High-activity and high-durability iron oxide-based ortho-para hydrogen conversion catalyst as well as preparation method and application thereof
A high activity and durability iron oxide catalyst is developed through a specific preparation method, enhancing magnetic interactions and catalyst strength to address degradation issues, ensuring efficient hydrogen isomerization and reducing equipment blockages.
Patent Information
- Application Number
- CN202510455058.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-07-15
AI Technical Summary
Existing iron oxide catalysts are prone to powder under long-term airflow erosion, resulting in a reduced catalytic activity and may cause blockage of hydrogen liquefaction equipment. The heat loss during the conversion of secondary hydrogen during the normal hydrogen can evaporate liquid hydrogen, affecting storage and transportation efficiency.
The iron oxide-based positive secondary hydrogen conversion catalyst was prepared by the sol-gel method. A catalyst with high activity and durability was prepared by doping high magnetic moment metal ions such as manganese, cobalt, and nickel, and using high viscosity solvents such as ethylene glycol, propylene glycol, butylene glycol, and supported substances such as alumina, molecular sieve, and silica gel, forming a gel and calcining, to prepare a catalyst with high activity and durability.
The particle strength and specific surface area of the catalyst are improved, the conversion capacity of the positive secondary hydrogen is enhanced, the risk of powdering is reduced, efficient catalytic activity and durability are maintained, and the evaporation loss of liquid hydrogen is reduced.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of hydrogen liquefaction, and particularly relates to an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, a preparation method thereof, and an application thereof. Background Art
[0002] Hydrogen energy provides an important development path for the adjustment of China's energy structure and the acceleration of achieving the "dual-carbon" goal. As the hydrogen storage form with the highest energy density per unit volume, liquid hydrogen occupies an important position in the entire hydrogen energy industry chain. However, hydrogen molecules have two spin isomers, ortho-hydrogen and para-hydrogen, and the equilibrium ratio between them is only related to temperature: at room temperature, the ratio of ortho-hydrogen to para-hydrogen in hydrogen is about 3:1, while at liquid hydrogen temperature (20K), almost all hydrogen molecules exist in the form of para-hydrogen. When hydrogen at room temperature is rapidly cooled and liquefied, the ortho-para hydrogen ratio in hydrogen will lag behind and remain consistent with the ratio at room temperature. At this time, the hydrogen molecules at low temperature can only undergo self-conversion very slowly, and this process often takes several weeks or even longer. However, the conversion of ortho-hydrogen to para-hydrogen is an exothermic reaction, which means that if only the temperature of hydrogen is reduced during the hydrogen liquefaction process without ortho-para hydrogen conversion catalytic treatment, the heat released by self-conversion will cause a large part of the liquid hydrogen to be lost due to evaporation. In order to reduce the loss during the storage and transportation of liquid hydrogen and reduce energy consumption, it is necessary to use an ortho-para hydrogen conversion catalyst during the hydrogen liquefaction process to make the content of para-hydrogen in the liquid hydrogen product exceed 95%.
[0003] Ortho-para hydrogen conversion catalysis is a reaction involving a magnetic mechanism. A strong local magnetic field, a larger specific surface area, and more unpaired electrons outside the nucleus in the catalyst have all been proven to have a good promoting effect on the ortho-para hydrogen conversion catalytic reaction. Iron oxide catalysts benefit from the abundant unpaired electrons in Fe 3+ and are the most widely used ortho-para hydrogen conversion catalysts. However, commercial iron oxide catalysts are prone to pulverization under long-term gas flow scouring, resulting in a decrease in catalytic activity. At the same time, fine particles entering the hydrogen liquefaction equipment will cause blockage, leading to potential safety hazards. To solve the above problems, it is very necessary to synthesize an ortho-para hydrogen conversion catalyst with high activity and high durability. Summary of the Invention
[0004] In view of this, the purpose of the present invention is to provide an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, a preparation method thereof, and an application thereof. The catalyst prepared by this method has excellent catalytic activity in the ortho-para hydrogen catalytic reaction.
