Oxygen reduction activity of BN decorated bulk defects in graphene

We use Density-Functional-Theory to investigate the interaction between O$_{2}$ and H$_{2}$O$_{2}$ with co-doped bulk BN defects in graphene. The results show that the mixed defects are thermodynamically stable in contrast to the nitrogen only defects that need a transition metal for stabilization. The interaction between O$_{2}$ and H$_{2}$O$_{2}$ and the BN defects are found to be very different: O$_{2}$ is adsorbed as a molecule on boron with a bond length increase of $\sim $20{\%}. H$_{2}$O$_{2}$, on the other hand, is predicted to adsorb dissociatively to form B(OH)$_{2}$. The predicted binding energy (BE) of O$_{2}$ is similar to the N only defects. This observation suggests that BN defects promote the reduction of O$_{2}$ to H$_{2}$O$_{2}$. However, we also found that the binding energy per OH is $\sim $75{\%} higher than the corresponding BE for the N only defect. Thus, restoring the catalytic site through OH removal is more difficult as compared to the N only defect. This implies that bulk BN defects are most likely less active than N only defects and edge BN defects which enhance ORR.