Evaluation of the catalytic activity of oxide nanoparticles synthesized by the polymeric precursor method on biodiesel production

This paper shows a comparison between different nanostructured oxides, obtained by polymeric precursor method, regarding their activity for biodiesel conversion from oil-methanol mixtures. The basicity/acidity and surface area (SA) of the oxides were taken in account to analyze the catalytic activity in the transesterification reaction. The temperature dependence for the heterogeneous catalysts was analyzed, where only CaO showed activities at 70 degrees C (similar to 98% of conversion), while the other oxides, SnO2, ZnO, TiO2, CaTiO3, were observed active only at 150 degrees C for the reaction parameters adopted. The results revealed that the highest activity observed is not associated to SA only but mainly with the surface basicity. This suggest that, for oxides synthesized by the polymeric precursor method, the surface basicity surpasses the particle size effects in catalysis in a way to promote the transesterification reaction.