Based on the M06-2X density functional, the catalytic oxidation of CO by O2 over Mo-embedded graphene was investigated in detail. The model with molybdenum atom embedded in double vacancy (DV) in a graphene sheet was considered. It is found that the complete CO oxidation reactions over Mo-DV-graphene include a two-step process, in which the first step prefers to Langmuir–Hinshelwood mechanism and followed the progress of CO oxidation with a remaining atomic Otop. Compared with the structure of Mo atom decorated at the single carbon vacancy on graphene (Mo-SV-graphene), the catalytic activity of Mo-DV-graphene is weaker. The present results imply that the catalytic activity of Mo-embedded graphene for CO oxidation can be improved by increasing the ratio of single vacancy (SV).

CO catalytic oxidation over graphene with double vacancy-embedded molybdenum: a DFT investigation
    Abstract
    1 Introduction
    2 Computational details
    3 Results and discussion
        3.1 Molybdenum-embedded graphene
        3.2 Adsorption of O2 and CO species over Mo-embedded graphene
        3.3 The CO oxidation on molybdenum-embedded graphene through ER mechanism
        3.4 The CO oxidation on molybdenum-embedded graphene through LH mechanism
        3.5 The recovery of catalyst
    4 Conclusions
    Acknowledgements 
    References

• Guoliang Dai(Jiangsu Key Laboratory for Environment Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology)
• Jiahui Liu(Jiangsu Key Laboratory for Environment Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology)
• Hui Qian(Jiangsu Key Laboratory for Environment Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology)