Double-layer coated hydrogen-absorbing oxygen-blocking microcapsules, and preparation method and application thereof

Abstract

This invention relates to the field of hydrogen absorption technology, specifically to a double-coated hydrogen-absorbing and oxygen-barrier microcapsule, its preparation method, and its application. The hydrogen-absorbing powder is compressed into tablets and then double-coated. The coating solution used in the coating contains hydroxypropyl methylcellulose and / or polystyrene (PS). By adding PS as the coating material and selecting an appropriate coating thickness, the hydrogen-absorbing microcapsule possesses both hydrogen absorption and oxygen-barrier properties.

Description

Technical Field

[0001] This invention relates to the field of hydrogen absorption technology, specifically to a double-coated hydrogen-absorbing and oxygen-barrier microcapsule, its preparation method, and its application. Background Technology

[0002] Hydrogen has extremely strong penetrating power and can undergo hydrogenation with metallic materials, forming brittle hydrides that lead to loss of plasticity and delayed cracking. The accumulation of hydrogen in confined environments also poses a risk of combustion and explosion; therefore, effective control of the hydrogen content in the system is necessary. Effectively removing or reducing the hydrogen content in the storage environment holds promise for fundamentally solving the problem of hydrogenation corrosion.

[0003] In recent years, research has found that 1,4-bis(phenylethynyl)benzene (DEB) exhibits the best performance. Because DEB contains two triple bonds, 1 mol of DEB can react with 4 mol of hydrogen gas. The reaction rate of DEB with hydrogen increases with increasing temperature, thus DEB hydrogen absorbers have received widespread attention and application both domestically and internationally. In practical applications, DEB hydrogen absorbers are often used in combination with catalysts Pd and carbon.

[0004] In the presence of a Pd / C catalyst, oxygen can initiate a reaction between hydrogen and oxygen. Although the system can achieve irreversible hydrogen absorption, oxygen is a common atmosphere in the environment, and the water produced by the reaction of oxygen and hydrogen will also have additional negative impacts on the environment. Therefore, it is necessary to coat the hydrogen absorption material with a highly selective gas membrane that blocks oxygen, water, and hydrogen to achieve the effect of blocking oxygen and allowing hydrogen to pass through.

[0005] Currently, there are no patents or journal articles on achieving the oxygen-blocking and hydrogen-permeable effects of hydrogen-absorbing materials through coating methods. Summary of the Invention

[0006] The purpose of this invention is to provide a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, its preparation method, and its application, thereby solving the technical problem that there is currently no method in the prior art to achieve the oxygen-barrier and hydrogen-permeable effect of hydrogen-absorbing materials through coating.

[0007] This invention discloses a method for preparing double-layer coated hydrogen-absorbing and oxygen-barrier microcapsules, comprising the following steps:

[0008] The hydrogen-absorbing powder is compressed into tablets and then coated in multiple layers. The coating solution used in the coating contains hydroxypropyl methylcellulose and / or polystyrene (PS).

[0009] Furthermore, the first coating layer and the second coating layer are arranged in the direction away from the hydrogen-absorbing powder.

[0010] Furthermore, the coating solution for the first coating layer is a hydroxypropyl methylcellulose solution, a hydroxypropyl cellulose solution, or an ethylcellulose solution.

[0011] Furthermore, the solvent of the coating solution for the first coating layer is anhydrous ethanol and dichloromethane.

[0012] Furthermore, the ratio of solute to anhydrous ethanol in the coating solution of the first coating layer is 1g:(20-30)mL, and the volume ratio of dichloromethane to anhydrous ethanol is (1.2-1.5):1.

[0013] Furthermore, the coating solution for the second coating layer is a polystyrene (PS) solution.

[0014] Furthermore, the solvent for the polystyrene (PS) solution is dichloromethane.

[0015] Furthermore, the ratio of polystyrene to dichloromethane in the polystyrene (PS) solution is 1 g : (100-150) mL.

[0016] Furthermore, after the first layer of coating is completed, the next layer of coating is applied.

[0017] Furthermore, the weight ratio of the hydrogen-absorbing powder to the polystyrene in the coating solution of the second coating layer is 500g:(5-30)g.

[0018] Furthermore, the coating rotation speed is (3-10) rpm, the coating temperature is (28-32)℃, the material is dried after coating, the material temperature is controlled at (40-45)℃, and the drying time is (20-30) min.

