Prediction of electrocatalytic activity of some nitrogen-doped polyaromatic hydrocarbons by molecular modelling

摘要

Density function theory calculations of minimum energy structure of an oxygen molecule and oxygen atom bonded to the two dimensional molecules, C23NH12, coronene and C21NH14, pentacene doped with nitrogen, indicate the structures are at a minimum on the potential energy surface having no imaginary frequencies. Calculation of the bond dissociation energy (BDE) to remove an oxygen atom from nitrogen-doped pentacene to which is bonded O-2, (C21NH14O2) shows it is less than that to dissociate O-2. However, this is not the case for nitrogen-doped coronene. This suggests that nitrogen-doped pentacene could be an effective catalyst for the oxygen reduction reaction in fuel cells assuming it is O-2 dissociation. It is also shown that O2H can bond to nitrogen-doped coronene and pentacene and that the BDE to remove OH is less than that to remove OH from O2H indicating that N-doped coronene and pentacene could also catalyse this reaction. The calculated adsorption energy for O-2 and O2H on these molecules is negative indicating they can bond to N-doped coronene and pentacene.