Yb-Modified Carbon-Based Bifunctional Oxygen Electrode Catalyst: A Density Functional Theory Study

The oxidation reduction reactions (ORR) and oxygen evolution reactions (OER) are crucial for the research of electrocatalysts. In this study, the single-atom catalysts (SACs) of Yb-doped graphene (YbNxC3-x) are extensively discussed using density functional theory (DFT), and the electronic properties of the active components are modulated by introducing OH axial ligands. By comparing the calculation results, it was found that the hydroxylation energy reduces the adsorption energy of the catalyst toward oxygen-containing intermediates, thereby effectively tuning the catalytic activity. In light of this, we designed two high-performance bifunctional electrocatalysts, YbN2C1-OH (eta(ORR) = 0.51 V, eta(OER) = 0.65 V) and YbN3C0-OH (eta(ORR) = 0.51 V, eta(OER) = 0.42 V). Finally, a volcano plot was constructed based on the scaling relationship to rapidly assess catalytic activity. These findings provide guidance for the development and design of potential rare-earth-based electrocatalysts.