We　report　a　new　strategy　for　strengthening　metal-support　interaction　and　stabilizing　Co　nanoparticles　at　high　temperature.　Through　the　use　of　dopamine　and　removal　of　carbon　layers　by　thermal　N-2　treatment,　ceria-based　Co　catalysts　that　are　efficient　and　highly　stable　for　ammonia　synthesis　can　be　obtained.　The　ammonia　synthesis　rate　at　425　degrees　C　and　1　MPa　is　enhanced　from　3.81　mmol(NH3)　g(cat)(-1)　h(-1)　over　Co/CeO2　to　19.12　mmol(NH3)　g(cat)(-1)　h(-1)　over　a　dopamine-mediated　catalyst.　The　superior　catalytic　performances　of　the　dopamine-mediated　Co/CeO2　catalyst　are　associated　with　smaller　crystalline　size,　stronger　metal-support　interaction　and　lower　N-2　activation　energy.