The irreversible sintering of supported ruthenium (Ru) catalyst in the preparation process has seriously affected its hydrogen evolution reaction (HER) activity and stability. Herein, ultrathin nitrogen-doped molybdenum carbide nanosheets (N-Mo₂C NSs) is used as a versatile support to stabilize Ru single atoms (SAs) sites via the anti-Ostwald ripening. Ru SAs are dispersed into the N-Mo₂C NSs matrix via the strong bonding between the Ru atoms and Mo₂C NSs regulated by N doping. The atomic isolated Ru SAs are confirmed by spherical aberration correction transmission electron microscopy (AC HAADF-STEM) and X-ray absorption fine structure (XAFS) measurements. Ru SAs/N-Mo₂C NSs exhibits outstanding HER performance, with a small overpotential of 43 mV at 10 mA/cm², and robust catalytic stability in 1.0 M KOH. Importantly, Ru SAs/N-Mo₂C NSs possesses a higher mass activity of 6.44 A/mg_Ru than that of 20 wt% Pt/C (0.91 A/mg_Pt) at the overpotential of 100 mV. Theoretical calculations further reveal that the high HER activity of Ru SAs/N-Mo₂C NSs is derived from the synergistically accelerated the dissociation of H₂O and the optimized H adsorption strength in Mo-Ru interface. This result provides a new direction for the rational designing monatomic electrocatalysts for HER via support interaction effect.

负载型钌（Ru）催化剂在制备过程中的不可逆烧结严重影响了其放氢反应（HER）的活性和稳定性。本文中，超薄氮掺杂碳化钼纳米片（N-Mo ₂ C NSs）用作通过反奥斯特瓦尔德熟化来稳定Ru单原子（SAs）位点的通用载体。Ru SA通过Ru原子与受N掺杂调节的Mo ₂ C NSs之间的牢固结合而分散到N-Mo ₂ C NSs基质中。原子分离的Ru SAs通过球面像差校正透射电子显微镜（AC HAADF-STEM）和X射线吸收精细结构（XAFS）测量得到确认。Ru SAs / N-Mo ₂C NSs具有出色的HER性能，在10 mA / cm ^2时具有43 mV的小过电位，并在1.0 M KOH中具有强大的催化稳定性。重要的是，在100 mV的超电势下，Ru SAs / N-Mo ₂ C NSs的质量活性比20 wt％Pt / C（0.91 A / mg _Pt）高，具有6.44 A / mg _Ru的质量活性。理论计算进一步表明，Ru SAs / N-Mo ₂ C NSs的高HER活性源自协同加速H ₂ O的离解和在Mo-Ru界面上优化的H吸附强度。该结果为通过载体相互作用效应合理设计HER的单原子电催化剂提供了新的方向。