One-step synthesis of mesoporous H4SiW12O40-SiO2 catalysts for the production of methyl and ethyl levulinate biodiesel

A novel one-step method for the synthesis of mesoporous H₄SiW₁₂O₄₀-SiO₂ catalysts with tunable composition was successfully developed using non-ionic polyethylene glycol dodecyl ether (Brij 30) as the structure-directing template. Different loadings of H₄SiW₁₂O₄₀ (up to 30 wt.%) were effectively confined within the mesoporous channels of SiO₂, which would facilitate easy recycling and allow for the efficient mass transport of reactants and products. The resultant mesoporous H₄SiW₁₂O₄₀-SiO₂ showed high catalytic activity for the production of methyl and ethyl levulinate biodiesel. The 20 wt.% H₄SiW₁₂O₄₀-SiO₂ catalyst exhibited the best performance in the synthesis of both methyl levulinate (73% yield achieved at 79% conversion of levulinic acid) and ethyl levulinate (67% yield obtained at 75% conversion of levulinic acid).