Single-atom manganese and nitrogen co-doped graphene as low-cost catalysts for the efficient CO oxidation at room temperature

Room temperature, low-cost and efficient single-atom catalysts for the CO oxidation was essential for the pollutant-free biological and ecological environment. Herein, the oxidation mechanism of CO on manganese (Mn) and nitrogen (N) co-doped single-vacancy graphene (MnN-SV) and double-vacancy graphene (MnN-DV) are studied through density functional theory (DFT) calculations. The MnN-SV have a more excellent catalytic performance for CO oxidation compared to MnN-DV due to the synergistic effect of the Mn and N atoms and the ligand effect. CO oxidation on MnN-SV results into two CO2 via the termolecular Eley-Rideal (TER) mechanism whose energy barrier of rate determining step (RDS) is 0.351 eV, indicating superior catalytic performance compared to the most known catalysts. In addition, MnN-SV catalyzes CO via the Langmuir-Hinshelwood (LH) mechanism with only an energy barrier of RDS is 0.727 eV, and the energy barrier for the second CO2 generated by Eley-Rideal (ER) mechanism is 0.691 eV. Technologically, present results provide a pathway for the development of an efficient and low-cost catalysts to oxidize CO at room temperature.