CO oxidation on Mn-N4 porphyrin-like carbon nanotube: A DFT-D study

Abstract

First-principle calculations based on dispersion-corrected density functional theory (DFT-D) are carried out to reveal the elementary steps of CO oxidation on Mn-N4 porphyrin-like carbon nanotube (MnN4-CNT). The stability of MnN4-CNT is confirmed by the first-principles molecular dynamics simulation. According to the energetic calculations, CO and O2 prefer to anchor at the MnN4 site and the adsorption of CO is slightly more favorable than O2. The three reaction mechanisms of CO oxidation on the MnN4-CNT are explored, namely, Eley-Rideal, Langmuir–Hinshelwood, and a “new” termolecular Eley-Rideal, respectively. It is found that the termolecular Eley-Rideal reaction mechanism is the most favorable one and the energy barrier for the rate-limiting step is merely 0.69eV. Our results suggest the high catalytic activity of MnN4-CNT for CO oxidation at room temperature.