KR20190099862A - Ionic Clathrate Nano-Cage Reactor and Method of Capturing and Decomposing Greenhouse Gases By Using the Same - Google Patents

Abstract

The present invention relates to a nano-cage reactor using ionic hydrate and a method for capturing and decomposing greenhouse gases using the same. More particularly, the ionic hydrate lattice can be used as a nano-cage reactor to capture the greenhouse gases such as nitrous oxide in the hydrate or efficiently decompose greenhouse gases.

Description

Ionic Clathrate Nano-Cage Reactor and Method of Capturing and Decomposing Greenhouse Gases By Using the Same}

The present invention relates to a method for capturing and decomposing greenhouse gases using ionic hydrate as a nano cage reactor, and more particularly, to capture a greenhouse gas such as nitrous oxide in hydrate using an ionic hydrate lattice as a nano cage reactor. The present invention relates to a method of decomposing or efficiently.

The development of materials that enable efficient use of resources and energy and environmentally friendly storage has been continually pursued both in academic and industrial terms. Although much research has been conducted on the natural state of water, the most abundant substance on the planet, ice, which is a solid phase formed by hydrogen bonds, has many unique properties. Ice freezing below freezing points to a specific crystal structure and does not have a closed space, but when the ice coexists with other compounds, proper structure of temperature and pressure can lead to crystal structure transformation and confined voids. have. This nano-size enclosed void can be used as a storage space where small organic molecules or gas molecules can be collected. This kind of clathrate compound is similar to ice or clathrate hydrate. Hydrates below ''. A small enclosed space within the hydrate is called a cage, a compound in which natural gas is naturally trapped in the pupil, and 'fuel gas hydrate,' which is widely regarded as a future energy source to replace coal and petroleum, is popular. Well-known and stable methods for recovering natural gas from this are being studied worldwide (Sloan, ED et al., Clathrate Hydrates of Natural Gases.CRC press (Taylor and Francis Group) 2008, 3rd ed.).

In addition, a method using an environmentally friendly, reliable, non-explosive characteristics of the hydrate which can store a large amount of methane effectively also been studied (Baek, S. et al., Enhanced Methane Hydrate Formation with Cyclopentane Hydrate Seeds. Appl. Energ. 2017 , 202, 32-41). As such, attempts have been made in the academia and industry to use quasi-ice material as a vehicle for efficient use and economical storage of energy from a macroscopic perspective.

Among the hydrates, the ionic hydrate, which is a special hydrate form, is a substance in which ionic object molecules are present in the pupil formed by the main lattice formed by hydrogen bonds of water molecules, and the counterion is doped in the main lattice (Shin, K). et al., Chem- Asian.J. 2010, 5, 22-34). Detection of hydrogen gas using rapid ionic conduction and inter-pupillary radical transport through the vacant proton sites of the subject lattice using several unique physicochemical properties resulting from subject-object interactions (Cha, JH et al., Angew . Chem . Int . Edit. 2009, 48, 8687-8690) or supercapacitors (Lee, W et al., Chem- Asian. J. 2013, 8, 1569-1573) have been identified, but the principles It is not clear and there is no basic research for further applications even in the hydrate academia.

Meanwhile, the Kyoto Protocol on the Climate Change Convention selected nitrous oxide as the third greenhouse gas to be reduced after carbon dioxide and methane, and the global warming potential of nitrous oxide was 310 times that of carbon dioxide. (Ravishankara, AR et al., Science 2009, 326, 123-125), with a lifespan of 114 years, nitrous oxide can deplete the stratospheric ozone layer. Unfortunately, anthropogenic emissions of nitrous oxide are increasing and will almost double in 2050 without special efforts (Ravishankara, AR et al., Science 2009, 326 , 123; Ramanathan, V. et al., P Natl). Acad Sci USA 2010, 107 , 8055; Li, L. et al., Environ Sci Technol 2014, 48 , 5290; Konsolakis, M. Acs Catal 2015, 5 , 6397). Nitrous oxide has almost the same molecular size as carbon dioxide, but carbon dioxide is physically adsorbed and captured (Pang, SH et al., J. Am. Chem . Soc . 2017, 139, 3627-3630) and converted to other high value materials. Research has been actively conducted (Song, CS, Catal . Today 2006, 115, 2-32), while nitrous oxide has been limited to reactions with metal oxide catalysts at high temperatures (300-700 ° C) due to their high reducing power. (Konsolakis, M., Mechanistic Considerations, and SurfaceChemistry Aspects. ACS Catal. 2015, 5, 6397-6421). Therefore, there is a need for a system capable of efficiently treating nitrous oxide.

