Evaluation of the CO2 reduction reaction using Mn and Cr single atom catalysts implanted on the g-C3N4 (heptazine): A DFT study

Abstract

Greenhouse gases, particularly CO2, contribute to the phenomenon of global warming. Here, we explore the hydrogenation reaction of CO2 in the presence of Cr or Mn atoms as a single-atom catalyst (SAC) joined to g-C3N4 substrate by DFT-D2 calculations to change it to more unhazardous and more useful materials such as formic acid. We proposed two reaction mechanisms. The first without and the second with the participation of the N atom of the g-C3N4 (Route A and B) carries out, and in both of them Cr and Mn atoms joined to g-C3N4 were used (labeled with 1 and 2, respectively). The results show that Mn is better than Cr as SAC for CO2 hydrogenation reaction, and the participation of the N atom in the mechanism facilitates this reaction. This study provides insights into designing g-C3N4-based catalysts for CO2 reduction reactions and CO2 elimination from the environment.