Flash joule heating drives structural ordering for efficient metal-support interaction in lignin-derived NiRu catalysts toward broad-pH seawater electrolysis.

The practical implementation of seawater electrolysis for hydrogen production is severely hampered by the corrosive chloride ions, which cause rapid catalyst deactivation. To overcome this, we developed a durable electrocatalyst via millisecond flash Joule heating (FJH). This ultrafast process converts amine-functionalized lignin into a highly graphitic, N,O-doped carbon matrix while confining in situ formed NiRu alloy nanoparticles within it. The resulting NiRu@NOLGC catalyst shows exceptional hydrogen evolution activity across a broad pH range, requiring only 130.1, 105.7, and 241.9 mV overpotential to drive 100 mA cm-2 in alkaline, acidic, and neutral media, respectively, and operates stably for over 100 h. Its superior chloride corrosion resistance in simulated seawater originates from the FJH-induced structural ordering. Density functional theory calculations indicate that the crystalline, heteroatom-doped support precisely modulates the electronic structure of NiRu sites, resulting in a near-ideal hydrogen adsorption free energy (-0.20 eV) and significantly weakened chloride adsorption. This work demonstrates a potent bifunctional catalyst for practical water splitting. Moreover, it underscores a key design principle: using ultrafast processing to create structurally ordered supports is essential for achieving efficient metal-support interactions, offering a viable pathway to corrosion-resistant catalysts for complex electrochemical systems.