Thus, the present inventors have made diligent efforts to solve the above problems, as a result of using the activated ionic hydrate lattice in which the electron movement between the pupils is actively used as a nano cage reactor, not only can the greenhouse gas be trapped in the hydrate, Through the redox reaction in the interior it was confirmed that the greenhouse gas, in particular nitrous oxide can be efficiently decomposed, and the present invention was completed.

It is an object of the present invention to provide a method for trapping or efficiently decomposing greenhouse gases into hydrates using an ionic hydrate lattice as a nano cage reactor.

In order to achieve the above object, the present invention provides a method using a ionic hydrate having a cavity as a nano cage reactor.

The present invention also provides a method for capturing a greenhouse gas, characterized in that the binary object hydrate is formed by collecting or injecting the greenhouse gas into an ionic hydrate having a pupil.

The present invention also comprises the steps of (a) injecting a greenhouse gas to the ionic hydrate and trapping in the pupil; And (b) activating the ionic hydrate to decompose the collected greenhouse gas, thereby providing a method for decomposing the greenhouse gas using the ionic hydrate having a pupil.

According to the present invention it is possible to decompose greenhouse gases such as nitrous oxide in activated ionic hydrates. Through the present invention, the hydrate has the effect of decomposing the greenhouse gas through the catalytic reaction as a nano cage reactor as well as the sequestration medium of the greenhouse gas.

1 is a view showing the structure of the Me ₄ NOH + N ₂ O binary object ionic hydrate according to an embodiment of the present invention.
2 is a diagram showing a PXRD pattern of Me ₄ NOH + N ₂ O hydrate according to an embodiment of the present invention.
3 shows ESR spectra of gamma-irradiated Me ₄ NOH + N ₂ O hydrates measured at 77K according to one embodiment of the present invention.
4 is a diagram illustrating a Raman spectrum of gamma-irradiated Me ₄ NOH + N ₂ O hydrate according to an embodiment of the present invention.
5 is a diagram schematically illustrating an N ₂ O decomposition reaction occurring in gamma-irradiated Me ₄ NOH + N ₂ O hydrate according to an embodiment of the present invention.
6 is a diagram showing a PXRD pattern of N ₂ O hydrate according to an embodiment of the present invention.
Figure 7 is a photograph showing the color change of the gamma irradiated Me ₄ NOH + 16H ₂ O (left) and Me ₄ NOH + 16H ₂ O + N ₂ O (right) hydrate according to an embodiment of the present invention.
FIG. 8 is an enlarged 14-28 ° PXRD pattern of (a) gamma-irradiated Me ₄ NOH + N ₂ O hydrate measured at 93K, 113K and 133K and (b) PXRD pattern according to one embodiment of the present invention It is a figure which shows the highlighted area.
FIG. 9 shows Raman spectra of gamma-irradiated pure N ₂ O cluster hydrates measured at various temperatures (93-273K) under flushing of cooled helium gas in accordance with one embodiment of the present invention.
FIG. 10 shows Raman spectra of unirradiated Me ₄ NOH + N ₂ O cluster hydrates measured at various temperatures (93-273K) without flushing cooled helium gas in accordance with one embodiment of the present invention. .
FIG. 11 shows Raman spectra of unirradiated Me ₄ NOH + N ₂ O chydrate hydrate measured at various temperatures (93-273 K) with flushing of cooled helium gas in accordance with one embodiment of the present invention. .
12 shows Raman spectra of Me ₄ NOH + N ₂ and Me ₄ NOH + O ₂ cluster hydrates measured at 93K and gamma-irradiated Me ₄ NOH + N ₂ O measured at 173K, according to an embodiment of the present invention. The Raman spectra of the crate hydrates are compared.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

The present invention focuses on the unique physicochemical properties of ionic hydrates, and not only captures greenhouse gases in hydrates using the pores of ionic hydrates as nano-cage reactors, but also through the redox reactions in the pores. In particular, it was confirmed that nitrous oxide can be efficiently decomposed.

Accordingly, the present invention relates to a method of using an ionic hydrate having a pupil as a nano cage reactor.

In addition, in another aspect of the present invention relates to a method for capturing a greenhouse gas, characterized in that to form a binary object hydrate by collecting or injecting the greenhouse gas in the ionic hydrate having a pupil.

In addition, in another aspect of the invention (a) injecting a greenhouse gas to the ionic hydrate to collect in the pupil; And (b) decomposing the greenhouse gas by activating the ionic hydrate to decompose the collected greenhouse gas.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In the present invention, attention is paid to the unique physicochemical properties of the ionic hydrate from the microscopic viewpoint, and the pupil of the ionic hydrate is used as the nano cage reactor. The ionic hydrate pupil can be utilized as a nano cage reactor to decompose greenhouse gases in the pupil.

