Synthesis and characterization of the acidic properties and pore texture of Al-SBA-15 supports for the canola oil transesterification

Ordered mesoporous SBA-15 was used as a support for the transesterification of canola oil to produce biodiesel. The pore size and surface acidity of SBA-15 were modified by synthesis conditions using different aging temperatures and the addition of heterogeneous Al atoms. The results of the characterization study indicated that a large amount of mesopore and surface acidity can greatly improve the transesterification reaction at a high aging temperature and with the incorporation of aluminum into the SBA-15 framework. This improvement in transesterification activity is due to the formation of more stable SiOAl bonds on the surface of the framework. The transesterification reaction was also compared with synthesis involving traditional supports such as acidic and basic γ-Al2O3, hydrotalcite, and SiO2. The activities of the catalysts were related to their acidic strength.