[0019] Furthermore, the hydrogen-absorbing powder tableting step involves granulating and sizing the hydrogen-absorbing powder before tableting.

[0020] Furthermore, the granulation process involves first dissolving the hydrogen-absorbing powder in a granulation solvent, and then adding a binder to granulate the mixture to obtain a soft material.

[0021] Furthermore, the granulation involves drying and granulating the soft material, and then mixing it with magnesium stearate.

[0022] Furthermore, the hydrogen-absorbing powder is DEB-Pd / C powder, and the granulation solvent is ethanol.

[0023] Furthermore, the ratio of the hydrogen-absorbing powder to the granulation solvent is 500g:(100-150)mL.

[0024] Furthermore, the ratio of the granulation solvent to the binder is 100ml:(10-30)g.

[0025] Furthermore, the adhesive is at least one of hydroxypropyl methylcellulose, carboxymethyl cellulose, or hydroxyethyl cellulose.

[0026] Furthermore, the ratio of the hydrogen-absorbing powder to magnesium stearate is 100g:(0.3-3)g.

[0027] Furthermore, the thickness of the first coating layer is 0.5 μm to 2 μm, and the thickness of the second coating layer is 15 μm to 35 μm.

[0028] A double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule was prepared using the above method.

[0029] An application of a double-coated hydrogen-absorbing and oxygen-barrier microcapsule for hydrogen absorption in oxygen-containing spaces.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. Add PS as a coating material and select an appropriate thickness for coating so that the hydrogen-absorbing microcapsules have both hydrogen absorption and oxygen barrier properties;

[0032] 2. The hydrogen-absorbing microcapsules with double coating have higher integrity and mechanical strength, and possess hydrogen permeability and oxygen barrier properties, meaning that the coating layer can effectively prevent oxygen from entering the particles. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This invention relates to PS1 hydrogen-absorbing and oxygen-barrier microcapsules.

[0035] Figure 2 This is a surface SEM image of the PS1 hydrogen absorption and oxygen barrier microcapsules of the present invention.

[0036] Figure 3 This is a cross-sectional SEM image of the PS1 hydrogen absorption and oxygen barrier microcapsule of the present invention.

[0037] Figure 4 This is a diagram showing the state of the PS1 hydrogen absorption and oxygen barrier microcapsules after thermal environment testing.

[0038] Figure 5 This is a surface SEM image of the PS1 hydrogen absorption and oxygen barrier microcapsules of the present invention after a 28-day thermal environment test at 55°C.

[0039] Figure 6 This is a cross-sectional SEM image of the PS1 hydrogen absorption and oxygen barrier microcapsules of the present invention after a 28-day thermal environment test at 55°C.

[0040] Figure 7 This invention relates to PS2 hydrogen-absorbing and oxygen-barrier microcapsules.

[0041] Figure 8 This is a surface SEM image of the PS2 hydrogen absorption and oxygen barrier microcapsules of the present invention.

[0042] Figure 9 This is a cross-sectional SEM image of the PS2 hydrogen absorption and oxygen barrier microcapsules of the present invention.

[0043] Figure 10 This is a SEM image showing the surface SEM test results of the PS3 microcapsules of this invention.

[0044] Figure 11 This is a cross-sectional SEM image of the PS3 microcapsules of the present invention.

[0045] Figure 12 This is a cross-sectional SEM test result of the PVC particles of the present invention.

[0046] Figure 13 This is a diagram showing the SEM cross-sectional test results of the PSF particles of this invention.

[0047] Figure 14 These are the particles prepared by flat die pressing according to the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0049] Example 1

[0050] This embodiment discloses a method for preparing double-layer coated hydrogen-absorbing and oxygen-barrier microcapsules, including the following steps:

[0051] 1) Preparation of hydroxypropyl methylcellulose binder: Add 15g of cellulose to 100mL of ethanol;

[0052] 2) Granulation: First, add 500g of DEB-Pd / C powder to a wet granulator, then slowly add 100mL of the prepared hydroxypropyl methylcellulose binder for granulation. Next, dry the soft material at 60℃ for 3 hours.

[0053] 3) Granulation: Finally, granulation is carried out by adding 5g of magnesium stearate to the granulated soft material and mixing.

