McBriarty, ME;
von Rudorff, GF;
Stubbs, JE;
Eng, PJ;
Blumberger, J;
Ross, KM;
(2017)
Dynamic Stabilization of Metal Oxide-Water Interfaces.
Journal of the American Chemical Society
, 139
(7)
pp. 2581-2584.
10.1021/jacs.6b13096.
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Abstract
The interaction of water with metal oxide surfaces plays a crucial role in the catalytic and geochemical behavior of metal oxides. In a vast majority of studies, the interfacial structure is assumed to arise from a relatively static lowest energy configuration of atoms, even at room temperature. Using hematite (α-Fe2O3) as a model oxide, we show through a direct comparison of in situ synchrotron X-ray scattering with density functional theory-based molecular dynamics simulations that the structure of the (11̅02) termination is dynamically stabilized by picosecond water exchange. Simulations show frequent exchanges between terminal aquo groups and adsorbed water in locations and with partial residence times consistent with experimentally determined atomic sites and fractional occupancies. Frequent water exchange occurs even for an ultrathin adsorbed water film persisting on the surface under a dry atmosphere. The resulting time-averaged interfacial structure consists of a ridged lateral arrangement of adsorbed water molecules hydrogen bonded to terminal aquo groups. Surface pKa prediction based on bond valence analysis suggests that water exchange will influence the proton-transfer reactions underlying the acid/base reactivity at the interface. Our findings provide important new insights for understanding complex interfacial chemical processes at metal oxide–water interfaces.
| Type: | Article |
|---|---|
| Title: | Dynamic Stabilization of Metal Oxide-Water Interfaces |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1021/jacs.6b13096 |
| Publisher version: | http://doi.org/10.1021/jacs.6b13096 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1541534 |
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