KR102284313B1 - Metal organic frameworks for chemical adsorption and decomposition of formaldehyde - Google Patents

Abstract

Formaldehyde removal method provided in one aspect of the present invention,
Even if there is a lot of moisture in the environment where formaldehyde is to be removed, the adsorption capacity of the metal-organic structure does not decrease, and formaldehyde can be irreversibly adsorbed and decomposed. It can be effectively removed.

Description

Metal organic frameworks for chemical adsorption and decomposition of formaldehyde

Metal organic frameworks (MOFs) for chemical adsorption and decomposition of formaldehyde.

Formaldehyde, which is generated from building materials, personal hygiene products, and numerous home appliances and furniture, is a volatile organic compound (VOCs) and is a representative substance known as a causative agent of sick house syndrome.

Substances that cause sick house syndrome, including formaldehyde, are most discharged 6 months after construction is built. , it can act as a factor that continuously harms health.

Accordingly, the Ministry of Environment amended and implemented the 「Indoor Air Quality Management Act in Multi-Use Facilities, etc.」, which significantly strengthens indoor air management in apartment houses and multi-use facilities to prevent sick house syndrome.

However, substances that cause sick house syndrome, such as formaldehyde, are still emitted from buildings built before the revision. the current situation.

As an example, Patent Document 1 (Korean Patent Registration No. 10-2008643) adsorbs, decomposes, and removes formaldehyde, toluene, ammonia and volatile organic compounds (VOCs) generated in new buildings, etc. to prevent sick house syndrome, adsorption, Volatile organic compounds (VOCs) and formaldehyde (HCHO) that have moisture absorptive and desorptive performance, antibacterial and antifungal performance, prevent cancer, improve atopy, reduce stress, and purify indoor air to benefit the human body A functional wallpaper containing an adsorption decomposition neutralizer for removing

However, the adsorption decomposition neutralizer included in the functional wallpaper disclosed in Patent Document 1 is guanidine sulfamate, urea, ethylene urea, glucose, hydroxyethyl acrylamide ( It is composed of numerous components such as Hydroxyethyl Acryl Amide) and Phosphoric Acid, and not only the desired content control of each of these is required, but also the adsorption capacity of formaldehyde is not reduced in an environment with a lot of moisture. There are limitations that cannot be directly proved that there is.

In this situation, the applicant of the present invention can be used for the purpose of separating oxygen or carbon dioxide in the air or separating olefin/paraffin in the prior art. Known Metal Organic Frameworks (MOFs),

It can be used for the irreversible adsorption and removal of formaldehyde, and further, since the adsorption capacity of formaldehyde is not reduced even in the presence of water (moisture) in the environment to remove formaldehyde,

It was confirmed that formaldehyde can be effectively removed even in the presence of moisture, and the present invention was completed.

It is an object of one aspect of the present invention to provide a formaldehyde removal method capable of effectively removing formaldehyde using a specific metal-organic structure even in an environment in which a lot of moisture exists.

Another object of the present invention is to provide an adsorbent for removing formaldehyde, including the metal-organic structure.

Another object of the present invention is to provide an air purifying filter comprising the adsorbent for removing formaldehyde.

Another object of the present invention is to provide an air purifier equipped with the air purifying filter.

In order to achieve the above object,

In one aspect of the present invention, formaldehyde is brought into contact with metal organic frameworks (MOFs) containing a 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by the following Chemical Formula 1 as a ligand. It provides a method for removing formaldehyde, comprising the step.

[Formula 1]

In Formula 1,

X is hydrogen (-H), chloro (-Cl), bromo (-Br), or iodo (-I).

In addition, another aspect of the present invention provides an adsorbent for removing formaldehyde, comprising a metal organic structure comprising the 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by Chemical Formula 1 as a ligand do.

Furthermore, another aspect of the present invention provides an air purification filter comprising the adsorbent for removing formaldehyde.

In addition, another aspect of the present invention provides an air purifier provided with the air purifying filter.

Formaldehyde removal method provided in one aspect of the present invention,

Even if there is a lot of moisture in the environment where formaldehyde is to be removed, the adsorption capacity of the metal-organic structure does not decrease, and formaldehyde can be irreversibly adsorbed and decomposed. It can be effectively removed.