In the present invention, the ionic hydrate may be a material in which an ionic object molecule is present in a pupil formed by a principal lattice composed of hydrogen bonds of water molecules, and the counterion is doped in the main lattice.

In the present invention, an appropriate cluster system must be selected for the nitrous oxide decomposition reaction. Tetramethylammonium hydroxide (Me ₄ NOH), an ionic cluster hydrate containing Me ₄ N ⁺ cation crusted in the cage and OH ⁻ contained in the object structure, electrons, hydrogen atoms, or other It is known to stably provide radicals (Bednarek, J. et al., J Phys Chem- Us 1996, 100 , 3910; Shin, K. et al., J Am Chem Soc 2011, 133 , 20399; Cha, M. et al., J Am Chem Soc 2010, 132 , 3694; Bednarek, J. et al., J Am Chem Soc 1991, 113 , 8990; Shin, K. et al., Chem- Asian J 2010, 5 , 22). Photochemical or photocatalytic nitrous oxide decomposition mechanisms previously reported include reactions between nitrous oxide molecules and electrons from the activating surface of the catalyst (Obalova, L. et al., Catal Today 2014, 230 , 61; Koci, K. et al., Catal Today 2012, 191 , 134; Koci, K. et al., Appl Surf Sci 2017, 396 , 1685). Hydroxyl ion doped object molecules of Me ₄ NOH cluster hydrate are a suitable solution in the cluster reactor for the decomposition of nitrous oxide.

In the present invention, the ionic object molecule may be a tetramethylammonium cation, and the counterion may be a hydroxide anion.

In the present invention, the greenhouse gas may be carbon dioxide, methane or nitrous oxide, in particular nitrous oxide, but is not limited thereto.

In the present invention, the ionic hydrate can be activated by irradiating gamma rays or X-rays, and preferably, irradiating gamma rays to activate the ionic hydrate, but is not limited thereto.

Specifically, in the present invention, tetramethylammonium cation (Me ₄ N ⁺ ) occupies a large pupil, and nitrous oxide is injected into an ionic hydrate which is a system in which a hydroxide anion (OH ⁻ ) is doped in the main lattice. Binary object hydrates can be formed (FIG. 1). As shown in FIG. 1, it is preferable to select the smallest Me ₄ N ⁺ among ionic materials because a large ionic object, such as a tetrabutylammonium cation, occupies several pores and reduces the storage capacity of small gas molecules. Do. And small pupils can be collected by injecting nitrous oxide (N ₂ O), which can be easily cleaved by reacting with electrons due to high reducing power in greenhouse gases.

When the binary object (Me ₄ NOH + N ₂ O) ionic hydrate is irradiated with gamma rays or X-rays to activate the hydrate lattice, the electrons generated from the water molecules forming the main lattice are raised as the temperature increases. to be moved between (... Ahn, YH et al, J. Phys Chem C 2016, 120, 17190-17195), when the induced electron transfer process through a number of the nitrous oxide N ₂ O + e ^- → N The reaction of ₂ + O ⁻ proceeds in small pores (FIG. 5). The reaction of nitrous oxide with the electrons transferred is known through several previous studies, but the use of a catalyst synthesized at a high temperature conditions reacted with N ₂ O in ppm unit is limited in practical use ( Koci, K. et al., Catal. Today 2012, 191, 134-137).

The core mechanism according to the present invention is supported by the following prior studies.

First, irradiating gamma rays to tetramethylammonium hydroxide hydrate may cause some water molecules constituting the lattice to be split into electrons, protons, and hydroxyl radicals (1). It is known that the following reactions are induced (2) (Bednarek, J., J. Am. Chem . Soc . 1991, 113, 8990-8991).

_{(1) H 2 O → e} - + H + + ° OH

^{(2) e - + (CH} 3) 4 N + → (CH 3) 3 N + ° CH 3 & ° OH + (CH ₃ ) ₄ N ⁺ → (CH ₃ ) ₃ N + ° CH ₂ + H ₂ O.

At this time, if the temperature rises to 110K, the reverse reaction in (2) reaction is induced and free electrons reappear ((CH ₃ ) ₃ N + ° CH ₃ ^{→ e -... + (} CH 3) 4 N +) (Bednarek, J., J. Am Chem Soc 1991, 113, 8990-8991), when the electromagnetic induction in activated hydrate pupil as gamma rays temperature rises Since the phenomenon of moving between the pupils has been verified (Ahn, YH et al., J. Phys. Chem . C 2016, 120, 17190-17195), the reaction of N ₂ O and electrons in neighboring pupils can be sufficiently expected ^{_{(N 2 O + e - →}} N 2 + O -). Further, jyeoteumeuro it revealed that this channel diffusion of molecules and radicals hydrate between the pupil available from previous studies exist (Choi, S., J. Phys Chem B 2007, 111, 10224-10230..), O - move from the pupil of the reaction and movement of the adjacent cavity of the O ₂ addition product of a mechanism which may be naturally derived ^- from a O ^- + N ₂ O → N ₂ + O ₂ + e.

