Dinitrogen　activation　in　ammonia　(NH3)　synthesis　usually　obeys　either　the　dissociative　or　associative　route.　We　report　here　a　combination　of　dissociative　and　associative　routes　over　a　titanium　carbonitride　(TiCN)-promoted　Ru-based　catalyst　to　achieve　an　outstanding　NH3　synthesis　rate.　The　developed　Ru/3TiCN/ZrH2　catalyst　shows　a　superior　NH3　synthesis　rate　of　25.6　mmol　gcat-1　h-1　at　400　°C　and　1　MPa.　Our　studies　reveal　that　TiCN　transfers　electrons　to　the　Ru　centers　and　reduces　the　aggregation　of　Ru　metal　particles　to　generate　more　B5　sites,　thus　accelerating　the　dissociation　of　N2　to　form　NH3　via　a　dissociative　route.　Meanwhile,　the　facile　formation　of　nitrogen　vacancies　on　TiCN　assisted　by　Ru　enables　the　associative　mechanism　initiated　with　N2　hydrogenation　to　form　*NNH.　The　synergistic　effect　of　Ru　and　TiCN　on　N2　activation　via　integrating　the　dissociative　and　associative　mechanisms　accounts　for　the　superior　NH3　synthesis　rate　of　our　catalyst　under　mild　conditions.　©　2022　American　Chemical　Society