1 shows the results of measuring the change in substituents in m-DOBDC of the _{metal organic structure Co 2} (m-DOBDC) as the reaction time with formaldehyde was 6h, 12h, 48h, and 72h through ^{1 H-NMR measurement.} It is a drawing showing
2 is a view showing the reaction mechanism of ^{m-DOBDC 4-} _{and formaldehyde present in Co 2} (m-DOBDC).
3 is a view showing a reaction mechanism in which a methyl alcohol group (-CH ₂ ^{OH) inserted into m-DOBDC 4-} is spontaneously converted into a methyl group (-CH _{3 ) by reaction with formaldehyde.
Figure 4 shows the crystal structures of Co 2} (5-methylalcohol-m-DOBDC) and Co ₂ (5-methyl-m-DOBDC) derived through SXRD (single crystal x-ray diffraction) analysis; It is a drawing.
Figure 5 is a view showing the microscopic images (Microscope images) of _{HCOH@Co 2} (m-DOBDC) after 24 hours have elapsed since the induction of adsorption of formaldehyde _{to Co 2 (m-DOBDC) at 100 ° C, scale} bar is 200 μm.
6 is a view of MOF crystals confirmed through a microscope when ^{Co 2+} is removed through acid treatment after 24 hours have elapsed since adsorption of formaldehyde _{to Co 2 (m-DOBDC) was induced at 100° C.} A diagram showing a highly porous organic replica of the MOF crystals, and the scale bar is 200 μm.
7 is a view showing an SEM image of a highly porous organic model of MOF crystals obtained through the acid treatment, and the scale unit is 10.0 μm.
8 is a diagram showing an SEM image of a highly porous organic model of a MOF crystal obtained through the acid treatment, and the scale unit is 500 nm.
9 is a view showing a specific polymerization (polymerized) reaction mechanism of ^{m-DOBDC 4-} _{and formaldehyde present in Co 2} (m-DOBDC) at 100 °C.
10 is a view confirming that the structure of the MOF is maintained even after adsorption of formaldehyde (HCOH@Co ₂ (m-DOBDC)) by an SEM image, and the scale unit is 4.00 μm.
11 is a view confirming that the structure of the MOF is maintained even after adsorption of formaldehyde (HCOH@Co ₂ (m-DOBDC)) by an SEM image, and the scale unit is 1.00 μm.

Hereinafter, the present invention will be described in detail.

On the other hand, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

Furthermore, "including" a certain element throughout the specification means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In one aspect of the present invention, formaldehyde is brought into contact with metal organic frameworks (MOFs) containing a 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by the following Chemical Formula 1 as a ligand. It provides a method for removing formaldehyde, comprising the step.

[Formula 1]

In Formula 1,

X is hydrogen (-H), chloro (-Cl), bromo (-Br), or iodo (-I).

In this case, the metal ions of the metal organic frameworks (MOFs) may be Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ^{2+ ,} or the like.

Furthermore, the metal-organic structure may be a porous metal-organic structure including a structural unit represented by the following formula (2).

[Formula 2]

M ₂ (L)

In Formula 2,

M is a metal ion (II),

L is a ligand represented by Formula 1 above.

Formaldehyde removal method provided in one aspect of the present invention,

Formaldehyde is irreversibly adsorbed to the ligand of the metal organic frameworks (MOFs) through a covalent bond, characterized in that the formaldehyde is decomposed.

In addition, when formaldehyde is irreversibly adsorbed to the ligand of the metal organic structure through a covalent bond, the formaldehyde is adsorbed to the ligand as a methyl alcohol group (-CH ₂ OH), and then spontaneously a methyl group (-CH _{3 )} ), which has the effect of further increasing thermal stability.

Another aspect of the present invention provides an adsorbent for removing formaldehyde comprising a metal organic structure including a 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by the following Chemical Formula 1 as a ligand.

[Formula 1]

In Formula 1,

X is hydrogen (-H), chloro (-Cl), bromo (-Br), or iodo (-I).

In this case, the metal ion of the metal organic structure may be Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ^{2+ ,} or the like.

Furthermore, the metal-organic structure may be a porous metal-organic structure including a structural unit represented by the following formula (2).

[Formula 2]

M ₂ (L)

In Formula 2,

M is a metal ion (II),

L is a ligand represented by Formula 1 above.

The adsorbent for removing formaldehyde provided in one aspect of the present invention,

Formaldehyde is irreversibly adsorbed to the ligand of the metal organic frameworks (MOFs) through a covalent bond, characterized in that the formaldehyde is decomposed.

