following: a supported metal oxide catalyst active ingredient, a supported transition metal catalyst active ingredient, and a supported noble metal catalyst active ingredient.
3. The method for preparing a plasma-coupled catalyst based on electron beam irradiation as described in claim 2, characterized in that, The active component of the supported metal oxide catalyst is one of MnO, CuO, Cr2O3, NiO and MoO3; the active component of the supported transition metal catalyst is one of Fe, Co, Ni and Cu; and the active component of the supported noble metal catalyst is one of Ru, Pt, Pd, Rh and Ir.
4. The method for preparing a plasma-coupled catalyst based on electron beam irradiation as described in claim 1, characterized in that, In step S1, the support is one of Al2O3, SiO2, TiO2 and CeO2.
5. The method for preparing a plasma-coupled catalyst based on electron beam irradiation as described in claim 1, characterized in that, In step S1, the temperature is increased to 400-600℃ in an air atmosphere in a muffle furnace for 2-3 hours.
6. The method for preparing a plasma-coupled catalyst based on electron beam irradiation as described in claim 1, characterized in that, In step S2, during irradiation, the electron beam current energy is 0.1-10 MeV, the average beam power is 19-21 KW, the average beam current intensity is 1-3 mA, the scan width is 600-800 mm, and the irradiation dose is 5-100 KGy.
7. A plasma-coupled catalyst based on electron beam irradiation prepared by the method for preparing a plasma-coupled catalyst based on electron beam irradiation according to any one of claims 1-6.
8. The application of the plasma-coupled catalyst based on electron beam irradiation as described in claim 7 in ammonia synthesis.
9. A method for synthesizing ammonia using a plasma-coupled catalyst based on electron beam irradiation as described in claim 7, characterized in that, Includes the following steps: A plasma-coupled catalyst based on electron beam irradiation was filled into a quartz glass tube and nitrogen and hydrogen were introduced. The quartz glass tube was then reduced and heated. After cooling, the quartz glass tube, inner electrode, and outer electrode formed a coaxial dielectric barrier discharge device. The quartz glass tube, low-temperature plasma power supply, high-voltage electrode, and low-voltage electrode formed a plasma dielectric barrier discharge catalytic device. The high-voltage electrode of the low-temperature plasma power supply was connected to the inner electrode, and the low-voltage electrode was connected to the outer electrode. The low-temperature plasma power supply energized the outer electrode, and ammonia was synthesized through the synergistic effect of plasma and the plasma-coupled catalyst based on electron beam irradiation.
10. The method for synthesizing ammonia using a plasma-coupled catalyst based on electron beam irradiation as described in claim 9, characterized in that, The flow rate ratio of nitrogen to hydrogen is 1-4:4-1.