Epitaxial Oxide Interfaces Create Poison‐Resistant CuO Sites for Environmental Catalysis

ABSTRACT Real exhaust streams rarely contain a single pollutant: NO x coexists with volatile organic compounds (VOCs) in flue gas from petrochemical production, chemical manufacturing, and waste incineration, yet catalysts that couple NH 3 ‐SCR with VOC oxidation typically suffer competitive adsorption, sulfur poisoning, and HCN byproduct formation. Here we engineer an epitaxially stabilized CuO overlayer on Ti 1‐x In x O 2 that breaks the activity–selectivity–stability constraint by creating electron‐poor, high‐symmetry Cu–O sites and activating lattice‐oxygen redox at the oxide–oxide interface. Interfacial strain and charge transfer increase Cu–O covalency and Lewis acidity, accelerating NO x reduction via an Eley–Rideal pathway while diverting sulfate deposition away from Cu. Concurrently, interface‐activated lattice oxygen sustains deep oxidation of CH 3 SH (a representative S‐VOC) through a Mars–van Krevelen cycle, suppressing HCN. Epitaxial interfaces thus offer a general route to poison‐resistant multipollutant catalysis.