In addition, when formaldehyde is irreversibly adsorbed to the ligand of the metal organic structure through a covalent bond, the formaldehyde is adsorbed to the ligand as a methyl alcohol group (-CH ₂ OH), and then spontaneously a methyl group (-CH _{3 )} ), which has the effect of further increasing thermal stability.

Another aspect of the present invention provides an air purification filter comprising an adsorbent for removing formaldehyde.

In this case, the adsorbent for removing formaldehyde included in the air purification filter may be the above-mentioned adsorbent for removing formaldehyde.

More specifically, the adsorbent for removing formaldehyde may include a metal organic structure including a 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by the following Chemical Formula 1 as a ligand.

[Formula 1]

In Formula 1,

X is hydrogen (-H), chloro (-Cl), bromo (-Br), or iodo (-I).

In this case, the metal ion of the metal organic structure may be Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ^{2+ ,} or the like.

Furthermore, the metal-organic structure may be a porous metal-organic structure including a structural unit represented by the following formula (2).

[Formula 2]

M ₂ (L)

In Formula 2,

M is a metal ion (II),

L is a ligand represented by Formula 1 above.

In the adsorbent for removing formaldehyde in the air purification filter provided in one aspect of the present invention, formaldehyde is irreversibly adsorbed to the ligand of the metal organic frameworks (MOFs) through a covalent bond, and formaldehyde is decomposed. characterized by being

In addition, when formaldehyde is irreversibly adsorbed to the ligand of the metal organic structure through a covalent bond, the formaldehyde is adsorbed to the ligand as a methyl alcohol group (-CH ₂ OH), and then spontaneously a methyl group (-CH _{3 )} ), which has the effect of further increasing thermal stability.

Another aspect of the present invention provides an air purifier for removing formaldehyde provided with the air purifying filter.

Conventional formaldehyde adsorbents physically adsorb formaldehyde, so there are cases in which formaldehyde is desorbed back into the air. was present.

However, in the formaldehyde removal method provided in one aspect of the present invention, the adsorption capacity of the metal-organic structure does not decrease even if a lot of moisture is present in the environment from which the formaldehyde is to be removed,

Since formaldehyde can be irreversibly adsorbed and decomposed, there is an effect of effectively removing formaldehyde even in an environment in which a lot of moisture exists, which is directly supported by the preparation examples and experimental examples described below.

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples.

However, the Examples and Experimental Examples described below are merely illustrative of the present invention in detail in one aspect, and the present invention is not limited thereto.

<Preparation Example 1> Co ₂ (m-DOBDC) preparation

Co ₂ (m-DOBDC) (m-DOBDC ^4- = 4,6-dioxo-1,3-benzenedicarboxylate) was prepared according to J. Am. Chem. Soc. 2017, 139, prepared according to the method disclosed in "MATERIALS AND METHODS" of 15363-15370. _{On the other hand, prepare Co 2} (m-DOBDC) prepared by other known methods (B. Lee, Y.-P. Chen, J. Park, ACS Appl. Mater. Interfaces 2019, 11, 25817-25823, etc.) it's free though

More specifically, CoCl ₂ .6H ₂ O (1498.9 mg, 6.3 mmol) and H ₄ m-DOBDC (519.8 mg, 2.6 mmol) were mixed with DMF/MeOH/H ₂ O/1-butanol (130 mL; 1.00:1.00: 0.40:0.72 v/v/v/v), followed by sonication for 15 minutes, and then heating at 80° C. for 72 hours. Thereafter, when cooled to room temperature, the title Co ₂ (m-DOBDC) can be obtained in the form of needle crystals of red-violet color.

<Experimental Example 1> Co ₂ Formaldehyde chemical adsorption and decomposition activity evaluation of (m-DOBDC)

_{When formaldehyde is treated with Co 2} (m-DOBDC) prepared in <Preparation Example 1>, the following experiment is performed to evaluate whether _{formaldehyde is chemically and irreversibly adsorbed and decomposed on Co 2 (m-DOBDC)} was performed.

More specifically, in a glove box filled with argon (Ar), a 4 mL vial containing 10.0 mg of _{Co 2 (m-DOBDC) prepared in <Preparation Example 1>, 50 mg of formaldehyde} It was placed in a 20 mL vial filled with aqueous solution (37 wt %, Sigma Aldrich). Thereafter, it was placed in an oven at 60°C.

