Tuning　surface　acidity　is　a　common　strategy　to　improve　the　reactivity　of　Ce-based　materials　for　selective　catalytic　reduction　(SCR)　of　NOx　with　NH3.　Traditionally,　it　is　achieved　by　wet　impregnation　of　sulfate　species　or　treatment　under　an　atmosphere　of　sulfur　dioxide　and　oxygen.　However,　the　two　methods　do　not　bring　any　change　to　the　electronic　state　of　CeO2,　and　Ce4+　ions　which　cause　undesired　side　reactions　are　largely　retained　on　the　surface.　Herein,　we　report　a　sulfation　strategy　that　can　tune　the　surface　acid　sites　and　regulate　the　electronic　state　of　nano-CeO2.　Using　SO2　as　reducible　gas　for　surface　sulfation,　we　prepared　sulfated　CeO2　(S-CeO2)　catalysts　of　different　morphologies　and　tested　them　for　the　NH3-SCR　reaction.　The　characterization　results　revealed　that　the　interaction　between　SO2　and　nano-CeO2　is　obviously　affected　by　ceria　morphology.　Among　the　sulfated　catalysts,　that　with　rod　morphology　(S-CeO2-Rod)　shows　the　highest　NOx　conversion,　and　exhibits　superior　sulfur　and　water　tolerance.　The　excellent　SCR　activity　of　S-CeO2-Rod　is　attributed　to　the　enrichment　of　oxygen　vacancies　and　surface　Ce3+　ions　as　a　result　of　the　abundant　presence　of　sulfate　species.　©　2019　Elsevier　B.V.