On the other hand, coexistence of reaction products with N ₂ molecules and O ^- radicals in small pores will cause repulsive forces between objects, causing a metastable state, resulting in the presence of small, unstable O ^- radicals. It moves to the pupil. At this time, the N ₂ O molecules present in the neighboring pupils and the unstable O ⁻ radicals may react as in Scheme 1.

Scheme 1

_{^{O - + N 2 O → N}} 2 + O 2 + e -

As with the result of the first reaction, the coexistence of N ₂ molecules and O ₂ molecules as reaction products in one small pupil increases the repulsive force between objects due to the metastable state, which results in smaller O ₂ molecules with a smaller kinetic diameter. Moves to the neighboring empty pupil. Considering that the occlusion of hydrated small pupils is generally around 0.8 (Sloan, ED et al., Clathrate Hydrates of Natural Gases.CRC press (Taylor and Francis Group) 2008, 3rd ed.) Since empty pupils will inevitably exist in the vicinity, the mechanism presented above is feasible.

Since the electrons induced after the reaction in the second reaction can migrate to the N ₂ O molecules present in the other pupils to induce the first or chain reaction, the scale is slightly larger than ppm in the activated ionic hydrate system. Large amounts of greenhouse gas decomposition reactions can be achieved.

The present invention specifically relates to electrons and radicals derived from activated tetramethylammonium hydrate, and inter-electron electron transfer phenomena in activated hydrates induced at elevated temperatures, and to the inter- Pupil molecule and radical transfer channels. It is a system that can be realized by nano cage reactor of hydrate.

In addition, it is possible to implement a successful decomposition reaction of nitrous oxide in pseudo ice to better understand the interaction between ionic subject-nonionic or nonionic objects of ionic hydrate that has not been clearly identified. Can be used to accelerate research on the development of new water-based materials and reaction matrices. The present invention may suggest the possibility that hydrates can decompose greenhouse gases through catalysis as nano cage reactors as well as the sequestration media of greenhouse gases.

According to the present invention, a new attempt to store greenhouse gases in ionic hydrates and then decompose them converts water, a universal substance closely related to our lives, into a highly functional, eco-friendly nano cage reactor. It can be said.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

EXAMPLE

Example  One: Cluster  Hydrate Nano Cage  Manufacture of reactor

Ultra high purity deionized water was supplied by Merck (Germany). Tetramethylammonium hydroxide 5 hydrate (Me ₄ NOH 5 H ₂ O) was supplied by Sigma-Aldrich Inc. and used without further purification. N ₂ O gas with a defined minimum purity of 99.999 mol% was purchased from Special Gas (Korea).

The well mixed solution according to the molar mixture of Me ₄ NOH ₁₆ H ₂ O was cooled at 210K for one day and triturated into powder (˜200 μm). The powder was placed in a pre-cooled vial and the vial was transferred to a high pressure cell previously cooled with liquid nitrogen (LN ₂ ). When the N ₂ O gas flows into the pre-cooled cell, the N ₂ O must liquefy due to the very low temperature. The powder was placed in a glass bottle to prevent direct contact between the powder and liquefied N ₂ O. The cell was then immersed in a rotary cooling vessel (Jeio Tech., RW-2025G) and held at 263K for one day. As the temperature rose, liquefied N ₂ O evaporated and gaseous N ₂ O molecules were introduced to form Me ₄ NOH + N ₂ O hydrate.

The cell was then quenched in liquid nitrogen for several seconds to collect the synthesized hydrate sample and the remaining N ₂ O gas was released into a fume hood. The collected sample was regrind with mortar at LN ₂ temperature (˜200 μm) and then stored in LN ₂ tank for PXRD analysis. For comparison, pure N ₂ O hydrate was also synthesized from pure water in the same manner as above. Some samples were gamma-irradiated at 60 kGy dose (10 kGy per hour) through ⁶⁰ Co gamma rays from KAERI in Jeongeup, Korea. The sample was immersed in liquid nitrogen during irradiation. Irradiated samples were also used for PXRD, ESR and Raman spectroscopic analysis.

