High-entropy oxide based biomimetic catalysis system enables robust oxidative desulfurization with an excellent regeneration ability

Abstract

Sulfur-containing compounds from the usage of fossil fuel have severe impacts on the ecological environment and human health. To eliminate sulfur species in fuels, oxidative desulfurization is served as an effective technology, whose core lies in constructing an efficient catalytic system under mild conditions. High-entropy oxides (HEOs) with maximized conformational entropy normally generates abundant catalytically active sites, which are beneficial for the enhancement in catalytic performance. On this basis, a biomimetic catalytic system coupling HEO with deep eutectic solvent (DES) was designed for oxidative desulfurization with molecular O2 oxidant by following the electron transfer mechanism. This catalytic system not only exhibited excellent sulfide removal with O2 oxidant under the ambient pressure, but also can resist the adverse effects of naphthalene and indole in an appropriate concentration range. Uniquely, this HEO was capable to be recovered from the DES phase, ensuring a good recycling and regeneration ability. During the whole catalytic process, the electron was transferred in the sequence of sulfide → DES → HEO → O2. These extraordinary features make it to be an alternative candidate for industrial applications under mild conditions.