▎ 摘　　要

The electrochemical nitrogen reduction reaction (ENRR) is regarded as a potential alternative to produce ammonia under ambient conditions. However, the lack of powerful electrocatalysts and the non-negligible hydrogen evolution reaction (HER) have become a bottleneck of further development of ENRR. In this work, [Mo3S13](2-) clusters were introduced onto 2D-structured Pd nanosheets (NSs) to form Pd-S-Mo NSs with abundant Mo active sites for N-2 activation. A Faradaic efficiency (FE) of 10.7 % was realized by Pd-S-Mo NSs on hydrophilic carbon support, superior to their single-component counterparts. Furthermore, loading Pd-S-Mo NSs on hydrophobic hierarchical graphene support was carried out to suppress HER, achieving a FE of 23.8 % and improved ammonia yield. This work provides a designed principle of efficient ENRR electrocatalysts by engineering Mo active sites and catalyst supports.