Ethanolic Transesterification with Methyl Acetate Catalyzed by SBA-15 Functionalized with Imidazolium–Sulfonic Groups

The global demand for biodiesel production is steadily increasing. Conventional homogeneous basic catalysts, while widely used in the industry, face significant drawbacks, such as the requirement for high-quality feedstock, excessive waste generation, and multiple purification steps. In this study, an acidic silane (IM-CPTMS-BS-H2SO4) containing imidazolium and sulfonic groups was synthesized. Heterogeneous catalysts were then prepared by anchoring varying proportions of the silane onto SBA-15 mesoporous solids. These materials were characterized by FTIR, 13C and 29Si NMR, TGA, XRD, CHNS and acidity measurements. The catalysts were evaluated in the transesterification of methyl acetate with ethanol, with increasing catalytic conversions with the amount of grafted IM-CPTMS-BS-H2SO4. Furthermore, increasing the catalyst loading (from 2% to 5% wt.) and the reaction temperature (from 50 °C to 65 °C) led to higher methyl acetate conversion rates.