Coordination unsaturation of vanadium nitride quantum dots boosts low-temperature aerobic oxidation of thiophenic sulfides

Abstract

Aerobic oxidative desulfurization (AODS) promises a sustainable alternative technology for diesel desulfurization, which necessitates the efficient aerobic oxidation of thiophenic sulfides under mild conditions to minimize energy input, yet being longstandingly plagued by the grand challenge in low-temperature activation of triplet oxygen. Here we synthesize vanadium nitride quantum dots on graphene to controllably create coordination-unsaturated edge/corner V sites for boosting the AODS reaction. The catalyst activates the reaction at 70 °C, and is two orders of magnitude more active than the best V-based catalysts. We demonstrate through computational studies that the low-coordinated edge/corner V sites can effectively activate oxygen and adsorb sulfides to lower the activation barrier, dramatically enhancing the activity. The catalyst achieves deep AODS of real diesel at 80 °C with negligible attenuation in successive reuses, which highlights its attractive industrial potential. These findings provide scientific and practical insights to develop high-performance catalysts for a sustainable AODS process.