High-entropy alloys (HEAs) with unique physicochemical properties have attracted tremendous attention in many fields, yet the precise control on dimension and morphology at atomic level remains formidable challenges. Herein, we synthesize unique PtRuNiCoFeMo HEA subnanometer nanowires (SNWs) for alkaline hydrogen oxidation reaction (HOR). The mass and specific activities of HEA SNWs/C reach 6.75 A mg_Pt+Ru⁻¹ and 8.96 mA cm⁻², respectively, which are 2.8/2.6, 4.1/2.4, and 19.8/18.7 times higher than those of HEA NPs/C, commercial PtRu/C and Pt/C, respectively. It can even display enhanced resistance to CO poisoning during HOR in the presence of 1000 ppm CO. Density functional theory calculations reveal that the strong interactions between different metal sites in HEA SNWs can greatly regulate the binding strength of proton and hydroxyl, and therefore enhances the HOR activity. This work not only provides a viable synthetic route for the fabrication of Pt-based HEA subnano/nano materials, but also promotes the fundamental researches on catalysis and beyond.

CO₂ hydrogenation has attracted great attention, yet the quest for highly-efficient catalysts is driven by the current disadvantages of poor activity, low selectivity, and ambiguous structure-performance relationship. We demonstrate here that C₃N₄-supported Cu single atom catalysts with tailored coordination structures, namely, Cu–N₄ and Cu–N₃, can serve as highly selective and active catalysts for CO₂ hydrogenation at low temperature. The modulation of the coordination structure of Cu single atom is readily realized by simply altering the treatment parameters. Further investigations reveal that Cu–N₄ favors CO₂ hydrogenation to form CH₃OH via the formate pathway, while Cu–N₃ tends to catalyze CO₂ hydrogenation to produce CO via the reverse water-gas-shift (RWGS) pathway. Significantly, the CH₃OH productivity and selectivity reach 4.2 mmol g^–1 h^–1 and 95.5%, respectively, for Cu–N₄ single atom catalyst. We anticipate this work will promote the fundamental researches on the structure-performance relationship of catalysts.

Realizing stable and efficient overall water splitting is highly desirable for sustainable and efficient hydrogen production yet challenging because of the rapid deactivation of electrocatalysts during the acidic oxygen evolution process. Here, we report that the single-site Pt-doped RuO ₂ hollow nanospheres (SS Pt-RuO ₂ HNSs) with interstitial C can serve as highly active and stable electrocatalysts for overall water splitting in 0.5 M H ₂ SO ₄ . The performance toward overall water splitting have surpassed most of the reported catalysts. Impressively, the SS Pt-RuO ₂ HNSs exhibit promising stability in polymer electrolyte membrane electrolyzer at 100 mA cm ⁻² during continuous operation for 100 hours. Detailed experiments reveal that the interstitial C can elongate Ru-O and Pt-O bonds, and the presence of SS Pt can readily vary the electronic properties of RuO ₂ and improve the OER activity by reducing the energy barriers and enhancing the dissociation energy of ^* O species.

Direct methane conversion (DMC) to high value-added products is of significant importance for the effective utilization of CH₄ to combat the energy crisis. However, there are ongoing challenges in DMC associated with the selective C−H activation of CH₄. The quest for high-efficiency catalysts for this process is limited by the current drawbacks including poor activity and low selectivity. Here we show a cerium dioxide (CeO₂) nanowires supported rhodium (Rh) single-atom (SAs Rh-CeO₂ NWs) that can serve as a high-efficiency catalyst for DMC to oxygenates (i.e., CH₃OH and CH₃OOH) under mild conditions. Compared to Rh/CeO₂ nanowires (Rh clusters) prepared by a conventional wet-impregnation method, CeO₂ nanowires supported Rh single-atom exhibits 6.5 times higher of the oxygenates yield (1231.7 vs. 189.4 mmol g_Rh⁻¹ h⁻¹), which largely outperforms that of the reported catalysts in the same class. This work demonstrates a highly efficient DMC process and promotes the research on Rh single-atom catalysts in heterogeneous catalysis.