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

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 O₂, (C₂₁NH₁₄O₂) shows it is less than that to dissociate O₂. 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 O₂ 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 O₂ and O₂H on these molecules is negative indicating they can bond to N-doped coronene and pentacene.