A xenon purification material and its preparation method

Abstract

The present invention discloses a xenon purification material and a preparation method thereof, comprising modified graphene loaded with zirconium, vanadium, iron, aluminum and titanium. The modified graphene loaded with zirconium is prepared by a hydrothermal reaction of a modified graphene dispersion liquid and zirconium oxychloride; the modified graphene is prepared by grafting after chlorinating graphene oxide and reacting with aminophthalamine. The modified graphene has strong selectivity for impurity gases such as CO, CO2 and methane, and the modified graphene loaded with zirconium has excellent catalytic and adsorption capabilities, and has a long service life and adsorption capacity. The xenon purification material provided by the present invention has strong absorption capacity, strong pertinence to impurity gases such as CO, CO2 and methane, large adsorption capacity and long service life.

Description

Technical Field

[0001] The present invention relates to the field of gas purification, and particularly relates to a xenon purification material and a preparation method thereof. Background Art

[0002] Since the discovery of noble gases, they have been widely used in fields such as optics, metallurgy, and medicine. However, due to the relatively low content of noble gases on the earth, which are rare resources, they need to be purified and separated for recycling. "Krypton" (GB / T5829-2006) and "Xenon" (GB / T5828-2006) have strict requirements for the content of individual impurities in krypton and xenon products. With the increase in the purity standard of xenon, the requirements for the purification work of xenon have also been further increased.

[0003] The purification work of noble gases generally involves the adsorption and catalysis of getter materials to remove impurity gases. A getter is a general term for a preparation or device that can effectively adsorb certain gas molecules, and can be used to obtain or maintain a vacuum and purify gases, etc. It is widely used in fields such as atomic physics, surface science, material preparation, and semiconductor industry, and has become the main solution to problems such as the acquisition and maintenance of ultra-high vacuum and extremely high vacuum, and the purification and purity maintenance of gas-containing impurities.

[0004] In practical engineering applications, since the getter material needs to be activated to obtain an active surface, according to the way of obtaining the active surface of the getter, it is divided into evaporable type and non-evaporable type. The non-evaporable type getter is a getter that can directly absorb gas after activation. Zirconium-based alloy materials are the most widely used non-evaporable type getters at present. They have a large gas absorption capacity, a long maintenance time, and the devices they are applied to can be repaired. Therefore, they can be widely used in the preparation of vacuum tubes, vacuum thermos cups, and the purification work of noble gases.

[0005] By using zirconium-based alloy materials to purify noble gases, most of the impurity gases such as oxygen, nitrogen, hydrogen, CO, CO2, and methane can be removed. However, with the emergence of the greenhouse effect and the aggravation of air pollution, the air quality of the raw materials of the air separation system has also declined, and the contents of carbon oxides and methane in the air have gradually increased, resulting in an increase in the content of impurity gases in the noble gas raw materials. At present, the absorption capacity of the zirconium-based alloy material getter is insufficient and its targeting for CO, CO2, and methane impurity gases is poor, and it can no longer meet the requirements of the latest national standard for the purification work of noble gases.

[0006] Therefore, there is an urgent need for a purification material with strong absorption capacity, strong targeting for CO, CO2, and methane impurity gases, large adsorption capacity, and long service life. Summary of the Invention

[0007] Object of the Invention: Aiming at the defects of the prior art, the object of the present invention is to provide a xenon purification material with strong absorption capacity, strong pertinence to CO, CO2 and methane impurity gases, large adsorption capacity and long service life, and a preparation method thereof.

