Development of a nano alumina-zirconia composite catalyst as an active thin film in biodiesel production

A Nano-alumina-zirconia composite catalyst was synthesized by a simple aqueous sol-gel method using AlCl 3 .6H 2 O and ZrCl 4 as precursors. Thermal decomposition of the precursor and subsequent formation of γ-Al 2 O 3 and t-ZrO 2 were investigated by thermal analysis. XRD analysis showed that γ-Al 2 O 3 and t-ZrO 2 phases were formed at 700 °C. FT-IR analysis also indicated the phase transition to γ-Al 2 O 3 occurred in corroboration with X-ray studies. TEM analysis of the calcined powder revealed that spherical particles were in the range of 8-12 nm. The nano alumina-zirconia composite particles were mesoporous and uniformly distributed in their crystalline phase. In order to measure the catalytic activity, esterification reaction was carried out. Biodiesel, as a renewable fuel, was formed in a continuous packed column reactor. Free fatty acid (FFA) was esterified with ethanol in a heterogeneous catalytic reactor. It was found that the synthesized γ-Al 2 O 3 /ZrO 2 composite had the potential to be used as a heterogeneous base catalyst for biodiesel production processes.