Oxidative desulfurization of diesel fuel with caprolactam-based acidic deep eutectic solvents: Tailoring the reactivity of DESs by adjusting the composition

Sulfur compounds are extracted into the DES phase, where they interact. The carboxylic acid moieties of the DES are oxidized by H2O2 to the corresponding peracids, which in turn oxidize the sulfur compounds to the corresponding sulfones.