Meso-Structured HPW-MAS-7 and HPW-MAS-9 Composite Catalysts for Biodiesel Synthesis from Unrefined Green Seed Canola Oil

H3PW12O40-MAS-7 and H3PW12O40-MAS -9 composite catalysts exhibiting different structural orderings were assembled from zeolite beta and ZSM-5 precursors by a one-pot template-assisted self-assembly mechanism. Characterization results suggest that H3PW12O40 was encapsulated into the mesoporous framework of the aluminosilicates without alteration of mesoporosity of the composites. The sequential introduction of H3PW12O40 during the synthesis of MAS-7 and MAS-9 affected the surface morphologies. The textural characteristics of the composites were improved owing to the introduction of HPW after the addition of an inorganic precursor to the template leading to a material with a high BET surface area. As novel heterogeneous solid acid catalysts, the activity of the composites was determined for the biodiesel synthesis from the unrefined green seed canola oil, giving 95.4 +/- 1.4 wt % methyl ester in 10 h at 180 degrees C with 5.5 wt % of catalyst and a 15.5:1 methanol to oil molar ratio. The recyclability of the composites is evaluated through four consecutive reactions.