Catalytic reduction of NO by CO over Fe-doped penta-graphene as a promising catalyst: A density functional study

Abstract

The potential of Fe-doped penta-graphene (Fe–PG) as a catalyst for reduction of NO by CO is investigated by a Density Functional Theory (DFT) calculation. The results of adsorption energy, charge transfer and partial density of states (PDOS) indicate that the adsorption of NO on the surface is stronger than that of CO. The direct dissociation of NO is barely possible to occur because the dissociation of NO has a very high activation energy of 5.38 eV. The structure of adsorbed (NO)2 dimers is discovered on the surface, which initiates the reaction described by the dimer mechanism. (NO)2 dimers dissociate into a N2O molecule and an Oads atom over a relatively small activation energy of 0.74 eV. Then the desorbed N2O molecule decomposes into a N2 molecule and an Oads atom on the surface or reacts with an upcoming CO molecule with small activation energies of 0.41 eV and 0.39 eV. The remaining surface Oads atoms are then reduced by CO to produce a CO2 with a small activation energy (0.44 eV). Attributed to the stable physical properties of penta-graphene, the cost-effectiveness of Fe, and relatively small energy barrier via the dimer mechanism, Fe–PG could be a promising catalyst for the reduction of NO by CO.