One-Step Preparation of Efficient and Reusable SO42−/ZrO2-Based Hybrid Solid Catalysts Functionalized by Alkyl-Bridged Organosilica Moieties for Biodiesel Production



A series of mesoporous sulfated zirconia materials functionalized by alkyl-bridged organosilica moieties (SO42−/ZrO2[BOND]SiO2(R) with various S/Si or Zr/Si molar ratios and R=CH2CH2 or C6H4) were developed by a one-step co-condensation technique combined with hydrothermal treatment with the aid of a triblock copolymer surfactant (P123). The structures, morphologies, porosities, and acid properties of the materials were well characterized. Subsequently, the catalytic performances (activity and stability) of SO42−/ZrO2[BOND]SiO2(R) were evaluated by the transesterification of both pure triglyceride (tripalmitin) and low-cost virgin plant oil (Eruca sativa Gars. oil) with methanol for biodiesel production under mild conditions (atmospheric pressure, 65 °C), and the enhanced catalytic activity with respect to alkyl-free sulfated zirconia was obtained. This excellent catalytic activity was explained in terms of the inherent Brønsted acidity, well-defined mesoporosity, and increased hydrophobicity of the as-prepared, hybrid, solid acid catalyst.