In this process, the formaldehyde aqueous solution is vaporized, and Co ₂ (m-DOBDC) adsorbs formaldehyde in an environment with very high relative humidity. If the chemical adsorption and decomposition activity of formaldehyde is excellent even in such an environment with very high relative humidity, it is directly proved that the limitation of the conventional formaldehyde adsorbent, which was lowered in the adsorption capacity of formaldehyde in an environment with a lot of moisture, is overcome. will be.

After the adsorption was completed, the MOF crystals were washed 3 times with methanol for 12 hours. Thereafter, Soxhlet extraction was performed with methanol for 24 hours to remove all unreacted substances present in the pores. Methanol was removed and the washed MOF crystals were activated under vacuum at 180° C. for 24 h.

Next, through ¹ H-NMR (Hydrogen nuclear magnetic resonance, Fourier transform nuclear magnetic resonance spectrometer) spectrum measurement, as the reaction time with formaldehyde elapses, m-DOBDC of the _{metal organic structure Co 2 (m-DOBDC)} Substituent change in ^{4- was evaluated.}

¹ H-NMR measurement results are shown in FIG. 1 when the reaction is 6h, 12h, 48h, and 72h, respectively.

1 shows the results of measuring the change in substituents in m-DOBDC of the _{metal organic structure Co 2} (m-DOBDC) as the reaction time with formaldehyde was 6h, 12h, 48h, and 72h through ^{1 H-NMR measurement.} It is a drawing showing

As shown in Figure 1,

As the reaction time with formaldehyde elapses, it can be seen that the peak intensity of _{the methyl alcohol group (-CH 2} OH) generated due to the irreversible adsorption of formaldehyde _{to the metal organic structure Co 2 (m-DOBDC) gradually increases.} can

In addition, it can be seen that the generated methyl alcohol group (-CH ₂ OH) is spontaneously _{converted to a methyl group (-CH 3 ).}

In this regard, ^{a specific reaction mechanism between m-DOBDC 4-} _{and formaldehyde present in Co 2} (m-DOBDC) is shown in FIG. 2 .

2 is a view showing the reaction mechanism of ^{m-DOBDC 4-} _{and formaldehyde present in Co 2} (m-DOBDC).

As shown in Figure 2,

By the reaction of m-DOBDC ^4- with formaldehyde, a methyl alcohol group (-CH ₂ OH) can be inserted into the C5 atom of ^{m-DOBDC 4-} without generating a proton.

Then, the above insertion of methyl alcohol group (-CH ₂ OH) is voluntary as methyl (-CH ₃₎ is converted to methyl alcohol group 3 spontaneous conversion mechanism to a methyl group (-CH ₃₎ in (-CH ₂ OH) shown in 3 is a view showing a specific reaction mechanism in which a methyl alcohol group (-CH ₂ ^{OH) inserted into m-DOBDC 4-} is spontaneously converted into a methyl group (-CH _{3 ) by reaction with formaldehyde.}

Furthermore, the coexistence of a methyl alcohol group (-CH ₂ OH) and a methyl group (-CH ₃ ) was confirmed through SXRD (single crystal x-ray diffraction, D8 Venture from Bruker and synchrotron radiation at Pohang Accelerator Laboratory Beamline) analysis, The 40:60 ratio of the methyl alcohol group and the methyl group derived from the SXRD analysis was consistent with the results of the NMR analysis. Figure 4 shows the crystal structure (Crystal structures) of Co ₂ (5- methyl alcohol -m-DOBDC) and Co ₂ (5- methyl -m-DOBDC). On the other hand, since there are no leaving groups in formaldehyde, only water is adsorbed on the ^{open Co 2+ sites.}

From this,

It is known that Co ₂ (m-DOBDC) can be used for the irreversible adsorption and removal of formaldehyde, and in particular, it shows excellent formaldehyde adsorption capacity even in the presence of a lot of water (moisture) in the environment to remove formaldehyde. can

<Experimental Example 2> Formaldehyde chemical adsorption and decomposition activity evaluation at 100°C

The experiment was performed in the same manner as in <Experimental Example 1>, but instead of proceeding with the reaction with formaldehyde at 60° C.,

It was evaluated whether chemical adsorption and decomposition of formaldehyde were possible by inducing a reaction with formaldehyde at 100°C higher than this.

After 24 hours of inducing the adsorption of formaldehyde _{to Co 2} (m-DOBDC) at 100° C., _{the microscope images of HCOH@Co 2} (m-DOBDC) are shown in FIG. 5 , and scale bar is 200 μm.

