An experimental and kinetic modeling study of aging impact on surface and subsurface oxygen storage in three-way catalysts

•OSC decreased by 44% at 400°C after Standard Bench Cycle aging at 955°C for 57h.•PGM and surface ceria deteriorated more severely compared to sub-surface ceria.•OSC-temperature relationship was changed due to altered thermodynamics of ceria.•A dual-site OSC model was used to predict OSCs on a fresh and an aged TWC.•Change of oxygen storage sites and kinetics in the OSC model are reported.