A copper-modified NaX molecular sieve adsorbent, a preparation method and application thereof
By constructing copper active sites on the surface of the NaX molecular sieve framework and pores, the problem of the lack of selective adsorption of boron and phosphorus impurities in the purification of high-purity electronic chemicals by NaX molecular sieve was solved, achieving efficient and stable deep purification effect and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUHAN XINGUI TECH QIANJIANG CO LTD
- Filing Date
- 2026-04-16
- Publication Date
- 2026-06-09
AI Technical Summary
Existing NaX molecular sieve adsorbents suffer from problems such as lack of adsorption selectivity, rapid dynamic adsorption penetration, poor thermal stability, and short service life in the purification of high-purity electronic chemicals, especially in the incomplete removal of boron and phosphorus impurities.
Copper-modified NaX molecular sieve adsorbents are used. Copper active sites are constructed in situ on the framework and pore surface of NaX molecular sieves, forming copper active sites for electron-rich phosphorus impurities and amino active sites for electron-deficient boron impurities. Combined with the copper-ammonia complex impregnation process, the preparation process is simplified and the pore utilization rate and active site density are improved.
It significantly improves the adsorption performance for boron and phosphorus impurities, solves the problem of penetration and desorption of trace impurities during dynamic adsorption, achieves efficient and stable deep purification effect, and reduces production costs.
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Figure CN122164365A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of adsorption and separation materials technology, specifically to a copper-modified NaX molecular sieve adsorbent, its preparation method, and its application. Background Technology
[0002] The purification technology for high-purity electronic chemicals entered a period of rapid development after 2010, with deep purification adsorption materials entering a large-scale research and development stage. Porous adsorption materials, represented by NaX molecular sieves, possess a typical octahedral zeolite topology and belong to the Fd-3m space group. For trace impurities such as B and P remaining in raw materials, as industry requirements for purity continue to increase, materials need to have even greater adsorption depths, but this also brings about a serious problem of "loss of adsorption selectivity." The extremely low concentration of impurity molecules and their diametrically opposed electronic properties not only reduce the effective adsorption capacity of the material but also hinder the steady-state residence of impurities within the pores. Therefore, while seeking high specific surface area, it is essential to construct bifunctional active sites to improve the chemoselectivity and structural stability of the adsorbent.
[0003] In recent years, traditional molecular sieve materials have revealed some defects in commercial applications, such as rapid dynamic adsorption penetration, incomplete removal of specific impurities, poor thermal stability, short service life, easy desorption, framework collapse, and difficulty in regeneration. Their failure mechanisms mainly include: (1) weak adsorption force: physical adsorption is carried out only by weak van der Waals forces, the binding energy is low, and impurity molecules are easily released under airflow disturbance or temperature fluctuation; (2) lack of specific coordination centers: the surface lacks active sites that can simultaneously cope with electron-deficient boron and electron-rich phosphorus, resulting in dual failure due to the inability to address both; (3) competitive adsorption effect: site shielding caused by the competitive adsorption of a large number of main component molecules, and the decrease in micropore utilization caused by diffusion resistance. Summary of the Invention
[0004] To address the aforementioned problems, this invention provides a copper-modified NaX molecular sieve adsorbent, its preparation method, and its application. The preparation method of this invention significantly simplifies the process flow and reduces production costs. The prepared copper-modified NaX molecular sieve adsorbent exhibits high pore utilization and a high density of active sites, thereby significantly improving the adsorption performance of NaX molecular sieves for boron and phosphorus impurities.
[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: The first objective of this invention is to provide a method for preparing a copper-modified NaX molecular sieve adsorbent, comprising the following steps: (1) Take powdered NaX molecular sieve and copper ammonia solution respectively, mix and stir to obtain a mixed suspension, filter the mixed suspension under reduced pressure to separate the solid product, and then wash and filter the solid product to obtain wet molecular sieve solid. (2) The wet molecular sieve solid is vacuum dried, and the solid is taken out and ground to obtain a powder sample of 10μm~75μm. The powder sample is calcined at a constant temperature to obtain copper-modified NaX molecular sieve adsorbent.
