Facial synthesis of ferric molybdate (Fe2(MoO4)3) nanoparticle and its efficiency for biodiesel synthesis via oleic acid esterification

Abstract

Catalytic esterification of fatty acids, such as oleic acid, is one of the most important chemical pathways for producing biofuels, and attention is now focused on looking for heterogeneous catalysts to avoid the defects of homogeneous catalysts. With this approach, an efficient Lewis acidic catalyst, Fe 2 (MoO 4 ) 3 , was successfully prepared with definite crystalline morphology to catalyze the esterification reaction of oleic acid together with ethanol. Under optimum conditions (70 °C, 9 alcohol: 1 oleic molar ratio and 3% catalyst amount), the catalytic conversion of oleic acid to biodiesel was 90.5% and 92.5 in case of 5% catalyst, indicating that the combined catalyst has good catalytic activity. The kinetic study of ethanol–oleic acid esterification was conducted, as the kinetic study follows first-order kinetics with the calculated activation energy E a = 25.21 kJ mol − 1 and pre-exponential factor A 0 = 2449.16 min − 1 . Thermodynamic showed a positive value of Δ H, Δ S, and Δ G (endothermic reaction). • The iron–molybdate catalysts Fe 2 (MoO 4 ) 3 was prepared using a sol–gel process. • The esterification reaction of oleic acid and ethanol using Fe 2 (MoO 4 ) 3 . • The catalyst showed high catalytic activity at 70 C with O/E molar ratio is 1:9. • The catalyst exhibited high efficiency and reusability up to six times.