ZIFs material for long-acting capture of CO2, preparation method and application of ZIFs material in carbon neutralization

Abstract

The invention relates to the technical field of inorganic material preparation, in particular to a ZIFs material for long-acting capture of CO2, a preparation method and application of the ZIFs material in carbon neutralization. The ZIFs material is obtained by carrying out surface coating on ZIFs-8 particles, the ZIFs material contains an Si element; the D90 particle size value is selected from 350-800nm, and the specific surface area is selected from 300-600m < 2 > / g. According to the invention, self-assembly coating is carried out on the surface of the ZIF-8 material, so that the ZIFs-based material which has good adsorption performance on CO2 and has good hydrophobicity and weather resistance is prepared.

Description

Technical Field

[0001] This disclosure relates to the field of inorganic material preparation technology, and in particular to a ZIFs material for long-term CO2 capture, its preparation method, and its application in carbon neutralization. Background Technology

[0002] Although new energy sources are gradually being developed and utilized, the use of fossil fuels still accounts for a large proportion of emissions, exacerbating the greenhouse effect. Therefore, reducing CO2 emissions into the atmosphere is urgent. Designing an adsorbent capable of adsorbing CO2 at normal temperature and pressure can effectively reduce atmospheric CO2 emissions and has significant application value for environmental protection. Existing CO2 air capture adsorbents mainly include: organic amines, hydroxides, alkaline salts, activated carbon, zeolites, and metal-organic frameworks (MOFs).

[0003] ZIFs are a type of MOF (Metal-Organic Facility), a crystal structure formed by the self-assembly of metal ions (zinc or cobalt) and imidazolate. The chemical formula of the former can be represented as Zn(MIm)₂, and it is also named ZIF-8. ZIF-8 belongs to the SOD series of ZIFs, with a metal ion density of 2.45 (T / nm). 3 With a pore size of 3.4 Å and a cage diameter of 11.6 Å, it belongs to the category of materials with small pore size and large cage diameter, and combines the characteristics of zeolites and MOFs. Among many ZIFs, ZIF-8 has a simple structure, good stability and pore capacity, and its raw materials are readily available and its synthesis method is simple. It is one of the most widely used ZIF materials in current research.

[0004] ZIF-8 is an excellent solid adsorbent due to its small pore size and fast adsorption / desorption kinetics for CO2 adsorption. However, despite these advantages, ZIFs still have some drawbacks, including poor weather resistance and easy loss of activity during long-term use. Therefore, there is an urgent need for a method to modify or coat the surface of ZIFs materials to give them the advantage of long-term weather resistance. Summary of the Invention

[0005] This disclosure provides a ZIFs material for long-term CO2 capture, a preparation method thereof, and its application in carbon neutralization, in order to address the shortcomings of related technologies.

[0006] According to a first aspect of the present disclosure, a ZIFs material for long-term CO2 capture is provided, wherein the ZIFs material is obtained by surface coating ZIFs-8 particles; the ZIFs material contains Si; and the D90 particle size of the ZIFs material is selected from 350-800 nm, and the specific surface area of ​​the ZIFs material is selected from 300-600 m². 2 / g.

[0007] In one aspect of this disclosure, the D90 particle size of the ZIFs material is selected from 450-600 nm, and the specific surface area of ​​the ZIFs material is selected from 350-450 m². 2 / g.

[0008] In one aspect of the embodiments of this disclosure, preferably, the D90 particle size value of the ZIFs material is selected from 450-500nm, or 500-550nm, or 550-600nm, or 600-650nm, or 650-700nm, or 700-750nm or 750-800nm.

[0009] In one aspect of this disclosure, preferably, the specific surface area of ​​the ZIFs material is selected from 300-350 m². 2 / g, or 350-400m 2 / g, or 400-450m 2 / g, or 450-500m 2 / g, or 500-550m 2 / g or 550-600m 2 / g.