[0008] Technical Solution:

[0009] A xenon purification material, comprising modified graphene loaded with zirconium, vanadium, iron, aluminum and titanium;

[0010] Based on the total mass fraction of 100%, the mass percentage content of each component is:

[0011]

[0012] Further, the modified graphene loaded with zirconium is prepared by the following steps:

[0013] (1) Ultrasonically disperse the modified graphene in deionized water to obtain a modified graphene dispersion;

[0014] (2) Add zirconyl chloride to the modified graphene dispersion, ultrasonically disperse for 5 - 10 minutes and then stir for 3 - 4 hours;

[0015] (3) Add the product of step (2) into a reactor, heat to 200 - 220 °C for hydrothermal reaction for 3 - 4 hours, then naturally cool to room temperature, wash and dry to obtain the modified graphene loaded with zirconium.

[0016] Through the hydrothermal reaction of the modified graphene dispersion and zirconyl chloride, zirconium particles are deposited on the surface of the modified graphene. On the one hand, graphene serves as a carrier for zirconium particles, enabling the zirconium particles to be evenly dispersed on its surface, stabilizing the progress of the chemical reaction, preventing the agglomeration of zirconium particles and reaction products, and accelerating the reaction; on the other hand, the zirconium particles can promote the separation and reduction of the modified graphene and prevent agglomeration. Through the mutual influence of the two, the modified graphene loaded with zirconium has excellent catalytic and adsorption capabilities, extends the service life of the purification material, and based on the single-layer structure of graphene, greatly improves the adsorption capacity of the purification material.

[0017] Further, the concentration of the modified graphene dispersion in step (1) is 3 - 5 mg / mL.

[0018] Further, 3 - 4 g of zirconyl chloride is added to every 100 ml of the modified graphene dispersion in step (2).

[0019] Further, the modified graphene is prepared by the following steps:

[0020] (1) Thionyl chloride is added to a reactor, and then graphene oxide is dispersed in thionyl chloride. After heating to 70 - 80 °C, N,N - dimethylformamide is added. After reacting for 18 - 24 hours, the excess thionyl chloride and N,N - dimethylformamide are removed by distillation to obtain chlorinated graphene oxide;

[0021] (2) N,N - dimethylformamide is added to a reactor, and chlorinated graphene oxide, triethylamine, and aminophthalic diamine are added. Under the protection of an inert gas, it is heated to 135 - 145 °C. After reacting for 60 - 72 hours, it is washed and dried to obtain the modified graphene.

[0022] In step (1), the carboxyl groups in graphene oxide are activated by thionyl chloride to produce -COCl groups, generating chlorinated graphene oxide. Then, in step (2), it reacts with aminophthalic diamine to form modified graphene. The modified graphene is grafted by reacting with aminophthalic diamine after chlorinating graphene oxide, so that aminophthalic diamine is widely distributed on the surface of graphene oxide. Free radicals are generated by aminophthalic diamine with easy homolysis and react with carbon - oxygen and carbon - hydrogen compounds, thereby improving the selectivity for impurity gases such as CO, CO2, and methane. And due to its large steric hindrance, the dispersion of graphene can be improved, making it not easy to agglomerate.

[0023] Furthermore, in step (1), the mass ratio of thionyl chloride to graphene oxide is 150 - 200:1.

[0024] Furthermore, in step (2), the mass ratio of chlorinated graphene oxide to aminophthalic diamine is 1:1.5 - 2.

[0025] Furthermore, the particle size of the xenon purification material is 400 - 600 μm.

[0026] The preparation method of the xenon purification material according to any one of the above, includes the following steps:

[0027] (1) Weigh the modified graphene supported with zirconium, vanadium, iron, aluminum, and titanium in proportion, ball - mill them, and then mechanically mix them and put them into a melting crucible for standby;

[0028] (2) Put the melting crucible in step (1) into an arc melting furnace, slowly heat it to 450 - 500 °C under the protection of argon, discharge and heat - stir for 8 - 12 hours, and then cool to form an alloy;

[0029] (3) Crush the alloy, sieve it, select the powder with a particle size of 400 - 600 μm, and then vacuum - seal the tube to obtain the xenon purification material.

[0030] Furthermore, in step (1), the alloy is ball - milled to a particle size of 400 - 600 μm and then mechanically mixed.

