Catalytic repurposing of corrosive O₂ for autonomous repair

Conventional corrosion protection strategies primarily rely on passive defensive approaches, essentially blocking or consuming corrosive agents. In contrast, we hypothesized that the primary corrosive agent, dissolved O₂, could be strategically repurposed from a destructive species into an active repair resource to enable autonomous self-healing. To validate this, we engineered an intelligent coating system incorporating a bimetallic FeCe metal-organic framework (MOF) capable of executing a precise chemical program upon defect exposure. When the coating is mechanically damaged, the subsequent chemical processes were systematically investigated using simulations (density functional theory) alongside experiments (electrochemistry and material testing). Our findings reveal that the MOF catalyzes the conversion of aggressive dissolved O₂ into highly reactive hydroxyl radicals (OH) with near-zero activation energy. These radicals are immediately consumed in a constructive reaction with metal ions and organic linkers released from the MOF, triggering the in-situ formation of a dense inorganic-organic composite film precisely over the damaged area. This on-demand conversion process effectively transforms the destructive agent into a protective barrier. Consequently, the resulting coating exhibits an order-of-magnitude improvement in corrosion resistance compared to conventional systems. This work establishes a new method in materials chemistry by demonstrating the feasibility of repurposing environmental aggressors into functional components for active, autonomous repair.