Establishing appropriate metal-support interactions is imperative for acquiring efficient and corrosion-resistant catalysts for water splitting. Herein, the interaction mechanism between Ru nanoparticles and a series of titanium oxides, including TiO, Ti₄O₇ and TiO_2, designed via facile non-stoichiometric engineering is systematically studied. Ti₄O_7, with the unique band structure, high conductivity and chemical stability, endows with ingenious metal-support interaction through interfacial Ti–O–Ru units, which stabilizes Ru species during OER and triggers hydrogen spillover to accelerate HER kinetics. As expected, Ru/Ti₄O₇ displays ultralow overpotentials of 8 mV and 150 mV for HER and OER with a long operation of 500 h at 10 mA cm⁻² in acidic media, which is expanded in pH-universal environments. Benefitting from the excellent bifunctional performance, the proton exchange membrane and anion exchange membrane electrolyzer assembled with Ru/Ti₄O₇ achieves superior performance and robust operation. The work paves the way for efficient energy conversion devices.

Developing ruthenium-based oxide catalysts capable of suppressing lattice oxygen participation in the catalytic reaction process is crucial for maintaining stable oxygen evolution reaction (OER) under acidic conditions. Herein, we delicately construct a RuO₂ nanoparticle-anchored LiCoO₂ nanosheet electrocatalyst (RuO₂/LiCoO₂), achieving dynamic optimization of RuO₂ during the reaction process and improving catalytic stability. Benefiting from the unique electrochemical delithiation characteristics of the LiCoO₂ support, the covalency of the Ru-O bond is effectively regulated during the OER process. The weakened Ru-O covalent bond inhibits the participation of lattice oxygen in the catalytic reaction and ensures the continuous operation of the Ru active sites. Moreover, the extended Ru-O bond in the optimized RuO₂/LiCoO₂ catalyst reduces the formation energy barrier of the *OOH intermediates, accelerating the progress of the OER. As a result, the RuO₂/LiCoO₂ catalyst requires only an overpotential of 150 ± 2 mV at 10 mA cm⁻² in 0.5 M H₂SO₄ and operates stably for 2000 h at 1 A cm⁻² in a proton exchange membrane water electrolysis. This work opens new avenues for designing efficient ruthenium-based catalysts.

Electrocatalytic N₂ reduction provides an attractive alternative to Haber-Bosch process for artificial NH₃ synthesis. The difficulty of suppressing competing proton reduction, however, largely impedes its practical use. Herein, we design a hydrophobic octadecanethiol-modified Fe₃P nanoarrays supported on carbon paper (C18@Fe₃P/CP) to effectively repel water, concentrate N₂, and enhance N₂-to-NH₃ conversion. Such catalyst achieves an NH₃ yield of 1.80 × 10⁻¹⁰ mol·s⁻¹·cm⁻² and a high Faradaic efficiency of 11.22% in 0.1 M Na₂SO₄, outperforming the non-modified Fe₃P/CP (2.16 × 10⁻¹¹ mol·s⁻¹·cm⁻², 0.9%) counterpart. Significantly, C18@Fe₃P/CP renders steady N₂-fixing activity/selectivity in cycling test and exhibits durability for at least 25 h. First-principles calculations suggest that the surface electronic structure and chemical activity of Fe₃P can be well tuned by the thiol modification, which facilitates N₂ electroreduction activity and catalytic formation of NH₃.