An adsorbent for removing metal ions in alcohol ether solvents, and a preparation method and application thereof

Abstract

The application discloses an adsorbent for removing trace metal ions in alcohol ether solvents and a preparation method and application thereof, and belongs to the field of chemical separation technology. The adsorbent is a zirconium-based metal organic cage material with discrete structure formed by coordination self-assembly of a zirconium metal salt and a nitrogen-containing polycarboxylic acid organic ligand. The adsorbent has specific ion nanowells, and can form a strong limited synergistic effect with metal ions. The adsorbent is suitable for adsorption and separation of trace metal ions in various alcohol ether solvents, and has high metal ion adsorption and removal efficiency.

Description

Technical Field

[0001] This invention belongs to the field of chemical separation technology, specifically relating to an adsorbent for removing metal ions from alcohol and ether solvents, its preparation method, and its application. Background Technology

[0002] Alcohol ether solvents are widely used in the chemical, coating, cleaning, and electronics industries due to their excellent solvent properties and relatively low toxicity. However, alcohol ether solvents are highly susceptible to contamination by trace metal ions during production, storage, and use. The presence of metal ions (such as chromium, cobalt, nickel, copper, and zinc) not only affects the performance of alcohol ether solvents but also poses potential hazards to the environment and human health. Therefore, effectively removing trace metal ions from alcohol ether solvents during production and use is a critical issue that urgently needs to be addressed.

[0003] Currently, the main technologies for removing metal ions from liquid media include chemical precipitation, ion exchange, membrane separation, and adsorption. Among these, adsorption has attracted much attention due to its simplicity, wide applicability, and relatively low cost. The selection and application of adsorbent materials play a decisive role in the adsorption effect; therefore, developing efficient and selective adsorbents is key to improving the effectiveness of adsorption in removing metal ions from liquid media.

[0004] Metal-organic cage materials have attracted widespread research interest due to their unique structural stability, high specific surface area, and tunable pore structure. Through the rational design of the metal-organic cage structure and surface properties, their adsorption capacity and specific recognition ability for specific metal ions can be achieved. In particular, the introduction of specific adsorption active sites has been shown to significantly enhance the interaction between the adsorbent and the metal ions. Summary of the Invention

[0005] The purpose of this invention is to develop a zirconium-based metal-organic cage adsorbent. The metal-organic cage structure is prepared in one step using bis(cyclopentadiene)zirconium dichloride and a 4,4'-(2,6-pyrazinidyl)dibenzoic acid ligand in a mixed solvent. By constructing ion nanotrapes to enhance the confined synergistic effect between the adsorbent and metal ions, it can be used for the efficient removal of trace metal ions from alcohol and ether solvents. This adsorbent not only improves the removal efficiency of metal ions but also has a simple preparation process, which helps to enhance solvent purification processes in industrial applications.

[0006] The adsorbent of this invention is a zirconium-based metal-organic cage material with a specific ion nanotrap structure. The confined pyrazine nitrogen active sites formed by the zirconium clusters and organic ligands synergistically constitute this unique ion nanotrap structure. On one hand, the resulting ion nanotrap possesses a specific confined microenvironment that enables good matching and recognition between the adsorbent and metal ions. On the other hand, the abundant pyrazine nitrogen active sites within the ion nanotrap exhibit a strong affinity for metal ions. This synergistic effect promotes the efficient adsorption and removal of metal ions by the adsorbent.

[0007] The method for preparing the adsorbent of the present invention includes the following steps:

[0008] Step 1, add respectively N , N - Dimethylacetamide, water, and acetonitrile are prepared as a mixed solvent;

[0009] Step 2: Dissolve bis(cyclopentadiene)zirconium dichloride and 4,4'-(2,6-pyrazinidyl)dibenzoic acid in a mixed solvent and sonicate for 10-30 minutes respectively;

[0010] Step 3: Place the ultrasonically treated mixture in an environment of 25-60℃ for 6-48 hours.

[0011] Step four, the reaction products are processed... N , N - Washed with dimethylacetamide and acetonitrile, then vacuum dried.

