Preparation and application of amino-functionalized M-coated UiO-66-NH-2 composite adsorbent

Abstract

The invention provides preparation and application of an amino-functionalized M-coated UiO-66-NH-2 composite adsorbent, and belongs to the technical field of environmental science and engineering. The adsorbent is characterized in that one of transition metal Cr, Fe, Co or Ni is used as an active component M, UiO-66-NH-2 is used as a carrier, and then the active component is uniformly dispersed into the carrier to obtain an octahedral structure with multiple active adsorption sites. The preparation method comprises the following steps: firstly, dissolving zirconium chloride and 2-aminoterephthalic acid in N, N-dimethylformamide, and carrying out ultrasonic treatment, hydrothermal reaction, washing centrifugation and drying to obtain UiO-66-NH-2; and dissolving the UiO-66-NH-2 and an M source in dimethyl sulfoxide, and carrying out ultrasonic treatment, hydrothermal reaction, washing centrifugation and drying to obtain the M-coated UiO-66-NH-2 composite adsorbent. The method has the advantages of simple preparation process and high activity, and the prepared adsorbent has octahedral morphology, high specific surface area and abundant porosity, shows excellent CO2 adsorption performance and cycling stability, and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the field of environmental science and engineering technology, and in particular to the preparation and application of an amino-functionalized M@UiO-66-NH-2 composite adsorbent. Background Art

[0002] With the continuous development of industrialization, the demand for non-renewable resources such as coal, oil, and natural gas is also increasing. The CO generated by the combustion of these fossil fuels 2 Gases can cause natural problems such as greenhouse effect, urban heat islands, and sea level rise, which seriously threaten the survival of humans and organisms. Therefore, it is necessary to develop a method that can efficiently capture CO 2 The adsorption material is particularly important.

[0003] Metal-organic frameworks (MOFs) are a new type of porous material formed by connecting metal salts and organic ligands. They have the characteristics of high crystallinity, adjustable pore size and ordered pore structure, and high specific surface area. MOFs materials are widely studied in the fields of catalysis, gas adsorption and separation, drug delivery, and optical properties. In recent years, metal-organic frameworks formed by coordination bonds between metal clusters and organic linkers have been widely studied due to their CO 2 The large adsorption capacity of MOFs and their structural and chemical stability have attracted more attention. 2 Adsorption test.

[0004] Among MOFs, zirconium metal organic framework (UiO-66) has attracted much attention due to its excellent chemical and thermal stability. However, due to the lack of effective adsorption of CO in the UiO-66 structure, 2 active site, so its CO 2 In order to improve its adsorption capacity, many researchers have explored the improvement of its structure by surface modification to increase the alkaline active sites, which will help to react with CO 2 For example: Chinese patent CN104826610A discloses a preparation method of PEI@UIO-66 and its 2 In the application of adsorption separation, they dissolved polyethyleneimine (PEI) in ethanol solution and successfully loaded it on the UIO-66 carrier. The prepared PEI@UIO-66 composite material has excellent CO 2 Selectivity and adsorption: Chinese patent CN118904098A discloses a method for preparing a UiO-66 gel composite membrane and its adsorption in H 2 and CO 2For separation applications, they obtained a UiO-66 gel composite membrane by spin-coating a mixed solution of UiO-66 gel and polyethyleneimine onto a flexible polymer substrate, and then cross-linked it to fix the network structure composed of UiO-66 gel and branched polyethyleneimine, ensuring the mechanical strength of the membrane, weakening the interaction between UiO-66 gel and polyethyleneimine, and improving the membrane flux. The branched polyethyleneimine in this material can strengthen the UiO-66 gel network, making it more flexible to adapt to the polymer substrate, and can also modify the pores of UiO-66 gel, reduce the pore size, and reduce CO 2 Transfer rate, for CO 2 With high adsorption capacity; Chinese patent CN119119492A discloses a method for preparing a bimetallic functionalized organic framework material and its adsorption in CO 2 In the application of adsorption separation, they used Ag + The sulfonic acid functionalized UiO-66 was used as the carrier to form a strong complex with double bonds. + Replaced with Ag + , bimetallic functionalized UiO-66-SO was prepared 3 Ag, due to its unique pore structure and bimetallic active sites, is effective for CO 2 It has strong selective adsorption and separation capabilities.

