Abstract This study presents the development of Fe–Co–Ni mixed-metals oxide composites that were synthesized via chemical precipitation method at different reaction times (05–8 h). These composites were subsequently utilized to achieve deep sulfur removal from diesel fuel through ultrasoumd-assisted oxidative desulfurization (UAOD). Among those composites, the obtained composite at a synthesis time of 0.5 h emerged as the most efficient catalyst, achieving nearly 60% sulfur removal under optimized operating conditions (60 °C, 90 min as reaction time, catalyst dose of 10 g/L and a 1:1 H 2 O 2 -to-feed ratio). A subsequent sulfur removal of 89% was achieved through post-treatment with a DMF–acetonitrile solvent mixture (4:1 solvent-to-feed ratio), validating the synergy between catalytic oxidation and solvent extraction. The exceptional performance by this Fe–Co–Ni composite was further amplified by a structure modification through production of core–shell composite using a layer of polystyrene. This composite achieved reduction of sulfur content to 920 ppm (from 21,700 ppm in feedstock) which represented a sulfur removal percentage of approximately 96%. Therefore, the introduced approach can be considered for scalable and energy-efficient processes for producing low-sulfur diesel, aligning with global environmental demands.
Zahran et al. (Fri,) studied this question.