Monatomic solution for carbon dioxide capture

Abstract

The invention belongs to the technical field of carbon dioxide emission reduction, and particularly relates to a monatomic solution for carbon dioxide capture. The monatomic solution for carbon dioxide capture comprises a metal monatomic compound and a solvent, the metal monatomic compound comprises a metal monatomic, a ligand combined with the metal monatomic and a carrier for loading the metal monatomic. The monatomic solution for carbon dioxide capture has the advantages that metal monatomic in the monatomic solution for carbon dioxide capture exists in the form of isolated atoms, active sites are completely exposed, and the situation that a large number of atoms in a traditional nanometer or block material are embedded and wasted, and the unit active sites are reduced is avoided; besides, the metal monatomic site in the monatomic solution for carbon dioxide capture can be used as a catalyst for further catalytic conversion of carbon dioxide, captured CO2 is directly converted into a high-added-value product, and capture and conversion are integrated.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide emission reduction technology, specifically relating to a single-atom solution for carbon dioxide capture. Background Technology

[0002] With the increasing severity of global warming, extreme weather events and other climate change phenomena have seriously threatened the Earth's environment on which humanity depends for survival. According to a report by the United Nations Commission on Climate Change (IPCC), CO2 accounts for 60% of global greenhouse gas emissions, making CO2 emission reduction a crucial means of addressing global warming. Carbon dioxide capture and storage (CCS) technology can collect and store CO2 generated by energy and industrial sectors, and is considered an effective means of reducing greenhouse gas emissions. CO2 capture technology can be directly applied to various CO2 emission sources; its principle is simple, and it is currently the most widely used capture method.

[0003] Currently, CO2 capture mainly employs chemical absorption, utilizing the weak acidity of CO2 and absorbing it with alkaline substances such as ethanolamine solvents. However, this method suffers from high energy consumption, significant absorbent loss, and severe equipment corrosion, resulting in high emission reduction costs and potential environmental pollution. Therefore, developing efficient and green new absorption media, as well as innovative capture technologies and processes, are crucial for promoting CCS technology and achieving CO2 emission reduction.

[0004] Single-atom materials are materials in which metallic or non-metallic elements are dispersed at the atomic level. In these materials, each atom serves as an active site, resulting in higher atomic utilization than nanomaterials and high adsorption efficiency per unit mass. Furthermore, by controlling the structure of the support and ligands, the coordination environment of the single-atom sites can be adjusted, selectively optimizing the performance of the single-atom material. Currently, single-atom materials are mostly used as catalysts for various catalytic reactions, such as the catalytic reduction of CO2. However, their application in CO2 capture suffers from problems such as small adsorption capacity and poor cycle stability, limiting their application. Summary of the Invention

[0005] This application provides a single-atom solution for carbon dioxide capture, aiming to solve the problems of small adsorption capacity and poor cycle stability of existing single-atom solutions for carbon dioxide capture.

[0006] This application provides a single-atom solution for carbon dioxide capture, comprising a metal single-atom complex and a solvent;

[0007] The metal single-atom complex includes a metal single atom, a ligand bound to the metal single atom, and a support carrying the metal single atom.

[0008] According to the single-atom solution for carbon dioxide capture described in this application, the metal single atom includes one or more of Fe, Cu, Ni, Zn, and Co.

[0009] According to the single-atom solution for carbon dioxide capture described in this application, the metal single atom includes Fe or Ni.

[0010] According to the single-atom solution for carbon dioxide capture described in this application, the ligand includes one or more of the nitrogen-containing ligand o-phenanthroline, ethylenediamine, polyvinylpyrrolidone, and the oxygen-containing ligand ethylenediaminetetraacetic acid and citric acid.

[0011] According to the single-atom solution for carbon dioxide capture described in this application, the carrier includes one or more of nitrogen-doped carbon, graphene oxide, silicon dioxide, and metal-organic frameworks.

[0012] According to the single-atom solution for carbon dioxide capture described in this application, the carrier contains amino groups.

[0013] The single-atom solution for carbon dioxide capture according to this application also includes amine compounds.