[0005] The present invention provides a preparation method for an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, comprising the following steps:
[0006] Mix an iron source, a high magnetic moment metal ion source, and a solvent to obtain a mixed solution; the cation in the high magnetic moment metal ion source is selected from one or more of manganese ions, cobalt ions, and nickel ions, and the anion is selected from one or more of nitrate ions, chloride ions, sulfate ions, and acetate ions;
[0007] Mix the mixed solution and the support evenly, and stir under heating conditions until a gel is obtained;
[0008] Calcine the gel to obtain an iron oxide-based ortho-para hydrogen conversion catalyst.
[0009] Preferably, the support is selected from one or more of alumina, molecular sieve, silica gel, and activated carbon.
[0010] Preferably, the solvent is selected from one or more of ethylene glycol, propylene glycol, and butylene glycol.
[0011] Preferably, the molar ratio of iron ions in the iron source to the cations in the high magnetic moment metal ion source is (1-10):1.
[0012] Preferably, the mass ratio of the support to the iron element in the iron source is 1-20:1.
[0013] Preferably, the heating temperature is 100-200 °C.
[0014] Preferably, the calcination temperature is 200-400 °C, and the calcination time is 1-5 h.
[0015] Preferably, after calcination, it further includes:
[0016] Crush and screen the calcined mass to obtain an iron oxide-based ortho-para hydrogen conversion catalyst.
[0017] The present invention provides a highly active and highly durable iron oxide-based ortho-para hydrogen conversion catalyst prepared by the preparation method described in the above technical solution;
[0018] The specific surface area of the highly active and highly durable iron oxide-based ortho-para hydrogen conversion catalyst is 40-110 m 2 / g, and the particle size is 40-50 mesh.
[0019] The present invention provides an application of an iron oxide-based ortho-para hydrogen conversion catalyst prepared by the preparation method described in the above technical solution in the ortho-para hydrogen conversion catalytic reaction.
[0020] The present invention provides a method for preparing an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, comprising the following steps: mixing an iron source, a high magnetic moment metal ion source, and a solvent to obtain a mixed solution; the cation in the high magnetic moment metal ion source is selected from one or more of manganese ions, cobalt ions, and nickel ions, and the anion is selected from one or more of nitrate ions, chloride ions, sulfate ions, and acetate ions; mixing the mixed solution and a support evenly, and stirring under heating conditions until a gel is obtained; calcining the gel to obtain the iron oxide-based ortho-para hydrogen conversion catalyst. The present invention uses an iron source to synthesize iron oxide as the catalyst active component, and uses specific types of high magnetic moment metal ions as dopants. These metal ions have more unpaired electrons outside the nucleus. After doping into the crystal lattice of iron oxide, they can interact with the unpaired electrons outside the nucleus of Fe 3+ in iron oxide, generating a stronger local magnetic field, providing a greater conversion force for ortho-para hydrogen conversion, and thus having higher activity compared to ordinary iron oxide catalysts. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 XRD patterns of the ortho-para hydrogen conversion catalysts in the examples and comparative examples;
[0022] Figure 2 SEM images of the support alumina (a), FeMn-400 prepared in Comparative Example 3 (b), and FeMn / Al-400 prepared in Example 1 (c);
[0023] Figure 3 XPS spectrum of Mn 2p of Mn element in the catalyst FeMn / Al-400 prepared in Example 1;
[0024] Figure 4 XPS spectrum of Fe 2p of Fe element in the catalyst FeMn / Al-400 prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention provides a method for preparing an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, comprising the following steps:
[0026] Mixing an iron source, a high magnetic moment metal ion source, and a solvent to obtain a mixed solution; the cation in the high magnetic moment metal ion source is selected from one or more of manganese ions, cobalt ions, and nickel ions, and the anion is selected from one or more of nitrate ions, chloride ions, sulfate ions, and acetate ions;
[0027] Mixing the mixed solution and a support evenly, and stirring under heating conditions until a gel is obtained;
[0028] Calcining the gel to obtain the iron oxide-based ortho-para hydrogen conversion catalyst.
[0029] The present invention mixes an iron source, a high magnetic moment metal ion source and a solvent to obtain a mixed solution. In the present invention, the iron source is selected from one or more of iron nitrate, iron chloride and iron sulfate; in a specific embodiment, the iron source is ferric chloride hexahydrate or ferric nitrate nonahydrate.