^{Next, it was confirmed through FIG. 6 that when Co 2+} was removed through acid treatment, a highly porous organic replica of the MOF crystals was obtained. The SEM images of the high porosity model of the obtained MOF crystal are shown in FIGS. 7 and 8 .

7 is a view showing an SEM image of a highly porous organic model of MOF crystals obtained through the acid treatment, and the scale unit is 10.0 μm.

8 is a diagram showing an SEM image of a highly porous organic model of a MOF crystal obtained through the acid treatment, and the scale unit is 500 nm.

From this, it can be seen that formaldehyde is efficiently adsorbed through a process in which formaldehyde is polymerized into resorcinol-formaldehyde resin at 100°C.

^{A specific polymerization reaction mechanism of m-DOBDC 4-} _{and formaldehyde present in Co 2} (m-DOBDC) at 100° C. is shown in FIG. 9 .

Finally, even after adsorption of formaldehyde (HCOH@Co ₂ (m-DOBDC)), it was confirmed through SEM images of FIGS. 10 and 11 that the structure of the MOF was maintained.

10 is a view confirming that the structure of the MOF is maintained even after adsorption of formaldehyde (HCOH@Co ₂ (m-DOBDC)) by an SEM image, and the scale unit is 4.00 μm.

11 is a view confirming that the structure of the MOF is maintained even after adsorption of formaldehyde (HCOH@Co ₂ (m-DOBDC)) by an SEM image, and the scale unit is 1.00 μm.

Claims (15)

Form comprising the step of contacting formaldehyde with metal organic frameworks (MOFs) containing a 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by the following formula (1) as a ligand Aldehyde removal method:
[Formula 1]

In Formula 1,
X is hydrogen (-H).
According to claim 1,
The metal ions of the metal organic frameworks (Metal Organic Frameworks, MOFs) are Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , or Zn ²⁺ , characterized in that the form Aldehyde removal method.
delete According to claim 1,
The metal organic frameworks (MOFs) are,
A method for removing formaldehyde, characterized in that it is a porous metal-organic structure comprising a structural unit represented by the following formula (2):
[Formula 2]
M ₂ (L)
In Formula 2,
M is a metal ion (II),
L is a ligand represented by the formula (1) of claim 1.
5. The method of claim 4,
The metal ion is Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , or Zn ²⁺ , the formaldehyde removal method.
According to claim 1,
The formaldehyde removal method comprises:
Formaldehyde removal method, characterized in that the formaldehyde is irreversibly adsorbed to the ligand of the metal organic frameworks (Metal Organic Frameworks, MOFs) through a covalent bond to remove the formaldehyde.
7. The method of claim 6,
When formaldehyde is irreversibly adsorbed to the ligand of the Metal Organic Frameworks (MOFs) through a covalent bond,
Formaldehyde is adsorbed to the ligand as a methyl alcohol group (-CH ₂ OH), and then spontaneously converted to a _{methyl group (-CH 3 ).}
An adsorbent for removing formaldehyde, comprising metal organic frameworks (MOFs) containing a 4,6-dioxo-1,3-benzenedicarboxylate derivative represented by the following formula (1) as a ligand:
[Formula 1]

In Formula 1,
X is hydrogen (-H).
9. The method of claim 8,
The metal ions of the metal organic frameworks (Metal Organic Frameworks, MOFs) are Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , or Zn ²⁺ , characterized in that the form Adsorbent for aldehyde removal.
delete 9. The method of claim 8,
The metal organic frameworks (MOFs) are,
An adsorbent for removing formaldehyde, characterized in that it is a porous metal-organic structure comprising a structural unit represented by the following formula (2).
[Formula 2]
M ₂ (L)
In Formula 2,
M is a metal ion (II),
L is a ligand represented by the formula (1) of claim 8.
12. The method of claim 11,
The metal ion is Mg ²⁺ , Mn ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , or Zn ²⁺ , an adsorbent for removing formaldehyde, characterized in that it is Zn 2+ .
9. The method of claim 8,
The adsorbent for removing formaldehyde,
Formaldehyde is irreversibly adsorbed through a covalent bond to the ligand of the metal organic frameworks (Metal Organic Frameworks, MOFs), characterized in that the formaldehyde is removed, an adsorbent for removing formaldehyde.
An air purification filter comprising the adsorbent for removing the formaldehyde of claim 8.
An air purifier equipped with the air purifying filter of claim 14.

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