[0014] According to the single-atom solution for carbon dioxide capture described in this application, the amine compound includes one or more of monoethanolamine, diethanolamine, methyldiethanolamine, polyethyleneimine, and 2-amino-2-methyl-1-propanol.

[0015] According to the single-atom solution for carbon dioxide capture described in this application, the solvent includes one or more of water, ethanol, and ethylene glycol.

[0016] According to the single-atom solution for carbon dioxide capture described in this application, the concentration of metal single atoms in the single-atom solution is 0.05-1 mmol / L.

[0017] According to the single-atom solution for carbon dioxide capture described in this application, in the metal single-atom complex, the molar ratio of the ligand to the metal single atom is ≥4.

[0018] According to the single-atom solution for carbon dioxide capture described in this application, in the metal single-atom complex, the mass ratio of the metal single atom to the support is 1:(7-3500).

[0019] According to the single-atom solution for carbon dioxide capture described in this application, the concentration of amine compounds in the single-atom solution is 10-50 wt%.

[0020] The beneficial effects of this application include: the metal single atoms in the single-atom solution for carbon dioxide capture described in this application exist in the form of isolated atoms, with 100% exposure of active sites, avoiding the waste of a large number of atoms being buried in traditional nanomaterials or bulk materials, thus reducing the unit active site; in addition, the metal single-atom sites in the single-atom solution for carbon dioxide capture described in this application can serve as catalysts for further catalytic conversion of carbon dioxide, directly converting the captured CO2 into high-value-added products, achieving integrated capture and conversion.

[0021] The single-atom solution described in this application can achieve CO2 desorption at a relatively low temperature (60-80℃), while the metal sites can catalyze the decomposition of oxalate, reducing the energy required for carbon dioxide desorption and thus reducing regeneration energy consumption. Detailed Implementation

[0022] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0024] This application provides a single-atom solution for carbon dioxide capture, comprising a metal single-atom complex and a solvent;

[0025] The metal single-atom complex comprises a metal single atom, a ligand bound to the metal single atom, and a support for loading the metal single atom. The single-atom solution described in this application can absorb carbon dioxide through physical action and also through Lewis acid-base action to chemically absorb carbon dioxide. It has a large capacity for absorbing carbon dioxide and can directly convert the captured carbon dioxide into high-value-added products.

[0026] In some embodiments of this application, the metal single atom includes one or more of Fe, Cu, Ni, Zn, and Co.

[0027] In some embodiments of this application, the metal single atom includes Fe or Ni.

[0028] In some embodiments of this application, the ligand includes one or more of the nitrogen-containing ligands o-phenanthroline, ethylenediamine, polyvinylpyrrolidone, and the oxygen-containing ligands ethylenediaminetetraacetic acid and citric acid. The addition of the ligand can stabilize the dispersion of metal single atoms and prevent their aggregation.

[0029] In some embodiments of this application, the support includes one or more of nitrogen-doped carbon, graphene oxide, silicon dioxide, and metal-organic frameworks. The support can serve as a matrix for dispersing metal single atoms, as a loading platform for metal single atoms, and can also prevent the aggregation of metal single atoms.

[0030] In some embodiments of this application, the support contains amino groups. Introducing amino groups onto the support through amination enhances its adsorption capacity for carbon dioxide.

[0031] In some embodiments of this application, amine compounds are also included. The addition of amine compounds can further improve the carbon dioxide absorption capacity.

[0032] In some embodiments of this application, the amine compounds include one or more of monoethanolamine, diethanolamine, methyldiethanolamine, polyethyleneimine, and 2-amino-2-methyl-1-propanol.

[0033] In some embodiments of this application, the solvent includes one or more of water, ethanol, and ethylene glycol.

[0034] In some embodiments of this application, the concentration of metal single atoms in the single-atom solution is 0.05-1 mmol / L, for example: 0.05 mmol / L, 0.08 mmol / L, 0.12 mmol / L, 0.38 mmol / L, 0.5 mmol / L, 0.67 mmol / L, 0.73 mmol / L, 0.89 mmol / L, 1 mmol / L, etc. Controlling the concentration of metal single atoms within this range ensures that the single-atom solution has a high absorption capacity and catalytic effect on carbon dioxide; however, if the concentration of metal single atoms is too high, it will lead to aggregation.