[0012] The mixed solvent consists of solvents with a volume ratio of 10:2:1. N , N -Dimethylacetamide, acetonitrile and water are mixed and homogenized to obtain the product.

[0013] In step two, the molar ratio of bis(cyclopentadiene)zirconium chloride to 4,4'-(2,6-pyrazinidyl)dibenzoic acid is 2:1.

[0014] The adsorbent of the present invention can be applied to the adsorption and removal of metal ions in alcohol and ether solvents.

[0015] Preferably, the alcohol ether solvents include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, and dipropylene glycol butyl ether.

[0016] Preferably, the metal ion contains Cr. 6+ Co 2+ Ni 2+ Cu 2+and Zn 2+ .

[0017] In the application of the present invention, a further technical solution is that the contact conditions between the adsorbent and the alcohol ether solvent containing metal ions during the adsorption of metal ions are as follows: the adsorbent and the alcohol ether solvent are mixed and adsorption is carried out at room temperature, the pressure is normal pressure, and the content of metal ions in the alcohol ether solvent is 1~100ppm.

[0018] Compared with the prior art, the present invention has the following beneficial results:

[0019] (1) The adsorbent described in this invention has significant structural advantages. The confined pyrazine nitrogen active site cages formed by zirconium clusters and organic ligands constitute a special ion nanotrap structure through synergistic effect; on the one hand, the ion nanotrap has a specific confined microenvironment that can form a good matching and recognition effect with metal ions; on the other hand, the abundant pyrazine nitrogen active sites in the ion nanotrap have a strong affinity for metal ions.

[0020] (2) The adsorbent described in this invention has significant advantages in the adsorption and removal of trace metal ions in alcohol and ether solvents. Based on the structural speciality of the ion nanotrap and the synergistic effect, the adsorbent described therein has a removal efficiency of more than 96% for trace metal ions in different alcohol and ether solvents, while the adsorbent without the ion nanotrap has a removal efficiency of less than 25% for metal ions in alcohol and ether solvents. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a structural diagram of the ion nanotrap adsorbent with confined active site cages in this invention. Detailed Implementation

[0023] The following specific embodiments further illustrate the technical solution of the present invention, but the present invention is not limited to the examples given: Example 1

[0024] Preparation of the adsorbent: 0.3 mmol of bis(cyclopentadiene)zirconium dichloride and 0.15 mmol of 4,4'-(2,6-pyrazinidyl)dibenzoic acid were dissolved in... N , NThe mixture was prepared by sonication in dimethylacetamide (0.5 mL), acetonitrile (0.1 mL), and water (0.05 mL) for 10 minutes. The resulting solution was then placed in an oven at 60°C for 6 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0025] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Cr-containing... 6+ An ethylene glycol methyl ether solvent containing 10 ppm ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. Atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry was used to analyze the adsorbent's effect on Cr in the ethylene glycol methyl ether solvent. 6+ The adsorption and removal efficiency of ions. Experimental results show that this adsorbent has a high efficiency in removing Cr from ethylene glycol methyl ether solvent. 6+ The adsorption and removal efficiency of ions is 96.5%. Example 2

[0026] Preparation of the adsorbent: 0.5 mmol of bis(cyclopentadiene)zirconium dichloride and 0.25 mmol of 4,4'-(2,6-pyrazinidyl)dibenzoic acid were dissolved in... N , N The mixture was prepared by sonication in dimethylacetamide (0.5 mL), acetonitrile (0.1 mL), and water (0.05 mL) for 20 minutes. The resulting mixture was then placed in an oven at 60°C for 10 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0027] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Co-containing... 2+ An ethylene glycol methyl ether solvent containing (10 ppm) ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. The adsorbent's effect on Co in the ethylene glycol methyl ether solvent was analyzed using atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. 2+ Adsorption and removal efficiency of ions. Experimental results show that this adsorbent has good adsorption efficiency for Co in ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is 98.6%. Example 3

