Preparation of Mesoporous Silica Materials MCM-41 and SBA-15 Using a Template Extraction Method with Supercritical CO2

In this study, mesoporous materials MCM-41 and SBA-15 were prepared by template extraction using supercritical carbon dioxide (CO2). When using the supercritical CO2 method, the extraction ratio of the template agent for MCM41 reached 97.8%, and silica with a high specific surface area, high pore volume, and uniform pore size was obtained compared to the conventional calcination method. For SBA-15, the template extraction ratio using the supercritical CO2 method was only 88%, but the supercritical CO2 method was superior to the calcination method in maintaining the uniformity of the pore size distribution. Furthermore, the pressure dependence of the template agent extraction ratio in the supercritical CO2 method was investigated, and it was found that the extraction ratio showed a maximum around 8 to 10 MPa, which could be interpreted in terms of the vapor-liquid equilibrium relationship between CO2 and methanol. Based on the above results, it was suggested that the supercritical CO2 method is an extremely effective method for maintaining the pore structure and producing high-performance mesoporous silicas (MCM-41 and SBA15) compared to conventional methods.