Oxygen Storage-Release Mechanism (OSC): To address fluctuations in the air/fuel ratio during different engine combustion conditions, the TWC utilizes a CeO₂–ZrO₂ oxygen storage system: • During oxygen-rich conditions, excess oxygen is stored. • During oxygen-lean conditions, the stored oxygen is released to ensure smooth CO/HC oxidation and NOₓ reduction reactions.

Substrate: Cordierite (low thermal expansion, strong thermal shock resistance). Gasoline engine TWC honeycomb matrix: Silicon carbide (SiC). High thermal conductivity, high strength. High-temperature diesel catalyst/industrial exhaust gas. The substrate structure typically features honeycomb or sheet-like corrugated channels to reduce backpressure and provide a large surface area.