Next-Generation Aerogel Electrocatalysts for Oxygen Reduction Reaction.

Aerogel-based electrocatalysts have become a groundbreaking class of materials for the oxygen reduction reaction (ORR), distinguished by their ultralight nature, pore networks, and outstanding electrical conductivity. Their interconnected three-dimensional frameworks offer abundant active sites, efficient diffusion channels, and continuous electron transport pathways-key attributes that overcome the kinetic and stability limitations traditionally faced in fuel cells and metal-air batteries. This study presents a comprehensive review of aerogel-based electrocatalyst materials for ORR. The overview of how structural configuration, composition, and reaction mechanisms influence ORR performance was discussed. Various fabrication approaches, such as sol-gel processing, freeze-drying, supercritical drying, and template-guided methods, are examined. Recent developments in metallic, heteroatom-doped carbon, and conductive hybrid aerogels are analyzed in detail, with emphasis on their performances for ORR, structure-property relationships, advanced characterization for identifying active centers, and mechanistic insights. Furthermore, the integration of these materials into functional devices, along with their operational stability, is critically discussed. Future progress will depend on the synergistic integration of scalable synthesis, mechanistic understanding, advanced characterization, and computational design. The convergence of materials informatics, green manufacturing, and bioinspired chemistry is expected to accelerate the transition of aerogel-based electrocatalysts from laboratory prototypes to practical energy technologies powering sustainable societies.