Synthesis and CO2 adsorption property of amino-functionalized silica nanospheres with centrosymmetric radial mesopores

Amino-functionalized silica nanospheres with centrosymmetric radial mesopores were successfully prepared using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltrimethoxysilane (APMS) as co-structure directing agent. The template was efficiently removed by extraction either using a basic solution of monoethanol amine (MEA) in ethanol or an acetonitrile solution acidified with HCl. The synthesized mesoporous silica materials were characterized by the FT-IR, TG-DTA, XRD, N2 adsorption–desorption and TEM techniques. CO2 adsorption at 25 °C was evaluated by a volumetric method, and CO2 desorption was studied by the TPD technique. The results indicate that, compared to the sorbent treated with acidic-acetonitrile, the sorbent treated with the MEA–ethanol solution has a much higher adsorption capacity towards CO2, exhibits a higher degree of reversibility in the adsorption process, and has a much higher CO2/N2 selectivity.