• Metal aerogel electrocatalysts combine high electrical conductivity, metallic nature, and hierarchical 3D porosity, enabling excellent Pt utilization and exposure of active sites for ORR.
• Several noble metal aerogel catalysts achieve higher mass activity than conventional Pt/C, reaching a mass activity target of 440 A per g Pt at 0.9 V vs. RHE.
• The review systematically analyses metal aerogel synthesis, microstructural effects on catalyst layers, fuel cell performance, and state-of-the-art modifications.
• Metal aerogels offer a promising pathway to reduce Pt loading and improve ORR stability, with future research focused on integrating these catalysts into realistic fuel cell devices.