[0031] Beneficial effects:

[0032] (1) In the xenon purification material provided by the present invention, modified graphene loaded with zirconium is added. Through the hydrothermal reaction of the modified graphene dispersion liquid with zirconium oxychloride, zirconium particles are deposited on the surface of the modified graphene. On the one hand, graphene serves as the carrier of zirconium particles, enabling the zirconium particles to be evenly dispersed on its surface, stabilizing the progress of the chemical reaction, preventing the agglomeration of zirconium particles and reaction products, and accelerating the reaction; on the other hand, the zirconium particles can promote the separation and reduction of the modified graphene and prevent agglomeration. Through the mutual influence of the two, the modified graphene loaded with zirconium has excellent catalytic and adsorption capacities, prolongs the service life of the purification material, and based on the single-layer structure of graphene, greatly improves the adsorption capacity of the getter.

[0033] (2) The modified graphene in the xenon purification material provided by the present invention is grafted by reacting oxidized graphene with amino phthalylamine after chlorination, enabling amino phthalylamine to be widely distributed on the surface of oxidized graphene. Free radicals generated by the easily homolytic amino phthalylamine react with carbon-oxygen and carbon-hydrogen compounds, thereby improving the selectivity for impurity gases such as CO, CO2, and methane, and improving the dispersibility of graphene through its large steric hindrance, making it not easily agglomerate. Specific embodiments

[0034] The present invention will be described below in conjunction with specific implementation examples. It should be noted that the following examples are examples of the present invention, only used to illustrate the present invention, and not used to limit the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the main idea or scope of the present invention.

[0035] The commercially available getter was the DF25 zirconium-aluminum getter purchased from Nanjing Yidonghui Technology Co., Ltd.; the crude xenon product with a purity of 99% was purchased from Henan Tianfu Chemical Co., Ltd.; the oxidized graphene was 796034 purchased from Merck; the rest of the reagents and equipment were conventional reagents and equipment in the technical field.

[0036] Preparation of modified graphene-1

[0037] Modified graphene-1 was prepared through the following steps:

[0038] (1) Add 100 ml of thionyl chloride to the reactor, then disperse 1 g of oxidized graphene in thionyl chloride, heat to 80 °C, add 3 ml of N,N-dimethylformamide, and after reacting for 24 hours, distill off the excess thionyl chloride and N,N-dimethylformamide to obtain chlorinated oxidized graphene;

[0039] (2) Add 100 ml of N,N-dimethylformamide to the reactor, add 1 g of graphene oxide chloride, 3 ml of triethylamine and 2 g of aminophthalenediamine, heat to 140 °C under nitrogen protection, wash and dry after reacting for 72 hours to obtain the modified graphene-1.

[0040] Preparation of modified graphene-2

[0041] It is basically the same as the preparation of modified graphene-1, except that in step (2), aminophthalenediamine is replaced with an equal amount of aniline.

[0042] Preparation of modified graphene-3

[0043] It is basically the same as the preparation of modified graphene-1, except that in step (2), aminophthalenediamine is replaced with an equal amount of maleimide.

[0044] Preparation of zirconium-loaded modified graphene-1

[0045] The zirconium-loaded modified graphene-1 is prepared through the following steps:

[0046] (1) Ultrasonically disperse 600 mg of modified graphene in 200 ml of deionized water to obtain a modified graphene dispersion;

[0047] (2) Add 3 g of zirconium oxychloride to 100 ml of the modified graphene dispersion, ultrasonically disperse for 5 minutes and then stir for 3 hours;

[0048] (3) Add the product of step (2) to the reactor, heat to 210 °C for hydrothermal reaction for 4 hours, naturally cool to room temperature, then wash and dry to obtain the zirconium-loaded modified graphene-1.

[0049] Preparation of zirconium-loaded modified graphene-2

[0050] It is basically the same as the preparation of zirconium-loaded modified graphene-1, except that modified graphene-1 is replaced with an equal amount of graphene oxide.