[0054] 4) Tableting: The granulated material is tableted using a tablet press. A 2.5mm shallow concave die tableting mold is installed, the tableting speed is 5rpm, and the tableting pressure is 6kg.

[0055] 5) Prepare the coating solution: Add 10g of hydroxypropyl methylcellulose to 200mL of anhydrous ethanol for dispersion, then add 240mL of dichloromethane and stir to dissolve to obtain the coating solution.

[0056] 6) Coating: Add the tableted material and coating solution to the coating machine, control the rotation speed at 5 rpm, the coating temperature at 30℃, and the coating time at 3 h. After coating, dry for 30 min at 40℃ to obtain HPMC1 hydrogen-absorbing particles.

[0057] 7) Preparation of the second coating solution: Add 10g of polystyrene (PS) to 1500mL of dichloromethane and stir until dissolved;

[0058] 8) Secondary Coating: HPMC1 hydrogen-absorbing particles and the prepared secondary coating solution are added to the coating machine; the coating time is 3 hours, the coating speed is 5 rpm, and the coating temperature is 30℃. No sticking or other phenomena occur during the coating process. After the secondary coating is completed, the material is dried at 40℃ for 30 minutes to obtain hydrogen-absorbing and oxygen-barrier microcapsules PS1.

[0059] like Figures 1-6 As shown, the surface and cross-section of PS1 are characterized. Due to the characteristics of PS, pores will be formed during coating molding. From the cross-section test results, it can be seen that the coating process thickness is appropriate at this time, and the pores will not be interconnected.

[0060] The hydrogen absorption performance of PS1 hydrogen-absorbing and oxygen-barrier microcapsules was tested, and its hydrogen absorption capacity reached 206 mL / g.

[0061] The PS1 hydrogen-absorbing and oxygen-barrier microcapsules were placed in a sealed environment with a hydrogen-oxygen mixture at a hydrogen concentration of 2.0% ± 1.0% and an oxygen concentration of 10%-30% for 7 days. The decrease in hydrogen and oxygen in the environment before and after the test was shown in Table 1. According to the test results, after 7 days, the oxygen concentration decreased slightly, and the hydrogen was basically absorbed, which proves the material's good oxygen-barrier and hydrogen-absorbing properties.

[0062] Table 1. Changes in hydrogen and oxygen levels after PS1 was placed in a hydrogen-oxygen mixture for 7 days.

[0063]

[0064] The PS1 hydrogen absorption and oxygen barrier microcapsules prepared by this method remained intact and unbroken after a 28-day thermal environment test at 55℃. The compressive strength before and after the test is shown in Table 2, indicating that the microcapsules have strong environmental adaptability and are suitable for various hydrogen absorption scenarios.

[0065] Table 2. Compression strength of PS1 hydrogen-absorbing and oxygen-barrier microcapsules before and after environmental testing

[0066] Environmental testing After thermal environment test 4.11 MPa 4.05 MPa (98.54%)

[0067] Example 2

[0068] This embodiment, as a preferred embodiment of the present invention, describes a method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, comprising the following steps:

[0069] 1) Preparation of hydroxypropyl methylcellulose binder: Add 15g of cellulose to 100mL of ethanol;

[0070] 2) Granulation: First, add 500g of DEB-Pd / C powder to a wet granulator, then slowly add 100mL of the prepared hydroxypropyl methylcellulose binder for granulation. Next, dry the soft material at 60℃ for 3 hours.

[0071] 3) Granulation: Finally, granulation is carried out by adding 5g of magnesium stearate to the granulated soft material and mixing.

[0072] 4) Tableting: The granulated material is tableted using a tablet press. A 2.5mm shallow concave die tableting mold is installed, the tableting speed is 5rpm, and the tableting pressure is 6kg.

[0073] 5) Prepare the coating solution: Add 10g of hydroxypropyl methylcellulose to 200mL of anhydrous ethanol for dispersion, then add 240mL of dichloromethane and stir to dissolve to obtain the coating solution.

[0074] 6) Coating: Add the tableted material and 440mL of coating solution to the coating machine, control the rotation speed at 5rpm, the coating temperature at 30℃, and the coating time at 3h. After coating, dry for 30min at 40℃.

