Developing　highly　effective　catalysts　for　ammonia　(NH3)　synthesis　is　a　challenging　task.　Even　the　current,　prevalent　iron-derived　catalysts　used　for　industrial　NH3　synthesis　require　harsh　reaction　conditions　and　involve　massive　energy　consumption.　Here　we　show　that　anchoring　buckminsterfullerene　(C-60)　onto　non-iron　transition　metals　yields　cluster-matrix　co-catalysts　that　are　highly　efficient　for　NH3　synthesis.　Such　co-catalysts　feature　separate　catalytic　active　sites　for　hydrogen　and　nitrogen.　The　＇electron　buffer＇　behaviour　of　C-60　balances　the　electron　density　at　catalytic　transition　metal　sites　and　enables　the　synergistic　activation　of　nitrogen　on　transition　metals　in　addition　to　the　activation　and　migration　of　hydrogen　on　C-60　sites.　As　demonstrated　in　long-term,　continuous　runs,　the　C-60-promoting　transition　metal　co-catalysts　exhibit　higher　NH3　synthesis　rates　than　catalysts　without　C-60.　With　the　involvement　of　C-60,　the　rate-determining　step　in　the　cluster-matrix　co-catalysis　is　found　to　be　the　hydrogenation　of　*NH2.　C-60　incorporation　exemplifies　a　practical　approach　for　solving　hydrogen　poisoning　on　a　wide　variety　of　oxide-supported　Ru　catalysts.