[0005] It can be seen that the modification of the active sites on the surface of UIO-66 by metal elements has a significant effect on CO 2 The improvement of adsorption capacity has important practical value. Summary of the invention

[0006] One object of the present invention is to improve the problems and shortcomings of the prior art and provide an amino-functionalized M@UiO-66-NH-2 composite adsorbent. Another object of the present invention is to provide a method for preparing the adsorbent. Another object of the present invention is to provide a method for preparing the adsorbent in CO. 2 Application in adsorption separation.

[0007] The technical solution of the present invention is: an amino-functionalized M@UiO-66-NH-2 composite adsorbent, characterized in that the active component is one of Cr, Fe, Co or Ni, UiO-66-NH-2 is used as a carrier, and the adsorbent morphology is an octahedral structure.

[0008] The present invention also provides a method for preparing the amino-functionalized M@UiO-66-NH-2 composite adsorbent, and the specific operation steps are as follows:

[0009] 1) Dissolving zirconium chloride and 2-aminoterephthalic acid in N,N-dimethylformamide, and then subjecting the mixture to ultrasonic treatment, hydrothermal reaction, washing, centrifugation and drying to obtain a UiO-66-NH-2 carrier;

[0010] 2) The UiO-66-NH-2 carrier and the M source were first dissolved in dimethyl sulfoxide, and then subjected to ultrasonic treatment, hydrothermal reaction, washing, centrifugation and drying to obtain the M@UiO-66-NH-2 composite adsorbent.

[0011] Preferably, in step (1), the molar ratio of zirconium chloride to 2-aminoterephthalic acid is 1:(0.5-1.5), the amount of N,N-dimethylformamide is 25-75 mL, the hydrothermal reaction temperature is 100-150° C., the hydrothermal reaction time is 12-36 h, the drying temperature is 80-120° C., and the drying time is 12-20 h.

[0012] Preferably, in step (2), the mass ratio of UiO-66-NH-2 carrier to M ion is 1:(0.005-0.02), the amount of dimethyl sulfoxide is 20-60 mL, the hydrothermal reaction temperature is 160-200° C., the hydrothermal reaction time is 12-24 h, the drying temperature is 100-150° C., and the drying time is 10-24 h.

[0013] Preferably, in step (2), the Cr source is any one of chromium nitrate, chromium chloride or chromium sulfate, the Fe source is any one of ferric chloride or ferric nitrate, the Co source is any one of cobalt chloride or cobalt nitrate, and the Ni source is any one of nickel sulfate or nickel nitrate.

[0014] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0015] (1) The amino-functionalized M@UiO-66-NH-2 composite adsorbent provided by the present invention has the advantages of simple preparation, convenient operation, mild conditions, high specific surface area, and a porous octahedral structure. The process is environmentally friendly and is conducive to large-scale production.

[0016] (2) The amino-functionalized M@UiO-66-NH-2 composite adsorbent provided by the present invention acts on CO 2 Adsorption separation direction, with higher CO 2 Adsorption performance and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 CO of the materials prepared in the examples and comparative examples 2 Summary graph of adsorption amount. DETAILED DESCRIPTION

[0018] The present invention is described in more detail below with reference to examples. These examples are merely descriptions of the best mode for carrying out the present invention and do not impose any limitation on the protection scope of the present invention.

[0019] Embodiment 1:

[0020] Place 0.9328 g ZrCl in a beaker containing 25 mL N,N-dimethylformamide reagent. 4 and 0.3623g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 100°C and maintained for 12 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 80°C for 12 hours to obtain the final UiO-66-NH-2 carrier.

