Engineering electronic structure of single-atom pd site on Ti0.87O2 nanosheet via charge transfer enables C-Br cleavage for room-temperature suzuki coupling

Abstract

The palladium (Pd)-catalyzed Suzuki reaction is widely applied in the pharmaceutical industry, where constructing highly active and low-cost Pd sites are impendent. Here, we report the fabrication of a heterogeneous Pd/Tio2 catalyst via engineering of an electronic structure of a single Pd1 atom on monolayered Ti0.87O2 nanosheet (Pd1-Ti0.87O2). This catalyst motivated the kinetically sluggish C-Br cleavage, thus boosting the Suzuki reaction at room temperature. Pd1-Ti0.87O2 exhibited an outstanding activity with turnover frequency (TOF) of 11,110 h−1, exceeding that of PdCl2 and Pd(OAc)2 catalysts by a factor of >200. Various in situ techniques were employed to investigate the C-Br activation process, which showed that Pd1 kinetic-feasibly dissociated the chemisorbed bromobenzene, especially the C-Br bond cleavage. Theoretical calculations further revealed that the improved activity is ascribed to the optimized charge state of Pd1 within the Pd1O4 realm via charge transfer.