Developing efficient approaches for selective oxidation of arene C-H bonds has been a challenging goal. Here we report a facile and practical strategy to fabricate an N-doped reduced graphene oxide (NRGO) based single-atom Cu catalyst (SACu-NRGO) by calcinating dicyandiamide (DCDA) and graphene oxide (GO) wrapped with Cu mesh for the selective oxidation of benzene to phenol at room temperature. According to extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) analyses and density functional theory (DFT) calculations, single atomic Cu is anchored by three adjacent pyrrolic N atoms to form CuN3 active sites in the NRGO skeleton, which originates from the gaseous Cu(NH3)n generated via the reaction between Cu mesh and the ammonia pyrolyzed from DCDA. The SACu-NRGO exhibits excellent catalytic performance towards oxidation of benzene with the selectivity of phenol up to 98.6%, owing to the large specific surface area, fully exposed and homogeneously dispersed CuN3 active sites, as well as the coordination effect between Cu and N species. Furthermore, the structure of the single-atom active sites and the mechanism of the oxidation process are elucidated in depth by DFT calculations.
ASJC Scopus subject areas
- Inorganic Chemistry