Alloy design based on single–principal-element systems has approached its limit for performance enhancements. A substantial increase in strength up to gigapascal levels typically causes the premature failure of materials with reduced ductility. Here, we report a strategy to break this trade-off by controllably introducing high-density ductile multicomponent intermetallic nanoparticles (MCINPs) in complex alloy systems. Distinct from the intermetallic-induced embrittlement under conventional wisdom, such MCINP-strengthened alloys exhibit superior strengths of 1.5 gigapascals and ductility as high as 50% in tension at ambient temperature. The plastic instability, a major concern for high-strength materials, can be completely eliminated by generating a distinctive multistage work-hardening behavior, resulting from pronounced dislocation activities and deformation-induced microbands. This MCINP strategy offers a paradigm to develop next-generation materials for structural applications.

Artificial nitrogen fixation through the nitrogen reduction reaction (NRR) under ambient conditions is a potentially promising alternative to the traditional energy-intensive Haber–Bosch process. For this purpose, efficient catalysts are urgently required to activate and reduce nitrogen into ammonia. Herein, by the combination of experiments and first-principles calculations, we demonstrate that copper single atoms, attached in a porous nitrogen-doped carbon network, provide highly efficient NRR electrocatalysis, which compares favorably with those previously reported. Benefiting from the high density of exposed active sites and the high level of porosity, the Cu SAC exhibits high NH3 yield rate and Faradaic efficiency (FE), specifically ∼53.3 μgNH3 h–1 mgcat –1 and 13.8% under 0.1 M KOH, ∼49.3 μgNH3 h–1 mgcat –1 and 11.7% under 0.1 M HCl, making them truly pH-universal. They also show good stability with little current attenuation over 12 h of continuous operation. Cu–N2 coordination is identified as the efficient active sites for the NRR catalysis.

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For mass production of high‐purity hydrogen fuel by electrochemical water splitting, seawater electrolysis is an attractive alternative to the traditional freshwater electrolysis due to the abundance and low cost of seawater in nature. However, the undesirable chlorine ion oxidation reactions occurring simultaneously with seawater electrolysis greatly hinder the overall performance of seawater electrolysis. To tackle this problem, electrocatalysts of high activity and selectivity with purposely modulated coordination and an alkaline environment are urgently required. Herein, it is demonstrated that atomically dispersed Ni with triple nitrogen coordination (Ni‐N3) can achieve efficient hydrogen evolution reaction (HER) performance in alkaline media. The atomically dispersed Ni electrocatalysts exhibit overpotentials as low as 102 and 139 mV at 10 mA cm–2 in alkaline freshwater and seawater electrolytes, respectively, which compare favorably with those previously reported. They also deliver large current densities beyond 200 mA cm–2 at lower overpotentials than Pt/C, as well as show negligible current attenuation over 14 h. The X‐ray absorption fine structure (XAFS) experimental analysis and density functional theory (DFT) calculations verify that the Ni‐N3 coordination, which exhibits a lower coordination number than Ni‐N4, facilitates water dissociation and hydrogen adsorption, and hence enhances the HER activity.

Previous research of molybdenum‐based electrocatalysts for nitrogen reduction reaction (NRR) has been largely considered on either isolated Mo single atoms (MoSAs) or Mo carbide particles (e.g., Mo2C) separately, while an integrated synergy (MoSAs‐Mo2C) of the two has never been considered. The theoretical calculations show that the Mo single atoms and Mo2C nanoparticles exhibit, respectively, different catalytic hydrogen evolution reaction and NRR selectivity. Therefore, a new role‐playing synergistic mechanism can be well enabled for the multistep NRR, when the two are combined on the same N‐doped carbon nanotubes (NCNTs). This hypothesis is confirmed experimentally, where the MoSAs‐Mo2C assembled on NCNTs (MoSAs‐Mo2C/NCNTs) yields an ammonia formation rate of 16.1 µg h−1 cmcat−2 at −0.25 V versus reversible hydrogen electrode, which is about four times that by the Mo2C alone (Mo2C/NCNTs) and 4.5 times that by the MoSAs alone (MoSAs/NCNTs). Moreover, the Faradic efficiency of the MoSAs‐Mo2C/NCNTs is raised up to twofold and sevenfold of the Mo2C/NCNTs and MoSAs/NCNTs, respectively. The MoSAs‐Mo2C/NCNTs also demonstrate outstanding stability by the almost unchanged catalytic performance over 10 h of the chronoamperometric test. The present study provides a promising new prototype of synchronizing the selectivity and activity for the multistep catalytic reactions.