Gram-Scale Synthesis of High-Loading Single-Atomic-Site Fe Catalysts for Effective Epoxidation of Styrene.

Single-atomic-site (SAS) catalysts, a new frontier of catalysts, always show extremely high atom efficiency and unexpected catalytic properties. Herein, a pyrolyzing coordinated polymer (PCP) strategy is developed, which is facile and widely applicable in the synthesis of a series of SAS catalysts including SAS-Fe, SAS-Ni, SAS-Cu, SAS-Zn, SAS-Ru, SAS-Rh, SAS-Pd, SAS-Pt, and SAS-Ir. The as-obtained SAS catalysts can be easily synthesized at gram scale and the metal loading of SAS-Fe catalysts achieves a record value of 30 wt%, which meets the requirement of practical applications. Moreover, it is discovered that SAS-Fe catalysts show unprecedented catalytic performance for epoxidation of styrene using O2 as the only oxidant (yield: 64%; selectivity: 89%), while Fe nanoparticles and ironporphyrin are inactive. This discovery is believed to pave the way for exploiting the unparalleled properties of SAS catalysts and promoting their industrial applications.