[0075] 7) Preparation of the second coating solution: Add 25g of polystyrene (PS) to 1800mL of dichloromethane and stir until dissolved;

[0076] 8) Second-layer coating: Add the hydrogen-absorbing material and the prepared second-layer coating solution to the coating machine; the coating time is 4 hours, the coating speed is 4 rpm, and the coating temperature is 32℃. No sticking or other phenomena occur during the coating process. After the second-layer coating is completed, dry the material at 42℃ for 30 minutes to obtain PS2 hydrogen-absorbing and oxygen-barrier microcapsules.

[0077] like Figures 7-9 As shown, the surface and cross-section of PS2 were characterized. Due to the characteristics of PS, bubbles will form during coating molding. From the cross-section test results, compared with the test results of PS1, the coating layer is thicker and the bubbles do not penetrate each other.

[0078] The hydrogen absorption performance of PS2 hydrogen absorption and oxygen barrier microcapsules was tested. Saturation hydrogen absorption was achieved after 60 minutes, with a saturation hydrogen absorption capacity of 198.8 mL / g, indicating a relatively fast hydrogen absorption rate.

[0079] Comparative Example 1

[0080] This embodiment, as a comparative example of the present invention, discloses a method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, comprising the following steps:

[0081] 1) Preparation of hydroxypropyl methylcellulose binder: Add 15g of cellulose to 100mL of ethanol, and then slowly add 0.5g of sodium chloride to dissolve it by magnetic stirring;

[0082] 2) Granulation: First, add 500g of DEB-Pd / C powder to a wet granulator, then slowly add 100mL of the prepared hydroxypropyl methylcellulose binder for granulation. Next, dry the soft material at 60℃ for 3 hours.

[0083] 3) Granulation: Finally, granulation is carried out by adding 5g of magnesium stearate to the granulated soft material and mixing.

[0084] 4) Tableting: The granulated material is tableted using a tablet press. A 2.5mm shallow concave die tableting mold is installed, the tableting speed is 5rpm, and the tableting pressure is 6kg.

[0085] 5) Prepare the coating solution: Add 10g of hydroxypropyl methylcellulose to 200mL of anhydrous ethanol for dispersion, then add 240mL of dichloromethane and stir to dissolve to obtain the coating solution.

[0086] 6) Coating: Add the tableted material and 440mL of coating solution to the coating machine, control the rotation speed at 5rpm, the coating temperature at 30℃, and the coating time at 3h. After coating, dry for 30min at 40℃.

[0087] 7) Preparation of the second coating solution: Add 3g of polystyrene (PS) to 360mL of dichloromethane and stir until dissolved;

[0088] 8) Second-layer coating: Add the hydrogen-absorbing material and the prepared second-layer coating solution to the coating machine; the coating time is 1 hour, the coating speed is 4 rpm, and the coating temperature is 28℃. No sticking or other phenomena occur during the coating process. After the second-layer coating is completed, dry the material at 40℃ for 30 minutes to obtain PS3 microcapsules.

[0089] like Figures 10-11 As shown, according to the cross-sectional SEM test results, the coating layer of the microcapsule is relatively thin at this time. The air bubbles formed during the coating process of the PS coating layer will penetrate the coating layer, resulting in low integrity of the coating layer.

[0090] Comparative Example 2

[0091] This embodiment, as a comparative example of the present invention, discloses a method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, comprising the following steps:

[0092] 1) Preparation of hydroxypropyl methylcellulose binder: Add 3g of cellulose to 100mL of ethanol;

[0093] 2) Granulation: First, add 100g of DEB-Pd / C powder to a wet granulator, then slowly add 20mL of the prepared hydroxypropyl methylcellulose binder for granulation. Next, dry the soft material at 60℃ for 3 hours.

[0094] 3) Granulation: Granulate the material by adding 1g of magnesium stearate to the granulated soft material and mixing.

[0095] 4) Tableting: The granulated material is tableted using a tablet press. A 2.5mm shallow concave die tableting mold is installed, the tableting speed is 5rpm, and the tableting pressure is 6kg.

[0096] 5) Prepare the coating solution: Add 2g of hydroxypropyl methylcellulose to 40mL of anhydrous ethanol for dispersion, then add 48mL of dichloromethane and stir to dissolve to obtain the coating solution.

[0097] 6) Coating: Add the tableted material and coating solution to the coating machine, control the rotation speed to 5 rpm, the coating temperature to 30℃, and the coating time to 3 hours. After coating, dry for 30 minutes at 40℃.

