Magnetic Field-Driven Interface Hydroxylation via the Vibrational Stark Effect Boosts Alkaline Hydrogen Evolution Reaction.

Tuning interfacial water structures is a fundamental yet underexplored strategy for advancing the hydrogen evolution reaction (HER) and broader electrocatalytic processes. Here, we demonstrate a universal and scalable catalytic optimization strategy via the magnetic field-driven reconfiguration of interfacial water at the molecular level. Unlike conventional magnetohydrodynamic (MHD) strategies focusing on mass transport, this work pioneers a molecular-level interfacial water structure modulation via the vibrational Stark effect (VSE), achieving intrinsic catalytic enhancement for HER. In situ Raman spectroscopy and molecular dynamics (MD) simulations reveal that the permanent magnetic field-induced amplification of the DDAA configuration population is governed by the VSE, leading to a restructured interfacial weak hydrogen bond (HB) network and enhanced charge transfer kinetics. As a result, under a 1 T permanent magnetic field and a controlled flow rate of 100 mL/min, the HER overpotential is reduced by 50 mV at 10 mA·cm, with stable performance sustained for over 10 h, a level of enhancement far exceeding previous magnetic field-assisted HER studies. Beyond HER, this strategy offers a generalizable approach for tuning interfacial water structures, which could be extended to other electrocatalytic reactions, where HB networks and interfacial water structuring play a critical role. As a result, the overpotential was reduced by 50 mV at 10 mA·cm, and a 15.40% increase in current density was achieved under industrial alkaline electrolysis conditions, demonstrating clear advantages over existing magnetic field-assisted HER strategies. This study provided a scalable, molecular-level catalytic interface engineering approach, offering valuable insights into advanced electrocatalytic processes and significant potential for industrial hydrogen production technologies.