The present research focused on the synthesis of nanocatalyst using manganese ferrite impregnated on sawdustderived biochar (MnFe2O4@biochar) through single-stage hydrothermal process and was subsequently employed as a recoverable and highly reactive catalyst in the conversion of edible waste oil (EWO) into biodiesel. Diverse characterization techniques were employed to assess the structural attributes of both MnFe2O4 and the prepared MnFe2O4@biochar nanocatalyst. Box-Behnken design (BBD) was exercised to optimize vital parameters in biodiesel synthesis. The highest predicted biodiesel yield using MnFe2O4 and MnFe2O4@biochar was 93.92% and 97.26% respectively, which were achieved at methanol/EWO molar proportion of 11.35:1, and voltage of 33.07 V using 1.75 wt% catalyst in 56.12 min. Furthermore, recyclability assessments demonstrated the considerable stability of prepared MnFe2O4@biochar nanocatalyst with biodiesel yield maintained at 90.18% even after seven cycles. The reaction employing MnFe2O4@biochar nanocatalyst as a novel catalyst was found to be endothermic (Delta Ho = 49 kJ/mol). Additionally, its dispersion in the biodiesel/diesel blend improved various performance parameters, including brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), and brake thermal efficiency (BTE), while reducing carbon monoxide (CO), nitrogen oxide (NOx), and unburned hydrocarbon (UHC) emissions. Moreover, nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy validated the catalytic conversion of EWO into biodiesel through the electrolysis procedure. Hence, due to its high retrievability, considerable biodiesel efficiency, and simple separation from the mixture, the prepared nanocatalyst is recommended for application in the industrial production of biodiesel.
