Non-metal atom anchored BC3 sheet: a promising low-cost and high-activity catalyst for CO oxidation†
Abstract
Graphene-like BC3 monolayer as a new semiconducting nanomaterial has many unique properties. First, we investigate the adsorption behaviors of different adatoms (N, Si and P) on pristine and single-vacancy of BC3 (pri- and SV-BC3) using first-principles calculations. It was found that the non-metal (NM) adatoms have small diffusion barriers and tend to be mobile on the pri-BC3 sheet; yet, these NM atom-doped BC3 systems (NM-BC3) exhibited high stability. Second, the adsorption of O2 molecule on the Si-BC3 system was more stable than that on other substrates (N- and P-BC3), resulting in a change in the electronic structure and magnetic properties of the system. Moreover, the possible CO oxidation reactions on the Si-BC3 sheet through the Eley–Rideal (ER) mechanism were comparatively investigated. For the initial step, the preadsorbed O2 reacting with CO to form CO3 or OOCO complex had a smaller energy barrier (<0.50 eV) than the dissociation reaction of the O2 molecule. The formation of the CO3 complex was quite stable on the Si-BC3 sheet; yet, the presence of the CO molecule promoted the decomposition of the CO3 complex and then formed two CO2 molecules through ER reactions. These results contribute toward designing more effective and metal-free single-atom catalysts and broaden the applications of graphene-like materials.