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Updated: Sep 18, 2025

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
External electric field modulation of cation-induced interfacial potential during hydrogen evolution on
Pengbo Ding1, Qitao Lian1, Dan Xing2
1School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300132, China.
None:
The impact of alkaline media on the hydrogen evolution reaction (HER) rate is crucial for water electrolysis. This study provides new insights into how alkali metal cations (AM+) influence the HER performance of Pt electrodes. We quantified interfacial potential drops modulated by an external electric field and discovered that the local surface concentration of AM+ is 5.0 to 8.6 times higher than in the bulk solution. The accumulation of AM+ in the outer Helmholtz plane (OHP) diminishes the interaction between H2O and Pt surface, thereby impeding H2O dissociation. The external electric field drives AM+ away from the OHP, mitigating this effect. Theoretical calculations indicate that AM+ enhance proton transfer by reorganizing interfacial water, with Li+ orienting surrounding OH bonds favorably towards the Pt surface, thus facilitating the HER process. Our combined experimental and theoretical studies elucidate the role of AM+ in the HER by influencing double-layer potential and interfacial water formation.
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To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
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