Synchroton  Powder X-ray diffraction ( PXRD Structure analysis

의 파장)를 갖는 ADSC 양자 210 CCD 회절계가 사용되었다. 액체 질소에 저장된 샘플 분말을 미리 냉각된 폴리이미드 배관(Cole-Parmer, 미국)에 빠르게 채우고 가능한 샘플 손상을 최소화하기 위해 약 93-113K에서 실험을 수행하였다. 샘플의 결정 구조를 결정하기 위해, 획득된 패턴은 Fullprof 프로그램의 프로파일 매칭을 사용하여 Le Bail 피팅 방법으로 분석하였다.PXRD patterns were obtained at a supramolecular crystallographic beamline (2D) facility in Pohang Accelerator Laboratory (PAL), Korea. Synchrotron radiation (0.900)

ADSC quantum 210 CCD diffractometer was used. Experiments were performed at about 93-113K to quickly fill sample powder stored in liquid nitrogen into pre-cooled polyimide tubing (Cole-Parmer, USA) and minimize possible sample damage. To determine the crystal structure of the sample, the obtained pattern was analyzed by Le Bail fitting method using profile matching of the Fullprof program.

Analysis of Object Molecular Distribution Using Raman Spectroscopy

Raman spectra were acquired using a Horiba Jobin Yvon ARAMIS HR UV / Vis / NIR high resolution dispersive Raman microscope. The focused 514.53 nm line of the Ar ion laser was used as the excitation source, with an average intensity of 30 mW. Scattered light was dispersed using a 1800 grating of the spectrometer and detected through a CCD detector with electrical cooling (203K). A LINKAM (THMS600G) device was used to adjust the sample temperature and enough time was used to reach equilibrium at each temperature. Pre-cooled helium gas was continuously introduced at the sample stage to remove nitrogen and oxygen from the atmosphere during annealing and measurement.

Electron spin  resonance( ESR Fundamental Characteristics Using Spectroscopy

Electron Spin Resonance (ESR) spectra were measured using a JEOL PX2300 device. Samples were stored under liquid nitrogen to maintain radical species during the experiment.

Me ₄ NOH cluster hydrate was prepared and the binary object Me ₄ NOH + N ₂ O cluster hydrate was produced. In the presence of small gaseous object molecules, Me ₄ NOH hydrates have been reported to be transformed into cube Fd3m structure II (sII) hydrates (Shin, K. et al., J Am Chem Soc 2011, 133 , 20399; Cha, M. et al., J Am Chem Soc 2010, 132 , 3694; Shin, K. et al., Chem- Asian J 2010, 5 , 22; Shin, K. et al., Chem Commun 2011, 47 , 674; Shin, K. et al., J Am Chem Soc 2008, 130 , 17234; Choi, S. et al., J Phys Chem B 2007, 111 , 10224). In sII hydrate Me ₄ N ⁺ s occupies eight large 5 ¹² 6 ⁴ cages and the secondary object molecule occupies 16 small 5 ¹² cages in the unit cell. The synthesized binary object hydrate powder samples were analyzed by Le-Bail fitting of synchrotron powder X-ray diffraction (PXRD) patterns using the profile matching method of the Fullprof program.

의 격자 파라미터로 Fd3m 공간군에 근접하게 일치했고 이는 문헌 값과 일치하였다(Sloan, E. D. et al., CRC press (Taylor and Francis Group) 2008, 3rd ed.). 도 2에서 빨간 원은 관측된 PXRD 패턴, 검정 실선은 계산된 PXRD 패턴, 초록색 눈금은 입방체 Fd3m sII 하이드레이트의 피크 위치를 나타낸다. 아산화 질소 가스가 단독으로 93K에서 a=11.8505(5)Å(도 6)의 격자 파라미터를 갖는 입방체 Pm3n 구조 I(sI) 하이드레이트를 구성하는 동안, 샘플은 이원객체 Me₄NOH + N₂O sII 하이드레이트였으며, 순수한 N₂O sI 하이드레이트 뿐만 아니라 고체 N₂O의 불순물도 거의 없었고 이는 액체 질소 온도에서 샘플 수집 공정 중에 예기치 않게 고형화될 수 있다. 방출 가스의 체적 측정으로 측정된 Me₄NOH + N₂O 하이드레이트에 포함된 N₂O 가스의 양은 298K 에서 89.2mL/g-solution 및 기압이었으며, 5¹² 케이지에서 N₂O 분자의 점유는 대략 0.79로 계산되었다.As shown in FIG. 2, the acquired pattern is a = 17.2074 (21) at 93K.

