Green synthesis of ZnO-Zn-MOF/bacterial nanocellulose for ultra oxidative desulfurization of actual diesel fuel

The oxidative desulfurization (ODS) process is a promising approach to reduce sulfur content in fossil fuels using efficient oxidant catalysts such as metal-organic frameworks (MOFs) and its composites. In this study, we aimed to exploit the amazing physicochemical properties of the naturally green polymer bacterial nanocellulose (BNC) as a platform for the ODS of actual diesel fuel. The methodology relied on a green one-pot solvothermal route to synthesize a ZnO-Zn-MOF/BNC nanocomposite. Owing to its 3D porous structure and richness of hydroxyl group, BNC served as a dispersing scaffold for growing the ZnO-Zn-MOF on its nanofibers, improved metal dispersion, and reduced catalyst aggregation. The prepared catalysts were thoroughly characterized using XRD, FTIR, SEM, TEM, and EDX. Moreover, BET analysis has interestingly revealed a morphological shift toward larger pores and enhanced interconnectivity, improving mass transfer and accessibility to active sites. Afterward, the ODS performance of the resulting ZnO-Zn-MOF/BNC nanocomposite was compared to the ZnO-Zn-MOF and ZnO-Zn-MOF/reduced graphene oxide (rGO) counterparts. Additionally, the impact of catalyst dosage, oxidant-to-sulfur molar ratio, extractant-to-oil ratio, reaction time, and temperature on the ODS efficiency of real diesel fuel was systematically investigated. Under optimized conditions 70 °C; O/S molar ratio of 8; catalyst dosage of 200 mg; solvent-to-oil ratio of 1.5:1; and 60 min reaction time, the ZnO-Zn-MOF/BNC catalyst attained 98.5% sulfur removal efficiency. Additionally, the catalyst maintained most of its structural integrity and catalytic activity over five successive cycles, demonstrating high resilience and potential for further in-depth studies to assess its viability for large-scale use as a green desulfurization toolkit.