[0098] 7) Preparation of the second coating solution: Add 2g of polyvinyl chloride (PVC) to 300mL of dichloromethane and stir until dissolved;

[0099] 8) Second-layer coating: Add the hydrogen-absorbing material and the prepared second-layer coating solution to the coating machine; the coating time is 3 hours, the coating speed is 5 rpm, and the coating temperature is 30℃. No sticking or other phenomena occur during the coating process. After the second-layer coating is completed, dry the material at 40℃ for 30 minutes to obtain granular PVC.

[0100] The microstructure of PVC particles shows that using PVC as a secondary coating material can form a complete coating layer on hydrogen-absorbing materials, such as... Figure 12 As shown.

[0101] Hydrogen absorption tests were conducted on the PVC particles. After 120 minutes, the hydrogen absorption capacity remained low, at only about 10 mL / g, indicating that the hydrogen absorption performance of the PVC particles prepared by this coating method was too low.

[0102] Comparative Example 3

[0103] This embodiment, as a comparative example of the present invention, discloses a method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, comprising the following steps:

[0104] 1) Preparation of hydroxypropyl methylcellulose binder: Add 3g of cellulose to 100mL of ethanol;

[0105] 2) Granulation: First, add 100g of DEB-Pd / C powder to a wet granulator, then slowly add 20mL of the prepared hydroxypropyl methylcellulose binder for granulation. Next, dry the soft material at 60℃ for 3 hours.

[0106] 3) Granulation: Granulate the material by adding 1g of magnesium stearate to the granulated soft material and mixing.

[0107] 4) Tableting: The granulated material is tableted using a tablet press. A 2.5mm shallow concave die tableting mold is installed, the tableting speed is 5rpm, and the tableting pressure is 6kg.

[0108] 5) Prepare the coating solution: Add 2g of hydroxypropyl methylcellulose to 40mL of anhydrous ethanol for dispersion, then add 48mL of dichloromethane and stir to dissolve to obtain the coating solution.

[0109] 6) Coating: Add the tableted material and coating solution to the coating machine, control the rotation speed to 5 rpm, the coating temperature to 30℃, and the coating time to 3 hours. After coating, dry for 30 minutes at 40℃.

[0110] 7) Preparation of the second coating solution: Add 2g of polysulfone (PSF) to 300mL of N,N-dimethylformamide (DMF) and stir until dissolved;

[0111] 8) Secondary Coating: Add the hydrogen-absorbing material and the prepared secondary coating solution to the coating machine; the coating time is 3 hours, the coating speed is 5 rpm, and the coating temperature is 30℃. No sticking or other phenomena occur during the coating process. After the secondary coating is completed, dry the material at 40℃ for 30 minutes to obtain granular PSF.

[0112] The obtained PSF particle morphology is as follows Figure 13 As shown, the particles were successfully coated with a material. Their hydrogen absorption performance was measured, revealing a slow hydrogen absorption rate and low absorption capacity. After approximately 20 hours, the particles reached near-saturation, with a hydrogen absorption capacity of only 170 mL / g.

[0113] Comparative Example 4

[0114] In this embodiment, as a comparative example of the present invention, a method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule is disclosed. The only change is the preparation of the secondary coating solution in step 7, which is a ratio of polystyrene to dichloromethane of 25g:2500mL. Due to the excessively high concentration of PS in the coating solvent, the coating process causes the particles to stick together, making it impossible to prepare uniform particles.

[0115] Comparative Example 5

[0116] This embodiment, as a comparative example of the present invention, discloses a method for preparing double-layer coated hydrogen-absorbing and oxygen-barrier microcapsules. The method differs from Example 1 only in that the shallow concave die in step 4 is replaced with a flat die, resulting in particles as shown in the image. Figure 14 As shown, the granules obtained by pressing with a flat die have sharper edges, and the edges cannot be well coated, resulting in incomplete coating.

[0117] test

[0118] 1. Mechanical strength

[0119] Table 3 shows the comparison of the compressive strength of different samples. Uncoated tablets have a certain compressive strength, but the compressive strength is low. After coating with HPMC, the compressive strength of the tablets is significantly improved.

