Density functional theory study of P-embedded SiC monolayer as a robust metal free catalyst for N2O reduction and CO oxidation

Abstract

In this work, spin-polarized density functional theory calculations are conducted to evaluate the possible applicability of a single P atom doped silicon carbide (P-SiC) monolayer for reduction of nitrous oxide (N2O). The calculations show that P-doping in SiC monolayer is energetically favorable, and the resulting P-SiC is both dynamically and thermodynamically stable. According to our findings, N2O spontaneously dissociates when it interacts with the P-SiC from its O site without the need for an energy barrier, releasing -2.59 eV of energy. The adsorption energy of CO molecule on the P-SiC is less negative than that of N2O, implying that N2O will predominately occupy the catalyst surface. The CO + Oad reaction is used to remove the remaining oxygen atom (Oad) from the P-SiC surface. The calculations show that the reaction proceeds through a low activation energy barrier of 0.33 eV, which is much lower than the previously reported catalysts. This demonstrates the high catalytic activity of P-SiC surface. Furthermore, the adsorption of H2O and O2 species on the P-SiC nanosheet is investigated. The results show that the presence of these species has no effect on the catalytic activity of the P-SiC surface for N2O reduction. These results show that the proposed novel P-SiC catalyst can be regarded as an efficient material in the development of promising active catalysts for N2O elimination from the environment.