Synthesis of mesoporous magnesium oxide: Its application to CO2 chemisorption

Mesoporous magnesium oxide (MgO) was synthesized using mesoporous carbon CMK-3 obtained from mesoporous SBA-15 as exotemplate. P123 was used as the structure-directing template and rice husk ash (RHA) as the silica source for the synthesis of SBA-15, which was subsequently treated with sucrose and sulphuric acid to obtain mesoporous carbon (CMK-3). X-ray powder diffraction (XRD) results and the type-IV adsorption isotherm with H1 hysteresis obtained by N2 adsorption/desorption study for SBA-15, CMK-3 and mesoporous MgO suggests its resemblance with materials synthesized using conventional silica sources. Mesoporous MgO was subjected for CO2 adsorption study in TGA; adsorption was 8 and 10 wt% at 25 and 100 °C, respectively. Finally, mesoporous MgO is selective to CO2 gas, thermally stable and regenerable. Thus, this study contributes a better route to enhance CO2 gas adsorption and use ecological waste rice husk for the synthesis of such efficient mesoporous materials.