[0030] The cations in the high magnetic moment metal ion source are selected from one or more of manganese ions, cobalt ions and nickel ions, and the anions are selected from one or more of nitrate ions, chloride ions, sulfate ions and acetate ions. The present invention uses the above types of high magnetic moment metal ions as dopants. These metal ions have more unpaired electrons outside the nucleus. After doping into the lattice of iron oxide, they can interact with the unpaired electrons outside the nucleus of Fe 3+ in iron oxide, generating a stronger local magnetic field, providing a greater conversion force for the ortho-para hydrogen conversion, and making the prepared catalyst have higher activity. In a specific embodiment, the high magnetic moment metal ion source is manganese sulfate monohydrate, cobalt nitrate hexahydrate or manganese acetate tetrahydrate.
[0031] The present invention uses one or more of ethylene glycol, propylene glycol and butylene glycol as solvents. The above types of solvents are non-toxic and have a high viscosity. They can not only provide conditions for the uniform mixing of the iron source, the high magnetic moment metal ion source and the load, but also provide adhesion during the heating and evaporation process to promote the granulation of the catalyst, improve the overall strength of the catalyst, eliminate the need for a secondary granulation process, are not easily pulverized after a long-term low-temperature hydrogen catalytic conversion reaction, can maintain a high activity, and have good durability. The results of the examples show that when using high-viscosity liquids such as ethylene glycol, propylene glycol and butylene glycol as solvents, compared with the catalysts obtained using water as a solvent and commercial catalysts, the prepared catalyst particles have greater strength, can resist the long-term erosion of the hydrogen flow, and have better durability.
[0032] The present invention preferably adds the iron source and the high magnetic moment metal ion source to the solvent and stirs for 5-10 min to completely dissolve them to obtain a mixed solution. The molar ratio of iron ions in the iron source to the cations in the high magnetic moment metal ion source is (1-10):1; specifically, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.
[0033] After obtaining the mixture solution, the present invention mixes the mixed solution and the load evenly and stirs under heating conditions until a gel is obtained. In the present invention, the load is selected from one or more of alumina, molecular sieve, silica gel and activated carbon. The above types of loads can provide a large number of sites for the precipitation of catalytic active component crystals, effectively reduce the agglomeration of the active components, and reduce the usage amounts of the iron source and the high magnetic moment metal ion source.
[0034] In the present invention, the mass ratio of the load to the iron element in the iron source is 1 to 20:1; specifically, it can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1.
[0035] In the present invention, the heating temperature is 100 to 200 °C; specifically, it can be 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C, 180 °C, 190 °C or 200 °C. The stirring rate is 200 to 500 rpm.
[0036] After obtaining the gel, the present invention calcines the gel to obtain an iron oxide-based ortho-para hydrogen conversion catalyst.
[0037] In the present invention, the calcination temperature is 200 to 400 °C, and specifically, the calcination temperature can be 200 °C, 210 °C, 220 °C, 230 °C, 240 °C, 250 °C, 260 °C, 270 °C, 280 °C, 290 °C, 300 °C, 310 °C, 320 °C, 330 °C, 340 °C, 350 °C, 360 °C, 370 °C, 380 °C, 390 °C or 400 °C; the calcination time is 1 to 5 h, and the calcination time can be 1 h, 1.5 h, 2.0 h, 2.5 h, 3.0 h, 3.5 h, 4.0 h or 5.0 h.
[0038] Preferably, after calcination, the present invention further includes: crushing and screening the obtained block to obtain an iron oxide-based ortho-para hydrogen conversion catalyst.
[0039] The particle size of the iron oxide-based ortho-para hydrogen conversion catalyst obtained by crushing and screening in the present invention is preferably 40 to 50 mesh.
[0040] The present invention provides a highly active and highly durable iron oxide-based ortho-para hydrogen conversion catalyst, which is prepared by the preparation method described in the above technical solution;
[0041] The specific surface area of the highly active and highly durable iron oxide-based ortho-para hydrogen conversion catalyst is 40 to 110 m 2 / g.
