Mesoporous silica supported amine and amine-copper complex for CO2 adsorption: Detailed reaction mechanism of hydrophilic character and CO2 retention

Abstract Mesoporous silica SBA-15 was functionalized with various amines and then doped with copper II cation (Cu 2+ ). The modified materials were tested for the retention of CO 2 at room temperature using temperature-programmed desorption (CO 2 -TPD). Several parameters affecting the CO 2 retention capacity (CRC) such as the nature of amine groups, repetitive adsorption-desorption cycles and dispersion of copper were investigated. CO 2 -TPD and H 2 O-TPD allowed correlating the hydrophilic character with the CO 2 retention capacity. The obtained results showed that amine-functionalized mesoporous materials containing their own moisture exhibit higher effectiveness in the retention of CO 2 . Triamine-functionalized SBA-15 displayed the highest CRC value as a result of the increase of the number of adsorption sites. Material reuse in three adsorption/desorption cycles revealed high stability with a slight decrease in CRC. The dispersion of copper induced a progressive decrease in the CRC value. The CRC decreased with increasing Cu 2+ content due to competitive complexation of Cu 2+ by the amino groups.