Atomically Dispersed Cu Atoms Anchored on N-Doped Porous Carbon as an Efficient Catalyst for C–C Bond Cleavage of Ketones toward Esters

Abstract

Efficient and selective cleavage and functionalization of C–C bonds is of critical significance in fine chemistry and lignocellulosic biomass valorization, yet it is still challenging due to their inert nature. In the present work, we report an atomically dispersed Cu catalyst encapsulated in N-doped porous carbon (Cu@NC-900) through a facile method using metal–organic frameworks (MOFs) as precursors, where Cu atoms were chelated and stabilized by N species. The resulting catalyst exhibited good performance for oxidative cleavage of C–C bonds toward esters, giving a 98.6% yield of methyl benzoate with complete conversion of acetophenone under base-free conditions. Further, the Cu@NC-900 catalyst was efficient for the conversion of a wide range of ketones, including (hetero)aryl methyl ketones or challenging alkyl ketones, to their corresponding esters. Experiments demonstrated that the highly dispersed Cu sites and incorporation of N species, as well as the rich pore structures, contributed to the high activity, selectivity, and stability. Theoretical calculations further attributed the high activity to the oxidation state formed by the electron loss of the isolated Cu atoms.