[0042] The catalyst provided by the present invention is a highly active and highly durable iron oxide-based catalyst prepared by the sol-gel method, which has the characteristics of good dispersibility, large specific surface area, and excellent catalytic performance. Moreover, the preparation process is controllable, the operation is simple, the obtained catalyst has high strength, does not require secondary granulation, and has good industrial application prospects.
[0043] The present invention provides an application of an iron oxide-based ortho-para hydrogen conversion catalyst prepared by the preparation method described in the above technical solution in an ortho-para hydrogen conversion catalytic reaction.
[0044] In the reaction, the space velocity is 15,000 - 60,000 h -1 , and the time is within 500 h.
[0045] To further illustrate the present invention, the following examples are used to describe in detail a highly active and highly durable iron oxide-based ortho-para hydrogen conversion catalyst provided by the present invention, its preparation method and application, but they should not be construed as limiting the protection scope of the present invention.
[0046] Example 1
[0047] 1.2925 g of ferric chloride hexahydrate and 0.169 g of manganese sulfate monohydrate were added to 25 ml of ethylene glycol, stirred for 10 min to completely dissolve, 2.8 g of alumina was added, and stirring was continued to mix evenly. Then the mixed solution was heated at 150 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 400 °C for 2 h to obtain a catalyst, denoted as FeMn / Al-400.
[0048] The specific surface area of the FeMn / Al-400 catalyst prepared in Example 1 was 103 m 2 / g.
[0049] Example 2
[0050] 2.02 g of ferric nitrate nonahydrate and 0.291 g of cobalt nitrate hexahydrate were added to 25 ml of propylene glycol, stirred for 10 min to completely dissolve, 2.8 g of alumina was added, and stirring was continued to mix evenly. Then the mixed solution was heated at 100 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 400 °C for 5 h to obtain a catalyst, denoted as FeCo / Al-400.
[0051] The specific surface area of the FeCo / Al-400 catalyst prepared in Example 2 was 81 m 2 / g.
[0052] Example 3
[0053] 1.2925 g of ferric chloride hexahydrate and 0.1225 g of manganese acetate tetrahydrate were added to 25 ml of ethylene glycol, stirred for 10 min to completely dissolve, 5.6 g of molecular sieve was added, and stirring was continued to mix evenly. Then the mixed solution was heated at 150 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 400 °C for 2 h to obtain a catalyst, denoted as FeMn / MS-400.
[0054] The specific surface area of the FeMn / MS-400 catalyst prepared in Example 3 is 43 m 2 / g.
[0055] Example 4
[0056] 1.2925 g of ferric chloride hexahydrate and 0.169 g of manganese sulfate monohydrate were added to 25 ml of ethylene glycol, stirred for 10 min to completely dissolve, 2.8 g of alumina was added, and stirring was continued until evenly mixed. Then the mixed solution was heated at 100 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 300 °C for 2 h to obtain a catalyst, denoted as FeMn / Al-300.
[0057] The specific surface area of the FeMn / Al-300 catalyst prepared in Example 4 is 109 m 2 / g.
[0058] Comparative Example 1
[0059] 1.2925 g of ferric chloride hexahydrate was added to 25 ml of ethylene glycol, stirred for 10 min to completely dissolve, 2.8 g of alumina was added, and stirring was continued until evenly mixed. Then the mixed solution was heated at 100 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 400 °C for 2 h to obtain a catalyst, denoted as Fe / Al-400.
[0060] The specific surface area of the Fe / Al-400 catalyst prepared in Comparative Example 1 is 105 m 2 / g.
[0061] Comparative Example 2
[0062] 1.2925 g of ferric chloride hexahydrate and 0.169 g of manganese sulfate monohydrate were added to 25 ml of ethylene glycol, stirred for 10 min to completely dissolve, and then the mixed solution was heated at 150 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 400 °C for 2 h to obtain a catalyst, denoted as FeMn-400.
[0063] The specific surface area of the FeMn-400 catalyst prepared in Comparative Example 2 is 10 m 2 / g.
