Bridged Mn─O─Ru Motifs in RuO ₂ Catalyst Promoting Hydrogen Production at Ampere‐Level Current Density

Abstract Accurately regulating the reactive sites of catalysts is vital for highly efficient catalytic processes but still faces considerable challenges. In view of this, a local oxidation‐state asymmetric Mn‐O‐Ru bridged moiety is developed by introducing Mn atoms into the RuO ₂ host. The synergistic effect of the respective active sites on the Mn‐O‐Ru microstructure ensures its excellent alkaline HER performance. Theoretical calculations profiled that induced by the Mn‐O‐Ru bridged moiety, the water dissociation ability of Ru sites is significantly boosted, while the bridging oxygen exhibits the optimal hydrogen adsorption free energy. As predicted, the Mn‐RuO ₂ catalyst achieved the overpotentials as low as 118 and 160 mV at the industrial level current densities of 1 and 2 A cm ^‒2 in 1 m KOH, respectively, superior to the RuO ₂ and commercial Pt/C catalyst. Such a Mn‐RuO ₂ electrocatalyst can operate stably with a long lifetime of 300 h at 10 mA cm ^‒2 under alkaline conditions. Furthermore, it only requires 1.87 V to reach the current density of 1.0 A cm ^‒2 when serving as the cathode in an assembled flow cell. This work provides new insight into catalytic local environment design for obtaining ideal efficient HER electrocatalysts.