[0010] According to a second aspect of the present disclosure, a method for preparing the aforementioned ZIFs material for long-term CO2 capture is provided, the method comprising the following steps: Step 1: Prepare compound A; the structural formula of compound A contains at least one aryl or heteroaryl group, two carboxyl groups, and at least one silicon atom; Step 2: React compound A with thionyl chloride and hydrazine hydrate respectively to generate compound B; Step 3: Dissolve the inorganic zinc salt and 2-methylimidazole separately in methanol, then mix them and stir for 2-30 min, then react at 30℃-40℃ for 10-30 h, and then centrifuge, wash and dry the resulting solution to obtain ZIF-8 particles; Step 4: Add the ZIF-8 particles to a n-butanol solution, then add compound B, heat to 50℃-60℃, and stir for 1-3 hours; then transfer to a reaction vessel, add compound C and an inorganic acid, and react at 130℃-150℃ for 12-24 hours; the structural formula of compound C contains at least one aryl or heteroaryl group and at least two carboxyl or aldehyde groups; Step 5: After the reaction is completed, the mixture in the reactor is centrifuged, washed and dried to obtain the ZIFs material for long-term CO2 capture.

[0011] In one aspect of the present disclosure, in steps 1-5, the mass ratio of zinc nitrate hexahydrate to 2-methylimidazole is selected from 1:(5-9); preferably 1:(5-6).

[0012] In one aspect of the present disclosure, in steps 1-5, the mass ratio of compound B to compound C is selected from 1:(0.35-0.95); preferably 1:(0.4-0.6).

[0013] In one aspect of this disclosure, compound A has the following structural formula: ; Wherein, R1 and R2 are each independently selected from hydrogen, hydroxyl, C1-10 alkyl, C1-10 alkoxy, or R3, R4 and R5 are each independently selected from hydrogen, hydroxyl, C1-5 alkyl or C1-5 alkoxy.

[0014] In one aspect of this disclosure, compound A has the following structural formula: ; Wherein, R1 and R2 are each independently selected from hydrogen, hydroxyl, C1-10 alkyl, C1-10 alkoxy, or R3, R4 and R5 are each independently selected from hydrogen, hydroxyl, C1-5 alkyl or C1-5 alkoxy.

[0015] In one aspect of this disclosure, compound A has the following structural formula: .

[0016] In one aspect of this disclosure, specifically, compound A is selected from the following compounds: .

[0017] In one aspect of this disclosure, compound B has the following structural formula: .

[0018] Wherein, R1 and R2 are each independently selected from hydrogen, hydroxyl, C1-10 alkyl, C1-10 alkoxy, or R3, R4 and R5 are each independently selected from hydrogen, hydroxyl, C1-5 alkyl or C1-5 alkoxy.

[0019] In one aspect of this disclosure, specifically, compound B is selected from the following compounds: .

[0020] In one aspect of this disclosure, the inorganic zinc salt is selected from zinc nitrate, zinc acetate, or zinc chloride. Specifically, the inorganic zinc salt is selected from zinc nitrate hexahydrate.

[0021] In one aspect of the embodiments of this disclosure, compound C is selected from 1,3,5-tris-(4-formylphenyl)triazine.

[0022] According to a third aspect of the present disclosure, a CO2 adsorbent is provided, the CO2 adsorbent comprising the aforementioned ZIFs material for long-term CO2 capture, or a ZIFs material for long-term CO2 capture prepared by the aforementioned method.

[0023] According to a fourth aspect of the present disclosure, the aforementioned ZIFs material for long-term CO2 capture, or the ZIFs material for long-term CO2 capture prepared by the aforementioned method, is provided for use in carbon neutralization.

[0024] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: As can be seen from the above embodiments, this disclosure prepares a ZIFs-based material with good CO2 adsorption performance and good hydrophobicity and weather resistance by self-assembling and coating the surface of ZIF-8 material.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Detailed Implementation

[0026] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0028] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0029] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] In this description, unless otherwise stated, "above" and "below" include the stated number.

[0031] Unless otherwise stated, the terms used in this disclosure have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the values ​​of the parameters mentioned in this disclosure can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this disclosure).

[0032] The term "about" is used to describe and indicate small variations. When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0033] The list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

[0034] In this disclosure, the term "alkyl" refers to an aliphatic hydrocarbon group, which can be straight-chain or branched. Branched refers to one or more lower alkyl groups, such as methyl, ethyl, or propyl, that link a linear alkyl chain. "Lower alkyl" refers to a group containing about 1 to about 6 carbon atoms in the chain, which can be straight-chain or branched.

