Enhanced CO2 capture by functionalization of SBA-15 with APTES and L-lysine

In this study, amine-based CO2 2 sorbents were synthesized after functionalizing SBA-15 mesoporous materials. Mesoporous SBA-15 was characterized and functionalized by APTES as an alkanolamine, L-lysine as an amino acid and a combination of both. CO2 2 adsorption tests were performed at 1.6 and 2 bar to estimate the carbon dioxide (CO2) 2 ) uptake on the sorbents. As expected, CO2 2 adsorption capacity (mmol/g) increases with pressure. Based on the elemental analysis of the sorbents and the results of Fourier transform infrared spectroscopy (FTIR), a proposal was made of the possible chemical reactions that may occur in order to describe the experimental results. It is important to mention that the pretreatment prior to the CO2 2 adsorption tests plays a key role for the application of amine-functionalized mesoporous silica. The presence of water conditions the formation of carbonic acid and carbonate adsorbed on the surface and, consequently, the CO2 2 adsorption capacity of the sorbent. APTES and L-lysine loaded onto mesoporous SBA-15 exhibited the highest CO2 2 adsorption capacity (4.53 mmol/ g) at 2 bar and room temperature. After reloading the sorbents with APTES and Lysine, no improvements in the CO2 2 absorption capacity were observed.