[0035] In some embodiments of this application, the molar ratio of the ligand to the metal single atom in the metal single atom complex is ≥4; for example, 4, 5, 6, 8, etc.

[0036] In some embodiments of this application, the mass ratio of the metal single atom to the carrier in the metal single atom composite is 1:(7-3500), for example 1:7, 1:20, 1:50, 1:100, 1:500, 1:1200, 1:1800, 1:2300, 1:2800, 1:3000, 1:3500, etc.

[0037] In some embodiments of this application, the concentration of amine compounds in the single-atom solution is 10-50 wt%, such as 10 wt%, 15 wt%, 20 wt%, 26 wt%, 32 wt%, 38 wt%, 43 wt%, 50 wt%, etc.

[0038] The technical solution of this application will be further described below with reference to specific embodiments.

[0039] Example 1

[0040] A method for preparing a single-atom solution for carbon dioxide capture includes the following steps: mixing a metal single-atom complex with water as a solvent.

[0041] The metal single-atom complex includes iron single atoms, polyvinylpyrrolidone, and nitrogen-doped carbon. The iron single atoms are loaded on the nitrogen-doped carbon, and the long-chain polyvinylpyrrolidone coordinates with the iron single atoms to prevent aggregation. The concentration of iron single atoms in the single-atom solution is 0.5 mmol / L, the molar ratio of polyvinylpyrrolidone to iron single atoms is 5:1, and the mass ratio of iron single atoms to the nitrogen-doped carbon support is 1:45.

[0042] Example 2

[0043] The method for preparing the single-atom solution for carbon dioxide capture described in Example 2 differs from that in Example 1 only in that copper single atoms are used instead of iron single atoms.

[0044] Example 3

[0045] The method for preparing the single-atom solution for carbon dioxide capture described in Example 3 differs from that in Example 1 only in that nickel single atoms are used instead of iron single atoms.

[0046] Example 4

[0047] The method for preparing the single-atom solution for carbon dioxide capture described in Example 4 differs from that in Example 1 only in that zinc single atoms are used instead of iron single atoms.

[0048] Example 5

[0049] The method for preparing the single-atom solution for carbon dioxide capture described in Example 5 differs from that in Example 1 only in that cobalt single atoms are used instead of iron single atoms.

[0050] Example 6

[0051] The only difference between the preparation method of the single-atom solution for carbon dioxide capture described in Example 6 and that in Example 1 is that the concentration of iron single atoms in the single-atom solution is 0.05 mmol / L.

[0052] Example 7

[0053] The only difference between the preparation method of the single-atom solution for carbon dioxide capture described in Example 7 and that in Example 1 is that the concentration of iron single atoms in the single-atom solution is 0.3 mmol / L.

[0054] Example 8

[0055] The method for preparing the single-atom solution for carbon dioxide capture described in Example 8 differs from that in Example 1 only in that the concentration of iron single atoms in the single-atom solution is 1 mmol / L.

[0056] Example 9

[0057] The method for preparing the single-atom solution for carbon dioxide capture described in Example 9 differs from that in Example 1 only in that the single-atom solution for carbon dioxide capture described in Example 9 further includes monoethanolamine, and the concentration of monoethanolamine in the single-atom solution is 30 wt%.

[0058] Example 10

[0059] The single-atom solution described in Example 1 was placed in an absorption bottle, and a mixture of carbon dioxide gas (CO2 and N2 in a volume ratio of 1:4) was introduced into the absorption bottle. When the mass of the introduced gas mixture no longer changed after being absorbed, the single-atom solution in the absorption bottle was heated at 90°C for 30 minutes to completely release the carbon dioxide absorbed by the solution. The carbon dioxide absorption experiment was then repeated according to the above operation. After repeating the operation 10 times, the absorption capacity of the single-atom solution for carbon dioxide was measured.

[0060] Comparative Example 1

[0061] The only difference between the preparation method of the single-atom solution for carbon dioxide capture described in Comparative Example 1 and Example 1 is that the metal single-atom complex in the single-atom solution for carbon dioxide capture described in Comparative Example 1 does not contain the ligand polyvinylpyrrolidone.