[0064] Comparative Example 3
[0065] 1.2925 g of iron(III) chloride hexahydrate and 0.169 g of manganese(II) sulfate monohydrate were added to 25 ml of water, and stirred for 10 min until completely dissolved. Then 2.8 g of alumina was added, and stirring was continued until the mixture was homogeneous. After that, the mixed solution was heated at 150 °C until the solvent evaporated to form a gel. Finally, the gel was calcined in a tube furnace at 400 °C for 2 h to obtain a catalyst, denoted as FeMn / Al-H2O-400.
[0066] The specific surface area of the FeMn / Al-H2O-400 catalyst prepared in Comparative Example 4 was 85 m 2 / g.
[0067] Comparative Example 4
[0068] 5.0 g of iron(III) chloride hexahydrate was weighed and placed in a covered crucible, and calcined in a muffle furnace at 400 °C for 2 h. After heating was completed, it was allowed to cool naturally to room temperature to obtain a catalyst, denoted as FeO-DS.
[0069] The specific surface area of the FeO-DS catalyst prepared in Comparative Example 4 was 32 m 2 / g.
[0070] Application Example
[0071] The catalyst was crushed and sieved to obtain catalyst particles of 40-50 mesh. 0.2 ml was measured and filled into the conversion device, heated at 120 °C and purged with pure hydrogen for 12 h. After activation was completed, the conversion device was immersed in liquid nitrogen (77 K), and the catalytic efficiency of the catalyst for ortho-para hydrogen conversion at different space velocities was measured by a gas chromatograph equipped with a thermal conductivity detector. The results are shown in Table 1. To test the durability of the catalyst, after the catalyst was continuously reacted at a space velocity of 30000 h -1 for 480 h, the catalytic efficiency of ortho-para hydrogen conversion is shown in Table 2.
[0072] Table 1 Catalytic efficiency of ortho-para hydrogen conversion of iron oxide-based catalysts at different space velocities
[0073]
[0074] Table 2 Catalytic efficiency of ortho-para hydrogen conversion of iron oxide-based catalysts within 480 h of reaction at a space velocity of 30000 h -1 space velocity
[0075]
[0076]
[0077] As can be seen from Table 1 and Table 2, the doping of high magnetic moment metal ions and the addition of loadings have a good promoting effect on the performance of the iron oxide-based ortho-para hydrogen conversion catalyst. Moreover, from the catalytic results of Example 1, Comparative Example 1, and Comparative Example 3, it can be seen that the doping of high magnetic moment metal ions and the addition of loadings have a combined effect. FeMn / Al-400 not only has the best catalytic performance but also can maintain high activity and high durability under a relatively large space velocity and a longer catalytic time.
[0078] Table 3 shows the particle strength (the magnitude of the force that destroys the catalyst per unit volume when compressed) of the catalysts prepared in Example 1, Example 2, Comparative Example 1, Comparative Example 2, Comparative Example 3, and the commercial iron oxide catalyst. As can be seen from Table 3, when using high-viscosity liquids such as ethylene glycol, propylene glycol, and butylene glycol as solvents, compared with the catalysts and commercial catalysts obtained using water as a solvent, the prepared catalysts have greater particle strength, can resist the long-term erosion of the hydrogen flow, and have better durability.
[0079] Table 3 Particle Strength of Iron Oxide-Based Catalysts
[0080]
[0081] The present invention conducts XRD tests on the above catalysts, and the results are as Figure 1 shown. The main phase composition of all catalysts is iron oxide. After the incorporation of high magnetic moment metal ions, diffraction peaks corresponding to the oxides appear. After the addition of the loading, the diffraction peak intensity of iron oxide is greatly weakened because the high specific surface area loading effectively inhibits the agglomeration of the oxides, reduces the crystallinity of iron oxide, and the internal disorder of the catalyst is higher.
[0082] The present invention conducts SEM tests on the micro-morphologies of the loadings alumina (a), FeMn-400 (b), and FeMn / Al-400 (c) in the above catalysts, as Figure 2 shown. Alumina is irregular particles with a relatively smooth surface, and FeMn-400 is a polygon crystal with an irregular shape. After the two are combined by the sol-gel method, the polygon crystal structure of FeMn-400 disappears, and a uniformly attached morphological structure appears on the surface of alumina. This shows that the addition of the loading alumina can effectively inhibit the agglomeration and crystallization of the active component iron oxide, make the nanoparticles smaller, the particle distribution more uniform, the specific surface area larger, and effectively improve the catalytic activity.
