Highly efficient oxidative removal of thiophene at ambient temperature over synthetic MnO2/zeolite nanocomposites

Abstract

Herein, we report the synthesis and characterization of MnO₂/zeolite nanocomposites as potential catalysts for the removal of thiophene (Th). MnO₂ nanoparticles were successfully synthesized from KMnO₄. Subsequently, MnO₂/zeolite nanocomposites with 5 wt% MnO₂ (MnO₂/Cu-Clin and MnO₂/Clin) were prepared by solid-state dispersion (SSD) and impregnation methods. The detailed characterization of the catalysts was carried out by employing X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and N₂ adsorption–desorption techniques. The catalytic activity of the composites was evaluated by the removal of Th. The effect of solvent type, initial Th concentration, temperature, and the catalyst preparation method were studied and discussed in detail. The results showed that the MnO₂/Cu-Clin composite completely removed the Th from a mixed solvent of water–ethanol in the presence of NaClO as the oxidant during the initial 40 min at 25 °C. Whereas, the MnO₂/Clin composite removed approximately 81% of the Th after 80 min under the same conditions, and at an elevated temperature of 60 °C, the removal efficiency reached 98%.