The rich anchoring site on carbon renders it a promising support for catalytically active metal nanoparticles (NPs), thereby enhancing their intrinsic catalytic activity towards hydrogen evolution reaction (HER) through interactions between the support and the metal. However, complex synthesis conditions often compromise the synergy between the metal and support. Herein, we report Re NPs embedded on XC-72 carbon support to investigate the robust interactions in affecting the HER activity. Consequently, Re NPs anchored on defect-rich XC-72 exhibit efficient and robust HER activity in acidic conditions, achieving an extremely low overpotential of 25 mV to deliver a current density of 10 mA cm−2 and a Tafel slope of 78 mV dec−1, surpassing that of Pt/C catalyst. Based on experimental investigations and density functional theory calculations, the high catalytic activities of as-obtained Re/C can be attributed to the enhanced electron transport kinetics facilitated by the interactions between Re NPs and carbon support, the exposure of the active site on Re NPs, and lowered reaction energy barrier towards HER. This study provides valuable insights for the rational development of Re-based efficient catalysts for HER.