[0006] The beneficial effects of this invention are as follows: This invention employs a copper-ammonia complex impregnation process to construct in situ copper active sites targeting electron-rich phosphorus impurities and amino active sites targeting electron-deficient boron impurities on the framework and pore surface of NaX molecular sieves, effectively solving the problem of penetration and desorption of trace impurities during dynamic adsorption. Simultaneously, this preparation method integrates the loading of metal active components and the introduction of surface functional groups into the same process, which not only significantly simplifies the process flow and reduces production costs, but also provides an efficient, stable, and economically feasible technical solution for the industrial-scale deep purification of high-purity electronic chemicals by improving pore utilization and active site density.
[0007] Based on the above technical solution, the present invention can be further improved as follows.
[0008] Furthermore, the volume ratio of NaX molecular sieve and copper ammonia solution in step (1) is 1:5~20.
[0009] Furthermore, the concentration of the copper ammonia solution is 0.02 mol / L.
[0010] Furthermore, the mixing temperature in step (1) is room temperature, the rotation speed is 200 rpm to 500 rpm, and the time is 8 h to 18 h.
[0011] The beneficial effect of adopting the above-mentioned further scheme is that, in this process, the copper ammonia complex ions in the solution undergo sufficient ion exchange with the sodium ions on the molecular sieve framework and diffuse into the interior of the molecular sieve channels.
[0012] Furthermore, the filtrate of the wet molecular sieve solid in step (1) is neutral.
[0013] Furthermore, in step (2), the vacuum drying temperature is 50℃~80℃, the vacuum degree is -0.05MPa~-0.1MPa, and the time is 12h~36h.
[0014] Furthermore, in step (2), the constant temperature calcination temperature is 300℃~700℃, and the time is 0.5h~12h.
[0015] The beneficial effects of adopting the above-mentioned further solutions are: (1) By thoroughly washing away the free ammonia and unexchanged copper salts remaining on the surface of the molecular sieve, the crystal surface covering or pore blockage caused by excessive local salt concentration during subsequent drying and calcination is effectively prevented, ensuring the uniform distribution of active sites inside the pores and laying the structural foundation for the efficient capture of boron and phosphorus impurities.
[0016] (2) The vacuum environment lowers the boiling point of water and solvent, and removes the physically adsorbed water in the pores at a lower temperature. This effectively avoids the agglomeration of active components caused by the rapid decomposition of copper ammonia complex ions at high temperatures, and maximizes the porosity and specific surface area of the modified molecular sieve.
[0017] (3) The copper species that enter the pores undergo thermal decomposition and structural reorganization to form highly chemically active monodisperse copper species or sub-nano clusters. These active sites interact strongly with the NaX molecular sieve framework, greatly enhancing the chemical adsorption capacity for nonpolar or weakly polar impurity molecules.
[0018] The second objective of this invention is to provide a copper-modified NaX molecular sieve adsorbent.
[0019] The beneficial effects of this invention are: This invention constructs in situ copper active sites for electron-rich phosphorus impurities and amino active sites for electron-deficient boron impurities on the framework and pore surface of NaX molecular sieves, resulting in high pore utilization and high density of active sites, effectively solving the problem of penetration and desorption of trace impurities during dynamic adsorption.
[0020] A third objective of this invention is the application of a copper-modified NaX molecular sieve adsorbent, characterized in that the copper-modified NaX molecular sieve adsorbent is used for the adsorption of impurities.
[0021] Furthermore, the copper-modified NaX molecular sieve adsorbent is used for the adsorption of boron and phosphorus impurities.
[0022] The beneficial effect of adopting the above-mentioned further scheme is that the modified NaX molecular sieve significantly improves the adsorption performance of boron and phosphorus impurities. Attached Figure Description
[0023] Figure 1 This is a flowchart illustrating the preparation process of the present invention; Figure 2 This is a comparison chart of impurity content before and after adsorption in Example 1 of the present invention (mass solid-liquid ratio 1:10). Detailed Implementation
[0024] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.
