Probing the room-temperature oxidative desulfurization activity of three-dimensional alkaline graphene aerogel

Abstract

Room-temperature catalytic oxidation of H2S has emerged as an intriguing solution to the H2S elimination, but is currently challenged by desulfurizers’ low capacity. Herein, three-dimensional alkaline graphene aerogels are prepared and demonstrated to be highly efficient catalysts for H2S oxidation, achieving 3.19 g/g of breakthrough capacity. Such high sulfur capacity is attributed to the interconnected graphene network consisting of graphene sheets, providing more product storehouse compared with traditional porous carbons. Further, a radical-induced reaction pathway of H2S oxidation is proposed that oxygen molecules could be activated to form superoxide radicals merely on graphene, which induces the dissociated HS− oxidation to sulfur. The characterization results also uncover that the formed sulfur goes through a process of nucleation and growth on graphene sheets. The current work could provide critical insights into the behavior of H2S oxidation and therefore offers a novel route of developing catalysts with large sulfur capacity at room temperature.