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CN-122006415-A - Synergistic enhancement type amino absorption liquid and preparation method and application thereof

CN122006415ACN 122006415 ACN122006415 ACN 122006415ACN-122006415-A

Abstract

The invention relates to the technical field of carbon dioxide trapping and electrocatalytic conversion, and discloses a synergistic enhancement type amino absorption liquid, a preparation method and application thereof. The synergistic enhanced amino absorption liquid comprises, by mass, 100% of the total mass of the absorption liquid, 28-32% of a compound amino component, 5-10% of electrolyte salt, 2-3% of a cationic interface modifier, 2-3% of a functional ionic liquid, 4-6% of synergistic amine and the balance of water. According to the invention, the functional ionic liquid is introduced into the difunctional amine-based absorption liquid system, so that the cooperative regulation and control of the micro-environment of the electrode interface are realized, the comprehensive performance advantage is shown in the integrated application of carbon dioxide trapping and in-situ electrocatalytic reduction, and the method has good practicability and application prospect.

Inventors

  • LIU HANZI
  • SUN ZHIQIANG
  • MAI XIAOFENG
  • LIANG DAKE
  • DONG JIARUI

Assignees

  • 中南大学

Dates

Publication Date
20260512
Application Date
20260306

Claims (10)

  1. 1. The synergistic enhancement type amino absorption liquid is characterized by comprising the following components in percentage by mass, based on 100% of the total mass of the absorption liquid: 28-32% of compound amino components, wherein the compound amino components comprise triethylenetetramine and N, N-dimethylethanolamine; 5-10% of electrolyte salt; 2-3% of cationic interface modifier; 2-3% of functional ionic liquid; 4-6% of synergistic amine, wherein the synergistic amine is at least one selected from N-methyldiethanolamine, diethanolamine, 1, 3-propylenediamine, 2-amino-2-methyl-1-propanol and 3-amino-1-propanol; The balance being water; Wherein the functional ionic liquid has an imidazolium-type and/or pyridinium-type organic cation structure.
  2. 2. The synergistic amine-based absorption liquid according to claim 1, wherein the molar ratio of triethylenetetramine to N, N-dimethylethanolamine in the formulated amine-based component is 1:5-15.
  3. 3. The synergistic amine-based absorbent as claimed in claim 1, wherein the electrolyte salt is at least one selected from sodium bicarbonate, potassium sulfate, tetramethyl ammonium chloride and potassium chloride, and/or The cationic interface modifier is at least one selected from dodecyl trimethyl ammonium bromide, polyethylenimine and hexadecyl trimethyl ammonium bromide, and/or The functional ionic liquid is at least one selected from 1-ethyl-3-methylimidazole tetrafluoroborate, 1-butyl-3-methylimidazole hexafluorophosphate and N-butylpyridine tetrafluoroborate.
  4. 4. A method for preparing the synergistic amine-based absorption liquid as claimed in any one of claims 1 to 3, wherein the proportions of the components in the synergistic amine-based absorption liquid as claimed in any one of claims 1 to 3 are such that the respective raw materials of corresponding mass are provided, and the operations comprising the steps of: (1) Dissolving a compound amino component in water to obtain a compound amino solution, wherein the compound amino component comprises triethylenetetramine and N, N-dimethylethanolamine; (2) Firstly mixing the compound amino solution with electrolyte salt and synergistic amine to obtain a precursor solution; (3) Carrying out ultrasonic treatment on the precursor solution, and then carrying out second mixing with a cationic interface modifier to obtain a mixed solution I; (4) And thirdly mixing the mixed solution I with the functional ionic liquid to obtain the synergistic enhancement type amino absorption liquid.
  5. 5. The method according to claim 4, wherein in the step (1), the content molar ratio of triethylenetetramine to N, N-dimethylethanolamine in the compound amine based component is 1:5-15.
  6. 6. The method according to claim 4, wherein in step (1), the amount of the water is controlled so that the mass fraction of the compound amine-based component in the compound amine-based solution is 28 to 38%.
  7. 7. The method according to claim 4, wherein in the step (3), the condition of the ultrasonic treatment is at least 40, 300-500W power and 1-2 hours.
  8. 8. The process according to claim 4, wherein in step (2), the first mixing is carried out with stirring and at least the temperatures of 20, the rotational speeds of 150-250rpm, the times of 20-30min, and/or In step (3), the second mixing is carried out with stirring and at least the temperature is 40, the rotational speed is 150-250rpm, the time is 1-2h, and/or In the step (4), the third mixing is performed under stirring, and at least the temperature is 70, the rotating speed is 250-350rpm, and the time is 60-80min.
  9. 9. Use of a synergistically enhanced amine-based absorption solution according to any one of claims 1 to 3 for the absorption of carbon dioxide and its in situ electrocatalytic reduction.
  10. 10. The use according to claim 9, wherein the functional ionic liquid in the absorption liquid and the cationic interface modifier are cooperatively adsorbed on the surface of the cathode in the electrocatalytic reduction process of carbon dioxide, so as to improve the selectivity of carbon monoxide generation reaction and inhibit hydrogen evolution side reaction.

