Ir0/graphdiyne atomic interface for selective epoxidation

The development of catalysts that can selectively and efficiently promote the alkene epoxidation at ambient temperatures and pressures is an important promising path to renewable synthesis of various chemical products. Here we report a new type of zerovalent atom catalysts comprised of zerovalent Ir atoms highly dispersed and anchored on graphdiyne (Ir-0/GDY) wherein the Ir-0 is stabilized by the incomplete charge transfer effect and the confined effect of GDY natural cavity. The Ir-0/GDY can selectively and efficiently produce styrene oxides (SO) by electro-oxidizing styrene (ST) in aqueous solutions at ambient temperatures and pressures with high conversion efficiency of & SIM;100%, high SO selectivity of 85.5%, and high Faradaic efficiency (FE) of 55%. Experimental and density functional theory (DFT) calculation results show that the intrinsic activity and stability due to the incomplete charge transfer between Ir-0 and GDY effectively promoted the electron exchange between the catalyst and reactant molecule, and realized the selective epoxidation of ST to SO. Studies of the reaction mechanism demonstrate that Ir-0/GDY proceeds a distinctive pathway for highly selective and active alkene-to-epoxide conversion from the traditional processes. This work presents a new example of constructing zerovalent metal atoms within the GDY matrix toward selective electrocatalytic epoxidation. An advanced catalytic system of graphdiyne-based zerovalent iridium atom catalysts with unique incomplete charge transfer between Ir-0 atoms and graphdiyne was developed to maximize atomic efficiency for epoxidation of olefins in aqueous solutions.

Automated summary

A new type of zerovalent atom catalysts comprised of zerovalent Ir atoms highly dispersed and anchored on graphdiyne (Ir-0/GDY) is developed. The catalyst can selectively and efficiently produce styrene oxides (SO) by electro-oxidizing styrene (ST) in aqueous solutions at ambient conditions. The incomplete charge transfer between Ir-0 and GDY plays a crucial role in enhancing the electron exchange and achieving the selective epoxidation of ST to SO.