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Simultaneously enhancing the reaction kinetics, mass transport, and gas release during alkaline hydrogen evolution reaction (HER) is critical to minimizing the reaction polarization resistance, but remains a big challenge. Through rational design of a hierarchical multiheterogeneous three‐dimensionally (3D) ordered macroporous Mo2C‐embedded nitrogen‐doped carbon with ultrafine Ru nanoclusters anchored on its surface (OMS Mo2C/NC‐Ru), we realize both electronic and morphologic engineering of the catalyst to maximize the electrocatalysis performance. The formed Ru‐NC heterostructure shows regulative electronic states and optimized adsorption energy with the intermediate H*, and the Mo2C‐NC heterostructure accelerates the Volmer reaction due to the strong water dissociation ability as confirmed by theoretical calculations. Consequently, superior HER activity in alkaline solution with an extremely low overpotential of 15.5 mV at 10 mA cm−2 with the mass activity more than 17 times higher than that of the benchmark Pt/C, an ultrasmall Tafel slope of 22.7 mV dec−1, and excellent electrocatalytic durability were achieved, attributing to the enhanced mass transport and favorable gas release process endowed from the unique OMS Mo2C/NC‐Ru structure. By oxidizing OMS Mo2C/NC‐Ru into OMS MoO3‐RuO2 catalyst, it can also be applied as efficient oxygen evolution electrocatalyst, enabling the construction of a quasi‐symmetric electrolyzer for overall water splitting. Such a device's performance surpassed the state‐of‐the‐art Pt/C || RuO2 electrolyzer. This study provides instructive guidance for designing 3D‐ordered macroporous multicomponent catalysts for efficient catalytic applications. [ABSTRACT FROM AUTHOR]

Aluminum–metal batteries show great potential as next‐generation energy storage due to their abundant resources and intrinsic safety. However, the crucial limitations of metallic Al anodes, such as dendrite and corrosion problems in conventional aluminum–metal batteries, remain challenging and elusive. Here, we report a novel electrodeposition strategy to prepare an optimized 3D Al anode on carbon cloth with an uniform deposition morphology, low local current density, and mitigatory volume change. The symmetrical cells with the 3D Al anode show superior stable cycling (>450 h) and low‐voltage hysteresis (~170 mV) at 0.5 mA cm−2. High reversibility (~99.7%) is achieved for the Al plating/stripping. The graphite | | Al‐4/CC full batteries show a long lifespan of 800 cycles with 54 mAh g−1 capacity at a high current density of 1000 mA g−1, benefiting from the high capacitive‐controlled distribution. This study proposes a novel strategy to design 3D Al anodes for metallic‐Al‐based batteries by eliminating the problems of planar Al anodes and realizing the potential applications of aluminum–graphite batteries. [ABSTRACT FROM AUTHOR]