C2H2 semi-hydrogenation over N-doped graphene supported diatomic metal catalysts: Unraveling the roles of metal type and its coordination environment in tuning catalytic performance

•Metal type and coordination environment of DACs effectively tune catalytic performance of C2H2 semi-hydrogenation.•High Bader charge transfer amount and moderate d-band center of DACs exhibit high C2H4 selectivity and formation activity.•The established descriptor φ over DACs can better describe C2H4 selectivity.•CoCu, CoPd, CoNi and CoPt anchored over N6V4-П exhibit better C2H4 selectivity, formation activity, and stability.