The　metal-anion　interaction　(MAI)　widely　exists　over　supported　metal　catalysts,　which　has　a　significant　effect　on　tuning　metal　sites　and　reaction　performance.　However,　the　effect　of　MAI　on　NH3　synthesis　and　the　reaction　mechanism　is　still　elusive.　Here,　we　report　that　the　strength　of　Ru-anion　interaction　gradually　increases　from　Ru-N　to　Ru-H　and　Ru-O　when　the　anion　of　the　support　is　changed　from　H　(ZrH2)　to　N　(ZrN)　and　O　(ZrO2).　Moreover,　the　Ru-anion　interaction　induced　by　different　support　compositions　can　affect　the　hydrogen　spillover　and　N-2　activation　route.　Due　to　the　weak　Ru-N　interaction,　the　aggregation　of　Ru　particles　is　observed　over　Ru/ZrN.　Although　Ru　particles　are　highly　dispersed　over　ZrO2　owing　to　the　strong　Ru-O　interaction,　hydrogen　poisoning　is　inevitable　over　Ru/ZrO2.　Comparatively,　hydrogen　poisoning　can　be　alleviated　over　Ru/ZrH2　via　hydrogen　spillover　to　its　support.　The　results　of　NEXAFS,　in　situ　diffuse　reflectance　infrared　Fourier　transform　spectroscopy　(DRIFTS),　and　isotope-labeling　experiments　show　that　N-2　can　be　activated　via　both　dissociative　and　associative　routes　over　Ru/ZrH2.　Consequently,　the　developed　Ba-promoted　Ru/ZrH2　catalyst　displays　a　high　NH3　synthesis　rate　of　27.5　mmol　g(-1)　h(-1)　and　robust　stability　during　300　h　time-on-stream　at　400　degrees　C　and　1　MPa.