In　this　study,　a　CeO2　and　BN　hybrid-supported　Ni　catalyst　(Ni/CeO2-BN)　was　developed　for　efficient　NH3-to-H2　conversion.　By　adding　BN　to　Ni/CeO2　as　an　additional　support　material,　there　is　increased　spatial　distribution　of　Ni　nanoparticles,　lessening　the　common　problem　of　Ni　aggregation　on　oxide　supports.　More　importantly,　the　introduction　of　BN　enriches　oxygen　vacancies　and　raises　Ce3+　concentration,　leading　to　enhanced　electron　transfer　from　the　support　to　Ni.　The　electron-rich　Ni　species　promote　NH3　activation　as　well　as　the　combination　of　surface　N　atoms　for　N2　desorption,　ultimately　boosting　NH3　decomposition.　The　5　wt　%Ni/CeO2-BN　catalyst　shows　robust　activity　for　NH3　conversion　with　a　H2　yield　of　approximately　516　mmol　gNi-1　min-1　at　600　°C.　This　study　provides　a　universal　strategy　to　boost　the　catalytic　performance　of　metal/oxide　catalysts　by　adding　a　second　support　material,　which　is　a　simple　but　effective　way　to　produce　efficient　catalysts　for　a　diversity　of　energy-conversion　systems.　©　2021　American　Chemical　Society.　All　rights　reserved.