Use of anhydrous sodium molybdate as an efficient heterogeneous catalyst for soybean oil methanolysis

Sodium molybdate (Na2MoO4) has been synthesized and investigated as a heterogeneous catalyst for the methanolysis of different types of renewable lipid sources derived from the soybean oil. Transesterification reactions occurred under relatively mild conditions, requiring low temperatures, short times and normal pressure. The methyl esters synthesized were characterized by reverse-phase and size-exclusion chromatography and hydrogen-nuclear magnetic resonance spectroscopy. The catalyst was characterized by X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy (FTIR). It is very efficient for the transesterification reaction of triglycericles with methanol, with yields higher than 95% of methyl esters. The molybdenum(VI)-complex has a high Lewis acidity and most certainly act on alcohol O-H bond leading to a transient species which has high nucleophilic character. The catalyst was easily recovered and after being washed showed capacity of recyclability for another catalytic reaction with similar activity. (C) 2008 Elsevier B.V. All rights reserved.