High-Oxidative Desulfurization of Fuels Catalyzed by Encapsulation of Tetranuclear Sandwich-Type Polyoxometalate on Hierarchical Ni-MOF

Abstract

Efforts to reduce sulfur content in transportation fuels have intensified due to the harmful environmental effects of sulfur emissions. Oxidative desulfurization (ODS) has been as a useful method for removing sulfur from fuels under mild operating conditions. Herein, nanocomposite FWF@NMF was synthesized via the supporting of Fe₆W₁₈O₇₀ (denoted as FWF) in the scaffold of Ni-MOF (NMF). Various techniques were employed to investigate the characteristics of the FWF@NMF nanocomposite, including Brunauer–Emmett–Teller (BET) surface area, Fourier transform infrared (FT-IR), X-ray Diffraction (XRD), Ultraviolet–Visible (UV–vis), Energy-Dispersive X-ray (EDX), and Scanning Electron Microscopy (SEM) analyses. These methods confirmed the successful synthesis of the nanocomposite and provided detailed insights into its structural and morphological properties. The FWF@NMF inorganic–organic hybrid composite was then applied in the ODS process for both real/model gasoline, using a combination of H₂O₂ and acetic acid (H₂O₂/AcOH) as an oxidizing agent. The results demonstrated that the FWF@NMF nanocatalyst exhibited a remarkable desulfurization efficiency, achieving sulfur removal of up to 98% with 0.10 g of catalyst at 35 °C for 60 min. Further, it was noted that a significant decrease in the total sulfur concentration in gasoline was observed, decreasing from 0.4995 to 0.0115 wt %. Furthermore, the FWF@NMF nanocatalyst exhibited excellent recyclability and maintained its activity without significant loss of performance over five consecutive cycles.