The Ni (II) complex, with its lower energy requirements and absence of significant thermodynamic hurdles, demonstrates superior rate-determining properties. The direct formation of hydroperoxide as an energetically favorable intermediate minimizes the activation energy, allowing for efficient electron transfer and intermediate stabilization. In contrast, the Co (II) complex's pathway, while thermodynamically feasible, suffers from suboptimal energy profiles that hinder catalytic performance. These distinctions underscore the Ni (II) complex's suitability as an ORR catalyst, driven by its low Gibbs free energy barriers and favorable intermediate formation, ultimately resulting in faster reaction kinetics and improved efficiency.