[0021] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0230g of chromium nitrate and ultrasonically disperse them in a beaker containing 20mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 160°C and keep it for 12 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 100°C for 10 hours to obtain a 0.5wt% Cr@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 1.82mmol / g.

[0022] Embodiment 2:

[0023] Place 0.9328 g ZrCl in a beaker containing 50 mL N,N-dimethylformamide reagent. 4 and 0.7246g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 130°C and maintained for 24 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 100°C for 16 hours to obtain the final UiO-66-NH-2 carrier.

[0024] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0305g of chromium chloride and ultrasonically disperse them in a beaker containing 40mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 180°C and keep it for 18 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 200°C for 24 hours to obtain a 1wt% Cr@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 2.01 mmol / g.

[0025] Embodiment 3:

[0026] Place 0.9328 g ZrCl in a beaker containing 75 mL N,N-dimethylformamide reagent. 4 and 1.0869g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 150°C and maintained for 36 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 120°C for 20 hours to obtain the final UiO-66-NH-2 carrier.

[0027] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0754g of chromium sulfate and ultrasonically disperse them in a beaker containing 60mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 200°C and keep it for 24 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 150°C for 24 hours to obtain a 2wt% Cr@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 1.68mmol / g.

[0028] Embodiment 4:

[0029] Place 0.9328 g ZrCl in a beaker containing 50 mL N,N-dimethylformamide reagent. 4and 0.3623g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 130°C and maintained for 12 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 100°C for 12 hours to obtain the final UiO-66-NH-2 carrier.

[0030] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0145g of ferric chloride and ultrasonically disperse them in a beaker containing 20mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 160°C and keep it for 18 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 100°C for 16 hours to obtain a 0.5wt% Fe@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 2.15mmol / g.

[0031] Embodiment 5:

[0032] Place 0.9328 g ZrCl in a beaker containing 75 mL N,N-dimethylformamide reagent. 4 and 0.7246g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 150°C and maintained for 24 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 120°C for 16 hours to obtain the final UiO-66-NH-2 carrier.

[0033] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0432g of ferric nitrate and ultrasonically disperse them in a beaker containing 40mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 180°C and keep it for 24 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 130°C for 24 hours to obtain a 1wt% Fe@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2Adsorption test, the obtained CO 2 The adsorption amount is 2.32mmol / g.

[0034] Embodiment 6:

[0035] Place 0.9328 g ZrCl in a beaker containing 25 mL N, N-dimethylformamide reagent. 4 and 1.0869g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 100°C and maintained for 36 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 80°C for 20 hours to obtain the final UiO-66-NH-2 carrier.

[0036] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0441g of cobalt chloride and ultrasonically disperse them in a beaker containing 60mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 200°C and keep it for 12 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 150°C for 10 hours to obtain a 2wt% Co@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 2.75mmol / g.

[0037] Embodiment 7:

[0038] Place 0.9328 g ZrCl in a beaker containing 75 mL N,N-dimethylformamide reagent. 4 and 0.3623g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 150°C and maintained for 12 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 120°C for 12 hours to obtain the final UiO-66-NH-2 carrier.

[0039] Take 1g of the synthesized UiO-66-NH-2 sample and 0.0155g of cobalt nitrate and ultrasonically disperse them in a beaker containing 20mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 160°C and keep it for 24 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 100°C for 24 hours to obtain a 0.5wt% Co@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 2.55mmol / g.

[0040] Embodiment 8:

[0041] Place 0.9328 g ZrCl in a beaker containing 25 mL N,N-dimethylformamide reagent. 4 and 0.7246g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 100°C and maintained for 24 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 80°C for 16 hours to obtain the final UiO-66-NH-2 carrier.

[0042] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0263g of nickel sulfate and ultrasonically disperse them in a beaker containing 40mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 180°C and keep it for 12 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 130°C for 10 hours to obtain a 1wt% Ni@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 3.17 mmol / g.