The lattice parameters of the Fd3m space group closely matched the literature values (Sloan, ED et al., CRC press (Taylor and Francis Group) 2008, 3rd ed .). In FIG. 2, the red circle shows the observed PXRD pattern, the black solid line shows the calculated PXRD pattern, and the green scale shows the peak position of the cube Fd3m sII hydrate. While nitrous oxide gas alone constitutes a cube Pm3n structure I (sI) hydrate with a lattice parameter of a = 11.8505 (5) Å (FIG. 6) at 93K, the sample is a binary object Me ₄ NOH + N ₂ O sII hydrate. And there was little impurity of solid N ₂ O as well as pure N ₂ O sI hydrate, which could unexpectedly solidify during the sample collection process at liquid nitrogen temperature. The amount of N ₂ O gas contained in Me ₄ NOH + N ₂ O hydrate measured by volumetric measurement of the release gas was 89.2 mL / g-solution and atmospheric pressure at 298K, and the occupancy of N ₂ O molecules in 5 ¹² cages was approximately 0.79. Was calculated.

After synthesizing the binary sII hydrate, we irradiated the sample with gamma radiation to activate the object molecule. Pure N ₂ O hydrate samples were also irradiated with gamma radiation for comparison. In the electron rotation resonance (ESR) spectrum of the irradiated Me ₄ NOH + N ₂ O hydrate (FIG. 3), CH ₃ and -NCH ₂ derived from Me ₄ N ⁺ were found in the irradiated cluster rate step (CH ₃ is g = 2.0016 and a _c (H) = 2.33 mT, and —NCH ₂ is g = 2.0015 and a _a (H) = 2.46 mT). In FIG. 3, the blue circle represents the quartet of the methyl group and the red square represents the triplet of the methylene group. Although dividing the peak of -NCH ₂ by binding the distant protons of the host (binding constant: 0.42 mT in the literature) is somewhat ambiguous, which may be due to the wide range of signals induced by the trapped electrons, _No major blue coloration of ₄ NOH + N ₂ O was found (FIG. 7). Therefore, most of the induced electrons were consumed to react with Me ₄ N ⁺ to form a methyl group, and at this stage, few electrons were trapped on the hydrate. This is not surprising since the generation of trapped electrons or hydrogen atoms is highly dependent on the electron or proton affinity of the secondary object molecule in the irradiated Me ₄ NOH sII hydrate.

Most of the electrons generated by irradiation were consumed in the formation of radicals, but there is still an electron source for the N ₂ O decomposition reaction on the hydrate. The breakdown of the resulting methyl group starts at about 100K and most of the radicals have been reported to disappear above 130K (Bednarek, J. et al., J Phys Chem- Us 1996, 100 , 3910; Bednarek, J. et al., J Am Chem Soc 1991, 113 , 8990). As a result of the reverse reaction between the methyl group and the trimethylamine, when the sample was annealed up to 190K, the trapped electrons in the X-irradiated and visually brightly bleached Me ₄ NOH 5 hydrate were reemerged and maintained. The PXRD pattern of the irradiated Me ₄ NOH + N ₂ O hydrate obtained showed peak splitting that should occur through the presence of methyl groups at 93K and 113K, the separated peaks being recombined at 133K and higher temperatures, mostly This means that the methyl group of is collapsed (Fig. 8). Therefore, a reverse reaction may occur at 100 K or higher, and electrons and Me ₄ N ⁺ may be regenerated as the temperature rises. The reappearance electrons can be reacted with N ₂ O molecules decompose N ₂ and O atoms.

