Biodiesel production from waste cooking oil using heterogeneous nanocatalyst-based magnetic polyaniline decorated with cobalt oxide

The development of novel heterogeneous catalyst materials with unique chemical/physical properties has attracted great attention in biodiesel production. Herein, the binary functional organic–inorganic nanocomposite based on polyaniline decorated with magnetic iron oxide and cobalt oxide nanoparticles were used to synthesis MPANI@Co₃O₄ as novel nanocatalyst. The proposed material was fabricated through a facile hydrothermal technique coupled with a one-pot polymerization method. The morphology and structure of as-prepared MPANI@Co₃O₄ materials were evaluated using field-emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FTIR), vibrating-sample magnetometer (VSM), and energy dispersive X-Ray spectrometer (EDX). The FESEM-EDX provided the metal oxide nanoparticles well incorporated onto polyaniline with C (28.32 %), N (48.45 %), O (21.44 %), Fe (1.69 %), and Co (1.10 %). The MPANI@Co₃O₄ was successfully used as a high-performance nanocatalyst in transesterification of waste cooking oil (WCO) to FAMEs (biodiesel). Due to the acidic-alkaline nature of the proposed catalyst, it has high potential to produce methoxy ions followed by attacking the carbonyl groups of triglycerides. In further experiments, the satisfactory reaction conditions obtained were MPANI to Co₃O₄ ratio of 1:1, WCO to methanol molar ratio of 1:10, 240 min reaction time and at 90 °C reaction temperature. Moreover, under optimum conditions, the catalyst offered desirable catalytic performance (>93%) to catalyze the triglycerides of WCO to biodiesel (FAMEs). Therefore, the novel binary organic–inorganic nanocomposite can be used as co-catalyst material in biodiesel processing.