Synergism between physicochemical properties of Ni-Co-Cu ferrites for boosting catalytic production of biodiesel from waste cooking oil

This study provides a synthesis of novel ternary cobalt-copper-nickel ferrites (Co 0.33 Cu 0.33 Ni 0.33 Fe 2 O 4 ) catalyst for boosting the biodiesel production from waste cooking oil. It investigates the effect of increasing calcination temperature (up to 900 °C) on the synergism between the material's structural, magnetic, and physicochemical properties. This synergism enhanced the catalytic activity of the ternary ferrites for biodiesel production. Among the synthesized catalysts with different calcination temperatures, the catalyst that was calcined at 900 °C produced the highest FAME content of 99 %. The transesterification process was optimized under the conditions of 1 wt. % catalyst, 60 °C, 120 min, and 6:1 methanol/oil molar ratio. This superior catalytic performance is attributed to high-temperature-induced phase transformations, a higher number of active catalytic sites, and improved surface charges. Additionally, the magnetic characteristic of the catalyst enabled recoverability and reusability for up to ten cycles, with the yield remaining above 90 % for the first six cycles before showing a gradual decline to 76 % in the tenth cycle. The assessment of sustainability factors showed that the process is efficient with minimized waste generation. This work introduces a novel approach for designing high-performance magnetic ternary ferrites material, demonstrating its potential as a robust and reusable catalyst for biodiesel production.