Sarcosine-anchored Fe₃O₄-supported iron(III) catalyst for efficient biodiesel and benzoxazole synthesis: kinetic and...

A new iron(III) complex was synthesized by anchoring a sarcosine-based mono phenol amine on Fe₃O₄. The material was then characterized using TEM, FE-SEM, FT-IR, TGA, VSM, XRD, NH3-TPD, EDS, and elemental analysis. Then, the transesterification process of canola oil was performed with 2.1 wt% catalyst under mild conditions led to the achievement of 98% yield of biodiesel. Furthermore, the reaction under mild conditions and with the aid of 0.21 wt% catalyst loading yielded 91% benzoxazole from 3,5-di-tert-butyl catechol, ammonium acetate, aldehyde in ethanol under oxygen balloon with 91% benzoxazole yield. The structure of the produced biodiesel and benzoxazole was confirmed by ¹H NMR and FT-IR spectroscopy, while the composition of the biodiesel was further analyzed using GC-MS. The hot filtration experiment confirmed the stable heterogeneous nature of the catalyst. The system was able to show good recyclibility for at least 7 and 5 consecutive cycles in the production of biodiesel and benzoxazole, respectively. The kinetics of the benzoxazole formation reaction were investigated using a modeling approach and consequetly, the rate constants and activation parameters, ΔH^≠ and ΔS^≠, were calculated. The key distinguishing figure of the catalyst was both double active sites and dual activity. Presence of chlorine substituents placed on mono phenol amine ligand and increasing the Lewis acidity of Fe(III) centre, results in consequently, high efficiency, low catalyst loading, mild medium and oxidative conditions for mentioned processes.