[0062] This application studies the effect of single-atom solution adsorption of carbon dioxide for carbon dioxide capture as described in Examples 1-9 and Comparative Example 1.

[0063] Take 50 ml of the single-atom solution for carbon dioxide capture described in Examples 1-9 and Comparative Example 1, respectively, and place it in 10 absorption bottles. Then, introduce a mixed gas (CO2 and N2 with a volume ratio of 1:4) at a flow rate of 100 ml / min into the absorption bottle, and measure and record the carbon dioxide content in the gas before and after entering the absorption bottle. Calculate the carbon dioxide absorption capacity, and the results are shown in Table 1.

[0064] Table 1

[0065] Carbon dioxide absorption capacity Example 1 3.5 mmol / mL Example 2 2.1 mmol / mL Example 3 3.0 mmol / mL Example 4 1.2 mmol / mL Example 5 2.5 mmol / mL Example 6 1.8 mmol / mL Example 7 4.5 mmol / mL Example 8 2.0 mmol / mL Example 9 4.1 mmol / mL Example 10 3.4 mmol / mL Comparative Example 1 0.2 mmol / mL

[0066] As can be seen from Table 1, the single-atom solution for carbon dioxide capture described in this application has excellent carbon dioxide adsorption performance and can be reused.

[0067] Comparing Examples 1-3, it can be seen that when polyvinylpyrrolidone (PVP) coordination and nitrogen-doped carbon are used as the support, the type of metal single atom has a great influence on the adsorption performance of carbon dioxide by the single atom solution. Among them, the effect is best when the metal single atom is Fe, followed by Ni single atom, Co single atom and Cu single atom prepared single atom solutions in that order.

[0068] Comparing Examples 1 and 6-8, it can be seen that the concentration of metal single atoms in the single-atom solution is the key factor affecting its carbon dioxide adsorption efficiency. When the concentration of metal single atoms is less than or equal to the optimal concentration range (0.3-0.5 mmol / L), the carbon dioxide adsorption performance of the single-atom solution gradually increases with increasing metal single-atom concentration; when the concentration of metal single atoms is greater than or equal to the optimal concentration range (0.3-0.5 mmol / L), the carbon dioxide adsorption performance of the single-atom solution gradually decreases with increasing metal single-atom concentration.

[0069] Comparing Examples 1 and 9, it can be seen that the addition of amine compounds helps to improve the performance of single-atom solutions in absorbing CO2.

[0070] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A single-atom solution for carbon dioxide capture, characterized in that, Including metal single-atom complexes and solvents; The metal single-atom complex includes a metal single atom, a ligand bound to the metal single atom, and a support carrying the metal single atom.

2. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, The metal single atom includes one or more of Fe, Cu, Ni, Zn, and Co; Preferably, the metal single atom includes Fe or Ni.

3. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, The ligands include one or more of the nitrogen-containing ligands o-phenanthroline, ethylenediamine, polyvinylpyrrolidone, and oxygen-containing ligands ethylenediaminetetraacetic acid and citric acid.

4. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, The carrier includes one or more of nitrogen-doped carbon, graphene oxide, silicon dioxide, and metal-organic frameworks; Preferably, the carrier contains amino groups.

5. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, It also includes amine compounds.

6. The single-atom solution for carbon dioxide capture according to claim 5, characterized in that, The amine compounds include one or more of monoethanolamine, diethanolamine, methyldiethanolamine, polyethyleneimine, and 2-amino-2-methyl-1-propanol.

7. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, The solvent includes one or more of water, ethanol, and ethylene glycol.

8. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, The concentration of metal single atoms in the single-atom solution is 0.05-1 mmol / L.

9. The single-atom solution for carbon dioxide capture according to claim 1, characterized in that, In the metal single-atom complex, the molar ratio of the ligand to the metal single atom is ≥4; And / or, in the metal single-atom composite, the mass ratio of the metal single atom to the support is 1:(7-3500).

10. The single-atom solution for carbon dioxide capture according to claim 5, characterized in that, The concentration of amine compounds in the single-atom solution is 10-50 wt%.