[0083] The present invention conducts XPS tests on the Mn element and Fe element in the catalyst FeMn / Al-400 prepared in Example 1, and the results are as Figure 3 and Figure 4 shown. The Mn element mainly exists as Mn 3+is doped into iron oxide in the form of, while most of the Fe element exists in the form of Fe 3 + exists in the form of, Mn 3+ and Fe 3+ both have abundant unpaired electrons outside the nucleus and can form a stronger local disordered magnetic field.
[0084] As can be seen from the above embodiments, the present invention provides a preparation method of an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, including the following steps: mixing an iron source, a high magnetic moment metal ion source and a solvent to obtain a mixed solution; the cation in the high magnetic moment metal ion source is selected from one or more of manganese ions, cobalt ions and nickel ions, and the anion is selected from one or more of nitrate ions, chloride ions, sulfate ions and acetate ions; mixing the mixed solution and a support evenly, stirring under heating conditions until a gel is obtained; calcining the gel to obtain an iron oxide-based ortho-para hydrogen conversion catalyst. The present invention uses an iron source to synthesize iron oxide as the catalyst active component, and uses a specific type of high magnetic moment metal ion as a dopant. These metal ions have more unpaired electrons outside the nucleus. After doping into the crystal lattice of iron oxide, they can interact with the unpaired electrons outside the nucleus of Fe 3+ in iron oxide to generate a stronger local magnetic field, providing a greater conversion force for ortho-para hydrogen conversion. Therefore, it has higher activity than ordinary iron oxide catalysts. The experimental results show that: the particle strength of the catalyst prepared by the method provided by the present invention reaches 0.5 GPa; the ortho-para hydrogen conversion catalytic efficiency is as high as 88.5% within 480 h of reaction at a space velocity of 30000 h -1 ;
[0085] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.
Claims
1. A preparation method of an iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, comprising the following steps: Mix an iron source, a high magnetic moment metal ion source and a solvent to obtain a mixed solution; the cation in the high magnetic moment metal ion source is selected from one or more of manganese ions, cobalt ions and nickel ions, and the anion is selected from one or more of nitrate ions, chloride ions, sulfate ions and acetate ions; Mix the mixed solution and a support evenly, and stir under heating conditions until a gel is obtained; Calcine the gel to obtain an iron oxide-based ortho-para hydrogen conversion catalyst.
2. The preparation method according to claim 1, characterized in that, The support is selected from one or more of alumina, molecular sieve, silica gel and activated carbon.
3. The preparation method according to claim 1, characterized in that, The solvent is selected from one or more of ethylene glycol, propylene glycol and butanediol.
4. The preparation method according to claim 1, characterized in that, The molar ratio of iron ions in the iron source to the cations in the high magnetic moment metal ion source is (1-10):
1.
5. The preparation method according to claim 1, characterized in that, The mass ratio of the support to the iron element in the iron source is 1-20:
1.
6. The preparation method according to claim 1, characterized in that, The heating temperature is 100-200 °C.
7. The preparation method according to claim 1, characterized in that The calcination temperature is 200-400 °C, and the calcination time is 1-5 h.
8. The preparation method according to claim 1, characterized in that, After calcination, it further includes: Crush and screen the obtained massive material after calcination to obtain an iron oxide-based ortho-para hydrogen conversion catalyst with a particle size of 40-50 mesh.
9. An iron oxide-based ortho-para hydrogen conversion catalyst with high activity and high durability, prepared by the preparation method according to any one of claims 1-8; The specific surface area of the highly active and durable iron oxide-based ortho-para hydrogen conversion catalyst is 40-110 m 2 / g.
10. Application of an iron oxide-based ortho-para hydrogen conversion catalyst prepared by the preparation method according to any one of claims 1-8 in an ortho-para hydrogen conversion catalytic reaction.