[0043] Embodiment 9:

[0044] Place 0.9328 g ZrCl in a beaker containing 50 mL N,N-dimethylformamide reagent. 4and 1.0869g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 130°C and maintained for 36 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 100°C for 20 hours to obtain the final UiO-66-NH-2 carrier.

[0045] Take 1g of the synthesized UiO-66-NH-2 carrier and 0.0620g of nickel nitrate and ultrasonically disperse them in a beaker containing 60mL of dimethyl sulfoxide. After stirring the mixed solution for half an hour, move it to a polytetrafluoroethylene container, install a well-sealed stainless steel autoclave on the outside, and heat it from room temperature to 200°C and keep it for 18 hours. Then rinse the mixture with acetone or ethanol three times and centrifuge to remove the residue of dimethyl sulfoxide. The final product is vacuum dried at 150°C for 16 hours to obtain a 2wt% Ni@UiO-66-NH-2 composite adsorbent. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 3.02mmol / g.

[0046] Comparative Example 1:

[0047] Place 0.9328 g ZrCl in a beaker containing 25 mL N,N-dimethylformamide reagent. 4 and 0.3623g 2-aminoterephthalic acid and ultrasonically dissolved for half an hour. After the time is completed, the mixed solution is transferred to a polytetrafluoroethylene container, and a well-sealed stainless steel autoclave is installed on the outside. It is continuously heated from room temperature to 100°C and maintained for 12 hours. After the autoclave is cooled down, the sample is rinsed and centrifuged three times with anhydrous methanol to ensure the elimination of N, N-dimethylformamide, and then dried in an oven at 80°C for 12 hours to obtain the final UiO-66-NH-2 carrier. The adsorbent is placed in a fixed bed adsorption device for CO 2 Adsorption test, the obtained CO 2 The adsorption amount is 1.28mmol / g.

Claims

1. An amino-functionalized M@UiO-66-NH-2 composite adsorbent, characterized in that: The active component is one of Cr, Fe, Co or Ni, UiO-66-NH-2 is used as a carrier, and the adsorbent morphology is an octahedral structure. The specific preparation steps are as follows: 1) Dissolving zirconium chloride and 2-aminoterephthalic acid in N,N-dimethylformamide, and then subjecting the mixture to ultrasonic treatment, hydrothermal reaction, washing, centrifugation and drying to obtain a UiO-66-NH-2 carrier; 2) The UiO-66-NH-2 carrier and the M source were first dissolved in dimethyl sulfoxide, and then subjected to ultrasonic treatment, hydrothermal reaction, washing, centrifugation and drying to obtain the M@UiO-66-NH-2 composite adsorbent.

2. The M@UiO-66-NH-2 composite adsorbent according to claim 1, characterized in that: In the step (1), the molar ratio of zirconium chloride to 2-aminoterephthalic acid is 1:(0.5-1.5), the amount of N,N-dimethylformamide is 25-75 mL, the hydrothermal reaction temperature is 100-150° C., the hydrothermal reaction time is 12-36 h, the drying temperature is 80-120° C., and the drying time is 12-20 h.

3. The M@UiO-66-NH-2 composite adsorbent according to claim 1, characterized in that: In the step (2), the mass ratio of the UiO-66-NH-2 carrier to the M ion is 1:(0.005-0.02), the amount of dimethyl sulfoxide is 20-60 mL, the hydrothermal reaction temperature is 160-200° C., the hydrothermal reaction time is 12-24 h, the drying temperature is 100-150° C., and the drying time is 10-24 h.

4. The M@UiO-66-NH-2 composite adsorbent according to claim 1, characterized in that: In the step (2), the Cr source is any one of chromium nitrate, chromium chloride or chromium sulfate; the Fe source is any one of ferric chloride or ferric nitrate; the Co source is any one of cobalt chloride or cobalt nitrate; and the Ni source is any one of nickel sulfate or nickel nitrate.

5. The M@UiO-66-NH-2 composite adsorbent according to claim 1, characterized in that: The adsorbent is used in CO2 adsorption separation.

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