Theoretical Understanding of Activity, Selectivity, and Stability in Oxygen Electrocatalysis

Abstract

Oxygen electrocatalysis is the cornerstone of sustainable electrochemical technologies. In this review, we discuss the role of theory in elucidating the anodic water oxidation reaction in electrolyzers and the cathodic oxygen reduction reaction in fuel cells. We first examine catalytic activity and selectivity by analyzing reaction mechanisms, linear scaling relationships, thermodynamic and kinetic descriptors, volcano relationships, insights from microkinetic modeling, and the influence of interfacial electric fields. We then focus on catalyst stability, exploring evaluations based on material phase diagrams, bulk and surface Pourbaix diagrams, segregation and aggregation energetics, surface dissolution potentials, and mechanistic understanding of degradation pathways. Finally, we highlight the current challenges and emerging opportunities for advancing the theoretical understanding and predictive modeling of oxygen electrocatalysis.