Theoretical study on CO2 reduction to methanol catalyzed by highly stable single-atom transition metal riveted bilayer 2D material

Abstract

The main factor limiting the high activity of single-atom catalysts (SACs) is the structural instability, which is caused by atomic aggregation or attack of reaction intermediates. In this paper, the single-atom transition metal copper and palladium was riveted between two layers of the monolayer materials (carbon nitride and graphene) respectively to enhance the structural stability, and used C3N-TM-C3N and GR-TM-C3N (TM= Cu, Pd) in the theoretical study of CO2 reduction to methanol (CO2RR). It is found that a single TM atom can be firmly anchored between two C3N or GR-C3N layers, which can prevent the aggregation of TM atoms (TM= Cu, Pd) in SACs and inhibit the attack of reaction intermediates. The TM atom enhances the catalytic activity of the material system by providing electrons to the protective layer GR/C3N. And C3N-Cu-C3N material has the best performance and the lowest reaction energy barrier in CO2RR, which is only 2.094 eV. It provides a feasible method to improve the catalytic activity and maintain the stability for the practical application of SACs systems.