ScholarWorks@성균관대학교

초록

Direct seawater electrolysis offers a promising route for hydrogen production, yet existing catalysts suffer from sluggish spin-electron transfer kinetics and severe anode corrosion. Herein, we report a heterostructured catalyst, LDH@MoO3, which employs an electron-mediated mechanism to modulate the electronic structure and spin state of Fe centers. In-depth analyses demonstrate that Mo6+ serves as electron trap, drawing electrons from Fe3+ through the Fe–O Mo interfacial channel, thereby promoting the formation of high-valence, low-spin Fe(3+δ)+ (t2g5-δeg0) species. This interfacial electron transfer simultaneously elevates Fe d-band center and lowers O p-band center, accelerating the kinetics of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Furthermore, MoO3 undergoes in-situ conversion to MoO42–, creating an electrostatic protective layer that markedly improves electrode stability during seawater electrolysis. Consequently, LDH@MoO3 exhibits low overpotentials of 35 mV for HER and 204 mV for OER at 10 mA cm–2. Moreover, it sustains stable operation at 0.5 A cm–2 for 800 h in alkaline seawater and requires 1.78 V to achieve 1.0 A cm–2 under industrial conditions (6.0 M KOH + seawater, 60 °C). This study elucidates the electron-trap role of Mo6+ in tuning Fe spin states, offering fresh insights for designing efficient spin-dependent catalysts for industrial water electrolysis.

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