[0035] In this disclosure, the term "aryl" refers to an aromatic monocyclic or polycyclic ring system. An aryl group may optionally be substituted with one or more "cyclic substituents," which may be the same or different, as defined herein. Non-limiting examples of suitable aryl groups include phenyl and naphthyl.

[0036] In this disclosure, the term "heteroaryl" refers to an aromatic monocyclic or polycyclic ring system, wherein one or more ring atoms are elements other than carbon, such as nitrogen, oxygen, or sulfur, either individually or in combination, and preferably a heteroaryl contains about 5 to about 6 ring atoms. A "heteroaryl" may optionally be substituted by one or more "cyclic substituents," which may be the same or different, as defined herein. The prefixes azido, oxa, or thiado preceding the name of a heteroaryl root indicate that at least one nitrogen, oxygen, or sulfur atom is present as a ring atom, respectively. The nitrogen atom of a heteroaryl may optionally be oxidized to the corresponding N-oxide. Suitable, non-limiting examples of heteroaryl groups include pyridyl, pyrazinyl, furanyl, phenylthio, pyrimidinyl, isoxazolyl, isothiazolyl, oxazolyl, thiazolyl, pyrazolyl, furazanyl, pyrroleyl, pyrazolyl, triazolyl, 1,2,4-thiadiazolyl, pyrazinyl, pyridazinyl, quinoxalinyl, 2,3-diazanaphthyl, imidazo[1,2-a]pyridyl, imidazo[2,1-b]thiazolyl, benzofurazanyl, indoleyl, azaindoleyl, benzimidazolyl, benzothiopheneyl, quinolinyl, imidazolyl, thienopyridyl, quinazolinyl, thienopyrimidinyl, pyrrolopyridyl, imidazopyridyl, isoquinolinyl, benzoazaindoleyl, 1,2,4-triazinyl, benzothiazolyl, etc.

[0037] In this disclosure, the term "alkoxy" refers to -O-alkyl. Alkoxy can refer to a straight-chain, branched, or cyclic, saturated or unsaturated oxy-hydrocarbon chain, including, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, and pentoxy. Alkoxy may optionally be substituted with one or more alkoxy groups ("substituted alkoxy").

[0038] In this disclosure, compound A is selected from the following compound A-1:

[0039] Compound A-1 In this disclosure, compound A-1 can be prepared by, but is not limited to, the following steps: At 0°C under an argon atmosphere, 1,4-dibromobenzene was dissolved in diethyl ether, and then a hexane solution containing n-butyllithium was added dropwise. The solution was then stirred at 0°C for 1 hour, followed by the dropwise addition of 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane dissolved in diethyl ether at 0°C. After the addition was complete, the solution was brought to room temperature and stirred for 18 hours. The reaction was terminated with saturated ammonium chloride solution. The organic layers were separated, extracted, and combined. The organic layers were dried over magnesium sulfate, filtered, and concentrated under vacuum to obtain a crude product. The crude product was then purified, rotary evaporated, and dried to obtain an intermediate product. The reaction steps are shown below:

[0040] At -10°C, under argon atmosphere, a hexane solution containing n-butyllithium was added dropwise to an anhydrous THF solution of the intermediate; the mixture was stirred for 1 hour; then, while maintaining the argon atmosphere, carbon dioxide gas was bubbled into the mixture for 1 hour, and the reaction mixture was brought to room temperature and stirred overnight. The reaction mixture was then quenched with water, and the resulting mixture was extracted with ethyl acetate (4 × 20 mL). Finally, the combined organic layers were dried over anhydrous MgSO4, filtered, and concentrated to obtain the crude product. The crude product was purified by column chromatography to obtain compound A-1. The reaction steps are as follows:

[0041] In this disclosure, compound B is selected from the following compound B-1:

