DFT Study of CN Oxidation (CN + ½O2 → OCN) on the Surfaces of Chromium-Doped Nanotubes (Cr–CNT (8, 0) and Cr–BNNT (8, 0))

Abstract

The Cr–carbon nanotubes and Cr–boron nitride nanotubesas novel catalysts were used to find out the details of mechanisms of CN oxidation. The oxidation of CN molecule can process via Cr–CNT and Cr–BNNT catalysts through the Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) mechanisms. The CN molecule joins to Cr atom and Cr–surface– $${\text{O}}_{2}^{*}$$ and Cr–surface–O* are created as important intermediate structures with low barrier energies. The cis-Cr–surface–OCNO* complex according to ER mechanisms more stable than four-elements–ring complex in LH mechanism, approximately 0.09 and 0.11 eV, respectively. In LH pathway, total activity was bounded by irretrievable adsorption of OCN molecules in Cr atom of Cr–CNT and Cr–BNNT. In ER pathway, two OCN molecules are released at normal temperature. The catalytic capabilities of Cr–CNT and Cr–BNNT to oxidation of CN molecule were demonstrated in this study.