Therefore, the irradiated hydrate samples were annealed to induce the reappearance of the electrons. Thermal stimulation of the hydrates allows the transfer of electrons or small radical species to adjacent cages (Ohgaki, K. et al., Phys Chem Chem Phys 2008, 10 , 80; Kobayashi, N. et al., Energies 2012, 5 , 1705; Sugahara, T. et al., J Phys Chem A 2012, 116 , 2405; Ahn, YH et al., J Phys Chem C 2016, 120 , 17190; Ahn, YH et al., ACS Omega 2017, 2 , 1601). During the annealing process from 93K to 273K, the Raman spectra tracked the changes in the appearance, disappearance and distribution of the object molecules of the hydrate (Figure 4 is Me ₄ NOH + N ₂ O hydrate, Figure 9 is pure N ₂ O hydrate). All spectra in FIGS. 4 and 9 show the CH ₃ asymmetric strain mode (1454 cm ⁻¹ ) of the clustered Me ₄ N ⁺ and the OH stretching mode of water (3100 cm) to compare the intensity of Raman peaks derived from the clustered object molecules. ^-1 ), respectively. And also two vibration mode observed in 4 means that the N ₂ O molecules are being captured by the cage ⁵¹² of the sII hydrate at 93K (1285cm ^-1 in the stretching NO (v _1), 2225cm ^-1 The stretch NN (v ₃ (Yang, YJ et al., Environ Sci) Technol 2017, 51 , 3550; Yang, Y. et al., Energ Fuel 2016, 30 , 9628; Olijnyk, H. et al., J Chem Phys 1990, 93 , 45). In FIG. 9, the red asterisk (2322 cm ^-1 ) represents a small amount of N ₂ captured from the atmosphere during sample synthesis and the black circle (2329 cm ^{- 1} ) represents the gas N ₂ in the atmosphere. As the temperature increased, the intensity of the clustered N ₂ O signal rapidly decreased and a new signal was generated. It suggests the appearance of N ₂ and O ₂ in hydrates at 2324 cm ⁻¹ and other 1546 cm ⁻¹ peaks, respectively, which began to increase at 113 K (FIG. 4 (b)) and 133 K (FIG. 4 (a)). Both peaks were highest at 173K and gradually decreased with increasing temperature. It was confirmed that the cooled helium gas flowed continuously to the sample stage during Raman measurements to avoid clustering N ₂ or O ₂ from the atmosphere (FIG. 10). In Figure 10, the larger Raman signal of N ₂ and O ₂ in the small cage of sII hydrate shows N ₂ and O ₂ captured from the atmosphere during the annealing process. Black circles (2329 cm ⁻¹ ) represent the gas N ₂ in the atmosphere. Therefore, the N ₂ and O ₂ signals of FIG. 4 must be derived from the N ₂ O molecules on the cluster. The appearance of the corresponding N ₂ and O ₂ is a unique phenomenon appearing on the ionic Me ₄ NOH hydrate. Raman spectra of the irradiated pure N ₂ O hydrate samples show no signal of trapped N ₂ or O ₂ but only a gradual decrease in N ₂ O peak with increasing temperature (FIG. 9). The intensity ratio (I _173K / I _93K ) of the N ₂ O peak (v ₁ ) between 93K and 173K was 0.40 for the irradiated Me ₄ NOH + N ₂ O hydrate (FIG. 4), and 0.94 for no irradiation. Appeared (FIG. 11). In FIG. 11, the red asterisk (2322 cm ^-1 ) represents a small amount of N ₂ captured from the atmosphere during sample synthesis and the circle of analysis (2329 cm ^{- 1} ) represents gas N ₂ in the atmosphere.

Therefore, most of the N ₂ O molecules that disappear from the irradiated Me ₄ NOH + N ₂ O hydrate may be due to the degradation reaction rather than the release of object molecules resulting from hydrate dissociation.

Notable in FIG. 4 is the temperature difference between the appearance of N ₂ (113K) and O ₂ (133K). As previously described, the breakdown of methyl groups in Me ₄ NOH 5 hydrates started at 100 K (Bednarek, J. et al., J Phys Chem- Us 1996, 100 , 3910). The electrons for the N ₂ O decomposition reaction may reappear above 100K. Part of the re-emergence and E are N ₂ O molecules react with the adjacent N ₂ O ^- to form an ion ^{_{(N 2 O + e - -}} > N 2 + O -). (Koci, K. et al, Catal Today 2012, 191 , 134; Koci, K. et al., Appl SurfSci 2017, 396 , 1685). When O ⁻ ions contact and react with other N ₂ O in adjacent cages, additional N ₂ and O ₂ may be produced (O ⁻ + N ₂ O −> N ₂ + O ₂ + e ⁻ ). O ^- ions are O because relatively large as compared to the ^{electro-thermal} effect of increasing the mobility of the ^O-is necessary to to move to the adjacent cage. It can be seen from FIG. 4 why the O ₂ emergence (133K) is observed at higher temperatures when compared to the N ₂ emergence (113K).

The intensity ratio of the Raman peak to the object molecule was calculated to assess the ratio of degraded N ₂ O to generated N ₂ and O ₂ . As described above, I _173K / I _93K (1285 cm ^{- 1} ) for unirradiated Me ₄ NOH + N ₂ O hydrate is 0.94, which releases only 6% of captured N ₂ O as the temperature rises ( 11). Since the intensity ratio of the irradiated hydrate is 0.40, about 54% of the N ₂ O is further degraded due to the transitioned electrons. In the overall decomposition reaction, two N ₂ O are decomposed into two N ₂ and one O ₂ . Considering the proportion of N ₂ O (0.79), 42% and 21% of 5 ¹² cages at 173K were ideally occupied by N ₂ and O ₂ , respectively. The ratio of N ₂ and O ₂ molecules actually produced was estimated by comparing peak intensities in Raman spectra of unirradiated Me ₄ NOH + N ₂ and O ₂ hydrates recorded at 93K (FIG. 12) (Cha, M. et al., J Am Chem Soc 2010, 132 , 3694; Shin, K. et al., J Am Chem Soc 2008, 130 , 17234). The two spectra were normalized to the CH ₃ asymmetric strain mode (1454 cm ^-1 ) and the cage occupancy ratios, respectively, calculated by volumetric measurement of the released gas were 1.0 for N ₂ ³² and 0.95 for O ₂ ²⁸ object molecules. The intensity ratio value I _173K (irradiated Me ₄ NOH + N ₂ O hydrate) / I _93K ( _unradiated Me ₄ NOH + N ₂ or O ₂ hydrate) was 0.30 for N ₂ and 0.20 for O ₂ molecules. Considering the occupation of N ₂ and O ₂ , 30% and 19% of 5 ¹² cages, respectively, were occupied by N ₂ and O ₂ at 173K as a result of the N ₂ O decomposition reaction. This occupancy value is consistent with the downward tendency of the N ₂ O peak intensity. However, care must be taken when using Raman spectra to investigate the distribution of object molecules. Because Raman spectroscopy only observes small points in the sample, information about the distribution of object molecules from the Raman spectra cannot be considered as the information of the entire sample. However, based on the Raman spectroscopic analysis of the examples, it can be concluded that a significant amount (approximately 30-50%) of the trapped N ₂ O molecules degrade in the active cage of the ionic Me ₄ NOH cluster hydrate.

