Background:　Single　metal　atom　oxide　(SMAO)　catalysts　hold　great　promise　for　fine-tuning　interfacial　geometries　and　electronic　structures,　significantly　enhancing　the　efficiency　of　the　oxygen　evolution　reaction　(OER).　Their　unique　properties　have　garnered　substantial　interest　in　advancing　electrocatalytic　technologies.　Methods:　This　study　presents　the　synthesis　of　a　novel　ternary　single　metal　atom　oxides　(SMAO)　catalyst　on　a　hybrid　support,　incorporating　single　tungsten　(W),　nickel　(Ni),　and　manganese　(Mn)　atoms　into　Co3O4,　CeO2,　and　reduced　graphene　oxides　(rGO)　(R-CoCe-WNM-3)　via　controlled　sonication　synthesis.　The　hybrid　support　leverages　the　complementary　benefits　of　Co3O4,　CeO2　and　rGO,　creating　a　synergistic　platform　for　enhanced　OER　electrocatalysis.　Significant　findings:　X-ray　diffraction　(XRD)　and　phase　fraction　analysis　confirm　excellent　compatibility　among　constituents.　High-angle　annular　dark-field　scanning　transmission　electron　microscopy　(STEM-HAADF)　demonstrate　successful　integration　of　ternary　metal　centers　onto　the　metal　oxides　support　at　the　single-atom　level.　R-CoCe-WNM-3　electrocatalyst　exhibits　unique　alkaline　OER　performance　due　to　the　interfacial　interaction,　mixed　oxidization　states　of　the　metals,　and　higher　numbers　of　SMAO　particles.　The　optimum　R-CoCe-WNM-3　electrocatalyst　shows　lower　overpotential　(279　and　351　mV)　than　other　catalysts　at　current　densities　of　10　and　100　mA　cm−2.　In　an　effort　to　enhance　OER　performance,　this　study　offers　a　simple　synthetic　technique　for　building　single　metal　atom　oxide　interfaces.　©　2024　Taiwan　Institute　of　Chemical　Engineers