Revealing the effect of electronic interaction between dual redox sites on CeO2-Fe2O3 NH3-SCR catalyst through interface contact tailoring

•The CeO2-Fe2O3 composite catalysts have continuously enhanced interface contact.•The electronic interaction between the dual redox sites were investigated.•The reactivities of different NH3 and NO adsorbed species were discussed.•The reaction pathways and the roles of active Fe and Ce sites were proposed.