CO2 Adsorption on SBA-15 Modified by Aminosilane

By grafting amines onto the mesoporous support SBA-15, a highly efficient adsorbent has been obtained. This material shows potential applications in the removal of CO2 from enclosed areas such as space shuttles and submarines. SBA-15 was modified with 3-aminopropyl-triethoxysilane (APTES) by post-synthesis silylation and one-step silylation methods using ethanol as the solvent. The physical properties of these adsorbents were characterized by X-ray powder diffraction and N2 adsorption-desorption. The ordered hex-agonal mesoporous structure of SBA-15 is well preserved after the modification. CO2 adsorption was tested using a static adsorption equipment. Adsorption isotherms demonstrate that the one-step silylation method is better than the post-synthesis silylation method. SBA-15 that was modified with APTES through one-step silylation can adsorb 34.2 mg/g of CO2 at room temperature when the partial pressure of CO2 is 0.005 MPa. Active carbon, the traditional adsorbent of CO2, was also tested. At room temperature, modified SBA-15 shows better performance than active carbon when the partial pressure of CO2 is lower than 0.02 MPa.