Spontaneous Charge Separation at the Metal-Water Interface
Journal article, 2024

Reactions at the metal-water interface are essential in a range of fundamental and technological processes. Using Density Functional Theory calculations, we demonstrate that water substantially affects the adsorption of H and O2 on Cu(111), Ag(111), Au(111), Pd(111) and Pt(111). In water, H is found to undergo a spontaneous charge separation, where a proton desorbs to the water solution while an electron is donated to the surface. The reaction is exothermic over Au and Pt and associated with low barriers. The process is facile also over Pd, albeit slightly endothermic. For O2, water is found to increase the metal-to-adsorbate charge transfer, enhancing the adsorption energy and O−O bond length as compared to the adsorption in the absence of water. The magnitudes of the effects are system dependent, which implies that calculations should treat water explicitly. The results elucidate previous experimental results and highlights the importance of charge-transfer effects at the metal-water interface; both to describe the potential energy landscape, and to account for alternative reaction routes in the presence of water.

charge transfer

catalysis

metal-water interface

Density functional theory

charge-separation

Author

Rasmus Svensson

Chalmers, Physics, Chemical Physics

Henrik Grönbeck

Chalmers, Physics, Chemical Physics

ChemPhysChem

1439-4235 (ISSN) 1439-7641 (eISSN)

Vol. 25 8 e202400099

Adaptive multiscale modeling in heterogeneous catalysis

Swedish Research Council (VR) (2020-05191), 2021-01-01 -- 2024-12-31.

Subject Categories

Physical Chemistry

Theoretical Chemistry

DOI

10.1002/cphc.202400099

More information

Latest update

5/4/2024 4