Toward enhancing the NH₃ synthesis activity of Ru-based catalysts under mild conditions, various electron donors have been intensively investigated. The electron donation typically originates from either the support itself or the external promoter that transforms into a near-metallic state during the reaction, yet single materials combining both pathways remain rarely reported. This work developed such a bifunctional support, strontium carbonate (SrCO₃). Over the Ru-SrCO₃/carbon nanotubes (CNTs) catalyst, surface SrCO₃ was partially reduced in-situ to form near-metallic Sr⁰ species, which, together with the unreduced basic Sr²⁺ in the bulk SrCO₃, donate electrons to Ru sites, achieving highly efficient N₂ activation. Moreover, the SrCO₃ support can also boost NH₃ desorption and mitigate hydrogen poisoning. The potassium-promoted catalyst K-Ru-SrCO₃/CNTs even delivers an outstanding NH₃-synthesis rate of 61.6 ${\text{mmol}}_{{\text{NH}}_3}$·g_cat⁻¹·h⁻¹ at 400 °C and 0.9 MPa, outperforming most state-of-the-art Ru-based catalysts with Ru mass-loading ≤ 5 wt.% reported to date.

While lithium–sulfur (Li–S) batteries are promising next-generation high-energy devices, the Li₂S cathode suffers from poor electrical conductivity, sluggish reaction kinetics, shuttle effect, and processing difficulty, limiting its practical applications. This work reports a new strategy to enhance Li₂S cathode performance by integrating a high-entropy sulfide catalyst, MnFeCoNiCuS, and a double-shell structure, Li₂S@Li₂S₆@Li₂S₂. The MnFeCoNiCuS catalyst was synthesized by calcining the metathesis-prepared precursors with the high-temperature shock (HTS)-based Joule heating technique. The Li₂S@Li₂S₆@Li₂S₂ structure was made by temperature-programmed heating a mixture of Li₂S and S powders. Compared with the unmodified Li₂S cathodes, the dual-composite Li₂S cathode exhibits significantly enhanced cyclability and rate performance in Li–S batteries, owing to the high-entropy sulfide with catalytic and conductive functions as well as the double-shell Li₂S@Li₂S₆@Li₂S₂ architecture with improved charge transport pathways. This study advances an insightful design concept for catalysts and cathodes toward high-performance Li–S batteries.

The oxygen evolution reaction (OER) is critical for sustainable energy technologies, including proton exchange membrane water electrolyzers (PEMWEs) and metal-air batteries. However, its implementation in acidic media remains constrained by sluggish kinetics, high energy barriers, and reliance on scarce noble-metal catalysts. Cobalt-based single-atom catalysts (Co-SACs) have emerged as a breakthrough solution, combining exceptional catalytic activity, stability, and atomic utilization efficiency. Its superior acidic OER performance stems from the electronic structure of low-spin Co³⁺ centers, which optimize t_2g–π orbital interactions with oxygen intermediates. This configuration promotes efficient surface reconstruction and thermodynamically favorable adsorption of OER species, accelerating reaction kinetics. Tailored coordination environments, engineered via supports like nitrogen-doped carbons, graphene, or metal oxides, can further modulate Co electronic and spin states, enhancing activity and durability. This review systematically analyzes advancements in Co-SAC design, elucidating correlations between atomic coordination, electronic properties, and catalytic mechanisms. Advanced synthesis methods and characterization tools are evaluated to discuss structure-activity relationships of Co-SAC. Finally, we address current challenges and future research directions that involve computational modeling, multi-metallic SAC architectures, and operando techniques to guide the rational design of high-performance Co-SACs. Addressing these challenges will accelerate the commercialization of PEMWEs for cost-effective green hydrogen production.