[0042] Compound B-1 In this disclosure, compound B-1 is obtained from compound A-1 as a starting material, and the process is as follows: Compound A-1 is added to thionyl chloride, a small amount of DMF is added dropwise, and the mixture is refluxed for 6-12 h. After the reaction is completed, the mixture is cooled to room temperature, and the solvent is removed by vacuum distillation. Then, methanol is added under ice bath conditions, and the mixture is heated for 3-6 h. After the reaction is completed, the mixture is cooled to room temperature, at which point a large amount of white solid precipitates, which is collected directly for the next reaction. This white solid is added to hydrazine hydrate and heated under reflux for 12-24 h. After the reaction is completed, the mixture is cooled to room temperature, and after extraction, rotary evaporation, and drying, compound B-1 is obtained. The reaction steps are as follows:

[0043] In this disclosure, the three ketone groups in 1,3,5-tris-(4-formylphenyl)triazine (compound C) form covalent bonds with the -NH-NH2 group of compound B-1, thereby forming a topological coating structure on the ZIF-8 surface.

[0044] The present disclosure will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present disclosure are obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process is carried out at room temperature.

[0045] Examples and comparative examples: Example 1: Example 1 includes the following steps: 1. Preparation of 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane: Under argon protection, diphenyldichlorosilane (10 mmol, 2.53 g) was dissolved in anhydrous THF solution (50 mL), and then trimethylchlorosilane (20 mmol, 2.16 g) and 0.05 g of Na were added as reducing agents. The reaction was carried out at 60 °C for 48 h. After rotary evaporation, extraction, and purification, an intermediate product was obtained. Then, under argon protection, at 0 °C, the intermediate product was added to 20 mL of benzene, followed by 1 mL of 2.5 mol / L hydrochloric acid solution and 0.167 g of AlCl3. The reaction was carried out for 1.5 h. After rotary evaporation, extraction, and purification, 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane was obtained.

[0046] 2. Preparation of compounds A-1 and B-1: 1,4-Dibromobenzene (2.35 g, 10 mmol) was dissolved in anhydrous diethyl ether (40 mL) at 0 °C under argon atmosphere, and then n-butyllithium solution (10 mmol of n-butyllithium was dissolved in 4 mL of hexane) was added dropwise. The solution was then stirred at 0 °C for 1 hour, and then 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane (1.21 g, 5.0 mmol) dissolved in 2.0 mL of diethyl ether was added dropwise at 0 °C. After the addition was complete, the solution was brought back to room temperature and stirred for 18 hours. The reaction was terminated with saturated ammonium chloride solution (20 mL). The organic layer was separated, and the aqueous layer was extracted with diethyl ether (3 × 20 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated under vacuum to obtain the crude product. The crude product was washed through a silica gel column with hexane as the eluent, and then evaporated and dried to obtain the intermediate product.

[0047] At -10°C under argon atmosphere, a hexane solution containing n-butyllithium (20 mmol of n-butyllithium dissolved in 8 mL of hexane) was added dropwise to an anhydrous THF solution (100 mL) of the intermediate product (4.91 g, 10 mmol). The mixture was stirred for 1 hour. Then, carbon dioxide gas was introduced into the mixture for 1 hour while maintaining the argon atmosphere. The reaction mixture was then brought to room temperature and stirred overnight. The reaction mixture was then quenched with water and the pH was adjusted to 6 with 1.0 mol / L HCl solution. The mixture was extracted with ethyl acetate (4 × 20 mL). Finally, the combined organic layers were dried over anhydrous MgSO4, filtered, and concentrated to obtain the crude product. The crude product was purified by column chromatography to obtain compound A-1.

[0048] 2.08 g of the prepared compound A-1 was weighed and added to 30 mL of thionyl chloride. 0.2 mL of LDMF was added dropwise, and the mixture was refluxed at 90 °C for 10 h. After the reaction was completed, the mixture was cooled to room temperature, and the solvent was removed by vacuum distillation. Then, 50 mL of methanol was added under ice bath conditions, and the mixture was reacted at 75 °C for 5 h. After the reaction was completed, the mixture was cooled to room temperature, at which point a large amount of white solid precipitated. This solid was collected directly for the next reaction. All the white solid was added to 15 mL of hydrazine hydrate and heated under reflux for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and after extraction, rotary evaporation, and drying, compound B-1 (total 1.73 g) was obtained.

