Stabilizing Low/Non‐Noble Metal Loading Cobalt Oxide‐Based Anode Catalysts for Proton Exchange Membrane Water Electrolysis

ABSTRACT Proton exchange membrane water electrolyzers (PEMWEs) are central to green hydrogen production, yet their anodic oxygen evolution reaction (OER) still relies on noble‐metal catalysts (Ir or Ru), raising concerns regarding cost and resource scarcity. Therefore, the exploration of stabilized supported materials is essential to achieve low/non‐noble metal loading anodes in PEMWEs. Recent studies indicate that Co ₃ O ₄ can not only serve as an efficient support for noble‐metal single atoms, but also act as a non‐noble active phase or an integral component of hybrid catalyst systems. However, its unsatisfactory long‐term stability in acidic environments remains a major barrier. In this review, we analyze the fundamental degradation mechanism of Co ₃ O ₄ under acidic OER and highlight the key factors underlying dissolution, lattice restructuring, and loss of electronic conductivity. In addition, strategies that improve durability are investigated. Practical considerations for device integration, such as catalyst‐layer design, dynamic‐load stability, and scalable fabrication, are also analyzed. To translate laboratory breakthroughs into commercial technologies, future research must now prioritize dynamic stability and scalable integration of membrane electrode assemblies over conventional activity metrics.