Amine-modified SBA-12 mesoporous silica for carbon dioxide capture: Effect of amine basicity on sorption properties

• Published in: Microporous and mesoporous materials 2008-12, Vol.116 (1), p.358-364
• Main Authors: Zelenak, V., Halamova, D., Gaberova, L., Bloch, E., Llewellyn, P.
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Mesoporous silica; Porous materials; SBA-12; Solid amine sorbents; Surface physical chemistry
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2008.04.023

SBA-12 mesoporous silica was modified by 3-aminopropyl (AP), 3-(methylamino)propyl (MAP) and 3-(phenylamino)propyl (PAP) ligands. The electronic effects in AP, MAP and PAP ligands resulted in different surface basicity of the modified silica materials. The materials were characterized by thermogravimetry, X-ray powder diffraction, nitrogen adsorption/desorption and transmission electron microscopy. The CO 2 sorption/desorption experiments performed at 25 oC by gravimetric method showed that carbon dioxide sorption capacities were 1.04 mmol/g for the sample SBA-12/AP, 0.98 mmol/g for the sample SBA-12/MAP and 0.68 mmol/g for the sample SBA-12/PAP. The modified silica can be regenerated by purge with inert gas without heating. The fastest desorption was observed for the SBA-12/PAP silica containing amine of low basicity (p K b = 8.9). The desorption process of SBA-12/AP and SBA-12/MAP samples was accompanied by consumption of heat evolved on adsorption, while no thermal effect was recorded on the DTA curve of SBA-12/PAP sample.