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　(C60)　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　C60　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　C60　sites.　As　demonstrated　in　long-term,　continuous　runs,　the　C60-promoting　transition　metal　co-catalysts　exhibit　higher　NH3　synthesis　rates　than　catalysts　without　C60.　With　the　involvement　of　C60,　the　rate-determining　step　in　the　cluster-matrix　co-catalysis　is　found　to　be　the　hydrogenation　of　*NH2.　C60　incorporation　exemplifies　a　practical　approach　for　solving　hydrogen　poisoning　on　a　wide　variety　of　oxide-supported　Ru　catalysts.　(Figure　presented.)　©　The　Author(s),　under　exclusive　licence　to　Springer　Nature　Limited　2024.