Multiscale porous single-atom Co catalysts for epoxidation with O2

Abstract

Epoxides are versatile intermediates in the production of a diverse set of chemical products. The direct epoxidation of alkenes using O₂ represents an environmentally friendly and economical process to replace the use of expensive H₂O₂ or organic peroxides for the synthesis of epoxides. Herein, single-atom Co anchored on N-doped carbon supports with a multiscale porous structure (Co₁/NC-h) has been successfully constructed by etching CoZn-ZIF metal–organic framework precursors before a carbonation process. Benefitting from the high intrinsic activity of Co–N_x active sites and the more accessibly exposed reactive sites of multiscale porous structures, the Co₁/NC-h catalysts can achieve the epoxidation of cyclooctene with 95% yield of 1,2-epoxycycloheptane at 140 °C and 0.5 MPa O₂. This research opens up opportunities for designing high-performance single-atom catalysts towards applications in diverse heterogeneous catalysis.