[0049] 3. Preparation of ZIFs material: 1 g of zinc nitrate hexahydrate was dissolved in 10 mL of methanol, and 5.53 g of 2-methylimidazole was dissolved in 25 mL of methanol. The two were then mixed and stirred for 20 min, and reacted at 40 °C for 20 h. The resulting solution was then centrifuged, washed, and dried to obtain ZIF-8 particles. The ZIF-8 particles were added to a n-butanol solution, and then all of compound B-1 (1.73 g) was added. The mixture was heated to 60 °C and stirred for 1 h. The mixture was then transferred to a reaction vessel, and 1,3,5-tris-(4-formylphenyl)triazine (0.93 g) and glacial acetic acid (2.5 mL) were added. The mixture was reacted at 130 °C for 18 h to obtain the ZIFs material of Example 1.

[0050] Comparative Example 1: Comparative Example 1 includes the following steps: 1 g of zinc nitrate hexahydrate was dissolved in 10 mL of methanol, and 5.53 g of 2-methylimidazole was dissolved in 25 mL of methanol. The two were then mixed and stirred for 20 min, and reacted at 40 °C for 20 h. The resulting solution was then centrifuged, washed, and dried to obtain ZIF-8 particles. The ZIF-8 particles were added to a n-butanol solution, transferred to a reaction vessel, and 0.93 g of 1,3,5-tris-(4-formylphenyl)triazine and glacial acetic acid (2.5 mL) were added. The mixture was reacted at 130 °C for 18 h to obtain the ZIFs material of Comparative Example 1.

[0051] Comparative Example 2: Comparative Example 2 includes the following steps: 1. Preparation of 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane: Under argon protection, diphenyldichlorosilane (10 mmol, 2.53 g) was dissolved in anhydrous THF solution (50 mL), and then trimethylchlorosilane (20 mmol, 2.16 g) and 0.05 g of Na were added as reducing agents. The reaction was carried out at 60 °C for 48 h. After rotary evaporation, extraction, and purification, an intermediate product was obtained. Then, under argon protection, at 0 °C, the intermediate product was added to 20 mL of benzene, followed by 1 mL of 2.5 mol / L hydrochloric acid solution and 0.167 g of AlCl3. The reaction was carried out for 1.5 h. After rotary evaporation, extraction, and purification, 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane was obtained.

[0052] 2. Preparation of compounds A-1 and B-1: 1,4-Dibromobenzene (2.35 g, 10 mmol) was dissolved in anhydrous diethyl ether (40 mL) at 0 °C under argon atmosphere, and then n-butyllithium solution (10 mmol of n-butyllithium was dissolved in 4 mL of hexane) was added dropwise. The solution was then stirred at 0 °C for 1 hour, and then 2,2-dichloro-1,1,1,3,3,3-hexamethyltrisilane (1.21 g, 5.0 mmol) dissolved in 2.0 mL of diethyl ether was added dropwise at 0 °C. After the addition was complete, the solution was brought back to room temperature and stirred for 18 hours. The reaction was terminated with saturated ammonium chloride solution (20 mL). The organic layer was separated, and the aqueous layer was extracted with diethyl ether (3 × 20 mL). The combined organic layers were dried over magnesium sulfate, filtered, and concentrated under vacuum to obtain the crude product. The crude product was washed through a silica gel column with hexane as the eluent, and then evaporated and dried to obtain the intermediate product.

[0053] At -10°C under argon atmosphere, a hexane solution containing n-butyllithium (20 mmol of n-butyllithium dissolved in 8 mL of hexane) was added dropwise to an anhydrous THF solution (100 mL) of the intermediate product (4.91 g, 10 mmol). The mixture was stirred for 1 hour. Then, carbon dioxide gas was introduced into the mixture for 1 hour while maintaining the argon atmosphere. The reaction mixture was then brought to room temperature and stirred overnight. The reaction mixture was then quenched with water and the pH was adjusted to 6 with 1.0 mol / L HCl solution. The mixture was extracted with ethyl acetate (4 × 20 mL). Finally, the combined organic layers were dried over anhydrous MgSO4, filtered, and concentrated to obtain the crude product. The crude product was purified by column chromatography to obtain compound A-1.

