Construction of H3PMo12O40@EB-COF for Biodiesel Preparation by Heterogeneous Catalytical Esterification of Oleic Acid and Rapeseed Oil.

To develop higher efficient heterogeneous solid acid catalyst for biodiesel production, H₃PMo₁₂O₄₀ is impregnated in the covalent framework EB-COF forming composite of H₃PMo₁₂O₄₀@EB-COF. The structure and composition of H₃PMo₁₂O₄₀@EB-COF are characterized by FT-IR, TGA, XPS, SEM-EDX and N₂ adsorption/desorption isotherms. The successful immobilization of H₃PMo₁₂O₄₀ on the covalent framework EB-COF resulted in the uniformly distribution and heterogeneity of H₃PMo₁₂O₄₀ in the porous EB-COF. Upon H₃PMo₁₂O₄₀@EB-COF is applied as a heterogeneous acidic catalyst for the esterification reactions of oleic acid, it exhibited excellent catalytic activity with good recyclability under optimal conditions. The strikingly catalytical performance is attributed to uniformly distribution of catalytical site H₃PMo₁₂O₄₀ and flexible covalent framework of EB-COF. Furthermore, the catalyst can catalyze the esterification of rapeseed oil with industrial application conversion rate of 85%. To the best of our knowledge, it is the first example that POMs@COFs catalyze commercially available vegetable oil for biodiesel preparation with competitive conversation. [ABSTRACT FROM AUTHOR]