Boosting graphene reactivity with co-doping of boron and nitrogen atoms: CO oxidation by O2 molecule

Abstract

The aim of this study is to compare the catalytic activity of BCmNn-doped graphene sheets (Gr-BCmNn; m, n = 0, 1, 2, 3 and m + n = 3) towards the oxidation of CO molecule. By performing periodic density functional theory calculations, we show how BN co-doping can boost the surface reactivity of graphene and improve its catalytic performance in the CO + O2 reaction. Our results indicate that the positively charged B atom in Gr-BCN2 and Gr-BN3 sheets is beneficial to the capture of O2 molecule and serve as the catalytic active sites for the CO oxidation reaction. Both Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) mechanisms are considered for the CO oxidation reaction over Gr-BCN2 and Gr-BN3. It is found that the CO oxidation proceeds first via the LH mechanism CO + O2 → OCOO → CO2 + O∗ and then via the ER mechanism CO + O∗ → CO2. The origin of high catalytic activity of these surfaces is attributed to the large electronegative difference between the B and N atoms.