[0025] Example 1: Preparation of copper-modified NaX molecular sieve adsorbent The preparation process in this embodiment is as follows: Figure 1 As shown, the details are as follows: (1) Powdered NaX molecular sieve and 0.02 mol / L copper ammonia solution were weighed at a mass ratio of 1:10 and placed in a magnetic stirrer at 250 rpm at room temperature for 12 h. After stirring, the mixed suspension was filtered under reduced pressure using a Buchner funnel and a vacuum filtration flask to separate the solid product. The solid product was then washed multiple times with deionized water until the filtrate was neutral to obtain wet molecular sieve solid. (2) The washed wet molecular sieve solid was transferred to a petri dish and placed in a vacuum drying oven. It was dried at 60°C for 24 hours to obtain a sample. After the sample was completely dried and cooled, the solid was taken out and ground to obtain a powder sample of 10μm~75μm. The powder sample was placed in a quartz crucible and placed in a muffle furnace for constant temperature calcination at 350°C for 3 hours to obtain copper-modified NaX molecular sieve adsorbent.
[0026] Example 2: Preparation of copper-modified NaX molecular sieve adsorbent (1) Powdered NaX molecular sieve and 0.05 mol / L copper ammonia solution were weighed at a mass ratio of 1:5 and placed in a magnetic stirrer at 200 rpm at room temperature for 18 h. After stirring, the mixed suspension was filtered under reduced pressure using a Buchner funnel and a vacuum filtration flask to separate the solid product. The solid product was then washed multiple times with deionized water until the filtrate was neutral to obtain wet molecular sieve solid. (2) The washed wet molecular sieve solid was transferred to a petri dish and placed in a vacuum drying oven. It was dried continuously for 36 hours at a temperature of 50°C and a vacuum of -0.05MPa to -0.1MPa to obtain a sample. After the sample was completely dried and cooled, the solid was taken out and ground to obtain a powder sample of 10μm to 75μm. The powder sample was placed in a quartz crucible and placed in a muffle furnace for constant temperature calcination at 300°C for 12 hours to obtain copper-modified NaX molecular sieve adsorbent.
[0027] Example 3: Preparation of copper-modified NaX molecular sieve adsorbent (1) Powdered NaX molecular sieve and 0.01 mol / L copper ammonia solution were measured at a mass ratio of 1:10 and placed in a magnetic stirrer at 500 rpm for 8 hours at room temperature. After stirring, the mixed suspension was filtered under reduced pressure using a Buchner funnel and a vacuum filtration flask to separate the solid product. The solid product was then washed multiple times with deionized water until the filtrate was neutral to obtain wet molecular sieve solid. (2) The washed wet molecular sieve solid was transferred to a petri dish and placed in a vacuum drying oven. It was dried at 80°C for 12 hours to obtain a sample. After the sample was completely dried and cooled, the solid was taken out and ground to obtain a powder sample of 10μm~75μm. The powder sample was placed in a quartz crucible and placed in a muffle furnace for constant temperature calcination at 700°C for 0.5 hours to obtain copper-modified NaX molecular sieve adsorbent.
[0028] Comparative Example 1: Preparation of Copper-Modified NaX Molecular Sieves Adsorbent Compared with Example 1, the only difference of Comparative Example 1 is that in step (1) of Comparative Example 1, the mass ratio of NaX molecular sieve to copper ammonia solution during mixing and stirring is adjusted from 1:10 to 1:25, while the other steps and parameters remain unchanged.
[0029] Comparative Example 2: Preparation of Copper-Modified NaX Molecular Sieve Adsorbent Compared with Example 1, Comparative Example 2 differs only in that it does not involve mixing and stirring the copper ammonia solution as described in step (1) and subsequent washing and drying processes. Instead, it directly takes powdered NaX molecular sieve raw powder, performs high-temperature activation treatment on it, and then grinds it. The remaining steps and conditions are the same as in Example 1.
[0030] Performance testing: Adsorption performance test: (1) Measure 40 mL of analytical grade dichloromethane and add appropriate amounts of boron trichloride and phosphorus trichloride solutions to it. Mix well to prepare a trace impurity test solution with a boron and phosphorus concentration of approximately 200 mg / L.
