Atomically dispersed single ruthenium sites anchored on bismuth tungstate with synergistic geometric and electronic effects for epoxidation of trans-stilbene

Abstract

The feasibility of elegantly tuned geometric structures and electronic environments of metal active sites in single atom catalysts (SACs) is crucial for developing highly robust and efficient catalytic materials. Here we report a straightforward and efficient approach to accessing single ruthenium (Ru) atoms over a Bi2WO6 assemblage, with each Ru atom coordinated with four neighboring oxygen atoms. This Ru catalyst, exhibits synergistic geometric and electronic effects, resulting in a significantly enhanced catalytic performance for epoxidation of trans-stilbene to give trans-stilbene oxide. The reaction takes place under mild conditions, with high conversion (>99 %) and selectivity (>99 %) within a mere 2 h and a high turnover frequency (TOF) of 558 h−1. The theoretical calculations demonstrate that the high catalytic activity originates from the strong electronic metal-support interaction and the charge state of ruthenium sites in Bi2WO6. This work opens an avenue to engineer SACs on Aurivillius (perovskite) phase materials at the atomic level and serves as a promising platform for further studies of many other organic transformations.