[0051] Preparation of zirconium-loaded modified graphene-3

[0052] It is basically the same as the preparation of zirconium-loaded modified graphene-1, except that modified graphene-1 is replaced with an equal amount of modified graphene-2.

[0053] Preparation of zirconium-loaded modified graphene-4

[0054] It is basically the same as the preparation of zirconium-loaded modified graphene-1, except that modified graphene-1 is replaced with an equal amount of modified graphene-3.

[0055] Example 1

[0056] The xenon purification material is prepared through the following steps:

[0057] (1) Weigh zirconium-loaded modified graphene-1, vanadium, iron, aluminum, and titanium proportionally, ball mill them to 400 - 600 μm, then mechanically mix them and put them into a melting crucible for standby;

[0058] (2) Put the melting crucible in step (1) into an arc melting furnace, slowly heat it to 500 °C under argon protection, discharge and heat with stirring for 12 hours, and then cool to form an alloy;

[0059] (3) Crush the alloy, sieve it, select the powder of 400 - 600 μm, and then vacuum seal it to obtain the xenon purification material.

[0060] Calculated by the total mass fraction of 100%, the mass percentage content of each component is as follows:

[0061]

[0062] Example 2

[0063] Basically the same as Example 1, the difference is that calculated by the total mass fraction of 100%, the components and their mass percentage contents are as follows:

[0064]

[0065]

[0066] Example 3

[0067] Basically the same as Example 1, the difference is that calculated by the total mass fraction of 100%, the components and their mass percentage contents are as follows:

[0068]

[0069] Comparative Example 1

[0070] Commercially available getter.

[0071] Comparative Example 2

[0072] Basically the same as Example 1, the difference is that zirconium-loaded modified graphene-1 is replaced with an equal amount of zirconium.

[0073] Comparative Example 3

[0074] Basically the same as Example 1, the difference is that zirconium-loaded modified graphene-1 is replaced with an equal amount of zirconium-loaded modified graphene-2.

[0075] Comparative Example 4

[0076] Basically the same as Example 1, the difference is that zirconium-loaded modified graphene-1 is replaced with an equal amount of zirconium-loaded modified graphene-3.

[0077] Comparative Example 5

[0078] Basically the same as Example 1, except that the modified graphene-1 loaded with zirconium was changed to the modified graphene-4 loaded with the same amount of zirconium.

[0079] Performance Test

[0080] The products of Examples 1-3 and Comparative Examples 1-5 were filled in a reaction tube with an inner diameter of Φ25 and equipped with a heater, and the filling thickness was 61 mm. After being heated to 900 °C by the heater and maintained for 8 hours for activation, the crude xenon gas with a purity of 99% was introduced, and the intake air volume was 500 ml / minute. The purified xenon gas was detected according to GB / T5828-2006, and the volume fractions of CO, CO2, CH4 and xenon were detected.

[0081] The test results are as follows:

[0082]

[0083] According to the comparison of the test results of Examples 1-3 and Comparative Examples 1 and 2, it can be seen that in the xenon purification material provided by the present invention, by adding the modified graphene loaded with zirconium, it has strong pertinence to CO, CO2, and CH4, can effectively absorb impurities in xenon gas, and has strong adsorption capacity. The purity of xenon and the impurity content in the crude xenon gas after purification reach the standard of first-class high-purity oxygen in GB / T5828-2006.

[0084] According to the comparison of the test results of Examples 1-3 and Comparative Examples 3-5, it can be seen that in the xenon purification material provided by the present invention, the modified graphene loaded with zirconium added is modified with amino phthalylamine to make the purification material selective to CO, CO2, and CH4, thereby enhancing the adsorption capacity for impurity gases.