[0031] (2) Accurately weigh 2.0g of the copper-modified NaX molecular sieve adsorbent prepared in Example 1, Comparative Example 1, and Comparative Example 2, place it in a dry ground glass three-necked flask, seal it with a flap stopper and a three-way valve, evacuate the three-necked flask with a vacuum pump, and then introduce nitrogen into the three-necked flask. Repeat this operation 2-3 times to completely remove air and moisture and prevent hydrolysis of the raw material. Inject 20mL of the trace impurity test solution prepared in step (1) with a dry syringe to ensure that the copper-modified NaX molecular sieve adsorbent is completely submerged. Then let it stand at room temperature for 0.5h to allow it to fully adsorb. After the adsorption is complete, take the supernatant and add 1ml of 99.9% high-purity acetonitrile and 1ml of 1% mannitol solution. After shaking it thoroughly, place it on a heating platform at 45°C to evaporate the organic solvent and obtain the residue. Dissolve the residue with dilute nitric acid and make up the volume. Then use an inductively coupled plasma optical emission spectrometer (ICP-OES) to determine the boron and phosphorus content.
[0032] The results are as follows: (1) The experimental results of Example 1 are as follows Figure 2As shown, the boron content in the test solution decreased sharply from the initial 200.69 mg / L to 4.387 mg / L, with an adsorption removal rate as high as 97.81%. This indicates that the copper active sites formed within the pores of the modified NaX molecular sieve have a strong affinity for boron impurities, enabling near-total capture of boron and meeting the requirements for high purity. Simultaneously, the phosphorus content in the test solution decreased from the initial 194.097 mg / L to 51.883 mg / L, with a removal rate of 73.27%. Even in the complex system where boron and phosphorus coexist, this adsorbent maintains a high phosphorus adsorption capacity, demonstrating a good synergistic adsorption effect.
[0033] (2) The experimental results of Comparative Example 1 are as follows: the boron content in the test solution decreased from the initial 231.36 mg / L to 11.0764 mg / L, and the adsorption removal rate was 95.21%; the phosphorus content decreased from the initial 250.52 mg / L to 133.78 mg / L, and the adsorption removal rate was only 46.60%.
[0034] (3) The experimental results of Comparative Example 2 are as follows: the boron content in the test solution decreased from the initial 199.45 mg / L to 81.88 mg / L, and the adsorption removal rate was only 58.95%; the phosphorus content decreased from the initial 206.12 mg / L to 74.34 mg / L, and the adsorption removal rate was 63.93%.
[0035] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A method for preparing a copper-modified NaX molecular sieve adsorbent, characterized in that, Includes the following steps: (1) Take powdered NaX molecular sieve and copper ammonia solution respectively, mix and stir to obtain a mixed suspension, filter the mixed suspension under reduced pressure to separate the solid product, and then wash and filter the solid product to obtain wet molecular sieve solid. (2) The wet molecular sieve solid is vacuum dried, and the solid is taken out and ground to obtain a powder sample of 10μm~75μm. The powder sample is calcined at a constant temperature to obtain copper-modified NaX molecular sieve adsorbent.
2. The method for preparing a copper-modified NaX molecular sieve adsorbent according to claim 1, characterized in that, The mass ratio of NaX molecular sieve and copper ammonia solution in step (1) is 1:5~20.
3. The method for preparing a copper-modified NaX molecular sieve adsorbent according to claim 1, characterized in that, The concentration of the copper ammonia solution mentioned in step (1) is 0.01~0.05 mol / L.
4. The method for preparing a copper-modified NaX molecular sieve adsorbent according to claim 1, characterized in that, The mixing temperature in step (1) is room temperature, the speed is 200 rpm to 500 rpm, and the time is 8 h to 18 h.
5. The method for preparing a copper-modified NaX molecular sieve adsorbent according to claim 1, characterized in that, The filtrate of the wet molecular sieve solid in step (1) is neutral.
6. The method for preparing a copper-modified NaX molecular sieve adsorbent according to claim 1, characterized in that, In step (2), the vacuum drying temperature is 50℃~80℃, the vacuum degree is -0.05MPa~-0.1MPa, and the time is 12h~36h.
7. The method for preparing a copper-modified NaX molecular sieve adsorbent according to claim 1, characterized in that, In step (2), the constant temperature calcination temperature is 300℃~700℃ and the time is 0.5h~12h.
8. A copper-modified NaX molecular sieve adsorbent, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 7.
9. An application of a copper-modified NaX molecular sieve adsorbent, characterized in that, The copper-modified NaX molecular sieve adsorbent according to claim 8 is used for the adsorption of impurities.
10. The application of the copper-modified NaX molecular sieve adsorbent according to claim 9, characterized in that, The copper-modified NaX molecular sieve adsorbent was used for the adsorption of boron and phosphorus impurities.