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

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.