Abstract <p>Transition metal nitrides (TMNs) have emerged as promising alternatives to commercial Pt/C in hydrogen evolution reaction (HER) owing to high conductivity and electronic structure similar to that of Pt. Nevertheless, the applications of TMNs-based catalysts are limited by the complex preparation processes. Developing highly efficient TMNs-based catalysts via simple and eco-friendly synthesis strategies still poses a substantial challenge. In the research, Ru/FeN_x/C catalysts are in-situ synthesized through combining ion-exchange and confined pyrolysis strategies by leveraging the intrinsic Fe-N coordination structure of Prussian Blue. The Ru components are preferentially anchored adjacent to FeN_x, forming abundant synergistic active centers. The contents of Ru and Fe in Ru/FeN_x/C-900 are as low as 0.31 wt% and 0.05 wt%, respectively. The Ru/FeN_x/C-900 attains a current density of 10&#xa0;mA cm⁻² at an overpotential of merely 15 mV in a 1.0&#xa0;M KOH solution, exhibiting superior performance to the commercial Pt/C. The systematic experimental results unveil that the electron transfer between Ru and FeN_x optimizes the distribution of active Ru and Fe-N_x species, thereby accelerating the reaction kinetics and improving the catalytic activity.</p> Graphical Abstract <p></p>