Coupled oxidative and adsorptive desulfurization of fuel using molybdenum-modified carbon derived from PET waste

Environmental pollution caused by (SO) _x emissions from the combustion of sulfur-containing fuels remains a significant challenge. Oxidation-coupled adsorptive desulfurization is a promising alternative technique to remove aromatic sulfur compounds from fuel. In this study, we developed a bifunctional material for coupled adsorptive and oxidative desulfurization by upcycling PET plastic bottles into a highly functional carbonaceous material via microwave-assisted KOH activation followed by impregnation with molybdenum. The high surface area and porous structure of carbonised PET, together with the metal impregnation, enhance the desulfurization capacity. The adsorbent material was characterised using FT-IR, BET, XRF, TGA, SEM-EDX, XRD, and XPS analysis. The maximum adsorption capacity of the material was found to be 63.76 mg g^-1, with a surface area of 254.93 m² g^-1. The overall removal process was thermodynamically favourable and endothermic, and the kinetic data was best described by pseudo-second-order kinetics. The adsorbent was stable up to four cycles after regeneration. The developed cost-effective adsorbent demonstrated effective coupled oxidative-adsorptive desulfurization of real diesel while supporting sustainable management of PET waste.