[0054] 2.08 g of the prepared compound A-1 was weighed and added to 30 mL of thionyl chloride. 0.2 mL of LDMF was added dropwise, and the mixture was refluxed at 90 °C for 10 h. After the reaction was completed, the mixture was cooled to room temperature, and the solvent was removed by vacuum distillation. Then, 50 mL of methanol was added under ice bath conditions, and the mixture was reacted at 75 °C for 5 h. After the reaction was completed, the mixture was cooled to room temperature, at which point a large amount of white solid precipitated. This solid was collected directly for the next reaction. All the white solid was added to 15 mL of hydrazine hydrate and heated under reflux for 24 h. After the reaction was completed, the mixture was cooled to room temperature, and after extraction, rotary evaporation, and drying, compound B-1 (total 1.73 g) was obtained.

[0055] 3. Preparation of ZIFs material: 1 g of zinc nitrate hexahydrate was dissolved in 10 mL of methanol, and 5.53 g of 2-methylimidazole was dissolved in 25 mL of methanol. The two were then mixed and stirred for 20 min, and reacted at 40 °C for 20 h. The resulting solution was then centrifuged, washed, and dried to obtain ZIF-8 particles. The ZIF-8 particles were added to a n-butanol solution, and then all of compound B-1 (1.73 g) was added. The mixture was heated to 60 °C and stirred for 1 h. The mixture was then transferred to a reaction vessel and reacted at 130 °C for 18 h to obtain the ZIFs material of Comparative Example 2.

[0056] Comparative Example 3: Comparative Example 3 includes the following steps: 1 g of zinc nitrate hexahydrate was dissolved in 10 mL of methanol, and 5.53 g of 2-methylimidazole was dissolved in 25 mL of methanol. The two were then mixed and stirred for 20 min, and then reacted at 40 °C for 20 h. The resulting solution was then centrifuged, washed, and dried to obtain ZIF-8 particles. The ZIF-8 particles were added to 50 mL of n-butanol and reacted at 130 °C for 18 h to obtain the ZIFs material of Comparative Example 3.

[0057] Particle size and specific surface area characterization: The particle size of the products of Example 1 and Comparative Examples 1-3 was tested using a laser particle size analyzer (Malvern Mastersizer 3000). The D90 particle size of Example 1 was 528 nm, the D90 particle size of Comparative Example 1 was 284 nm, the D90 particle size of Comparative Example 2 was 342 nm, and the D90 particle size of Comparative Example 3 was 165 nm.

[0058] The products of Example 1 and Comparative Examples 1-3 were placed in glass sample tubes and degassed under vacuum. Then, using an ANTON PAAR Nova 600 analyzer with nitrogen as the adsorbate gas, the amount of nitrogen adsorbed at different pressures was measured, adsorption isotherms were obtained, and the BET specific surface area was calculated. The specific surface area of ​​Example 1 was measured to be 402 m². 2 / g, the specific surface area of ​​Comparative Example 1 is 446m². 2 / g, the specific surface area of ​​Comparative Example 2 is 231m². 2 / g, the specific surface area of ​​Comparative Example 3 is 878m². 2 / g.

[0059] Long-term CO2 adsorption capacity test: The CO2 adsorption performance of the products of Example 1 and Comparative Examples 1-3 was tested using CO2-TPD; high-purity CO2 was adsorbed for 1 hour at a temperature of 40℃, followed by purging with nitrogen for 1 hour; the CO2-TPD program was executed with a temperature range of 40-250℃ and a heating rate of 10℃ / min; the peak area calculation results are shown in Table 1 below.

[0060] The products of Example 1 and Comparative Examples 1-3 were then placed at room temperature for 45 days before the above tests were performed again. The peak area calculation results are shown in Table 1 below.

