Surface reconstruction induced highly efficient N-doped carbon nanosheet supported copper cluster catalysts for dimethyl carbonate synthesis

Abstract

N-doped hierarchical porous carbon nanosheets-supported copper catalysts (Cu/NCNS-x) were fabricated to solve the problem of deactivation caused by the leaching, agglomeration and oxidation of Cu nanoparticles (NPs) in the dimethyl carbonate (DMC) synthesis. The optimal Cu/NCNS-12 exhibited superb activity and stability without obvious deactivation after 10 cycles. The nanosheet structure produced new defects resulting in Cu reconstruction during the reaction process, while the strong interaction between Cu0 and N atoms greatly inhibited the oxidation of Cu0. The reconstruction of Cu was stimulated at above 100 °C, regardless of atmosphere, solvent types, pressure and rotation speed. The mechanism was elaborated that the initial Cu NPs (11 nm) migrated and then was trapped into newly created defects, finally formed into clusters (0.91 nm) as well as single-atom sites. This work provides profound potential in understanding metal reconstruction and developing a promising synthetic strategy of metal cluster catalysts.