Insights into the electronic properties and reactivity of graphene-like BC3 supported metal catalysts

Abstract

Graphene-like BC₃ monolayer is a new two-dimensional nanomaterial with many unique properties, but is still largely unknown. First, we investigated the adsorption behaviors for different metal adatoms (Mo, Pd, Pt and Au) absorbed on pristine and defective BC₃ (pri- and D-BC₃) using first-principles calculations. It was found that the small barriers of the metal adatoms are more likely to diffuse on the pri-BC₃ sheet; yet, the metal atoms doped BC₃ systems (MD-BC₃) exhibit high stability. Second, as O₂ molecule is adsorbed more stably than CO, it regulates the electronic structures and magnetic properties of the MD-BC₃ systems. Moreover, the possible reaction processes for CO oxidation on the Mo-BC₃ substrate were systematically investigated using the Eley–Rideal (ER) and Langmuir–Hinshelwood (LH) mechanisms. For the ER mechanism, the preadsorbed O₂ reacts with CO to form CO₃ or the OOCO complex with smaller energy barrier (<0.30 eV) than that of the LH reaction. In comparison, the dissociative adsorption of O₂ on the Mo-BC₃ sheet as the starting step is an energetically more favorable process and the generated O_ads atoms easily interact with two CO molecules via the ER reactions. This study provides insights into the physical properties and chemical reactivity of BC₃-based nanomaterials.