Development of efficient amine-modified mesoporous silica SBA-15 for CO2 capture

Graphical abstract: - Highlights: • A secondary amine AN-TEPA is used to modify the SBA-15. • CO2 adsorption capacity (180.1 mg g−1-adsorbent for 70% amine loading) is high. • The sorbent exhibits a high stability after 12 cycling runs. • The modified SBA-15 achieves complete desorption at low temperature (100 °C). - Abstract: A novel CO2 sorbent was prepared by impregnating mesoporous silica, SBA-15, with acrylonitrile (AN)-modified tetraethylenepentamine (TEPA) in order to increase CO2 adsorption capacity and improve cycling stability. The mesoporous silica with pre- and post-surface modification was investigated by X-ray diffraction characterization (XRD), N2 adsorption–desorption test (N2-BET), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The adsorption/desorption performance of S-TN (TN: AN modified TEPA) and S-TEPA was studied by dynamic adsorption. Test results showed that the solid base-impregnated SBA-15 demonstrated high CO2 adsorption capacity (180.1 mg g−1-adsorbent for 70% amine loading level). Compared to S-TEPA (24.1% decrease of initial capacity), S-TN with 50% amine loading exhibited improved cycling stability, 99.9% activity reserved (from initial 153.0 mg g−1 to 151.3 mg g−1) after 12 cycles of adsorption/desorption at 100 °C. A mechanism of molecular structure of the loaded amine was attributed to the improved performance