Aerobic oxidative desulfurization coupling of Co polyanion catalysts and p-TsOH-based deep eutectic solvents through a biomimetic approach

Abstract

A unique coupled redox biomimetic catalytic system using the Anderson-type polyoxometallate (POM) (NH₄)₃Co(OH)₆Mo₆O₁₈ and p-toluenesulfonic acid (p-TsOH)-based deep eutectic solvents (DESs) as cocatalysts, which served as electron donors and electron-transfer mediators (ETMs), can selectively oxidize the sulfides in diesel into their corresponding sulfones. The use of coupled redox systems with ETMs facilitates the reaction process by transporting electrons from Co-POM to the oxidant along a low-energy pathway, making DBT prone to oxidize to DBTO₂. The biomimetic system demonstrates outstanding desulfurization performance with oxygen as an oxidant in the absence of sacrificial agents and under mild conditions.