The　additional　cost　of　Hg0　capture　in　coal-fired　power　plants　has　facilitated　the　demand　for　environmental　pollutants　mitigation　material　for　Hg0　oxidation　to　Hg2+　for　an　ultra-low　Hg　emission　technology.　Herein,　a　suite　of　CeO2-based　catalysts　were　investigated　aiming　at　ultra-low　gaseous　Hg0　emission　at　coal-fired　power　stations.　Gaseous　elemental　mercury　is　feasible　to　be　catalytically　oxidized　to　Hg2+.　The　co-regulated　dispersion,　exposure　and　defect　sites　on　CeO2　(111)　surface　with　2　wt%　Ce　and　8　wt%　Mo　compositions　on　γ-Al2O3　was　found　to　be　the　most　promising　catalyst　demonstrating　a　high　catalytic　oxidation　efficiency,　a　broad　operating　temperature　range　and　a　low　activation　energy.　Specifically,　it　is　shown　that　the　oxidation　of　Hg0　on　the　Ce-based　catalysts　can　be　enhanced　by　the　addition　of　Mo　(up　to　8　wt%)　via　promoting　the　CeO2　(111)　surface　dispersion　and　exposure.　Moreover,　insights　into　the　Ce　and　Mo　synergistic　interactions　showed　that　it　facilitated　the　formation　of　defect-containing　surface　sites.　Besides,　the　co-regulation　of　dispersion,　exposure　and　defect　sites　on　CeO2　(111)　surface　was　further　studied　by　DFT　calculations.　This　study　provides　a　feasible　approach　in　optimization　of　CeO2-based　catalysts　for　catalytic　oxidation　of　Hg0　to　achieve　efficient　removal　of　environmental　pollutants.　©　2021