Meitan kexue jishu (Jun 2024)

TEPA modification Cu-BTC@SiO2 preparation of composite aerogel and its CO2 capture characteristics

  • Gang ZHOU,
  • Siao YANG,
  • Kaili WANG,
  • Xiaosu DONG,
  • Rulin LIU,
  • Biao SUN,
  • Cuicui XU

DOI
https://doi.org/10.12438/cst.2023-1044
Journal volume & issue
Vol. 52, no. 7
pp. 235 – 247

Abstract

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Under the dual strategic background of “carbon peaking and carbon neutrality”, CO2 capture has become an important task at present. Solid adsorbent adsorption is widely used in CO2 capture process, among which SiO2 aerogel has the advantages of low cost, flexible synthesis method, high separation efficiency, easy surface modification, etc. However, SiO2 aerogel materials also have some defects, such as low CO2/N2 adsorption selectivity and CO2 adsorption capacity to be further improved. To address the above issues, this article has prepared a Cu-BTC@SiO2 Composite aerogel CO2 adsorption material. Firstly, the surface chemistry and pore structure were systematically characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption and desorption tests. Then, the CO2 adsorption capacity, selective adsorption, and cyclic adsorption were studied through carbon dioxide adsorption testing. Finally, a combination of theoretical and experimental research was used to study the CO2 adsorption kinetics of the adsorbent. The results show that the SiO2 aerogel compounded with Cu BTC has a high specific surface area of 726.431 m2/g, a specific surface area of 570.781 m2/g, and a high microporous volume of 0.184 cm3/g. After loading tetraethylenepentamine(TEPA), the adsorption capacity of CO2 is up to 2.95 mmol/g, and the selective adsorption is 40.8, after 10 cycles of CO2 adsorption, the adsorption capacity decreased slightly. Therefore, TEPA-modified Cu-BTC@SiO2 composite aerogels can significantly improve the CO2 adsorption performance of SiO2 aerogels. The metal organic framework material Cu BTC with rich micropore structure is compounded with SiO2 aerogel, and is prepared by the sol gel method Cu-BTC@SiO2 Composite aerogel to make the composite have hierarchical micro/mesoporous structure and enhance the physical adsorption of CO2 by enhancing the intermolecular force (van der Waals force); The material is impregnated with TEPA, and the chemical adsorption of CO2 is enhanced by acid-base interaction between organic amine and acid gas.

Keywords