Partial dissociation of water on Fe$_{3}$O$_{4}$(001): adsorbate induced charge and orbital order

TL;DR

This study uses DFT calculations and LEED analysis to explore how water interacts with Fe3O4(001), revealing defect-promoted dissociation, hydrogen-bonded networks, and charge/orbital order changes that influence catalytic activity.

Contribution

It provides new insights into water adsorption mechanisms on Fe3O4(001), highlighting defect effects, mixed adsorption modes, and the impact on surface reconstruction and electronic properties.

Findings

Dissociative adsorption is promoted at defect sites.

Hydrogen-bonded networks form at higher water coverages.

Adsorption induces electron transfer affecting catalytic activity.

Abstract

The interaction of water with Fe$_3$O$_4$(001) is studied by density functional theory (DFT) calculations including an on-site Coulomb term. For isolated molecules dissociative adsorption is strongly promoted at surface defect sites, while at higher coverages a hydrogen-bonded network forms with alternating molecular and dissociated species. This mixed adsorption mode and a suppression of the $(\sqrt{2}\times \sqrt{2})R45^{\circ}$-reconstruction are confirmed by a quantitative low energy electron diffraction (LEED) analysis. Adsorbate induced electron transfer processes add a new dimension towards understanding the catalytic activity of magnetite(001).