Computational Screening of Single Non-Noble Transition-Metal Atoms Confined Inside Boron Nitride Nanotubes for CO Oxidation

Based on density functional theory calculations, the stability and catalytic activity of a series of single non-noble transition-metal (TM) atoms confined on the interior surface of boron nitride nanotubes (BNNTs) with nitrogen vacancy for CO oxidation have been systematically studied. By searching for the reaction pathways of CO oxidation in the Eley-Rideal (ER) mechanism catalyzed by single TM atoms (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Cu, Zn) confined inside BNNT(6,6), we found that Cu-BNNT(6,6) and Mn-BNNT(6,6) are good candidates as highly efficient catalysts, with the energy barriers of the rate-determining step for CO oxidation being 0.24 and 0.37 eV, respectively. Compared with ER reactions, CO oxidation proceeds via the Langmuir-Hinshelwood mechanism with relatively larger energy barriers. We confirmed that the interior surface of BNNT(6,6) provides a better confinement environment than the exterior surface for developing single-atom catalysts. With the appropriate energy barriers, Cu-BNNT(6,6) and Mn-BNNT(6,6) show the satisfactory catalytic performance for CO oxidation.