Controllable electronic effect via deep eutectic solvents modification for boosted aerobic oxidative desulfurization.

• A novel electronic modulation strategy on metal-free catalyst via organic modification was proposed. • The electron transfer effect was well proved and the electron transfer direction was clarified. • A deep oxidative desulfurization can be achieved with the residual sulfur content less than 10 ppm. • The mechanism of the improved catalytic activity was illustrated clearly. Tuning electronic structure of metal catalysts by organic modification is an efficient strategy for domination of their catalytic performances. However, the electronic structure tuning over metal-free catalysts remains to be a challenge. In this work, an organic modification strategy with deep eutectic solvents (DES) as organic modifier over metal-free catalysts was proposed to tune the electronic structure of hexagonal boron nitride (h-BN). Detailed experiments showed that the electronic properties of h-BN was rationally tuned by the introduced DES, in which the B atoms in h-BN were positively charged. Meanwhile, the modulated electronic properties can lower the activation energy for the generation of hydroxyl radicals (•OH) from hydrogen peroxide (H 2 O 2), thus leading to a promoted catalytic performance in oxidative desulfurization. This finding may pave a new strategy for tuning metal-free catalysts with highly-active catalytic performance. An organic ligand modification strategy over metal-free boron nitride catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]