(544aq) First Principles Study of Active Sites on High Performance PGM-Free ORR Catalyst

Free energy diagrams are computed using first principles calculation under density functional theory framework. The BEEF-vdW exchange correlation functional allows the estimation of experimental uncertainty by training the parameters of the functional form on experimental data. Results from Holby et al are benchmarked in present work using this functional. DFT simulation shows that the edge hosted FeN4 site with OH ligand has the highest thermodynamic limiting potential which explains the high activity experimentally observed by Holby et al. The activity volcano displays the limiting potential as a function of OH* adsorption energy for the cases considered.