The reaction pathways of the oxygen reduction reaction on IrN₄ doped divacancy graphene: A theoretical study

The transition metal and nitrogen co-doped graphene as efficient electrocatalysts of oxygen reduction reaction (ORR) is promising to achieve large-scale applications of the full cells. In this work, we investigated the active sites and ORR mechanism on IrN₄ doped divacancy graphene (IrN₄-Gra) by using the density functional method. The active sites are identified as the IrN₄ moiety and its adjacent ten C atoms. ORR on IrN₄-Gra is a four-electron process. OOH hydrogenated into OH + OH is the kinetically most favorable pathway. The rate-determining step is OOH + H → OH + OH with energy barrier 1.01 eV. The predicted working potential is 0.41 V. Hence, IrN₄-Gra might be a promising ORR catalyst.