[0061] Table 1:

[0062] As can be seen, the product prepared in Example 1 not only has good carbon dioxide adsorption capacity but also good weather resistance, maintaining a long-term carbon dioxide adsorption capacity. For the ZIF-8 material, the nitrogen atom on the imidazole ligand has a certain basicity, allowing it to interact with the carbon atom in the carbon dioxide molecule to form a Lewis acid-base-like coordination bond. This coordination enhances the adsorption capacity of carbon dioxide molecules within the pores. Furthermore, the imidazole ligand can also form hydrogen bonds with the carbon dioxide molecule through its hydrogen atoms, further increasing the adsorption strength. In Example 1, however,... The three ketone groups in 1,3,5-tris-(4-formylphenyl)triazine (compound C) form covalent bonds with the -NH-NH2 groups of compound B-1, thereby forming a topological coating structure on the ZIF-8 surface. This surface coating structure has abundant and active nitrogen and hydrogen atoms, which can greatly enhance the adsorption capacity for carbon dioxide. Therefore, this coating structure has a good promoting effect on the adsorption capacity of ZIF-8. In contrast, the specific surface area of ​​Comparative Example 2 decreased significantly because compound B-1 could not form a topological coating structure and simply coated the surface of ZIF-8 material, thus blocking the pores and affecting CO2 adsorption. The silane groups on compound B-1 have good hydrophobicity, which can prevent water vapor from condensing in the pores of ZIF-8 material and avoid pore blockage, thus exhibiting good weather resistance.

Claims

1. A ZIFs material for long-term CO2 capture, characterized in that, The ZIFs material is obtained by surface coating of ZIFs-8 particles; the ZIFs material contains Si element; Furthermore, the D90 particle size of the ZIFs material is selected from 350-800 nm, and the specific surface area of ​​the ZIFs material is selected from 300-600 m². 2 / g.

2. The ZIFs material for long-term CO2 capture according to claim 1, characterized in that, The D90 particle size of the ZIFs material is selected from 450-600 nm, and the specific surface area of ​​the ZIFs material is selected from 350-450 m². 2 / g.

3. A method for preparing the ZIFs material for long-term CO2 capture as described in claim 1 or 2, characterized in that, The method includes the following steps: Step 1: Prepare compound A; the structural formula of compound A contains at least one aryl or heteroaryl group, two carboxyl groups, and at least one silicon atom; Step 2: React compound A with thionyl chloride and hydrazine hydrate respectively to generate compound B; Step 3: Dissolve the inorganic zinc salt and 2-methylimidazole separately in methanol, then mix them and stir for 2-30 min, then react at 30℃-40℃ for 10-30 h, and then centrifuge, wash and dry the resulting solution to obtain ZIF-8 particles; Step 4: Add the ZIF-8 particles to a n-butanol solution, then add compound B, heat to 50℃-60℃, and stir for 1-3 hours; then transfer to a reaction vessel, add compound C and an inorganic acid, and react at 130℃-150℃ for 12-24 hours; the structural formula of compound C contains at least one aryl or heteroaryl group and at least two carboxyl or aldehyde groups; Step 5: After the reaction is completed, the mixture in the reactor is centrifuged, washed and dried to obtain the ZIFs material for long-term CO2 capture.

4. The method according to claim 3, characterized in that, Compound A has the following structural formula: R1 and R2 are each independently selected from hydrogen, hydroxyl, C1-10 alkyl, C1-10 alkoxy, or... R3, R4 and R5 are each independently selected from hydrogen, hydroxyl, C1-5 alkyl or C1-5 alkoxy.

5. The method according to claim 4, characterized in that, The compound B has the following structural formula: R1 and R2 are each independently selected from hydrogen, hydroxyl, C1-10 alkyl, C1-10 alkoxy, or... R3, R4 and R5 are each independently selected from hydrogen, hydroxyl, C1-5 alkyl or C1-5 alkoxy.

6. The method according to claim 3, characterized in that, The inorganic zinc salt is selected from one of zinc nitrate, zinc acetate, or zinc chloride.

7. The method according to claim 3, characterized in that, The compound C is selected from 1,3,5-tris-(4-formylphenyl)triazine.

8. A CO2 adsorbent, characterized in that, The CO2 adsorbent comprises the ZIFs material for long-term CO2 capture as described in claim 1 or 2, or the ZIFs material for long-term CO2 capture prepared by the method described in any one of claims 3-7.

9. The application of the ZIFs material for long-term CO2 capture as described in claim 1 or 2, or the ZIFs material for long-term CO2 capture prepared by the method described in any one of claims 3-7, in carbon neutralization.

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