[0120] Table 3. Comparison of compressive strength of different samples

[0121] Sample Name Compressive strength (MPa) Uncoated tablets 1.89 HPMC1 4.09 PS1 4.11

[0122] 2. Integrity of coating / water-blocking properties

[0123] During the granulation process of the hydrogen-absorbing material, NaCl was added to the hydroxypropyl methylcellulose binder solution at a weight ratio of 1g:30g, and the mixture was thoroughly mixed. Five hydrogen-absorbing particles were placed in deionized water, and the Na+ content in the water was tested by ICP-OES after 24h and 48h, respectively, to evaluate the coating integrity and water-blocking properties.

[0124] NaCl was mixed in during the processing of hydrogen-absorbing materials. The hydrogen-absorbing particles were then soaked in water, and the solubility of Na+ in the water was tested. According to the test results, only the HPMC-coated hydrogen-absorbing particles had a thinner coating layer. During soaking, water gradually entered the interior of the hydrogen-absorbing particles, causing Na+ to dissolve in the water. PS3, due to its thin and uneven coating layer, showed higher Na+ solubility. + The content is low, and the water-blocking ability of the particles is poor; the coating layer of PS1 particles has an appropriate thickness and complete coating, and has a certain water-blocking effect, as shown in Table 4.

[0125] Table 4. Water-blocking properties of particles

[0126] sample <![CDATA[Na + 24-hour content (mg / L) <![CDATA[Na + 48h content (mg / L) HPMC1 24.11 27.49 PS3 14.15 23.66 PS1 7.30 7.34

[0127] 3. Hydrogen absorption performance

[0128] Table 5. Comparison of Saturated Hydrogen Absorption Capacity

[0129] Sample Name Saturated hydrogen absorption capacity (mL / g) HPMC1 210 PS1 206

[0130] As shown in Table 5, since HPC and PS coating materials themselves do not have hydrogen absorption properties, HPMC1 has the highest hydrogen absorption capacity with only one layer of coating. After coating with PS1, its hydrogen absorption capacity decreases slightly, but the decrease is small, and the saturated hydrogen absorption capacity can still reach 206 mL / g.

[0131] 4. Hydrogen permeability and oxygen barrier properties

[0132] As shown in Table 6, compared with HPMC1, the H2 / O2 consumption ratio of the hydrogen-absorbing microcapsules was significantly increased after further coating treatment, indicating that the particles have oxygen barrier properties and can effectively reduce the proportion of oxygen entering the hydrogen-absorbing microcapsules and reacting with H2.

[0133] Table 6. Comparison of hydrogen permeability and oxygen barrier properties of different samples

[0134]

[0135]

[0136] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments based on the inspiration of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, characterized in that: The hydrogen-absorbing powder is compressed into tablets and then double-coated. The coating solution used in the coating contains hydroxypropyl methylcellulose and / or polystyrene.

2. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 1, characterized in that: The first coating layer and the second coating layer are arranged in the direction away from the hydrogen-absorbing powder.

3. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 2, characterized in that: The coating solution for the first coating layer is a hydroxypropyl methylcellulose solution, a hydroxypropyl cellulose solution, or an ethylcellulose solution.

4. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 3, characterized in that: The solvent for the coating solution of the first coating layer is anhydrous ethanol and dichloromethane.

5. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 2, characterized in that: The coating solution for the second coating layer is a polystyrene solution.

6. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 5, characterized in that: The solvent for the polystyrene solution is dichloromethane.

7. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 6, characterized in that: The ratio of polystyrene to dichloromethane in the polystyrene solution is 1g: 100-150mL.

8. The method for preparing a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule according to claim 1, characterized in that: The weight ratio of the hydrogen-absorbing powder to the polystyrene in the second coating solution is 500g: 5-30g. The coating speed is 3-10 rpm, the coating temperature is 28-32℃, and the material is dried after coating, with the material temperature controlled at 40-45℃ and the drying time being 20-30 minutes.

9. A double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule, characterized in that: The microcapsules were prepared using the method described in any one of claims 1-8 for the preparation of a double-layer coated hydrogen-absorbing and oxygen-barrier microcapsule.

10. The hydrogen-absorbing and oxygen-barrier microcapsules prepared by the method for preparing double-layer coated hydrogen-absorbing and oxygen-barrier microcapsules according to claims 1-8, or the application of the double-layer coated hydrogen-absorbing and oxygen-barrier microcapsules according to claim 9, characterized in that: Used for hydrogen absorption in oxygen-containing spaces.

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