Robust Organic-Cage-Encapsulated Polysulfidometallates for Catalytic Hydrodesulfurization

Hydrodesulfurization (HDS) is an important catalytic process widely used to remove sulfur from natural gas or refined petroleum products. Metal sulfide-based catalysts are the main HDS catalysts widely used, especially MoS2 materials. It’s believed that the unsaturated sites on the edges of catalysts are active sites to initial reactants binding and then undergo further reactions. The low density of active sites on sulfide sheet materials leads to a low catalytic efficiency of traditional 2D materials. Studies have been done to deposit metal sulfides onto supports with high surface areas, such as alumina, to distribute widely and give rise to more catalytic sites. Our previous and current studies demonstrated that polyoxometallates (POMs) could be incorporated into a mesoporous Zr-based MOF (NU-1000) via an postsynthetic impregnation method in aqueous media and further treatment using H2S gas can lead to sulfide product of S-POM@NU-1000. By taking advantage of this approach, we propose to use organic molecular cages to confine the POMs. The same chemistry is expected to occur and to form a new type of materials, S-POM@Cage. As shape‐persistent organic molecules, but with permanent and accessible cavities, these cages can host POM guest anions to form complexes and prevent aggregation during the reactions. Hydrodesulfurization of organosulfur compounds (e.g., dibenzothiophenes) is our target reactions to investigate. We propose materials synthesis, catalytic measurements, and computational modeling to elucidate the optimal structures and working mechanism for hydrodesulfurization of sulfur contamination from refined petroleum products.