Conventional vs. hybrid methods for dispersion of MgO over magnetic Mg–Fe mixed oxides nanocatalyst in biofuel production from vegetable oil

Abstract In this research, MgO/MgFe2O4 heterogeneous magnetic nanocatalyst was used in biodiesel production and to study its structural and morphological characteristics, various methods have been used in MgO addition on the support. Impregnation, Precipitation, Precipitation – Hydrothermal, Precipitation – Ultrasonic and Combustion methods were utilized to add the MgO on the MgFe2O4 to find the suitable surface structure and catalytic activity. Combustion synthesis was used as a facile and low cost preparation route for fabrication of all nanocatalysts’ support because of suitable porosity for the biodiesel production reaction. For this purpose, the samples were analysed by XRD, FESEM, EDX, BET-BJH, and FTIR and then used in the transesterification reaction. Results indicate the sheet like morphology in precipitation and precipitation-hydrothermal methods and lower particle size in combustion synthesized nanocatalyst. Suitable surface structure and proper pore size and volume caused the combustion prepared sample to score the highest yield of 92.9% in biodiesel production from sunflower oil. This sample showed proper stability and reusability potential while the structure remained intact after five times being used in the reaction. Due to the magnetic characteristic of the support the catalyst separation was easy and this caused negligible catalyst loss.