[0085] The products of Examples 1-3 and Comparative Examples 1-5 were used to purify 500 m of crude xenon gas 3 After that, again through the above detection method, the volume fractions of CO, CO2, CH4 and xenon in the purified xenon gas were detected.

[0086] The test results are as follows:

[0087]

[0088]

[0089] According to the comparison of the test results of Examples 1-3 and Comparative Examples 1 and 2, it can be seen that the xenon purification material provided by the present invention has a longer service life and adsorption capacity.

[0090] According to the comparison of the detection results of Examples 1-3 and Comparative Examples 3-5, it can be seen that in the xenon purification material provided by the present invention, the graphene oxide is modified by amino phthalyl diamine, which enhances the dispersibility of graphene, and has stronger dispersibility after loading zirconium particles, thereby extending the service life of the purification material.

[0091] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it. It cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A xenon purification material, characterized in that, Containing modified graphene loaded with zirconium, vanadium, iron, aluminum, and titanium; Based on a total mass fraction of 100%, the mass percentage content of each component is as follows: Modified graphene loaded with zirconium: 45 - 50% Vanadium: 10 - 15% Iron: 7 - 12% Aluminum: 25 - 30% Titanium: 3 - 5%; The modified graphene is prepared through the following steps: (1) Add thionyl chloride to a reactor, then disperse graphene oxide in thionyl chloride, heat to 70 - 80 °C, add N,N - dimethylformamide, and after reacting for 18 - 24 hours, distill off the excess thionyl chloride and N,N - dimethylformamide to obtain chlorinated graphene oxide; (2) Add N,N - dimethylformamide to a reactor, add chlorinated graphene oxide, triethylamine, and aminophthalic diamine, heat to 135 - 145 °C under the protection of an inert gas, and after reacting for 60 - 72 hours, wash and dry to obtain the modified graphene.

2. The xenon purification material according to claim 1, characterized in that, The modified graphene loaded with zirconium is prepared through the following steps: (1) Ultrasonically disperse the modified graphene in deionized water to obtain a modified graphene dispersion; (2) Add zirconyl chloride to the modified graphene dispersion, ultrasonically disperse for 5 - 10 minutes, and then stir for 3 - 4 hours; (3) Add the product of step (2) to a reactor, heat to 200 - 220 °C for hydrothermal reaction for 3 - 4 hours, naturally cool to room temperature, wash and dry to obtain the modified graphene loaded with zirconium.

3. The xenon purification material according to claim 2, characterized in that, In step (1), the concentration of the modified graphene dispersion is 3 - 5 mg / mL.

4. The xenon purification material according to claim 2, wherein In step (2), 3 - 4 g of zirconyl chloride is added to every 100 mL of the modified graphene dispersion.

5. The xenon purification material according to claim 1, wherein In step (1), the mass ratio of thionyl chloride to graphene oxide is 150 - 200:

1.

6. The xenon purification material according to claim 1, characterized in that, In step (2), the mass ratio of chlorinated graphene oxide to aminophthalic diamine is 1:1.5 - 2.

7. The xenon purification material according to claim 1, characterized in that, The particle size of the xenon purification material is 400 - 600 μm.

8. The preparation method of the xenon purification material according to any one of claims 1-7, characterized in that, Including the following steps: (1) Weigh the modified graphene loaded with zirconium, vanadium, iron, aluminum, and titanium in proportion, perform ball milling, then mechanically mix and put them into a melting crucible for standby; (2) Put the melting crucible of step (1) into an arc melting furnace, slowly heat to 450 - 500 °C under the protection of argon, discharge and heat with stirring for 8 - 12 hours, and then cool to form an alloy; (3) Crush the alloy, sieve it, select the powder with a particle size of 400 - 600 μm, and then perform vacuum sealing in a tube to obtain the xenon purification material.

9. The preparation method of the xenon purification material according to claim 8, wherein, In step (1), the alloy is ball - milled to a particle size of 400 - 600 μm and then mechanically mixed.

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