Electrolysis combined with magnetic CeO2/ZSM-5@Fe3O4 catalyst to boost transesterification for biodiesel production

The current transesterification for biodiesel is normally conducted with heat input and the resource is required to remove the contained water, which is complicated and costly. The novel magnetic catalyst of the bimetallic oxides of CeO2 and Fe3O4 supported on the hierarchical pore ZSM-5 was prepared and used for the biodiesel production through transesterification of palm oil with methanol under the electrolytic assistance. The prepared catalysts were characterized by SEM-EDS, TEM, FTIR, XRD, CO2/NH3-TPD, N2 adsorption-desorption and VSM, etc. The loaded cerium stimulated the particles growth and abundant catalytic active sites were obtained due to the coral-like structure and they were beneficial for transesterification. The presence of both acidic and basic sites guaranteed the strong catalytic capability of the CeO2/ZSM-5@Fe3O4 catalyst. Under the optimized transesterification condition of the catalyst dosage of 3 wt%, methanol to oil molar ratio of 18:1, reaction time of 2.5 h, electrolysis voltage of 40 V, presence of 2 % wt/wt of water added and reaction temperature of 25 degree celsius, the FAME yield of approximately 95 % was achieved. Also, the catalyst showed an acceptable reusability, where the FAME yield of 79 % was obtained after fourth reused cycle. In conclusion, the water in the resource promotes the electrolytic transesterification to occur efficiently at the room temperature.