Description

Synergistic enhancement type amino absorption liquid and preparation method and application thereof Technical Field The invention relates to the technical field of carbon dioxide trapping and electrocatalytic conversion, in particular to a synergistic enhancement type amino absorption liquid and a preparation method and application thereof. Background Under the background of a double-carbon target, an integrated technology for capturing carbon dioxide and in-situ coupling of electrocatalytic reduction is expected to remarkably reduce energy consumption and cost, and has become an important research direction in the field of CCU. Among them, it is the core of the technology to develop a bifunctional electrolyte system with both efficient CO 2 absorption capacity and high selectivity electrocatalytic reduction performance. Earlier studies mainly used single amine-based absorbing solutions (e.g., MEA, DEA) to trap CO 2, but they were poor in conductivity under electrolysis conditions, and amine molecules themselves were susceptible to degradation or side reactions at the electrode interface, which was difficult to use directly for electrocatalytic reduction. In order to overcome the above problems, the current improvement scheme is generally focused on constructing an amine-salt compound system, namely adding inorganic electrolyte salt (such as KHCO 3 and KCl) into high-concentration amine-based absorption liquid to improve the conductivity of the solution. Although this idea enables to some extent a preliminary coupling of trapping and electrolysis, it is limited by its single design dimension, exposing in practical use the following inherent and difficult limitations: First, the performance of an "amine-salt" system is severely dependent on the exact match of a particular amine to a particular salt. Once the electrolysis conditions (e.g., potential, current density) or run time change, the ionic strength, pH, and distribution of amine species in the solution change dynamically, resulting in a CO 2 absorption capacity that is offset by the electroreduction selectivity (e.g., CO faraday efficiency) and difficult to stabilize for long periods of time. Second, existing systems indirectly affect the interface, primarily through bulk phase concentrations of amines or salts, and lack direct, active and synergistic regulatory capability for the electrode/electrolyte interface. On the cathode surface, proton reduction Hydrogen Evolution (HER) competes strongly with CO 2 reduction (CO 2 RR). Conventional "amine-salt" electrolytes are not effective in inhibiting HER, resulting in selectivity to target products (e.g., CO) that is generally lower at higher current densities and large amounts of electrical energy being consumed by side reactions. Thirdly, in the process of high current density and long-time continuous operation, mass transfer, chemical reaction and electric field distribution at the electrode interface are extremely complex, and the simple 'amine-salt' combination is easy to lead to catalyst deactivation, degradation or salting-out of amine components due to unstable interface structure, so that the performance attenuation rate is obvious, and the industrial application requirement is difficult to meet. Therefore, a new electrolyte design strategy is urgently needed in the field, and the capability of efficiently capturing CO 2 by amine groups is maintained, and meanwhile, the electrode interface microenvironment can be actively and synergistically constructed and stabilized, so that the difficulty of cooperative improvement of selectivity and stability is solved at a molecular/mesoscopic level. Disclosure of Invention The invention aims to solve the problem that the selectivity (such as CO Faraday efficiency) and long-term operation stability of carbon dioxide in-situ electrocatalytic reduction are difficult to cooperatively improve due to the lack of cooperative and stable regulation and control of the microenvironment of an electrode interface in the conventional amine-based electrolyte system. In order to achieve the above object, a first aspect of the present invention provides a synergistic amine-based absorption liquid, comprising the following components in mass fraction, based on 100% of the total mass of the absorption liquid: 28-32% of compound amino components, wherein the compound amino components comprise triethylenetetramine and N, N-dimethylethanolamine; 5-10% of electrolyte salt; 2-3% of cationic interface modifier; 2-3% of functional ionic liquid; 4-6% of synergistic amine, wherein the synergistic amine is at least one selected from N-methyldiethanolamine, diethanolamine, 1, 3-propylenediamine, 2-amino-2-methyl-1-propanol and 3-amino-1-propanol; The balance being water; Wherein the functional ionic liquid has an imidazolium-type and/or pyridinium-type organic cation structure. According to a second aspect of the present invention, there is provided a method for preparing the synergistic