Possible mechanisms of degradation reactions occurring in Me ₄ NOH + N ₂ O hydrate are shown (FIG. 5).

(1) electron, proton, and a hydroxyl group is generated by the irradiation, ^{_{(H 2 O -> e -}} + H + + OH).

(2) Most of the generated electrons are consumed to produce a methyl group _{^{(e - + (CH 3)}} 4 N + -> (CH 3) 3 N + CH 3). Methylene groups are also produced via hydroxyl groups (OH + (CH ₃ ) ₄ N ⁺ -> (CH ₃ ) ₃ N + CH ₂ + H ₂ O).

(3) temperature starts to rise as the group is collapsed along, and electrons are re-emergence _{^{(e -) ((CH 3}} ) 3 N + CH 3 -> (CH 3) 4 N + + e -).

(4) Some of the re-emergence electrons move to the adjacent cage ⁵¹² and reacted with N ₂ O molecules _{^{(e - + N 2 O -}} > N 2 + O -).

5, the oxygen anion production in the previous step (O ^-) See the adjacent cage ⁵¹² and reacts with another molecule N ₂ O _{^{(O - + N 2 O -}} > N 2 + O 2 + e -).

(6) The electrons regenerated in step (5) move again and repeat steps (4) to (6) until the electrons can be stably present in the hydrate.

Having described the specific parts of the present invention in detail, it will be apparent to those skilled in the art that these specific descriptions are merely preferred embodiments, and thus the scope of the present invention is not limited thereto. will be. Thus, the substantial scope of the present invention will be defined by the claims and their equivalents.

Claims (13)

A method of using ionic hydrate having pores as a nano cage reactor.
The method of claim 1, wherein the ionic hydrate is characterized in that the ionic object molecules are present in the pupil formed by the principal lattice composed of hydrogen bonds of water molecules, the pair ion is a material of the doped form in the main lattice Way.
The method of claim 2, wherein the ionic object molecule is a tetramethylammonium cation and the counterion is a hydroxide anion.
A method for capturing greenhouse gases, characterized in that the formation of binary object hydrates is achieved by capturing or injecting greenhouse gases into ionic hydrates having pupils.
The method of claim 4, wherein the ionic hydrate is characterized in that the ionic object molecules are present in the pupil formed by the subject lattice composed of hydrogen bonds of water molecules, the pair ion is a material of the doped form in the subject lattice How to collect greenhouse gases.
The method of claim 5, wherein the ionic object molecule is a tetramethylammonium cation cation and the counterion is a hydroxide anion.
The method of capturing GHG according to claim 4, wherein the greenhouse gas is nitrous oxide.
Greenhouse gas decomposition method using an ionic hydrate having a pupil comprising the following steps.
(a) injecting a greenhouse gas into the ionic hydrate and collecting it in the pupil; And
(b) decomposing the collected greenhouse gases by activating the ionic hydrate.
The method of claim 8, wherein gamma rays or X-rays are irradiated to activate the ionic hydrate.
The method of claim 8, wherein the step (b) is activated to generate and co-move electrons from water molecules of the ionic hydrate.
10. The method of claim 8, wherein the ionic hydrate is characterized in that the ionic object molecules are present in the pupil formed by the principal lattice composed of hydrogen bonds of water molecules, the counterion is a material of the doped form in the main lattice Decomposition of Greenhouse Gases.
The method of claim 11, wherein the ionic object molecule is a tetramethylammonium cation and the counterion is a hydroxide anion.
The method of claim 8, wherein the greenhouse gas is nitrous oxide.

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