Tuning the adsorption and interaction of CO and O2 on graphene-like BC3-supported non-noble metal atoms

Abstract

Research into suitable substrate-supported single-atom catalysts has become a major challenge for electrochemical sensors and energy devices. Firstly, we investigate the adsorption properties of metal atoms (MA = Fe, Co, Ni, Cu and Al) on pristine and defective BC₃ sheets through using first-principles calculations. It is found that the MA-doped BC₃ configurations (MA-BC₃) are quite stable at high temperature and the positively charged MAs as surface active sites can effectively regulate the stability of reactive gases. Secondly, the adsorption of individual O₂ molecules is more stable than that of CO molecules, which can modify the electronic and magnetic properties of MA-BC₃ systems. Moreover, the possible reaction processes of CO oxidation on the Fe-BC₃ substrate are comparably analyzed through the Eley–Rideal (ER) and Langmuir–Hinshelwood (LH) mechanisms. In the LH mechanism, the coadsorbed O₂ and CO as starting materials start to form an OOCO complex with a smaller energy barrier (0.38 eV), which is an energetically more favorable process than that of the OOCO (0.65 eV) or CO₃ complex (0.42 eV) formed through ER mechanisms. This result indicates that the functionalized MA-BC₃ sheets have low cost and high activity.