A　challenge　hindering　the　development　of　durable　solid　oxide　fuel　cells　(SOFCs)　is　the　significant　performance　degradation　of　cathodes　owing　to　poisoning　by　volatile　Cr　originating　from　the　Fe─Cr　alloy　interconnect.　Herein,　a　heterogeneous　catalyst　coating,　composed　of　Ba1−xCe0.8Gd0.2O3–δ　and　BaCO3,　remarkably　improves　the　oxygen　adsorption,　dissociation　capability,　and　Cr　resistance　of　a　La0.6Sr0.4Co0.2Fe0.8O3–δ　(LSCF)　cathode　is　demonstrated.　The　coherent　heterointerface　interactions　formed　between　the　catalyst　coating　and　LSCF　result　in　varied　levels　of　surface　strain　and　electrostatic　interactions,　significantly　suppressing　Sr　surface　segregation　on　LSCF.　A　single　cell　with　the　catalyst　coating-decorated　LSCF　(CC-LSCF)　achieves　a　peak　power　density　of　1.73 W cm−2　at　750 °C,　with　no　noticeable　performance　degradation　for　100 h.　The　CC-LSCF　cathode　also　exhibits　outstanding　durability　under　accelerated　Cr　poisoning　conditions,　compared　with　the　tremendous　degradation　rate　of　0.42% h−1　for　the　bare　LSCF　cathode.　The　enhanced　Cr　resistance　is　attributed　to　synergy　induced　by　the　stabilization　of　the　lattice　Sr　cations　by　heterointerface　interactions　and　the　remarkable　structural　stability　of　the　catalyst　coating　under　Cr　poisoning　conditions.　The　novel　heterointerface　engineering　strategy　in　this　study　provides　insight　into　the　design　and　development　of　active　and　Cr-tolerant　cathodes.　©　2024　Wiley-VCH　GmbH.