Abstract

The efficiency and sustainability of water splitting processes for green hydrogen production are inherently governed by the properties of the electrocatalyst and the kinetic limitations of the anodic reaction. In this regard, the presented study reports a strategically designed cobalt-integrated ruthenium–ruthenium phosphide (Co/Ru–RuP_x) electrocatalyst for the hydrazine-assisted water splitting reaction. The integration of laser-tuned metallic Co with Ru–RuP_x forms a hierarchical structure that achieves a low overpotential of 337 mV for the oxygen evolution reaction and 49 mV for the hydrazine oxidation reaction (HzOR) at 10 mA cm⁻². Interestingly, the electrocatalytic performance of Co(4)/Ru–RuP_x catalyst (Co:Ru-RuP_x=4:1) surpasses that of conventional IrO₂ catalysts across all studied reactions. Additionally, the overall hydrazine splitting process in a Pt/C||Co(4)/Ru–RuP_x cell demonstrates remarkable energy savings (ΔE ≈ 1.39 V) compared to conventional water electrolysis. In situ Raman spectroscopy reveals a nonsequential dehydrogenation mechanism during HzOR, involving efficient N–N bond dissociation and rapid intermediate conversion on Co(4)/Ru–RuP_x. Complementary, theoretical calculations demonstrate the interfacial electronic stability with is favourable d-band positioning in Co(4)/Ru–RuP_x results in effective adsorption of N₂H₄ and its intermediate. Interestingly, a low energy barrier (0.31 eV) for the rate-determining step and substantial charge redistribution across Co, Ru, and RuP₂ further confirm the contribution in HzOR. Thus, the present study presents a rationally designed cobalt-based Ru–RuP_x material employing HzOR as a promising strategy for high-yield green H₂ production, contributing to the global initiative of clean energy prospects.