A DFT Study of Single-Atom Catalysis of CO Oxidation Using Carbon-Embedded Hexagonal Boron Nitride Monolayer

The catalytic oxidation of CO by O-2 molecule under mild conditions is one of the attractive processes in chemistry and industry. In the present study, by means of periodic density functional theory calculations, the potential of experimentally available carbon-doped hexagonal boron nitride (h-BN) nanosheets as a metal-free catalyst for the CO oxidation is investigated. It is found that C-doping induces high spin density into BN monolayer which is mainly localized over the C and its neighboring N or B atoms. Both Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms are considered for the CO oxidation reaction. The calculated reaction barriers reveal that the CO oxidation proceeds first via the LH mechanism CO + O-2 -> OCOO -> CO2 + O* and then via the ER mechanism CO + O* -> OCO* -> CO2. Our results suggest that the CO oxidation catalyzed by the C-doped h-BN sheets is likely to occur at the normal condition.