[0028] Preparation of the adsorbent: 0.7 mmol of bis(cyclopentadiene)zirconium dichloride and 0.35 mmol of 4,4'-(2,6-pyrazinidyl)dibenzoic acid were dissolved in... N , NThe mixture was prepared by sonication in dimethylacetamide (0.5 mL), acetonitrile (0.1 mL), and water (0.05 mL) for 30 minutes. The resulting mixture was then placed in an oven at 60°C for 48 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0029] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Ni-containing... 2+ An ethylene glycol methyl ether solvent containing 10 ppm of ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. The adsorbent's effect on Ni in the ethylene glycol methyl ether solvent was analyzed using atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. 2+ The adsorption and removal efficiency of ions. Experimental results show that this adsorbent has a high efficiency in removing Ni ions from ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is 97.3%. Example 4

[0030] Preparation of the adsorbent: 0.3 mmol of bis(cyclopentadiene)zirconium dichloride and 0.15 mmol of 4,4'-(2,6-pyrazinidyl)dibenzoic acid were dissolved in... N , N The mixture was prepared by sonication for 30 minutes in a solution of dimethylacetamide (1 mL), acetonitrile (0.2 mL), and water (0.1 mL). The resulting solution was then placed in an oven at 60°C for 24 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0031] Ion adsorption experiment: Weigh 0.1g of the vacuum-activated adsorbent and add it to the adsorption cell. Transfer 10mL of Cu-containing... 2+ An ethylene glycol methyl ether solvent containing 10 ppm of Cu ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. Atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry was used to analyze the adsorbent's effect on Cu in the ethylene glycol methyl ether solvent. 2+ Adsorption and removal efficiency of ions. Experimental results show that this adsorbent has good adsorption efficiency for Cu in ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is 97.9%. Example 5

[0032] Preparation of the adsorbent: 0.3 mmol of bis(cyclopentadiene)zirconium dichloride and 0.15 mmol of 4,4'-(2,6-pyrazinidyl)dibenzoic acid were dissolved in... N , NThe mixture was prepared by sonication in dimethylacetamide (1.5 mL), acetonitrile (0.3 mL), and water (0.15 mL) for 30 minutes. The resulting mixture was then placed in an oven at 60°C for 48 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0033] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Zn-containing... 2+ An ethylene glycol methyl ether solvent containing 10 ppm Zn ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. The adsorbent's effect on Zn in the ethylene glycol methyl ether solvent was analyzed using atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. 2+ Adsorption and removal efficiency of ions. Experimental results show that this adsorbent has good adsorption efficiency for Zn in ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is 98.2%.

[0034] Comparative Example 1

[0035] Preparation of the adsorbent: 0.3 mmol of bis(cyclopentadiene)zirconium dichloride and 0.15 mmol of 1,1':3',1''-terphenyl-4,4''-dicarboxylic acid were dissolved in... N , N The mixture was prepared by sonication in dimethylacetamide (1.5 mL), acetonitrile (0.3 mL), and water (0.15 mL) for 30 minutes. The resulting mixture was then placed in an oven at 60°C for 48 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0036] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Cr-containing... 6+ An ethylene glycol methyl ether solvent containing 10 ppm ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. Atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry was used to analyze the adsorbent's effect on Cr in the ethylene glycol methyl ether solvent. 6+ Adsorption and removal efficiency of ions. Experimental results show that this adsorbent has good adsorption efficiency for Zn in ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is only 20.7%.

[0037] Comparative Example 2

[0038] Preparation of the adsorbent: 0.5 mmol of bis(cyclopentadiene)zirconium dichloride and 0.25 mmol of 1,1':3',1''-terphenyl-4,4''-dicarboxylic acid were dissolved in... N , N The mixture was prepared by sonication in dimethylacetamide (0.5 mL), acetonitrile (0.1 mL), and water (0.05 mL) for 20 minutes. The resulting mixture was then placed in an oven at 60°C for 10 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0039] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Co-containing... 2+ An ethylene glycol methyl ether solvent containing (10 ppm) ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. The adsorbent's effect on Co in the ethylene glycol methyl ether solvent was analyzed using atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. 2+ Adsorption and removal efficiency of ions. Experimental results show that this adsorbent has good adsorption efficiency for Co in ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is 24.3%.

[0040] Comparative Example 3

[0041] Preparation of the adsorbent: 0.7 mmol of bis(cyclopentadiene)zirconium dichloride and 0.35 mmol of 1,1':3',1''-terphenyl-4,4''-dicarboxylic acid were dissolved in... N , N The mixture was prepared by sonication in dimethylacetamide (0.5 mL), acetonitrile (0.1 mL), and water (0.05 mL) for 30 minutes. The resulting mixture was then placed in an oven at 60°C for 48 hours. The product was then subjected to... N , N The adsorbent was obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying.

[0042] Ion adsorption experiment: Weigh 0.1g of the adsorbent after vacuum activation and add it to the adsorption cell. Transfer 10mL of Ni-containing... 2+ An ethylene glycol methyl ether solvent containing 10 ppm of ions was added, and the resulting mixed solvent was stirred thoroughly at 400 rpm. The adsorbent's effect on Ni in the ethylene glycol methyl ether solvent was analyzed using atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. 2+ The adsorption and removal efficiency of ions. Experimental results show that this adsorbent has a high efficiency in removing Ni ions from ethylene glycol methyl ether solvent. 2+ The adsorption and removal efficiency of ions is 18.6%.

[0043] Based on the results of the examples and comparative examples, the adsorbent described in this invention exhibits a significant enhancement effect on the removal of metal ions from alcohol and ether solvents. Benefiting from its unique ion nanotrap structure, its confined microenvironment forms a good match and recognition with metal ions, further synergizing with its abundant pyrazine nitrogen active sites, thereby promoting the adsorption and removal efficiency of metal ions from alcohol and ether solvents.

[0044] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An adsorbent for removing metal ions from alcohol and ether solvents, characterized in that: The adsorbent is a zirconium-based metal-organic cage material, and the metal-organic cage structure is prepared in one step by bis(cyclopentadiene)zirconium dichloride and 4,4'-(2,6-pyrazinidyl)dibenzoic acid ligand in a mixed solvent. The preparation method of the adsorbent includes the following steps: Step 1, add respectively N , N - Dimethylacetamide, acetonitrile, and water are prepared as a mixed solvent; Step 2: Dissolve bis(cyclopentadiene)zirconium dichloride and 4,4'-(2,6-pyrazinidyl)dibenzoic acid ligand separately in a mixed solvent and sonicate for 10-30 minutes. Step 3: Place the ultrasonically treated mixed solution in an environment of 25~60℃ for 6~48 hours; Step four, the reaction products are processed... N , N The adsorbent is obtained by washing with dimethylacetamide and acetonitrile and then vacuum drying. In step two, the molar ratio of bis(cyclopentadiene)zirconium chloride to 4,4'-(2,6-pyrazinidyl)dibenzoic acid ligand is 2:

1.

2. The adsorbent for removing metal ions from alcohol-ether solvents according to claim 1, characterized in that: The mixed solvent consists of solvents with a volume ratio of 10:2:

1. N , N -Dimethylacetamide, acetonitrile and water are mixed and homogenized to obtain the product.

3. The application of an adsorbent as described in claim 1 or 2 for removing metal ions from alcohol-ether solvents, characterized in that: The adsorbent has a specific ion nanotrap structure, which is composed of confined pyrazine nitrogen active sites. The ion nanotrap structure can form a strong confined synergistic effect with metal ions, and is used to adsorb and remove trace metal ions in alcohol and ether solvents.

4. The application of the adsorbent for removing metal ions from alcohol-ether solvents according to claim 3, characterized in that: The alcohol ether solvents include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, and dipropylene glycol butyl ether.

5. The application of the adsorbent for removing metal ions from alcohol-ether solvents according to claim 3, characterized in that: The trace metal ions in the alcohol ether solvent include Cr 6+ Co 2+ Ni 2+ Cu 2+ and Zn 2+ .

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