Catalytic Activity of Non-Metal Doped Graphene for Electrocatalytic ORR

This book employs DFT to study the electrocatalytic ORR activity of nonmetal-doped graphene. Results show ORR intermediates (O₂ OOH O OH) preferentially adsorb on positively charged sites with large atomic magnetic moments with adsorption strength correlating to these properties. Most dopants (B P As Si S) lose electrons becoming positively charged with small magnetic moments serving as primary active sites. Highly electronegative dopants (N O F Cl) gain electrons making adjacent carbon atoms the active sites potentially creating multiple catalytic centers. Adsorption strength directly affects activity: weak adsorption hinders *O₂/*OOH hydrogenation while strong adsorption limits *O/*OH hydrogenation possibly favoring 2e⁻ H₂O₂ formation over the 4e⁻ pathway. By analyzing Gibbs free energy changes the rate-determining steps were identified. The As-N₄ configuration shows exceptional stability and activity with an overpotential of 0.53 V. Dual/multiple doping effectively tunes graphene's electronic structure optimizing intermediate adsorption and enhancing performance. Optimal adsorption energies were determined: O₂ (−0.55 eV) OOH (−1.81 eV) O (−3.33 eV) OH (−2.42 eV). Near these values ΔG at 1.23 V approaches zero enabling prediction of rate-limiting steps. This validated method aids in screening high-performance ORR catalysts. In summary this work provides key insights for improving nonmetal-doped graphene's ORR activity and designing advanced electrocatalysts.