Electronically Asymmetric RuNP–Co2N Heterostructures Trigger Chloride-Adaptive Kinetic Acceleration for Industrial High-Current-Simulated Seawater Electrolysis

Abstract The development of efficient electrocatalysts for the hydrogen evolution reaction (HER) under universal-pH and seawater conditions is highly desirable for practical hydrogen production. In this work, an electronically asymmetric heterostructure catalyst of RuNP–Co2N is constructed to optimize HER kinetics. The experimental and theoretical calculation results demonstrate that the electron-deficient Ru sites exhibit a fast Volmer process and optimize hydrogen intermediate adsorption. A distinctive apparent activation energy (Ea) sequence is revealed: acidic < simulated seawater < pristine alkaline media. Multi-salt control experiments confirm that the anomalous kinetic acceleration is exclusively triggered by chloride (Cl-) adsorption, firmly excluding sodium (Na+) hydration effects. Consequently, RuNP–Co2N delivers exceptional simulated seawater performance, with its high-current performance outshining its alkaline counterparts. It requires 245 and 350 mV to achieve 500 and 1000 mA cm–2 in simulated seawater, respectively, highlighted by a 39 mV reduction at 500 mA cm–2 compared to that in 1 M KOH. Concurrently, it only needs 145 mV to reach 1000 mA cm-2 in acidic electrolyte. Moreover, outstanding HER stability is also maintained in diverse electrolytes at industrial-level current densities. This work provides an effective method for constructing high-performance Ru-based HER electrocatalysts through electronically asymmetric interfacial engineering.