The construction of efficient and durable electrocatalysts with highly dispersed metal clusters and hydrophilic surface for alkaline hydrogen evolution reaction (HER) remains a great challenge. Herein, we prepared hydrophilic nanocomposites of Ru clusters (~ 1.30 nm) anchored on Na⁺, K⁺-decorated porous carbon (Ru/Na⁺, K⁺-PC) through hydrothermal method and subsequent annealing treatment at 500 °C. The Ru/Na⁺, K⁺-PC exhibits ultralow overpotential of 7 mV at 10 mA·cm⁻², mass activity of 15.7 A·mg_Ru⁻¹ at 100 mV, and long-term durability of 20,000 cycles potential cycling and 200 h chronopotentiometric measurement with a negligible decrease in activity, much superior to benchmarked commercial Pt/C. Density functional theory based calculations show that the energy barrier of H–OH bond breaking is efficiently reduced due to the presence of Na and K ions, thus favoring the Volmer step. Furthermore, the Ru/Na⁺, K⁺-PC effectively employs solar energy for obtaining H₂ in both alkaline water and seawater electrolyzer. This finding provides a new strategy to construct high-performance and cost-effective alkaline HER electrocatalyst.

Developing highly stable and active non-Pt oxygen reduction reaction (ORR) electrocatalysts for power generation device raises great concerns and remains a challenge. Here, we report novel truncated Pd tetrahedrons (T-Pd-Ths) enclosed by {111} facets with excellent uniformity, which have both low-coordinated surface sites and distinct lattice distortions that would induce “local strain”. In alkaline electrolyte, the T-Pd-Ths/C achieves remarkable ORR specific/mass activity (SA/MA) of 2.46 mA·cm⁻²/1.69 A·mg_Pd⁻¹, which is 12.3/16.9 and 10.7/14.1 times higher than commercial Pd/C and Pt/C, respectively. The T-Pd-Ths/C also exhibits high in-situ carbon monoxide (CO) tolerance and 50,000 cycles durability with an activity loss of 7.69% and morphological stability. The rotating ring-disk electrode (RRDE) measurements show that a 4-electron process occurs on T-Pd-Ths/C. Theoretical calculations demonstrate that the low-coordinated surface sites contribute largely to the enhancement of ORR activity. In actual direct methanol fuel cell (DMFC) device, the T-Pd-Ths/C delivers superior open-circuit voltage (OCV) and peak power density (PPD) to commercial Pt/C from 25 to 80 °C, and the maximum PPD can reach up to 163.7 mW·cm⁻². This study demonstrates that the T-Pd-Ths/C holds promise as alternatives to Pt for ORR in DMFC device.

It is challenging and desirable to construct Pt-based nanocomposites with oxygen storage function as efficient oxygen reduction reaction (ORR) catalysts for practical proton exchange membrane fuel cells (PEMFCs). Herein, we achieve novel porous nanocomposites of PtCu₃ nanoalloys-embedded in the PWO_x matrix (PtCu₃@PWO_x), which has an oxygen container feature. The PtCu₃@PWO_x/C exhibits an ultrahigh mass activity (MA) of 3.94 A·mg_Pt⁻¹ for ORR, which is 26.3 times as high as the commercial Pt/C and the highest value ever reported for PtCu-based binary system. Theoretical calculations reveal that the compressive strain and d-band center downshift of Pt intrinsically contribute to the excellent ORR performance. In H₂-air PEMFCs at room temperature, furthermore, the PtCu₃@PWO_x/C delivers a high power density (218.6 mW·cm⁻²), much superior to commercial Pt/C (131.6 mW·cm⁻²). In H₂-O₂ PEMFCs, PtCu₃@PWO_x/C outputs a maximum power density of 420.1 mW·cm⁻². This work provides an effective idea for designing oxygen-storing ORR catalysts used for practical room-temperature H₂-air fuel cells.