Covalent organic framework-supported Zn single atom catalyst for highly efficient N-formylation of amines with CO2 under mild conditions

Transformation of CO2 into value-added chemicals with efficient and recyclable catalyst is an effective way to reduce carbon emissions. It is valuable to develop an efficient catalyst that can promote the N-formylation reaction under mild conditions with a high activity and excellent recyclability. Single atom catalysts (SACs) possess ultimate atom utilization efficiency and outstanding catalytic performance. Herein, we synthesize Zn SACs (Zn-TpPa) anchored on a COF (TpPa-1) using a facile solution method. Catalyzed by Zn-TpPa, CO2 and N-methylamine are transformed into N-methylformanilide under mild reaction conditions with a TOF of 17,155 h−1, which is the highest among all reported recyclable Zn-based catalysts. Zn-TpPa can also catalyze N-formylation of many other amines with excellent yields. The higher reactivity was attributable to the well-dispersed Zn active sites on COF and outstanding adsorption of CO2 owing to high surface area of COF. Our research provides a facile method for constructing SACs as well as an effective pathway for CO2 transformation and environmental protection.