Catalytically, the clustered peaks around the Fermi level suggest an optimized overlap between the metal d-orbitals and the ligand's π-system [27], enabling robust adsorption and activation of reactant molecules, such as oxygen in ORR. For the Ni(II) complex, the balanced DOS around the Fermi level may favor stable binding of reaction intermediates, ensuring controlled catalytic turnover. In contrast, the Co(II) complex, with its high-spin configuration, benefits from enhanced spin-polarized DOS near the Fermi level, facilitating unpaired electron interactions critical for multi-electron reduction processes. This electronic structure not only promotes the dissociation of molecular oxygen but also stabilizes transition states, thereby reducing the activation energy and improving overall catalytic efficiency. These features collectively highlight the pivotal role of DOS characteristics in tuning the electronic and catalytic profiles of these metal complexes.