In this work, we employ density functional theory calculations to investigate the CO oxidation mechanisms over B _(12) N _(12) and B _(11) N _(12) C nanocages. Two possible reaction pathways can be proposed for the oxidation of CO with O _(2) molecule over these surfaces: CO + O _(2) → OOCO → CO _(2) + O _(ads) and CO + O _(ads) → CO _(2) . Both Eley–Rideal (ER) and Langmuir–Hinshelwood (LH) mechanisms are considered for these two reaction pathways. Our calculations indicate that the CO oxidation reaction over the B _(11) N _(12) C nanocage proceeds via the ER mechanism followed by LH mechanism with an activation energy ( E _(act) ) of 0.58 eV. In the case of the B _(12) N _(12) nanocage, it can be estimated that both reaction pathways go through the LH mechanism. The E _(act) of the first reaction step is about 2.5 eV, while it is negligible for the second route. Based on the present theoretical results, the catalytic activity of the B _(11) N _(12) C nanocage toward the CO oxidation reaction is more than that of the B _(12) N _(12) cluster. This can be related to the presence of a C atom that plays a significant role in the activation of the whole cluster. Meanwhile, the performance of the B _(11) N _(12) C nanocage as a catalyst used for the oxidation of CO with O _(2) molecules may proceeded at near ambient temperatures. These results indicate that the B _(11) N _(12) C nanocage can be utilized as a favorable low-cost catalyst for the CO oxidation reaction.
展开▼
