Well-Defined\nCo<sub>2</sub> Dual-Atom Catalyst Breaks\nScaling Relations of Oxygen Reduction Reaction

The\n4-electron oxygen reduction reaction (ORR) under alkaline conditions\nis central to the development of non-noble metal-based hydrogen fuel\ncell technologies. However, the kinetics of ORR are constrained by\nscaling relations, where the adsorption free energy of *OOH is intrinsically\nlinked to that of *OH with a nearly constant difference larger than\nthe optimal value. In this study, a well-defined binuclear Co<sub>2</sub> complex was synthesized and adsorbed onto carbon black, serving\nas a model dual-atom catalyst. This catalyst achieved a record half-wave\npotential of 0.972 V versus the reversible hydrogen electrode in an\nalkaline electrolyte. Density functional theory simulations and in\nsitu infrared spectroscopy revealed that the dual-atom site stabilizes\nthe *OOH intermediate through bidentate coordination, thereby reducing\nthe free energy gap between *OOH and *OH. By altering the adsorption\nconfiguration of *OOH on the dual-atom site, the scaling relations\nare effectively disrupted, leading to a significant enhancement in\nORR activity.