In this work, ordered mesoporous SBA-15 was synthesized and functionalized by polyethyleneimine (PEI). The morphological properties were characterized by N-2 adsorption/desorption, field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM) and Fourier transform infrared (FTIR) spectroscopy methods. The carbon dioxide (CO2) uptake on the sorbents, kinetics of CO2 adsorption/desorption and long-term multicycle stability of PEI-impregnated sorbent were measured. An optimal amine loading of 50 wt.% showed a CO2 adsorption capacity similar to 3.09 mmol g(-1) using 10% pre-humidified CO2 at 75 degrees C. The presence of moisture in flue gas showed a promoting effect in CO2 sorption capacity. The temperature swing adsorption/desorption cycles showed excellent multicycle stability over 60 cycles during 65 h of operations under humid CO2.