Efficient Production of Biodiesel by the Transesterification of Neem Oil Using Ni-Doped ZnO Nanoparticles as Heterogeneous Catalysts

The shocking ecological variations and dangers of phasing out fossil fuels are concerning for human progress. It has raised the apprehension of workers about shifting from old energy capitals to ecologically sustainable biofuels. The current work involves the preparation of biodiesel (BD) using non-edible neem oil via transesterification reaction (TR). The transesterification process was carried out using nickel-doped zinc oxide (Ni–ZnO) nanocatalysts produced using the sonochemical technique. XRD, EDX, and SEM were employed for characterizing synthesized nanoparticles. TR was performed for the evaluation of the catalytic performance of Ni–ZnO. Various parameters affecting reaction rates, such as catalyst amount, temperature, and the methyl alcohol to neem oil ratio, were tested to determine where the maximum BD production could be achieved. It was found that the best BD (90.1%) was produced at 60 °C with a 1:10 oil-to-methyl alcohol ratio using 0.9 g of the catalytic system. First-order kinetic modeling is best suited for TR. Vital thermodynamic factors such as energy of activation (E*), enthalpy (H*), and entropy (S*) were also found. TR was endothermic and entropy-driven. A Ni–ZnO nanocatalyst could be an appropriate catalytic system for the heterogeneous catalysis of transesterification, a key reaction for BD making.