A comparative study of the CO oxidation reaction over pristine and C-doped boron nitride fullerene

Abstract

In this work, we employ density functional theory calculations to investigate the CO oxidation mechanisms over B₁₂N₁₂ and B₁₁N₁₂C nanocages. Two possible reaction pathways can be proposed for the oxidation of CO with O₂ molecule over these surfaces: CO + O₂ → OOCO → CO₂ + O_ads and CO + O_ads → CO₂. 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 B₁₁N₁₂C 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 B₁₂N₁₂ 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 B₁₁N₁₂C nanocage toward the CO oxidation reaction is more than that of the B₁₂N₁₂ 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 B₁₁N₁₂C nanocage as a catalyst used for the oxidation of CO with O₂ molecules may proceeded at near ambient temperatures. These results indicate that the B₁₁N₁₂C nanocage can be utilized as a favorable low-cost catalyst for the CO oxidation reaction.