▎ 摘　　要

Nonprecious-metal-doped graphene catalysts have been proposed recently as promising candidates to substitute Pt catalysts for the oxygen reduction reaction (ORR) in fuel cells. We codoped Mn and P in divacancy graphene (MnPx, x=1-4) and we studied the stability and the catalytic activity for the ORR. The calculated formation energy indicates that MnP2-doped divacancy graphene is energetically the most stable. The MnP2 moiety and its adjacent six C atoms are catalytically active sites for the ORR. The kinetically most favorable pathway is the hydrogenation of OOH to form O+H2O, which is a four-electron process. The rate-determining step is the second H2O formation, which has an energy barrier of 0.91 eV. The free energy diagrams show that for OOH hydrogenation into O+H2O all of the elementary steps are downhill at potentials of 0.0-0.67 V except for the second H2O formation.